td

package
v1.9.2 Latest Latest
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 Go to latest Published: Mar 18, 2021 License: BSD-2-Clause Imports: 33 Imported by: 2

Documentation

Overview

Package td (aka go-testdeep) allows extremely flexible deep comparison, it is built for testing.

It is a go rewrite and adaptation of wonderful Test::Deep perl module (see https://metacpan.org/pod/Test::Deep).

In golang, comparing data structure is usually done using reflect.DeepEqual or using a package that uses this function behind the scene.

This function works very well, but it is not flexible. Both compared structures must match exactly.

The purpose of td package is to do its best to introduce this missing flexibility using "operators" when the expected value (or one of its component) cannot be matched exactly.

See https://go-testdeep.zetta.rocks/ for details, and for easy HTTP API testing, see the tdhttp helper https://pkg.go.dev/github.com/maxatome/go-testdeep/helpers/tdhttp

Example of use

Imagine a function returning a struct containing a newly created database record. The Id and the CreatedAt fields are set by the database layer: 

type Record struct {
  Id        uint64
  Name      string
  Age       int
  CreatedAt time.Time
}

func CreateRecord(name string, age int) (*Record, error) {
  // Do INSERT INTO … and return newly created record or error if it failed
}

Using standard testing package

To check the freshly created record contents using standard testing package, we have to do something like that: 

import (
  "testing"
  "time"
)

func TestCreateRecord(t *testing.T) {
  before := time.Now().Truncate(time.Second)
  record, err := CreateRecord()

  if err != nil {
    t.Errorf("An error occurred: %s", err)
  } else {
    expected := Record{Name: "Bob", Age: 23}

    if record.Id == 0 {
      t.Error("Id probably not initialized")
    }
    if before.After(record.CreatedAt) ||
      time.Now().Before(record.CreatedAt) {
      t.Errorf("CreatedAt field not expected: %s", record.CreatedAt)
    }
    if record.Name != expected.Name {
      t.Errorf("Name field differs, got=%s, expected=%s",
        record.Name, expected.Name)
    }
    if record.Age != expected.Age {
      t.Errorf("Age field differs, got=%s, expected=%s",
        record.Age, expected.Age)
    }
  }
}

Using basic go-testdeep approach

td package, via its Cmp* functions, handles the tests and all the error message boiler plate. Let's do it: 

import (
  "testing"
  "time"

  "github.com/maxatome/go-testdeep/td"
)

func TestCreateRecord(t *testing.T) {
  before := time.Now().Truncate(time.Second)
  record, err := CreateRecord()

  if td.CmpNoError(t, err) {
    td.Cmp(t, record.Id, td.NotZero(), "Id initialized")
    td.Cmp(t, record.Name, "Bob")
    td.Cmp(t, record.Age, 23)
    td.Cmp(t, record.CreatedAt, td.Between(before, time.Now()))
  }
}

As we cannot guess the Id field value before its creation, we use the NotZero operator to check it is set by CreateRecord() call. The same it true for the creation date field CreatedAt. Thanks to the Between operator we can check it is set with a value included between the date before CreateRecord() call and the date just after.

Note that if `Id` and `CreateAt` could be known in advance, we could simply do: 

import (
  "testing"
  "time"

  "github.com/maxatome/go-testdeep/td"
)

func TestCreateRecord(t *testing.T) {
  before := time.Now().Truncate(time.Second)
  record, err := CreateRecord()

  if td.CmpNoError(t, err) {
    td.Cmp(t, record, &Record{
      Id:        1234,
      Name:      "Bob",
      Age:       23,
      CreatedAt: time.Date(2019, time.May, 1, 12, 13, 14, 0, time.UTC),
   })
  }
}

But unfortunately, it is common to not know exactly the value of some fields…

Using advanced go-testdeep technique

Of course we can test struct fields one by one, but with go-testdeep, the whole struct can be compared with one Cmp call. 

import (
  "testing"
  "time"

  "github.com/maxatome/go-testdeep/td"
)

func TestCreateRecord(t *testing.T) {
  before := time.Now().Truncate(time.Second)
  record, err := CreateRecord()

  if td.CmpNoError(t, err) {
    td.Cmp(t, record,
      td.Struct(
        &Record{
          Name: "Bob",
          Age:  23,
        },
        td.StructFields{
          "Id":        td.NotZero(),
          "CreatedAt": td.Between(before, time.Now()),
        }),
      "Newly created record")
  }
}

See the use of the Struct operator. It is needed here to overcome the go static typing system and so use other go-testdeep operators for some fields, here NotZero and Between.

Not only structs can be compared. A lot of operators can be found below to cover most (all?) needed tests. See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#TestDeep

Using go-testdeep Cmp shortcuts

The Cmp function is the keystone of this package, but to make the writing of tests even easier, the family of Cmp* functions are provided and act as shortcuts. Using CmpStruct function, the previous example can be written as: 

import (
  "testing"
  "time"

  "github.com/maxatome/go-testdeep/td"
)

func TestCreateRecord(t *testing.T) {
  before := time.Now().Truncate(time.Second)
  record, err := CreateRecord()

  if td.CmpNoError(t, err) {
    td.CmpStruct(t, record,
      &Record{
        Name: "Bob",
        Age:  23,
      },
      td.StructFields{
        "Id":        td.NotZero(),
        "CreatedAt": td.Between(before, time.Now()),
      },
      "Newly created record")
  }
}

Using T type

testing.T can be encapsulated in td.T type, simplifying again the test: 

import (
  "testing"
  "time"

  "github.com/maxatome/go-testdeep/td"
)

func TestCreateRecord(tt *testing.T) {
  t := td.NewT(tt)

  before := time.Now().Truncate(time.Second)
  record, err := CreateRecord()

  if t.CmpNoError(err) {
    t.RootName("RECORD").Struct(record,
      &Record{
        Name: "Bob",
        Age:  23,
      },
      td.StructFields{
        "Id":        td.NotZero(),
        "CreatedAt": td.Between(before, time.Now()),
      },
      "Newly created record")
  }
}

Note the use of RootName method, it allows to name what we are going to test, instead of the default "DATA".

A step further with operator anchoring

Overcome the go static typing system using the Struct operator is sometimes heavy. Especially when structs are nested, as the Struct operator needs to be used for each level surrounding the level in which an operator is involved. Operator anchoring feature has been designed to avoid this heaviness: 

import (
  "testing"
  "time"

  "github.com/maxatome/go-testdeep/td"
)

func TestCreateRecord(tt *testing.T) {
  before := time.Now().Truncate(time.Second)
  record, err := CreateRecord()

  t := td.NewT(tt) // operator anchoring needs a *td.T instance

  if t.CmpNoError(err) {
    t.Cmp(record,
      &Record{
        Name:      "Bob",
        Age:       23,
        ID:        t.A(td.NotZero(), uint64(0)).(uint64),
        CreatedAt: t.A(td.Between(before, time.Now())).(time.Time),
      },
      "Newly created record")
  }
}

See the A method (or its full name alias Anchor) documentation for details.

Example 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	dateToTime := func(str string) time.Time {
		t, err := time.Parse(time.RFC3339, str)
		if err != nil {
			panic(err)
		}
		return t
	}

	type PetFamily uint8

	const (
		Canidae PetFamily = 1
		Felidae PetFamily = 2
	)

	type Pet struct {
		Name     string
		Birthday time.Time
		Family   PetFamily
	}

	type Master struct {
		Name         string
		AnnualIncome int
		Pets         []*Pet
	}

	// Imagine a function returning a Master slice...
	masters := []Master{
		{
			Name:         "Bob Smith",
			AnnualIncome: 25000,
			Pets: []*Pet{
				{
					Name:     "Quizz",
					Birthday: dateToTime("2010-11-05T10:00:00Z"),
					Family:   Canidae,
				},
				{
					Name:     "Charlie",
					Birthday: dateToTime("2013-05-11T08:00:00Z"),
					Family:   Canidae,
				},
			},
		},
		{
			Name:         "John Doe",
			AnnualIncome: 38000,
			Pets: []*Pet{
				{
					Name:     "Coco",
					Birthday: dateToTime("2015-08-05T18:00:00Z"),
					Family:   Felidae,
				},
				{
					Name:     "Lucky",
					Birthday: dateToTime("2014-04-17T07:00:00Z"),
					Family:   Canidae,
				},
			},
		},
	}

	// Let's check masters slice contents
	ok := td.Cmp(t, masters, td.All(
		td.Len(td.Gt(0)), // len(masters) should be > 0
		td.ArrayEach(
			// For each Master
			td.Struct(Master{}, td.StructFields{
				// Master Name should be composed of 2 words, with 1st letter uppercased
				"Name": td.Re(`^[A-Z][a-z]+ [A-Z][a-z]+\z`),
				// Annual income should be greater than $10000
				"AnnualIncome": td.Gt(10000),
				"Pets": td.ArrayEach(
					// For each Pet
					td.Struct(&Pet{}, td.StructFields{
						// Pet Name should be composed of 1 word, with 1st letter uppercased
						"Name": td.Re(`^[A-Z][a-z]+\z`),
						"Birthday": td.All(
							// Pet should be born after 2010, January 1st, but before now!
							td.Between(dateToTime("2010-01-01T00:00:00Z"), time.Now()),
							// AND minutes, seconds and nanoseconds should be 0
							td.Code(func(t time.Time) bool {
								return t.Minute() == 0 && t.Second() == 0 && t.Nanosecond() == 0
							}),
						),
						// Only dogs and cats allowed
						"Family": td.Any(Canidae, Felidae),
					}),
				),
			}),
		),
	))
	fmt.Println(ok)

}

Output:

true

Index

Examples

Constants

This section is empty.

Variables

View Source 
var DefaultContextConfig = ContextConfig{
	RootName:       contextDefaultRootName,
	MaxErrors:      getMaxErrorsFromEnv(),
	FailureIsFatal: false,
	UseEqual:       false,
	BeLax:          false,
}

DefaultContextConfig is the default configuration used to render tests failures. If overridden, new settings will impact all Cmp* functions and *T methods (if not specifically configured.)

Functions

func AddAnchorableStructType 

func AddAnchorableStructType(fn interface{})

AddAnchorableStructType declares a struct type as anchorable. "fn" is a function allowing to return a unique and identifiable instance of the struct type.

"fn" has to have the following signature: 

func (nextAnchor int) TYPE

TYPE is the struct type to make anchorable and "nextAnchor" is an index to allow to differentiate several instances of the same type.

For example, the time.Time type which is anchrorable by default, could be declared as: 

AddAnchorableStructType(func (nextAnchor int) time.Time {
  return time.Unix(int64(math.MaxInt64-1000424443-nextAnchor), 42)
})

Just as a note, the 1000424443 constant allows to avoid to flirt with the math.MaxInt64 extreme limit and so avoid possible collision with real world values.

It panics if the provided "fn" is not a function or if it has not the expected signature (see above).

func AssertRequire 

func AssertRequire(t testing.TB, config ...ContextConfig) (*T, *T)

AssertRequire returns 2 instances of *T. The first one called "assert" with FailureIsFatal flag set to false, and the second called "require" with FailureIsFatal flag set to true. 

assert, require := AssertRequire(t)

is roughly equivalent to: 

assert, require := Assert(t), Require(t)

See NewT documentation for usefulness of "config" optional parameter.

func Cmp 

func Cmp(t TestingT, got, expected interface{}, args ...interface{}) bool

Cmp returns true if "got" matches "expected". "expected" can be the same type as "got" is, or contains some TestDeep operators. If "got" does not match "expected", it returns false and the reason of failure is logged with the help of "t" Error() method. 

got := "foobar"
td.Cmp(t, got, "foobar")            // succeeds
td.Cmp(t, got, td.HasPrefix("foo")) // succeeds

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

func CmpAll 

func CmpAll(t TestingT, got interface{}, expectedValues []interface{}, args ...interface{}) bool

CmpAll is a shortcut for: 

td.Cmp(t, got, td.All(expectedValues...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#All for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo/bar"

	// Checks got string against:
	//   "o/b" regexp *AND* "bar" suffix *AND* exact "foo/bar" string
	ok := td.CmpAll(t, got, []interface{}{td.Re("o/b"), td.HasSuffix("bar"), "foo/bar"},
		"checks value %s", got)
	fmt.Println(ok)

	// Checks got string against:
	//   "o/b" regexp *AND* "bar" suffix *AND* exact "fooX/Ybar" string
	ok = td.CmpAll(t, got, []interface{}{td.Re("o/b"), td.HasSuffix("bar"), "fooX/Ybar"},
		"checks value %s", got)
	fmt.Println(ok)

	// When some operators or values have to be reused and mixed between
	// several calls, Flatten can be used to avoid boring and
	// inefficient []interface{} copies:
	regOps := td.Flatten([]td.TestDeep{td.Re("o/b"), td.Re(`^fo`), td.Re(`ar$`)})
	ok = td.CmpAll(t, got, []interface{}{td.HasPrefix("foo"), regOps, td.HasSuffix("bar")},
		"checks all operators against value %s", got)
	fmt.Println(ok)

}

Output:

true
false
true

func CmpAny 

func CmpAny(t TestingT, got interface{}, expectedValues []interface{}, args ...interface{}) bool

CmpAny is a shortcut for: 

td.Cmp(t, got, td.Any(expectedValues...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Any for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo/bar"

	// Checks got string against:
	//   "zip" regexp *OR* "bar" suffix
	ok := td.CmpAny(t, got, []interface{}{td.Re("zip"), td.HasSuffix("bar")},
		"checks value %s", got)
	fmt.Println(ok)

	// Checks got string against:
	//   "zip" regexp *OR* "foo" suffix
	ok = td.CmpAny(t, got, []interface{}{td.Re("zip"), td.HasSuffix("foo")},
		"checks value %s", got)
	fmt.Println(ok)

	// When some operators or values have to be reused and mixed between
	// several calls, Flatten can be used to avoid boring and
	// inefficient []interface{} copies:
	regOps := td.Flatten([]td.TestDeep{td.Re("a/c"), td.Re(`^xx`), td.Re(`ar$`)})
	ok = td.CmpAny(t, got, []interface{}{td.HasPrefix("xxx"), regOps, td.HasSuffix("zip")},
		"check at least one operator matches value %s", got)
	fmt.Println(ok)

}

Output:

true
false
true

func CmpArray 

func CmpArray(t TestingT, got, model interface{}, expectedEntries ArrayEntries, args ...interface{}) bool

CmpArray is a shortcut for: 

td.Cmp(t, got, td.Array(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Array for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Array) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := [3]int{42, 58, 26}

	ok := td.CmpArray(t, got, [3]int{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks array %v", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedArray) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyArray [3]int

	got := MyArray{42, 58, 26}

	ok := td.CmpArray(t, got, MyArray{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks typed array %v", got)
	fmt.Println(ok)

	ok = td.CmpArray(t, &got, &MyArray{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

	ok = td.CmpArray(t, &got, &MyArray{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

	ok = td.CmpArray(t, &got, (*MyArray)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func CmpArrayEach 

func CmpArrayEach(t TestingT, got, expectedValue interface{}, args ...interface{}) bool

CmpArrayEach is a shortcut for: 

td.Cmp(t, got, td.ArrayEach(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#ArrayEach for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Array) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := [3]int{42, 58, 26}

	ok := td.CmpArrayEach(t, got, td.Between(25, 60),
		"checks each item of array %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{42, 58, 26}

	ok := td.CmpArrayEach(t, got, td.Between(25, 60),
		"checks each item of slice %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedArray) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyArray [3]int

	got := MyArray{42, 58, 26}

	ok := td.CmpArrayEach(t, got, td.Between(25, 60),
		"checks each item of typed array %v is in [25 .. 60]", got)
	fmt.Println(ok)

	ok = td.CmpArrayEach(t, &got, td.Between(25, 60),
		"checks each item of typed array pointer %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
true
Example (TypedSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	got := MySlice{42, 58, 26}

	ok := td.CmpArrayEach(t, got, td.Between(25, 60),
		"checks each item of typed slice %v is in [25 .. 60]", got)
	fmt.Println(ok)

	ok = td.CmpArrayEach(t, &got, td.Between(25, 60),
		"checks each item of typed slice pointer %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
true

func CmpBag 

func CmpBag(t TestingT, got interface{}, expectedItems []interface{}, args ...interface{}) bool

CmpBag is a shortcut for: 

td.Cmp(t, got, td.Bag(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Bag for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are present
	ok := td.CmpBag(t, got, []interface{}{1, 1, 2, 3, 5, 8, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Does not match as got contains 2 times 1 and 8, and these
	// duplicates are not expected
	ok = td.CmpBag(t, got, []interface{}{1, 2, 3, 5, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	got = []int{1, 3, 5, 8, 2}

	// Duplicates of 1 and 8 are expected but not present in got
	ok = td.CmpBag(t, got, []interface{}{1, 1, 2, 3, 5, 8, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Matches as all items are present
	ok = td.CmpBag(t, got, []interface{}{1, 2, 3, 5, td.Gt(7)},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5}
	ok = td.CmpBag(t, got, []interface{}{td.Flatten(expected), td.Gt(7)},
		"checks all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
false
false
true
true

func CmpBetween 

func CmpBetween(t TestingT, got, from, to interface{}, bounds BoundsKind, args ...interface{}) bool

CmpBetween is a shortcut for: 

td.Cmp(t, got, td.Between(from, to, bounds), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Between for details.

Between() optional parameter "bounds" is here mandatory. td.BoundsInIn value should be passed to mimic its absence in original Between() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.CmpBetween(t, got, 154, 156, td.BoundsInIn,
		"checks %v is in [154 .. 156]", got)
	fmt.Println(ok)

	// BoundsInIn is implicit
	ok = td.CmpBetween(t, got, 154, 156, td.BoundsInIn,
		"checks %v is in [154 .. 156]", got)
	fmt.Println(ok)

	ok = td.CmpBetween(t, got, 154, 156, td.BoundsInOut,
		"checks %v is in [154 .. 156[", got)
	fmt.Println(ok)

	ok = td.CmpBetween(t, got, 154, 156, td.BoundsOutIn,
		"checks %v is in ]154 .. 156]", got)
	fmt.Println(ok)

	ok = td.CmpBetween(t, got, 154, 156, td.BoundsOutOut,
		"checks %v is in ]154 .. 156[", got)
	fmt.Println(ok)

}

Output:

true
true
false
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.CmpBetween(t, got, "aaa", "abc", td.BoundsInIn,
		`checks "%v" is in ["aaa" .. "abc"]`, got)
	fmt.Println(ok)

	// BoundsInIn is implicit
	ok = td.CmpBetween(t, got, "aaa", "abc", td.BoundsInIn,
		`checks "%v" is in ["aaa" .. "abc"]`, got)
	fmt.Println(ok)

	ok = td.CmpBetween(t, got, "aaa", "abc", td.BoundsInOut,
		`checks "%v" is in ["aaa" .. "abc"[`, got)
	fmt.Println(ok)

	ok = td.CmpBetween(t, got, "aaa", "abc", td.BoundsOutIn,
		`checks "%v" is in ]"aaa" .. "abc"]`, got)
	fmt.Println(ok)

	ok = td.CmpBetween(t, got, "aaa", "abc", td.BoundsOutOut,
		`checks "%v" is in ]"aaa" .. "abc"[`, got)
	fmt.Println(ok)

}

Output:

true
true
false
true
false

func CmpCap 

func CmpCap(t TestingT, got, expectedCap interface{}, args ...interface{}) bool

CmpCap is a shortcut for: 

td.Cmp(t, got, td.Cap(expectedCap), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Cap for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := make([]int, 0, 12)

	ok := td.CmpCap(t, got, 12, "checks %v capacity is 12", got)
	fmt.Println(ok)

	ok = td.CmpCap(t, got, 0, "checks %v capacity is 0", got)
	fmt.Println(ok)

	got = nil

	ok = td.CmpCap(t, got, 0, "checks %v capacity is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true
Example (Operator) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := make([]int, 0, 12)

	ok := td.CmpCap(t, got, td.Between(10, 12),
		"checks %v capacity is in [10 .. 12]", got)
	fmt.Println(ok)

	ok = td.CmpCap(t, got, td.Gt(10),
		"checks %v capacity is in [10 .. 12]", got)
	fmt.Println(ok)

}

Output:

true
true

func CmpCode 

func CmpCode(t TestingT, got, fn interface{}, args ...interface{}) bool

CmpCode is a shortcut for: 

td.Cmp(t, got, td.Code(fn), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Code for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "12"

	ok := td.CmpCode(t, got, func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 10 && n < 100
	},
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

	// Same with failure reason
	ok = td.CmpCode(t, got, func(num string) (bool, string) {
		n, err := strconv.Atoi(num)
		if err != nil {
			return false, "not a number"
		}
		if n > 10 && n < 100 {
			return true, ""
		}
		return false, "not in ]10 .. 100["
	},
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

	// Same with failure reason thanks to error
	ok = td.CmpCode(t, got, func(num string) error {
		n, err := strconv.Atoi(num)
		if err != nil {
			return err
		}
		if n > 10 && n < 100 {
			return nil
		}
		return fmt.Errorf("%d not in ]10 .. 100[", n)
	},
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

}

Output:

true
true
true

func CmpContains 

func CmpContains(t TestingT, got, expectedValue interface{}, args ...interface{}) bool

CmpContains is a shortcut for: 

td.Cmp(t, got, td.Contains(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Contains for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (ArraySlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpContains(t, [...]int{11, 22, 33, 44}, 22)
	fmt.Println("array contains 22:", ok)

	ok = td.CmpContains(t, [...]int{11, 22, 33, 44}, td.Between(20, 25))
	fmt.Println("array contains at least one item in [20 .. 25]:", ok)

	ok = td.CmpContains(t, []int{11, 22, 33, 44}, 22)
	fmt.Println("slice contains 22:", ok)

	ok = td.CmpContains(t, []int{11, 22, 33, 44}, td.Between(20, 25))
	fmt.Println("slice contains at least one item in [20 .. 25]:", ok)

	ok = td.CmpContains(t, []int{11, 22, 33, 44}, []int{22, 33})
	fmt.Println("slice contains the sub-slice [22, 33]:", ok)

}

Output:

array contains 22: true
array contains at least one item in [20 .. 25]: true
slice contains 22: true
slice contains at least one item in [20 .. 25]: true
slice contains the sub-slice [22, 33]: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.CmpContains(t, got, "oob", "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = td.CmpContains(t, got, 'b', "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = td.CmpContains(t, got, byte('a'), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = td.CmpContains(t, got, td.Between('n', 'p'), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true
Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpContains(t, map[string]int{"foo": 11, "bar": 22, "zip": 33}, 22)
	fmt.Println("map contains value 22:", ok)

	ok = td.CmpContains(t, map[string]int{"foo": 11, "bar": 22, "zip": 33}, td.Between(20, 25))
	fmt.Println("map contains at least one value in [20 .. 25]:", ok)

}

Output:

map contains value 22: true
map contains at least one value in [20 .. 25]: true
Example (Nil) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	num := 123
	got := [...]*int{&num, nil}

	ok := td.CmpContains(t, got, nil)
	fmt.Println("array contains untyped nil:", ok)

	ok = td.CmpContains(t, got, (*int)(nil))
	fmt.Println("array contains *int nil:", ok)

	ok = td.CmpContains(t, got, td.Nil())
	fmt.Println("array contains Nil():", ok)

	ok = td.CmpContains(t, got, (*byte)(nil))
	fmt.Println("array contains *byte nil:", ok) // types differ: *byte ≠ *int

}

Output:

array contains untyped nil: true
array contains *int nil: true
array contains Nil(): true
array contains *byte nil: false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.CmpContains(t, got, "oob", "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = td.CmpContains(t, got, []byte("oob"), "checks %s", got)
	fmt.Println("contains `oob` []byte:", ok)

	ok = td.CmpContains(t, got, 'b', "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = td.CmpContains(t, got, byte('a'), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = td.CmpContains(t, got, td.Between('n', 'p'), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains `oob` []byte: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.CmpContains(t, got, "oob", "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = td.CmpContains(t, got, 'b', "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = td.CmpContains(t, got, byte('a'), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = td.CmpContains(t, got, td.Between('n', 'p'), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true

func CmpContainsKey 

func CmpContainsKey(t TestingT, got, expectedValue interface{}, args ...interface{}) bool

CmpContainsKey is a shortcut for: 

td.Cmp(t, got, td.ContainsKey(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#ContainsKey for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"strings"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpContainsKey(t, map[string]int{"foo": 11, "bar": 22, "zip": 33}, "foo")
	fmt.Println(`map contains key "foo":`, ok)

	ok = td.CmpContainsKey(t, map[int]bool{12: true, 24: false, 42: true, 51: false}, td.Between(40, 50))
	fmt.Println("map contains at least a key in [40 .. 50]:", ok)

	ok = td.CmpContainsKey(t, map[string]int{"FOO": 11, "bar": 22, "zip": 33}, td.Smuggle(strings.ToLower, "foo"))
	fmt.Println(`map contains key "foo" without taking case into account:`, ok)

}

Output:

map contains key "foo": true
map contains at least a key in [40 .. 50]: true
map contains key "foo" without taking case into account: true
Example (Nil) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	num := 1234
	got := map[*int]bool{&num: false, nil: true}

	ok := td.CmpContainsKey(t, got, nil)
	fmt.Println("map contains untyped nil key:", ok)

	ok = td.CmpContainsKey(t, got, (*int)(nil))
	fmt.Println("map contains *int nil key:", ok)

	ok = td.CmpContainsKey(t, got, td.Nil())
	fmt.Println("map contains Nil() key:", ok)

	ok = td.CmpContainsKey(t, got, (*byte)(nil))
	fmt.Println("map contains *byte nil key:", ok) // types differ: *byte ≠ *int

}

Output:

map contains untyped nil key: true
map contains *int nil key: true
map contains Nil() key: true
map contains *byte nil key: false

func CmpDeeply 

func CmpDeeply(t TestingT, got, expected interface{}, args ...interface{}) bool

CmpDeeply works the same as Cmp and is still available for compatibility purpose. Use shorter Cmp in new code. 

got := "foobar"
td.CmpDeeply(t, got, "foobar")            // succeeds
td.CmpDeeply(t, got, td.HasPrefix("foo")) // succeeds

func CmpEmpty 

func CmpEmpty(t TestingT, got interface{}, args ...interface{}) bool

CmpEmpty is a shortcut for: 

td.Cmp(t, got, td.Empty(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Empty for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpEmpty(t, nil) // special case: nil is considered empty
	fmt.Println(ok)

	// fails, typed nil is not empty (expect for channel, map, slice or
	// pointers on array, channel, map slice and strings)
	ok = td.CmpEmpty(t, (*int)(nil))
	fmt.Println(ok)

	ok = td.CmpEmpty(t, "")
	fmt.Println(ok)

	// Fails as 0 is a number, so not empty. Use Zero() instead
	ok = td.CmpEmpty(t, 0)
	fmt.Println(ok)

	ok = td.CmpEmpty(t, (map[string]int)(nil))
	fmt.Println(ok)

	ok = td.CmpEmpty(t, map[string]int{})
	fmt.Println(ok)

	ok = td.CmpEmpty(t, ([]int)(nil))
	fmt.Println(ok)

	ok = td.CmpEmpty(t, []int{})
	fmt.Println(ok)

	ok = td.CmpEmpty(t, []int{3}) // fails, as not empty
	fmt.Println(ok)

	ok = td.CmpEmpty(t, [3]int{}) // fails, Empty() is not Zero()!
	fmt.Println(ok)

}

Output:

true
false
true
false
true
true
true
true
false
false
Example (Pointers) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	ok := td.CmpEmpty(t, MySlice{}) // Ptr() not needed
	fmt.Println(ok)

	ok = td.CmpEmpty(t, &MySlice{})
	fmt.Println(ok)

	l1 := &MySlice{}
	l2 := &l1
	l3 := &l2
	ok = td.CmpEmpty(t, &l3)
	fmt.Println(ok)

	// Works the same for array, map, channel and string

	// But not for others types as:
	type MyStruct struct {
		Value int
	}

	ok = td.CmpEmpty(t, &MyStruct{}) // fails, use Zero() instead
	fmt.Println(ok)

}

Output:

true
true
true
false

func CmpError 

func CmpError(t TestingT, got error, args ...interface{}) bool

CmpError checks that "got" is non-nil error. 

_, err := MyFunction(1, 2, 3)
td.CmpError(t, err, "MyFunction(1, 2, 3) should return an error")

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := fmt.Errorf("Error #%d", 42)
	ok := td.CmpError(t, got, "An error occurred")
	fmt.Println(ok)

	got = nil
	ok = td.CmpError(t, got, "An error occurred") // fails
	fmt.Println(ok)

}

Output:

true
false

func CmpFalse 

func CmpFalse(t TestingT, got bool, args ...interface{}) bool

CmpFalse is a shortcut for: 

td.Cmp(t, got, false, args...)

Returns true if the test is OK, false if it fails. 

td.CmpFalse(t, IsAvailable(x), "x should not be available")

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := false
	ok := td.CmpFalse(t, got, "check that got is false!")
	fmt.Println(ok)

	got = true
	ok = td.CmpFalse(t, got, "check that got is false!")
	fmt.Println(ok)

}

Output:

true
false

func CmpGt 

func CmpGt(t TestingT, got, minExpectedValue interface{}, args ...interface{}) bool

CmpGt is a shortcut for: 

td.Cmp(t, got, td.Gt(minExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Gt for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.CmpGt(t, got, 155, "checks %v is > 155", got)
	fmt.Println(ok)

	ok = td.CmpGt(t, got, 156, "checks %v is > 156", got)
	fmt.Println(ok)

}

Output:

true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.CmpGt(t, got, "abb", `checks "%v" is > "abb"`, got)
	fmt.Println(ok)

	ok = td.CmpGt(t, got, "abc", `checks "%v" is > "abc"`, got)
	fmt.Println(ok)

}

Output:

true
false

func CmpGte 

func CmpGte(t TestingT, got, minExpectedValue interface{}, args ...interface{}) bool

CmpGte is a shortcut for: 

td.Cmp(t, got, td.Gte(minExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Gte for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.CmpGte(t, got, 156, "checks %v is ≥ 156", got)
	fmt.Println(ok)

	ok = td.CmpGte(t, got, 155, "checks %v is ≥ 155", got)
	fmt.Println(ok)

	ok = td.CmpGte(t, got, 157, "checks %v is ≥ 157", got)
	fmt.Println(ok)

}

Output:

true
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.CmpGte(t, got, "abc", `checks "%v" is ≥ "abc"`, got)
	fmt.Println(ok)

	ok = td.CmpGte(t, got, "abb", `checks "%v" is ≥ "abb"`, got)
	fmt.Println(ok)

	ok = td.CmpGte(t, got, "abd", `checks "%v" is ≥ "abd"`, got)
	fmt.Println(ok)

}

Output:

true
true
false

func CmpHasPrefix 

func CmpHasPrefix(t TestingT, got interface{}, expected string, args ...interface{}) bool

CmpHasPrefix is a shortcut for: 

td.Cmp(t, got, td.HasPrefix(expected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#HasPrefix for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.CmpHasPrefix(t, got, "foo", "checks %s", got)
	fmt.Println("using string:", ok)

	ok = td.Cmp(t, []byte(got), td.HasPrefix("foo"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.CmpHasPrefix(t, got, "foo", "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.CmpHasPrefix(t, got, "foo", "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func CmpHasSuffix 

func CmpHasSuffix(t TestingT, got interface{}, expected string, args ...interface{}) bool

CmpHasSuffix is a shortcut for: 

td.Cmp(t, got, td.HasSuffix(expected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#HasSuffix for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.CmpHasSuffix(t, got, "bar", "checks %s", got)
	fmt.Println("using string:", ok)

	ok = td.Cmp(t, []byte(got), td.HasSuffix("bar"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.CmpHasSuffix(t, got, "bar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.CmpHasSuffix(t, got, "bar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func CmpIsa 

func CmpIsa(t TestingT, got, model interface{}, args ...interface{}) bool

CmpIsa is a shortcut for: 

td.Cmp(t, got, td.Isa(model), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Isa for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type TstStruct struct {
		Field int
	}

	got := TstStruct{Field: 1}

	ok := td.CmpIsa(t, got, TstStruct{}, "checks got is a TstStruct")
	fmt.Println(ok)

	ok = td.CmpIsa(t, got, &TstStruct{},
		"checks got is a pointer on a TstStruct")
	fmt.Println(ok)

	ok = td.CmpIsa(t, &got, &TstStruct{},
		"checks &got is a pointer on a TstStruct")
	fmt.Println(ok)

}

Output:

true
false
true
Example (Interface) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := bytes.NewBufferString("foobar")

	ok := td.CmpIsa(t, got, (*fmt.Stringer)(nil),
		"checks got implements fmt.Stringer interface")
	fmt.Println(ok)

	errGot := fmt.Errorf("An error #%d occurred", 123)

	ok = td.CmpIsa(t, errGot, (*error)(nil),
		"checks errGot is a *error or implements error interface")
	fmt.Println(ok)

	// As nil, is passed below, it is not an interface but nil… So it
	// does not match
	errGot = nil

	ok = td.CmpIsa(t, errGot, (*error)(nil),
		"checks errGot is a *error or implements error interface")
	fmt.Println(ok)

	// BUT if its address is passed, now it is OK as the types match
	ok = td.CmpIsa(t, &errGot, (*error)(nil),
		"checks &errGot is a *error or implements error interface")
	fmt.Println(ok)

}

Output:

true
true
false
true

func CmpJSON 

func CmpJSON(t TestingT, got, expectedJSON interface{}, params []interface{}, args ...interface{}) bool

CmpJSON is a shortcut for: 

td.Cmp(t, got, td.JSON(expectedJSON, params...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#JSON for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob",
		Age:      42,
	}

	ok := td.CmpJSON(t, got, `{"age":42,"fullname":"Bob"}`, nil)
	fmt.Println("check got with age then fullname:", ok)

	ok = td.CmpJSON(t, got, `{"fullname":"Bob","age":42}`, nil)
	fmt.Println("check got with fullname then age:", ok)

	ok = td.CmpJSON(t, got, `
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42     /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
}`, nil)
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = td.CmpJSON(t, got, `{"fullname":"Bob","age":42,"gender":"male"}`, nil)
	fmt.Println("check got with gender field:", ok)

	ok = td.CmpJSON(t, got, `{"fullname":"Bob"}`, nil)
	fmt.Println("check got with fullname only:", ok)

	ok = td.CmpJSON(t, true, `true`, nil)
	fmt.Println("check boolean got is true:", ok)

	ok = td.CmpJSON(t, 42, `42`, nil)
	fmt.Println("check numeric got is 42:", ok)

	got = nil
	ok = td.CmpJSON(t, got, `null`, nil)
	fmt.Println("check nil got is null:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got with gender field: false
check got with fullname only: false
check boolean got is true: true
check numeric got is 42: true
check nil got is null: true
Example (Embedding) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := td.CmpJSON(t, got, `{"age": NotZero(), "fullname": NotEmpty()}`, nil)
	fmt.Println("check got with simple operators:", ok)

	ok = td.CmpJSON(t, got, `{"age": $^NotZero, "fullname": $^NotEmpty}`, nil)
	fmt.Println("check got with operator shortcuts:", ok)

	ok = td.CmpJSON(t, got, `
{
  "age":      Between(40, 42, "]]"), // in ]40; 42]
  "fullname": All(
    HasPrefix("Bob"),
    HasSuffix("bar")  // ← comma is optional here
  )
}`, nil)
	fmt.Println("check got with complex operators:", ok)

	ok = td.CmpJSON(t, got, `
{
  "age":      Between(40, 42, "]["), // in ]40; 42[ → 42 excluded
  "fullname": All(
    HasPrefix("Bob"),
    HasSuffix("bar"),
  )
}`, nil)
	fmt.Println("check got with complex operators:", ok)

}

Output:

check got with simple operators: true
check got with operator shortcuts: true
check got with complex operators: true
check got with complex operators: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender"
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := td.CmpJSON(t, got, filename, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = td.CmpJSON(t, got, file, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := td.CmpJSON(t, got, `{"age": $1, "fullname": $2}`, []interface{}{42, "Bob Foobar"})
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = td.CmpJSON(t, got, `{"age": $1, "fullname": $2}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar")})
	fmt.Println("check got with numeric placeholders:", ok)

	ok = td.CmpJSON(t, got, `{"age": "$1", "fullname": "$2"}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar")})
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = td.CmpJSON(t, got, `{"age": $age, "fullname": $name}`, []interface{}{td.Tag("age", td.Between(40, 45)), td.Tag("name", td.HasSuffix("Foobar"))})
	fmt.Println("check got with named placeholders:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true

func CmpJSONPointer added in v1.8.0 

func CmpJSONPointer(t TestingT, got interface{}, pointer string, expectedValue interface{}, args ...interface{}) bool

CmpJSONPointer is a shortcut for: 

td.Cmp(t, got, td.JSONPointer(pointer, expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#JSONPointer for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Has_hasnt) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := json.RawMessage(`
{
  "name": "Bob",
  "age": 42,
  "children": [
    {
      "name": "Alice",
      "age": 16
    },
    {
      "name": "Britt",
      "age": 21,
      "children": [
        {
          "name": "John",
          "age": 1
        }
      ]
    }
  ]
}`)

	// Has Bob some children?
	ok := td.CmpJSONPointer(t, got, "/children", td.Len(td.Gt(0)))
	fmt.Println("Bob has at least one child:", ok)

	// But checking "children" exists is enough here
	ok = td.CmpJSONPointer(t, got, "/children/0/children", td.Ignore())
	fmt.Println("Alice has children:", ok)

	ok = td.CmpJSONPointer(t, got, "/children/1/children", td.Ignore())
	fmt.Println("Britt has children:", ok)

	// The reverse can be checked too
	ok = td.Cmp(t, got, td.Not(td.JSONPointer("/children/0/children", td.Ignore())))
	fmt.Println("Alice hasn't children:", ok)

	ok = td.Cmp(t, got, td.Not(td.JSONPointer("/children/1/children", td.Ignore())))
	fmt.Println("Britt hasn't children:", ok)

}

Output:

Bob has at least one child: true
Alice has children: false
Britt has children: true
Alice hasn't children: true
Britt hasn't children: false
Example (Rfc6901) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := json.RawMessage(`
{
   "foo":  ["bar", "baz"],
   "":     0,
   "a/b":  1,
   "c%d":  2,
   "e^f":  3,
   "g|h":  4,
   "i\\j": 5,
   "k\"l": 6,
   " ":    7,
   "m~n":  8
}`)

	expected := map[string]interface{}{
		"foo": []interface{}{"bar", "baz"},
		"":    0,
		"a/b": 1,
		"c%d": 2,
		"e^f": 3,
		"g|h": 4,
		`i\j`: 5,
		`k"l`: 6,
		" ":   7,
		"m~n": 8,
	}
	ok := td.CmpJSONPointer(t, got, "", expected)
	fmt.Println("Empty JSON pointer means all:", ok)

	ok = td.CmpJSONPointer(t, got, `/foo`, []interface{}{"bar", "baz"})
	fmt.Println("Extract `foo` key:", ok)

	ok = td.CmpJSONPointer(t, got, `/foo/0`, "bar")
	fmt.Println("First item of `foo` key slice:", ok)

	ok = td.CmpJSONPointer(t, got, `/`, 0)
	fmt.Println("Empty key:", ok)

	ok = td.CmpJSONPointer(t, got, `/a~1b`, 1)
	fmt.Println("Slash has to be escaped using `~1`:", ok)

	ok = td.CmpJSONPointer(t, got, `/c%d`, 2)
	fmt.Println("% in key:", ok)

	ok = td.CmpJSONPointer(t, got, `/e^f`, 3)
	fmt.Println("^ in key:", ok)

	ok = td.CmpJSONPointer(t, got, `/g|h`, 4)
	fmt.Println("| in key:", ok)

	ok = td.CmpJSONPointer(t, got, `/i\j`, 5)
	fmt.Println("Backslash in key:", ok)

	ok = td.CmpJSONPointer(t, got, `/k"l`, 6)
	fmt.Println("Double-quote in key:", ok)

	ok = td.CmpJSONPointer(t, got, `/ `, 7)
	fmt.Println("Space key:", ok)

	ok = td.CmpJSONPointer(t, got, `/m~0n`, 8)
	fmt.Println("Tilde has to be escaped using `~0`:", ok)

}

Output:

Empty JSON pointer means all: true
Extract `foo` key: true
First item of `foo` key slice: true
Empty key: true
Slash has to be escaped using `~1`: true
% in key: true
^ in key: true
| in key: true
Backslash in key: true
Double-quote in key: true
Space key: true
Tilde has to be escaped using `~0`: true
Example (Struct) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// Without json tags, encoding/json uses public fields name
	type Item struct {
		Name  string
		Value int64
		Next  *Item
	}

	got := Item{
		Name:  "first",
		Value: 1,
		Next: &Item{
			Name:  "second",
			Value: 2,
			Next: &Item{
				Name:  "third",
				Value: 3,
			},
		},
	}

	ok := td.CmpJSONPointer(t, got, "/Next/Next/Name", "third")
	fmt.Println("3rd item name is `third`:", ok)

	ok = td.CmpJSONPointer(t, got, "/Next/Next/Value", td.Gte(int64(3)))
	fmt.Println("3rd item value is greater or equal than 3:", ok)

	ok = td.CmpJSONPointer(t, got, "/Next", td.JSONPointer("/Next",
		td.JSONPointer("/Value", td.Gte(int64(3)))))
	fmt.Println("3rd item value is still greater or equal than 3:", ok)

	ok = td.CmpJSONPointer(t, got, "/Next/Next/Next/Name", td.Ignore())
	fmt.Println("4th item exists and has a name:", ok)

	// Struct comparison work with or without pointer: &Item{…} works too
	ok = td.CmpJSONPointer(t, got, "/Next/Next", Item{
		Name:  "third",
		Value: 3,
	})
	fmt.Println("3rd item full comparison:", ok)

}

Output:

3rd item name is `third`: true
3rd item value is greater or equal than 3: true
3rd item value is still greater or equal than 3: true
4th item exists and has a name: false
3rd item full comparison: true

func CmpKeys 

func CmpKeys(t TestingT, got, val interface{}, args ...interface{}) bool

CmpKeys is a shortcut for: 

td.Cmp(t, got, td.Keys(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Keys for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 1, "bar": 2, "zip": 3}

	// Keys tests keys in an ordered manner
	ok := td.CmpKeys(t, got, []string{"bar", "foo", "zip"})
	fmt.Println("All sorted keys are found:", ok)

	// If the expected keys are not ordered, it fails
	ok = td.CmpKeys(t, got, []string{"zip", "bar", "foo"})
	fmt.Println("All unsorted keys are found:", ok)

	// To circumvent that, one can use Bag operator
	ok = td.CmpKeys(t, got, td.Bag("zip", "bar", "foo"))
	fmt.Println("All unsorted keys are found, with the help of Bag operator:", ok)

	// Check that each key is 3 bytes long
	ok = td.CmpKeys(t, got, td.ArrayEach(td.Len(3)))
	fmt.Println("Each key is 3 bytes long:", ok)

}

Output:

All sorted keys are found: true
All unsorted keys are found: false
All unsorted keys are found, with the help of Bag operator: true
Each key is 3 bytes long: true

func CmpLax 

func CmpLax(t TestingT, got, expectedValue interface{}, args ...interface{}) bool

CmpLax is a shortcut for: 

td.Cmp(t, got, td.Lax(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Lax for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	gotInt64 := int64(1234)
	gotInt32 := int32(1235)

	type myInt uint16
	gotMyInt := myInt(1236)

	expected := td.Between(1230, 1240) // int type here

	ok := td.CmpLax(t, gotInt64, expected)
	fmt.Println("int64 got between ints [1230 .. 1240]:", ok)

	ok = td.CmpLax(t, gotInt32, expected)
	fmt.Println("int32 got between ints [1230 .. 1240]:", ok)

	ok = td.CmpLax(t, gotMyInt, expected)
	fmt.Println("myInt got between ints [1230 .. 1240]:", ok)

}

Output:

int64 got between ints [1230 .. 1240]: true
int32 got between ints [1230 .. 1240]: true
myInt got between ints [1230 .. 1240]: true

func CmpLen 

func CmpLen(t TestingT, got, expectedLen interface{}, args ...interface{}) bool

CmpLen is a shortcut for: 

td.Cmp(t, got, td.Len(expectedLen), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Len for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[int]bool{11: true, 22: false, 33: false}

	ok := td.CmpLen(t, got, 3, "checks %v len is 3", got)
	fmt.Println(ok)

	ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

	got = nil

	ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true
Example (OperatorMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[int]bool{11: true, 22: false, 33: false}

	ok := td.CmpLen(t, got, td.Between(3, 8),
		"checks %v len is in [3 .. 8]", got)
	fmt.Println(ok)

	ok = td.CmpLen(t, got, td.Gte(3), "checks %v len is ≥ 3", got)
	fmt.Println(ok)

}

Output:

true
true
Example (OperatorSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{11, 22, 33}

	ok := td.CmpLen(t, got, td.Between(3, 8),
		"checks %v len is in [3 .. 8]", got)
	fmt.Println(ok)

	ok = td.CmpLen(t, got, td.Lt(5), "checks %v len is < 5", got)
	fmt.Println(ok)

}

Output:

true
true
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{11, 22, 33}

	ok := td.CmpLen(t, got, 3, "checks %v len is 3", got)
	fmt.Println(ok)

	ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

	got = nil

	ok = td.CmpLen(t, got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true

func CmpLt 

func CmpLt(t TestingT, got, maxExpectedValue interface{}, args ...interface{}) bool

CmpLt is a shortcut for: 

td.Cmp(t, got, td.Lt(maxExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Lt for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.CmpLt(t, got, 157, "checks %v is < 157", got)
	fmt.Println(ok)

	ok = td.CmpLt(t, got, 156, "checks %v is < 156", got)
	fmt.Println(ok)

}

Output:

true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.CmpLt(t, got, "abd", `checks "%v" is < "abd"`, got)
	fmt.Println(ok)

	ok = td.CmpLt(t, got, "abc", `checks "%v" is < "abc"`, got)
	fmt.Println(ok)

}

Output:

true
false

func CmpLte 

func CmpLte(t TestingT, got, maxExpectedValue interface{}, args ...interface{}) bool

CmpLte is a shortcut for: 

td.Cmp(t, got, td.Lte(maxExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Lte for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.CmpLte(t, got, 156, "checks %v is ≤ 156", got)
	fmt.Println(ok)

	ok = td.CmpLte(t, got, 157, "checks %v is ≤ 157", got)
	fmt.Println(ok)

	ok = td.CmpLte(t, got, 155, "checks %v is ≤ 155", got)
	fmt.Println(ok)

}

Output:

true
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.CmpLte(t, got, "abc", `checks "%v" is ≤ "abc"`, got)
	fmt.Println(ok)

	ok = td.CmpLte(t, got, "abd", `checks "%v" is ≤ "abd"`, got)
	fmt.Println(ok)

	ok = td.CmpLte(t, got, "abb", `checks "%v" is ≤ "abb"`, got)
	fmt.Println(ok)

}

Output:

true
true
false

func CmpMap 

func CmpMap(t TestingT, got, model interface{}, expectedEntries MapEntries, args ...interface{}) bool

CmpMap is a shortcut for: 

td.Cmp(t, got, td.Map(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Map for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := td.CmpMap(t, got, map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()},
		"checks map %v", got)
	fmt.Println(ok)

	ok = td.CmpMap(t, got, map[string]int{}, td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks map %v", got)
	fmt.Println(ok)

	ok = td.CmpMap(t, got, (map[string]int)(nil), td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks map %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := td.CmpMap(t, got, MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()},
		"checks typed map %v", got)
	fmt.Println(ok)

	ok = td.CmpMap(t, &got, &MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()},
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

	ok = td.CmpMap(t, &got, &MyMap{}, td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

	ok = td.CmpMap(t, &got, (*MyMap)(nil), td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func CmpMapEach 

func CmpMapEach(t TestingT, got, expectedValue interface{}, args ...interface{}) bool

CmpMapEach is a shortcut for: 

td.Cmp(t, got, td.MapEach(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#MapEach for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := td.CmpMapEach(t, got, td.Between(10, 90),
		"checks each value of map %v is in [10 .. 90]", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := td.CmpMapEach(t, got, td.Between(10, 90),
		"checks each value of typed map %v is in [10 .. 90]", got)
	fmt.Println(ok)

	ok = td.CmpMapEach(t, &got, td.Between(10, 90),
		"checks each value of typed map pointer %v is in [10 .. 90]", got)
	fmt.Println(ok)

}

Output:

true
true

func CmpN 

func CmpN(t TestingT, got, num, tolerance interface{}, args ...interface{}) bool

CmpN is a shortcut for: 

td.Cmp(t, got, td.N(num, tolerance), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#N for details.

N() optional parameter "tolerance" is here mandatory. 0 value should be passed to mimic its absence in original N() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 1.12345

	ok := td.CmpN(t, got, 1.1234, 0.00006,
		"checks %v = 1.1234 ± 0.00006", got)
	fmt.Println(ok)

}

Output:

true

func CmpNaN 

func CmpNaN(t TestingT, got interface{}, args ...interface{}) bool

CmpNaN is a shortcut for: 

td.Cmp(t, got, td.NaN(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NaN for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Float32) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := float32(math.NaN())

	ok := td.CmpNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(math.NaN()) is float32 not-a-number:", ok)

	got = 12

	ok = td.CmpNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(12) is float32 not-a-number:", ok)

}

Output:

float32(math.NaN()) is float32 not-a-number: true
float32(12) is float32 not-a-number: false
Example (Float64) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := math.NaN()

	ok := td.CmpNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("math.NaN() is not-a-number:", ok)

	got = 12

	ok = td.CmpNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("float64(12) is not-a-number:", ok)

	// math.NaN() is not-a-number: true
	// float64(12) is not-a-number: false
}

Output:

func CmpNil 

func CmpNil(t TestingT, got interface{}, args ...interface{}) bool

CmpNil is a shortcut for: 

td.Cmp(t, got, td.Nil(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Nil for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	var got fmt.Stringer // interface

	// nil value can be compared directly with nil, no need of Nil() here
	ok := td.Cmp(t, got, nil)
	fmt.Println(ok)

	// But it works with Nil() anyway
	ok = td.CmpNil(t, got)
	fmt.Println(ok)

	got = (*bytes.Buffer)(nil)

	// In the case of an interface containing a nil pointer, comparing
	// with nil fails, as the interface is not nil
	ok = td.Cmp(t, got, nil)
	fmt.Println(ok)

	// In this case Nil() succeed
	ok = td.CmpNil(t, got)
	fmt.Println(ok)

}

Output:

true
true
false
true

func CmpNoError 

func CmpNoError(t TestingT, got error, args ...interface{}) bool

CmpNoError checks that "got" is nil error. 

value, err := MyFunction(1, 2, 3)
if td.CmpNoError(t, err) {
  // one can now check value...
}

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := fmt.Errorf("Error #%d", 42)
	ok := td.CmpNoError(t, got, "An error occurred") // fails
	fmt.Println(ok)

	got = nil
	ok = td.CmpNoError(t, got, "An error occurred")
	fmt.Println(ok)

}

Output:

false
true

func CmpNone 

func CmpNone(t TestingT, got interface{}, notExpectedValues []interface{}, args ...interface{}) bool

CmpNone is a shortcut for: 

td.Cmp(t, got, td.None(notExpectedValues...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#None for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 18

	ok := td.CmpNone(t, got, []interface{}{0, 10, 20, 30, td.Between(100, 199)},
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	got = 20

	ok = td.CmpNone(t, got, []interface{}{0, 10, 20, 30, td.Between(100, 199)},
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	got = 142

	ok = td.CmpNone(t, got, []interface{}{0, 10, 20, 30, td.Between(100, 199)},
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	prime := td.Flatten([]int{1, 2, 3, 5, 7, 11, 13})
	even := td.Flatten([]int{2, 4, 6, 8, 10, 12, 14})
	for _, got := range [...]int{9, 3, 8, 15} {
		ok = td.CmpNone(t, got, []interface{}{prime, even, td.Gt(14)},
			"checks %v is not prime number, nor an even number and not > 14")
		fmt.Printf("%d → %t\n", got, ok)
	}

}

Output:

true
false
false
9 → true
3 → false
8 → false
15 → false

func CmpNot 

func CmpNot(t TestingT, got, notExpected interface{}, args ...interface{}) bool

CmpNot is a shortcut for: 

td.Cmp(t, got, td.Not(notExpected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Not for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 42

	ok := td.CmpNot(t, got, 0, "checks %v is non-null", got)
	fmt.Println(ok)

	ok = td.CmpNot(t, got, td.Between(10, 30),
		"checks %v is not in [10 .. 30]", got)
	fmt.Println(ok)

	got = 0

	ok = td.CmpNot(t, got, 0, "checks %v is non-null", got)
	fmt.Println(ok)

}

Output:

true
true
false

func CmpNotAny 

func CmpNotAny(t TestingT, got interface{}, notExpectedItems []interface{}, args ...interface{}) bool

CmpNotAny is a shortcut for: 

td.Cmp(t, got, td.NotAny(notExpectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotAny for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{4, 5, 9, 42}

	ok := td.CmpNotAny(t, got, []interface{}{3, 6, 8, 41, 43},
		"checks %v contains no item listed in NotAny()", got)
	fmt.Println(ok)

	ok = td.CmpNotAny(t, got, []interface{}{3, 6, 8, 42, 43},
		"checks %v contains no item listed in NotAny()", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using notExpected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	notExpected := []int{3, 6, 8, 41, 43}
	ok = td.CmpNotAny(t, got, []interface{}{td.Flatten(notExpected)},
		"checks %v contains no item listed in notExpected", got)
	fmt.Println(ok)

}

Output:

true
false
true

func CmpNotEmpty 

func CmpNotEmpty(t TestingT, got interface{}, args ...interface{}) bool

CmpNotEmpty is a shortcut for: 

td.Cmp(t, got, td.NotEmpty(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotEmpty for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpNotEmpty(t, nil) // fails, as nil is considered empty
	fmt.Println(ok)

	ok = td.CmpNotEmpty(t, "foobar")
	fmt.Println(ok)

	// Fails as 0 is a number, so not empty. Use NotZero() instead
	ok = td.CmpNotEmpty(t, 0)
	fmt.Println(ok)

	ok = td.CmpNotEmpty(t, map[string]int{"foobar": 42})
	fmt.Println(ok)

	ok = td.CmpNotEmpty(t, []int{1})
	fmt.Println(ok)

	ok = td.CmpNotEmpty(t, [3]int{}) // succeeds, NotEmpty() is not NotZero()!
	fmt.Println(ok)

}

Output:

false
true
false
true
true
true
Example (Pointers) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	ok := td.CmpNotEmpty(t, MySlice{12})
	fmt.Println(ok)

	ok = td.CmpNotEmpty(t, &MySlice{12}) // Ptr() not needed
	fmt.Println(ok)

	l1 := &MySlice{12}
	l2 := &l1
	l3 := &l2
	ok = td.CmpNotEmpty(t, &l3)
	fmt.Println(ok)

	// Works the same for array, map, channel and string

	// But not for others types as:
	type MyStruct struct {
		Value int
	}

	ok = td.CmpNotEmpty(t, &MyStruct{}) // fails, use NotZero() instead
	fmt.Println(ok)

}

Output:

true
true
true
false

func CmpNotNaN 

func CmpNotNaN(t TestingT, got interface{}, args ...interface{}) bool

CmpNotNaN is a shortcut for: 

td.Cmp(t, got, td.NotNaN(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotNaN for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Float32) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := float32(math.NaN())

	ok := td.CmpNotNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(math.NaN()) is NOT float32 not-a-number:", ok)

	got = 12

	ok = td.CmpNotNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(12) is NOT float32 not-a-number:", ok)

}

Output:

float32(math.NaN()) is NOT float32 not-a-number: false
float32(12) is NOT float32 not-a-number: true
Example (Float64) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := math.NaN()

	ok := td.CmpNotNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("math.NaN() is not-a-number:", ok)

	got = 12

	ok = td.CmpNotNaN(t, got,
		"checks %v is not-a-number", got)

	fmt.Println("float64(12) is not-a-number:", ok)

	// math.NaN() is NOT not-a-number: false
	// float64(12) is NOT not-a-number: true
}

Output:

func CmpNotNil 

func CmpNotNil(t TestingT, got interface{}, args ...interface{}) bool

CmpNotNil is a shortcut for: 

td.Cmp(t, got, td.NotNil(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotNil for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	var got fmt.Stringer = &bytes.Buffer{}

	// nil value can be compared directly with Not(nil), no need of NotNil() here
	ok := td.Cmp(t, got, td.Not(nil))
	fmt.Println(ok)

	// But it works with NotNil() anyway
	ok = td.CmpNotNil(t, got)
	fmt.Println(ok)

	got = (*bytes.Buffer)(nil)

	// In the case of an interface containing a nil pointer, comparing
	// with Not(nil) succeeds, as the interface is not nil
	ok = td.Cmp(t, got, td.Not(nil))
	fmt.Println(ok)

	// In this case NotNil() fails
	ok = td.CmpNotNil(t, got)
	fmt.Println(ok)

}

Output:

true
true
true
false

func CmpNotPanic 

func CmpNotPanic(t TestingT, fn func(), args ...interface{}) bool

CmpNotPanic calls "fn" and checks no panic() occurred. If a panic() occurred false is returned then the panic() parameter and the stack trace appear in the test report.

Note that calling panic(nil) in "fn" body is detected as a panic. 

td.CmpNotPanic(t, func() {}) // succeeds as function does not panic

td.CmpNotPanic(t, func() { panic("I am panicking!") }) // fails
td.CmpNotPanic(t, func() { panic(nil) })               // fails too

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpNotPanic(t, func() {})
	fmt.Println("checks a panic DID NOT occur:", ok)

	// Classic panic
	ok = td.CmpNotPanic(t, func() { panic("I am panicking!") },
		"Hope it does not panic!")
	fmt.Println("still no panic?", ok)

	// Can detect panic(nil)
	ok = td.CmpNotPanic(t, func() { panic(nil) }, "Checks for panic(nil)")
	fmt.Println("last no panic?", ok)

}

Output:

checks a panic DID NOT occur: true
still no panic? false
last no panic? false

func CmpNotZero 

func CmpNotZero(t TestingT, got interface{}, args ...interface{}) bool

CmpNotZero is a shortcut for: 

td.Cmp(t, got, td.NotZero(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotZero for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpNotZero(t, 0) // fails
	fmt.Println(ok)

	ok = td.CmpNotZero(t, float64(0)) // fails
	fmt.Println(ok)

	ok = td.CmpNotZero(t, 12)
	fmt.Println(ok)

	ok = td.CmpNotZero(t, (map[string]int)(nil)) // fails, as nil
	fmt.Println(ok)

	ok = td.CmpNotZero(t, map[string]int{}) // succeeds, as not nil
	fmt.Println(ok)

	ok = td.CmpNotZero(t, ([]int)(nil)) // fails, as nil
	fmt.Println(ok)

	ok = td.CmpNotZero(t, []int{}) // succeeds, as not nil
	fmt.Println(ok)

	ok = td.CmpNotZero(t, [3]int{}) // fails
	fmt.Println(ok)

	ok = td.CmpNotZero(t, [3]int{0, 1}) // succeeds, DATA[1] is not 0
	fmt.Println(ok)

	ok = td.CmpNotZero(t, bytes.Buffer{}) // fails
	fmt.Println(ok)

	ok = td.CmpNotZero(t, &bytes.Buffer{}) // succeeds, as pointer not nil
	fmt.Println(ok)

	ok = td.Cmp(t, &bytes.Buffer{}, td.Ptr(td.NotZero())) // fails as deref by Ptr()
	fmt.Println(ok)

}

Output:

false
false
true
false
true
false
true
false
true
false
true
false

func CmpPPtr 

func CmpPPtr(t TestingT, got, val interface{}, args ...interface{}) bool

CmpPPtr is a shortcut for: 

td.Cmp(t, got, td.PPtr(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#PPtr for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	num := 12
	got := &num

	ok := td.CmpPPtr(t, &got, 12)
	fmt.Println(ok)

	ok = td.CmpPPtr(t, &got, td.Between(4, 15))
	fmt.Println(ok)

}

Output:

true
true

func CmpPanic 

func CmpPanic(t TestingT, fn func(), expectedPanic interface{},
	args ...interface{}) bool

CmpPanic calls "fn" and checks a panic() occurred with the "expectedPanic" parameter. It returns true only if both conditions are fulfilled.

Note that calling panic(nil) in "fn" body is detected as a panic (in this case "expectedPanic" has to be nil). 

td.CmpPanic(t,
  func() { panic("I am panicking!") },
  "I am panicking!",
  "The function should panic with the right string") // succeeds

td.CmpPanic(t,
  func() { panic("I am panicking!") },
  Contains("panicking!"),
  "The function should panic with a string containing `panicking!`") // succeeds

td.CmpPanic(t, func() { panic(nil) }, nil, "Checks for panic(nil)") // succeeds

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpPanic(t,
		func() { panic("I am panicking!") }, "I am panicking!",
		"Checks for panic")
	fmt.Println("checks exact panic() string:", ok)

	// Can use TestDeep operator too
	ok = td.CmpPanic(t,
		func() { panic("I am panicking!") }, td.Contains("panicking!"),
		"Checks for panic")
	fmt.Println("checks panic() sub-string:", ok)

	// Can detect panic(nil)
	ok = td.CmpPanic(t, func() { panic(nil) }, nil, "Checks for panic(nil)")
	fmt.Println("checks for panic(nil):", ok)

	// As well as structured data panic
	type PanicStruct struct {
		Error string
		Code  int
	}

	ok = td.CmpPanic(t,
		func() {
			panic(PanicStruct{Error: "Memory violation", Code: 11})
		},
		PanicStruct{
			Error: "Memory violation",
			Code:  11,
		})
	fmt.Println("checks exact panic() struct:", ok)

	// or combined with TestDeep operators too
	ok = td.CmpPanic(t,
		func() {
			panic(PanicStruct{Error: "Memory violation", Code: 11})
		},
		td.Struct(PanicStruct{}, td.StructFields{
			"Code": td.Between(10, 20),
		}))
	fmt.Println("checks panic() struct against TestDeep operators:", ok)

	// Of course, do not panic = test failure, even for expected nil
	// panic parameter
	ok = td.CmpPanic(t, func() {}, nil)
	fmt.Println("checks a panic occurred:", ok)

}

Output:

checks exact panic() string: true
checks panic() sub-string: true
checks for panic(nil): true
checks exact panic() struct: true
checks panic() struct against TestDeep operators: true
checks a panic occurred: false

func CmpPtr 

func CmpPtr(t TestingT, got, val interface{}, args ...interface{}) bool

CmpPtr is a shortcut for: 

td.Cmp(t, got, td.Ptr(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Ptr for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 12

	ok := td.CmpPtr(t, &got, 12)
	fmt.Println(ok)

	ok = td.CmpPtr(t, &got, td.Between(4, 15))
	fmt.Println(ok)

}

Output:

true
true

func CmpRe 

func CmpRe(t TestingT, got, reg, capture interface{}, args ...interface{}) bool

CmpRe is a shortcut for: 

td.Cmp(t, got, td.Re(reg, capture), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Re for details.

Re() optional parameter "capture" is here mandatory. nil value should be passed to mimic its absence in original Re() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo bar"
	ok := td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (Capture) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo bar biz"
	ok := td.CmpRe(t, got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.CmpRe(t, got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (Compiled) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := "foo bar"
	ok := td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCapture) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile(`^(\w+) (\w+) (\w+)$`)

	got := "foo bar biz"
	ok := td.CmpRe(t, got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.CmpRe(t, got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledError) 
package main

import (
	"errors"
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := errors.New("foo bar")
	ok := td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (CompiledStringer) 
package main

import (
	"bytes"
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.CmpRe(t, got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foo bar")
	ok := td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.CmpRe(t, got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true

func CmpReAll 

func CmpReAll(t TestingT, got, reg, capture interface{}, args ...interface{}) bool

CmpReAll is a shortcut for: 

td.Cmp(t, got, td.ReAll(reg, capture), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#ReAll for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Capture) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo bar biz"
	ok := td.CmpReAll(t, got, `(\w+)`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but all catured groups do not match Set
	got = "foo BAR biz"
	ok = td.CmpReAll(t, got, `(\w+)`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CaptureComplex) 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "11 45 23 56 85 96"
	ok := td.CmpReAll(t, got, `(\d+)`, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 10 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but 11 is not greater than 20
	ok = td.CmpReAll(t, got, `(\d+)`, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 20 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCapture) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile(`(\w+)`)

	got := "foo bar biz"
	ok := td.CmpReAll(t, got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but all catured groups do not match Set
	got = "foo BAR biz"
	ok = td.CmpReAll(t, got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCaptureComplex) 
package main

import (
	"fmt"
	"regexp"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile(`(\d+)`)

	got := "11 45 23 56 85 96"
	ok := td.CmpReAll(t, got, expected, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 10 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but 11 is not greater than 20
	ok = td.CmpReAll(t, got, expected, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 20 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false

func CmpSStruct 

func CmpSStruct(t TestingT, got, model interface{}, expectedFields StructFields, args ...interface{}) bool

CmpSStruct is a shortcut for: 

td.Cmp(t, got, td.SStruct(model, expectedFields), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SStruct for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type Person struct {
		Name        string
		Age         int
		NumChildren int
	}

	got := Person{
		Name:        "Foobar",
		Age:         42,
		NumChildren: 0,
	}

	// NumChildren is not listed in expected fields so it must be zero
	ok := td.CmpSStruct(t, got, Person{Name: "Foobar"}, td.StructFields{
		"Age": td.Between(40, 50),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model can be empty
	got.NumChildren = 3
	ok = td.CmpSStruct(t, got, Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Works with pointers too
	ok = td.CmpSStruct(t, &got, &Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model does not need to be instanciated
	ok = td.CmpSStruct(t, &got, (*Person)(nil), td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

}

Output:

true
true
true
true

func CmpSet 

func CmpSet(t TestingT, got interface{}, expectedItems []interface{}, args ...interface{}) bool

CmpSet is a shortcut for: 

td.Cmp(t, got, td.Set(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Set for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are present, ignoring duplicates
	ok := td.CmpSet(t, got, []interface{}{1, 2, 3, 5, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Duplicates are ignored in a Set
	ok = td.CmpSet(t, got, []interface{}{1, 2, 2, 2, 2, 2, 3, 5, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Tries its best to not raise an error when a value can be matched
	// by several Set entries
	ok = td.CmpSet(t, got, []interface{}{td.Between(1, 4), 3, td.Between(2, 10)},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5, 8}
	ok = td.CmpSet(t, got, []interface{}{td.Flatten(expected)},
		"checks all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
true
true
true

func CmpShallow 

func CmpShallow(t TestingT, got, expectedPtr interface{}, args ...interface{}) bool

CmpShallow is a shortcut for: 

td.Cmp(t, got, td.Shallow(expectedPtr), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Shallow for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyStruct struct {
		Value int
	}
	data := MyStruct{Value: 12}
	got := &data

	ok := td.CmpShallow(t, got, &data,
		"checks pointers only, not contents")
	fmt.Println(ok)

	// Same contents, but not same pointer
	ok = td.CmpShallow(t, got, &MyStruct{Value: 12},
		"checks pointers only, not contents")
	fmt.Println(ok)

}

Output:

true
false
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	back := []int{1, 2, 3, 1, 2, 3}
	a := back[:3]
	b := back[3:]

	ok := td.CmpShallow(t, a, back)
	fmt.Println("are ≠ but share the same area:", ok)

	ok = td.CmpShallow(t, b, back)
	fmt.Println("are = but do not point to same area:", ok)

}

Output:

are ≠ but share the same area: true
are = but do not point to same area: false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	back := "foobarfoobar"
	a := back[:6]
	b := back[6:]

	ok := td.CmpShallow(t, a, back)
	fmt.Println("are ≠ but share the same area:", ok)

	ok = td.CmpShallow(t, b, a)
	fmt.Println("are = but do not point to same area:", ok)

}

Output:

are ≠ but share the same area: true
are = but do not point to same area: false

func CmpSlice 

func CmpSlice(t TestingT, got, model interface{}, expectedEntries ArrayEntries, args ...interface{}) bool

CmpSlice is a shortcut for: 

td.Cmp(t, got, td.Slice(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Slice for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{42, 58, 26}

	ok := td.CmpSlice(t, got, []int{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks slice %v", got)
	fmt.Println(ok)

	ok = td.CmpSlice(t, got, []int{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks slice %v", got)
	fmt.Println(ok)

	ok = td.CmpSlice(t, got, ([]int)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks slice %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
Example (TypedSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	got := MySlice{42, 58, 26}

	ok := td.CmpSlice(t, got, MySlice{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks typed slice %v", got)
	fmt.Println(ok)

	ok = td.CmpSlice(t, &got, &MySlice{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

	ok = td.CmpSlice(t, &got, &MySlice{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

	ok = td.CmpSlice(t, &got, (*MySlice)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func CmpSmuggle 

func CmpSmuggle(t TestingT, got, fn, expectedValue interface{}, args ...interface{}) bool

CmpSmuggle is a shortcut for: 

td.Cmp(t, got, td.Smuggle(fn, expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Smuggle for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Auto_unmarshal) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// Automatically json.Unmarshal to compare
	got := []byte(`{"a":1,"b":2}`)

	ok := td.CmpSmuggle(t, got, func(b json.RawMessage) (r map[string]int, err error) {
		err = json.Unmarshal(b, &r)
		return
	}, map[string]int{
		"a": 1,
		"b": 2,
	})
	fmt.Println("JSON contents is OK:", ok)

}

Output:

JSON contents is OK: true
Example (Complex) 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// No end date but a start date and a duration
	type StartDuration struct {
		StartDate time.Time
		Duration  time.Duration
	}

	// Checks that end date is between 17th and 19th February both at 0h
	// for each of these durations in hours

	for _, duration := range []time.Duration{48, 72, 96} {
		got := StartDuration{
			StartDate: time.Date(2018, time.February, 14, 12, 13, 14, 0, time.UTC),
			Duration:  duration * time.Hour,
		}

		// Simplest way, but in case of Between() failure, error will be bound
		// to DATA<smuggled>, not very clear...
		ok := td.CmpSmuggle(t, got, func(sd StartDuration) time.Time {
			return sd.StartDate.Add(sd.Duration)
		}, td.Between(
			time.Date(2018, time.February, 17, 0, 0, 0, 0, time.UTC),
			time.Date(2018, time.February, 19, 0, 0, 0, 0, time.UTC)))
		fmt.Println(ok)

		// Name the computed value "ComputedEndDate" to render a Between() failure
		// more understandable, so error will be bound to DATA.ComputedEndDate
		ok = td.CmpSmuggle(t, got, func(sd StartDuration) td.SmuggledGot {
			return td.SmuggledGot{
				Name: "ComputedEndDate",
				Got:  sd.StartDate.Add(sd.Duration),
			}
		}, td.Between(
			time.Date(2018, time.February, 17, 0, 0, 0, 0, time.UTC),
			time.Date(2018, time.February, 19, 0, 0, 0, 0, time.UTC)))
		fmt.Println(ok)
	}

}

Output:

false
false
true
true
true
true
Example (Convert) 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := int64(123)

	ok := td.CmpSmuggle(t, got, func(n int64) int { return int(n) }, 123,
		"checks int64 got against an int value")
	fmt.Println(ok)

	ok = td.CmpSmuggle(t, "123", func(numStr string) (int, bool) {
		n, err := strconv.Atoi(numStr)
		return n, err == nil
	}, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	ok = td.CmpSmuggle(t, "123", func(numStr string) (int, bool, string) {
		n, err := strconv.Atoi(numStr)
		if err != nil {
			return 0, false, "string must contain a number"
		}
		return n, true, ""
	}, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	ok = td.CmpSmuggle(t, "123", func(numStr string) (int, error) { // nolint: gocritic
		return strconv.Atoi(numStr)
	}, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	// Short version :)
	ok = td.CmpSmuggle(t, "123", strconv.Atoi, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

}

Output:

true
true
true
true
true
Example (Field_path) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type Body struct {
		Name  string
		Value interface{}
	}
	type Request struct {
		Body *Body
	}
	type Transaction struct {
		Request
	}
	type ValueNum struct {
		Num int
	}

	got := &Transaction{
		Request: Request{
			Body: &Body{
				Name:  "test",
				Value: &ValueNum{Num: 123},
			},
		},
	}

	// Want to check whether Num is between 100 and 200?
	ok := td.CmpSmuggle(t, got, func(t *Transaction) (int, error) {
		if t.Request.Body == nil ||
			t.Request.Body.Value == nil {
			return 0, errors.New("Request.Body or Request.Body.Value is nil")
		}
		if v, ok := t.Request.Body.Value.(*ValueNum); ok && v != nil {
			return v.Num, nil
		}
		return 0, errors.New("Request.Body.Value isn't *ValueNum or nil")
	}, td.Between(100, 200))
	fmt.Println("check Num by hand:", ok)

	// Same, but automagically generated...
	ok = td.CmpSmuggle(t, got, "Request.Body.Value.Num", td.Between(100, 200))
	fmt.Println("check Num using a fields-path:", ok)

	// And as Request is an anonymous field, can be simplified further
	// as it can be omitted
	ok = td.CmpSmuggle(t, got, "Body.Value.Num", td.Between(100, 200))
	fmt.Println("check Num using an other fields-path:", ok)

}

Output:

check Num by hand: true
check Num using a fields-path: true
check Num using an other fields-path: true
Example (Interface) 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	gotTime, err := time.Parse(time.RFC3339, "2018-05-23T12:13:14Z")
	if err != nil {
		t.Fatal(err)
	}

	// Do not check the struct itself, but its stringified form
	ok := td.CmpSmuggle(t, gotTime, func(s fmt.Stringer) string {
		return s.String()
	}, "2018-05-23 12:13:14 +0000 UTC")
	fmt.Println("stringified time.Time OK:", ok)

	// If got does not implement the fmt.Stringer interface, it fails
	// without calling the Smuggle func
	type MyTime time.Time
	ok = td.CmpSmuggle(t, MyTime(gotTime), func(s fmt.Stringer) string {
		fmt.Println("Smuggle func called!")
		return s.String()
	}, "2018-05-23 12:13:14 +0000 UTC")
	fmt.Println("stringified MyTime OK:", ok)

	// Output
	// stringified time.Time OK: true
	// stringified MyTime OK: false
}

Output:
Example (Lax) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// got is an int16 and Smuggle func input is an int64: it is OK
	got := int(123)

	ok := td.CmpSmuggle(t, got, func(n int64) uint32 { return uint32(n) }, uint32(123))
	fmt.Println("got int16(123) → smuggle via int64 → uint32(123):", ok)

}

Output:

got int16(123) → smuggle via int64 → uint32(123): true

func CmpString 

func CmpString(t TestingT, got interface{}, expected string, args ...interface{}) bool

CmpString is a shortcut for: 

td.Cmp(t, got, td.String(expected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#String for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.CmpString(t, got, "foobar", "checks %s", got)
	fmt.Println("using string:", ok)

	ok = td.Cmp(t, []byte(got), td.String("foobar"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.CmpString(t, got, "foobar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.CmpString(t, got, "foobar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func CmpStruct 

func CmpStruct(t TestingT, got, model interface{}, expectedFields StructFields, args ...interface{}) bool

CmpStruct is a shortcut for: 

td.Cmp(t, got, td.Struct(model, expectedFields), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Struct for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type Person struct {
		Name        string
		Age         int
		NumChildren int
	}

	got := Person{
		Name:        "Foobar",
		Age:         42,
		NumChildren: 3,
	}

	// As NumChildren is zero in Struct() call, it is not checked
	ok := td.CmpStruct(t, got, Person{Name: "Foobar"}, td.StructFields{
		"Age": td.Between(40, 50),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model can be empty
	ok = td.CmpStruct(t, got, Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Works with pointers too
	ok = td.CmpStruct(t, &got, &Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model does not need to be instanciated
	ok = td.CmpStruct(t, &got, (*Person)(nil), td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

}

Output:

true
true
true
true

func CmpSubBagOf 

func CmpSubBagOf(t TestingT, got interface{}, expectedItems []interface{}, args ...interface{}) bool

CmpSubBagOf is a shortcut for: 

td.Cmp(t, got, td.SubBagOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubBagOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := td.CmpSubBagOf(t, got, []interface{}{0, 0, 1, 1, 2, 2, 3, 3, 5, 5, 8, 8, 9, 9},
		"checks at least all items are present, in any order")
	fmt.Println(ok)

	// got contains one 8 too many
	ok = td.CmpSubBagOf(t, got, []interface{}{0, 0, 1, 1, 2, 2, 3, 3, 5, 5, 8, 9, 9},
		"checks at least all items are present, in any order")
	fmt.Println(ok)

	got = []int{1, 3, 5, 2}

	ok = td.CmpSubBagOf(t, got, []interface{}{td.Between(0, 3), td.Between(0, 3), td.Between(0, 3), td.Between(0, 3), td.Gt(4), td.Gt(4)},
		"checks at least all items match, in any order with TestDeep operators")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5, 9, 8}
	ok = td.CmpSubBagOf(t, got, []interface{}{td.Flatten(expected)},
		"checks at least all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
false
true
true

func CmpSubJSONOf 

func CmpSubJSONOf(t TestingT, got, expectedJSON interface{}, params []interface{}, args ...interface{}) bool

CmpSubJSONOf is a shortcut for: 

td.Cmp(t, got, td.SubJSONOf(expectedJSON, params...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubJSONOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob",
		Age:      42,
	}

	ok := td.CmpSubJSONOf(t, got, `{"age":42,"fullname":"Bob","gender":"male"}`, nil)
	fmt.Println("check got with age then fullname:", ok)

	ok = td.CmpSubJSONOf(t, got, `{"fullname":"Bob","age":42,"gender":"male"}`, nil)
	fmt.Println("check got with fullname then age:", ok)

	ok = td.CmpSubJSONOf(t, got, `
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42,    /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
  "gender":   "male" // This field is ignored as SubJSONOf
}`, nil)
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = td.CmpSubJSONOf(t, got, `{"fullname":"Bob","gender":"male"}`, nil)
	fmt.Println("check got without age field:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got without age field: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender",
  "details":  {
    "city": "TestCity",
    "zip":  666
  }
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := td.CmpSubJSONOf(t, got, filename, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = td.CmpSubJSONOf(t, got, file, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := td.CmpSubJSONOf(t, got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{42, "Bob Foobar", "male"})
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = td.CmpSubJSONOf(t, got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with numeric placeholders:", ok)

	ok = td.CmpSubJSONOf(t, got, `{"age": "$1", "fullname": "$2", "gender": "$3"}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = td.CmpSubJSONOf(t, got, `{"age": $age, "fullname": $name, "gender": $gender}`, []interface{}{td.Tag("age", td.Between(40, 45)), td.Tag("name", td.HasSuffix("Foobar")), td.Tag("gender", td.NotEmpty())})
	fmt.Println("check got with named placeholders:", ok)

	ok = td.CmpSubJSONOf(t, got, `{"age": $^NotZero, "fullname": $^NotEmpty, "gender": $^NotEmpty}`, nil)
	fmt.Println("check got with operator shortcuts:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true
check got with operator shortcuts: true

func CmpSubMapOf 

func CmpSubMapOf(t TestingT, got, model interface{}, expectedEntries MapEntries, args ...interface{}) bool

CmpSubMapOf is a shortcut for: 

td.Cmp(t, got, td.SubMapOf(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubMapOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42}

	ok := td.CmpSubMapOf(t, got, map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666},
		"checks map %v is included in expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42}

	ok := td.CmpSubMapOf(t, got, MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666},
		"checks typed map %v is included in expected keys/values", got)
	fmt.Println(ok)

	ok = td.CmpSubMapOf(t, &got, &MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666},
		"checks pointed typed map %v is included in expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
true

func CmpSubSetOf 

func CmpSubSetOf(t TestingT, got interface{}, expectedItems []interface{}, args ...interface{}) bool

CmpSubSetOf is a shortcut for: 

td.Cmp(t, got, td.SubSetOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubSetOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are expected, ignoring duplicates
	ok := td.CmpSubSetOf(t, got, []interface{}{1, 2, 3, 4, 5, 6, 7, 8},
		"checks at least all items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

	// Tries its best to not raise an error when a value can be matched
	// by several SubSetOf entries
	ok = td.CmpSubSetOf(t, got, []interface{}{td.Between(1, 4), 3, td.Between(2, 10), td.Gt(100)},
		"checks at least all items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 4, 5, 6, 7, 8}
	ok = td.CmpSubSetOf(t, got, []interface{}{td.Flatten(expected)},
		"checks at least all expected items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

}

Output:

true
true
true

func CmpSuperBagOf 

func CmpSuperBagOf(t TestingT, got interface{}, expectedItems []interface{}, args ...interface{}) bool

CmpSuperBagOf is a shortcut for: 

td.Cmp(t, got, td.SuperBagOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperBagOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := td.CmpSuperBagOf(t, got, []interface{}{8, 5, 8},
		"checks the items are present, in any order")
	fmt.Println(ok)

	ok = td.CmpSuperBagOf(t, got, []interface{}{td.Gt(5), td.Lte(2)},
		"checks at least 2 items of %v match", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{8, 5, 8}
	ok = td.CmpSuperBagOf(t, got, []interface{}{td.Flatten(expected)},
		"checks the expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
true
true

func CmpSuperJSONOf 

func CmpSuperJSONOf(t TestingT, got, expectedJSON interface{}, params []interface{}, args ...interface{}) bool

CmpSuperJSONOf is a shortcut for: 

td.Cmp(t, got, td.SuperJSONOf(expectedJSON, params...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperJSONOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	ok := td.CmpSuperJSONOf(t, got, `{"age":42,"fullname":"Bob","gender":"male"}`, nil)
	fmt.Println("check got with age then fullname:", ok)

	ok = td.CmpSuperJSONOf(t, got, `{"fullname":"Bob","age":42,"gender":"male"}`, nil)
	fmt.Println("check got with fullname then age:", ok)

	ok = td.CmpSuperJSONOf(t, got, `
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42,    /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
  "gender":   "male" // The gender!
}`, nil)
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = td.CmpSuperJSONOf(t, got, `{"fullname":"Bob","gender":"male","details":{}}`, nil)
	fmt.Println("check got with details field:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got with details field: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender"
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := td.CmpSuperJSONOf(t, got, filename, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = td.CmpSuperJSONOf(t, got, file, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	ok := td.CmpSuperJSONOf(t, got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{42, "Bob Foobar", "male"})
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = td.CmpSuperJSONOf(t, got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with numeric placeholders:", ok)

	ok = td.CmpSuperJSONOf(t, got, `{"age": "$1", "fullname": "$2", "gender": "$3"}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = td.CmpSuperJSONOf(t, got, `{"age": $age, "fullname": $name, "gender": $gender}`, []interface{}{td.Tag("age", td.Between(40, 45)), td.Tag("name", td.HasSuffix("Foobar")), td.Tag("gender", td.NotEmpty())})
	fmt.Println("check got with named placeholders:", ok)

	ok = td.CmpSuperJSONOf(t, got, `{"age": $^NotZero, "fullname": $^NotEmpty, "gender": $^NotEmpty}`, nil)
	fmt.Println("check got with operator shortcuts:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true
check got with operator shortcuts: true

func CmpSuperMapOf 

func CmpSuperMapOf(t TestingT, got, model interface{}, expectedEntries MapEntries, args ...interface{}) bool

CmpSuperMapOf is a shortcut for: 

td.Cmp(t, got, td.SuperMapOf(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperMapOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := td.CmpSuperMapOf(t, got, map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15)},
		"checks map %v contains at leat all expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := td.CmpSuperMapOf(t, got, MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15)},
		"checks typed map %v contains at leat all expected keys/values", got)
	fmt.Println(ok)

	ok = td.CmpSuperMapOf(t, &got, &MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15)},
		"checks pointed typed map %v contains at leat all expected keys/values",
		got)
	fmt.Println(ok)

}

Output:

true
true

func CmpSuperSetOf 

func CmpSuperSetOf(t TestingT, got interface{}, expectedItems []interface{}, args ...interface{}) bool

CmpSuperSetOf is a shortcut for: 

td.Cmp(t, got, td.SuperSetOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperSetOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := td.CmpSuperSetOf(t, got, []interface{}{1, 2, 3},
		"checks the items are present, in any order and ignoring duplicates")
	fmt.Println(ok)

	ok = td.CmpSuperSetOf(t, got, []interface{}{td.Gt(5), td.Lte(2)},
		"checks at least 2 items of %v match ignoring duplicates", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3}
	ok = td.CmpSuperSetOf(t, got, []interface{}{td.Flatten(expected)},
		"checks the expected items are present, in any order and ignoring duplicates")
	fmt.Println(ok)

}

Output:

true
true
true

func CmpTrue 

func CmpTrue(t TestingT, got bool, args ...interface{}) bool

CmpTrue is a shortcut for: 

td.Cmp(t, got, true, args...)

Returns true if the test is OK, false if it fails. 

td.CmpTrue(t, IsAvailable(x), "x should be available")

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := true
	ok := td.CmpTrue(t, got, "check that got is true!")
	fmt.Println(ok)

	got = false
	ok = td.CmpTrue(t, got, "check that got is true!")
	fmt.Println(ok)

}

Output:

true
false

func CmpTruncTime 

func CmpTruncTime(t TestingT, got, expectedTime interface{}, trunc time.Duration, args ...interface{}) bool

CmpTruncTime is a shortcut for: 

td.Cmp(t, got, td.TruncTime(expectedTime, trunc), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#TruncTime for details.

TruncTime() optional parameter "trunc" is here mandatory. 0 value should be passed to mimic its absence in original TruncTime() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	dateToTime := func(str string) time.Time {
		t, err := time.Parse(time.RFC3339Nano, str)
		if err != nil {
			panic(err)
		}
		return t
	}

	got := dateToTime("2018-05-01T12:45:53.123456789Z")

	// Compare dates ignoring nanoseconds and monotonic parts
	expected := dateToTime("2018-05-01T12:45:53Z")
	ok := td.CmpTruncTime(t, got, expected, time.Second,
		"checks date %v, truncated to the second", got)
	fmt.Println(ok)

	// Compare dates ignoring time and so monotonic parts
	expected = dateToTime("2018-05-01T11:22:33.444444444Z")
	ok = td.CmpTruncTime(t, got, expected, 24*time.Hour,
		"checks date %v, truncated to the day", got)
	fmt.Println(ok)

	// Compare dates exactly but ignoring monotonic part
	expected = dateToTime("2018-05-01T12:45:53.123456789Z")
	ok = td.CmpTruncTime(t, got, expected, 0,
		"checks date %v ignoring monotonic part", got)
	fmt.Println(ok)

}

Output:

true
true
true

func CmpValues 

func CmpValues(t TestingT, got, val interface{}, args ...interface{}) bool

CmpValues is a shortcut for: 

td.Cmp(t, got, td.Values(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Values for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 1, "bar": 2, "zip": 3}

	// Values tests values in an ordered manner
	ok := td.CmpValues(t, got, []int{1, 2, 3})
	fmt.Println("All sorted values are found:", ok)

	// If the expected values are not ordered, it fails
	ok = td.CmpValues(t, got, []int{3, 1, 2})
	fmt.Println("All unsorted values are found:", ok)

	// To circumvent that, one can use Bag operator
	ok = td.CmpValues(t, got, td.Bag(3, 1, 2))
	fmt.Println("All unsorted values are found, with the help of Bag operator:", ok)

	// Check that each value is between 1 and 3
	ok = td.CmpValues(t, got, td.ArrayEach(td.Between(1, 3)))
	fmt.Println("Each value is between 1 and 3:", ok)

}

Output:

All sorted values are found: true
All unsorted values are found: false
All unsorted values are found, with the help of Bag operator: true
Each value is between 1 and 3: true

func CmpZero 

func CmpZero(t TestingT, got interface{}, args ...interface{}) bool

CmpZero is a shortcut for: 

td.Cmp(t, got, td.Zero(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Zero for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.CmpZero(t, 0)
	fmt.Println(ok)

	ok = td.CmpZero(t, float64(0))
	fmt.Println(ok)

	ok = td.CmpZero(t, 12) // fails, as 12 is not 0 :)
	fmt.Println(ok)

	ok = td.CmpZero(t, (map[string]int)(nil))
	fmt.Println(ok)

	ok = td.CmpZero(t, map[string]int{}) // fails, as not nil
	fmt.Println(ok)

	ok = td.CmpZero(t, ([]int)(nil))
	fmt.Println(ok)

	ok = td.CmpZero(t, []int{}) // fails, as not nil
	fmt.Println(ok)

	ok = td.CmpZero(t, [3]int{})
	fmt.Println(ok)

	ok = td.CmpZero(t, [3]int{0, 1}) // fails, DATA[1] is not 0
	fmt.Println(ok)

	ok = td.CmpZero(t, bytes.Buffer{})
	fmt.Println(ok)

	ok = td.CmpZero(t, &bytes.Buffer{}) // fails, as pointer not nil
	fmt.Println(ok)

	ok = td.Cmp(t, &bytes.Buffer{}, td.Ptr(td.Zero())) // OK with the help of Ptr()
	fmt.Println(ok)

}

Output:

true
true
false
true
false
true
false
true
false
true
false
true

func EqDeeply 

func EqDeeply(got, expected interface{}) bool

EqDeeply returns true if "got" matches "expected". "expected" can be the same type as "got" is, or contains some TestDeep operators. 

got := "foobar"
td.EqDeeply(got, "foobar")            // returns true
td.EqDeeply(got, td.HasPrefix("foo")) // returns true
Example 
package main

import (
	"fmt"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	type MyStruct struct {
		Name  string
		Num   int
		Items []int
	}

	got := &MyStruct{
		Name:  "Foobar",
		Num:   12,
		Items: []int{4, 5, 9, 3, 8},
	}

	if td.EqDeeply(got,
		td.Struct(&MyStruct{},
			td.StructFields{
				"Name":  td.Re("^Foo"),
				"Num":   td.Between(10, 20),
				"Items": td.ArrayEach(td.Between(3, 9)),
			})) {
		fmt.Println("Match!")
	} else {
		fmt.Println("NO!")
	}

}

Output:

Match!

func EqDeeplyError 

func EqDeeplyError(got, expected interface{}) error

EqDeeplyError returns nil if "got" matches "expected". "expected" can be the same type as got is, or contains some TestDeep operators. If "got" does not match "expected", the returned *ctxerr.Error contains the reason of the first mismatch detected. 

got := "foobar"
if err := td.EqDeeplyError(got, "foobar"); err != nil {
  // …
}
if err := td.EqDeeplyError(got, td.HasPrefix("foo")); err != nil {
  // …
}
Example 
package main

import (
	"fmt"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
//line /testdeep/example.go:1
	type MyStruct struct {
		Name  string
		Num   int
		Items []int
	}

	got := &MyStruct{
		Name:  "Foobar",
		Num:   12,
		Items: []int{4, 5, 9, 3, 8},
	}

	err := td.EqDeeplyError(got,
		td.Struct(&MyStruct{},
			td.StructFields{
				"Name":  td.Re("^Foo"),
				"Num":   td.Between(10, 20),
				"Items": td.ArrayEach(td.Between(3, 8)),
			}))
	if err != nil {
		fmt.Println(err)
	}

}

Output:

DATA.Items[2]: values differ
	     got: 9
	expected: 3 ≤ got ≤ 8
[under operator Between at example.go:18]

func Flatten added in v1.5.0 

func Flatten(sliceOrMap interface{}) flat.Slice

Flatten allows to flatten any slice, array or map in parameters of operators expecting ...interface{}.

For example the Set operator is defined as: 

func Set(expectedItems ...interface{}) TestDeep

so when comparing to a []int slice, we usually do: 

got := []int{42, 66, 22}
td.Cmp(t, got, td.Set(22, 42, 66))

it works but if the expected items are already in a []int, we have to copy them in a []interface{} as it can not be flattened directly in Set parameters: 

expected := []int{22, 42, 66}
expectedIf := make([]interface{}, len(expected))
for i, item := range expected {
  expectedIf[i] = item
}
td.Cmp(t, got, td.Set(expectedIf...))

but it is a bit boring and less efficient, as Set does not keep the []interface{} behind the scene.

The same with Flatten follows: 

expected := []int{22, 42, 66}
td.Cmp(t, got, td.Set(td.Flatten(expected)))

Several Flatten calls can be passed, and even combined with normal parameters: 

expectedPart1 := []int{11, 22, 33}
expectedPart2 := []int{55, 66, 77}
expectedPart3 := []int{99}
td.Cmp(t, got,
  td.Set(
    td.Flatten(expectedPart1),
    44,
    td.Flatten(expectedPart2),
    88,
    td.Flatten(expectedPart3),
  ))

is exactly the same as: 

td.Cmp(t, got, td.Set(11, 22, 33, 44, 55, 66, 77, 88, 99))

Note that Flatten calls can even be nested: 

td.Cmp(t, got,
  td.Set(
    td.Flatten([]interface{}{
      11,
      td.Flatten([]int{22, 33}),
      td.Flatten([]int{44, 55, 66}),
    }),
    77,
  ))

is exactly the same as: 

td.Cmp(t, got, td.Set(11, 22, 33, 44, 55, 66, 77))

Maps can be flattened too, keeping in mind there is no particular order: 

td.Flatten(map[int]int{1: 2, 3: 4})

is flattened as 1, 2, 3, 4 or 3, 4, 1, 2.

Types

type ArrayEntries 

type ArrayEntries map[int]interface{}

ArrayEntries allows to pass array or slice entries to check in functions Array and Slice. It is a map whose each key is the item index and the corresponding value the expected item value (which can be a TestDeep operator as well as a zero value).

type BoundsKind 

type BoundsKind uint8

BoundsKind type qualifies the "Between" bounds. 

const (
	// BoundsInIn allows to match between "from" and "to" both included.
	BoundsInIn BoundsKind = iota
	// BoundsInOut allows to match between "from" included and "to" excluded.
	BoundsInOut
	// BoundsOutIn allows to match between "from" excluded and "to" included.
	BoundsOutIn
	// BoundsOutOut allows to match between "from" and "to" both excluded.
	BoundsOutOut
)

type ContextConfig 

type ContextConfig struct {
	// RootName is the string used to represent the root of got data. It
	// defaults to "DATA". For an HTTP response body, it could be "BODY"
	// for example.
	RootName string
	// MaxErrors is the maximal number of errors to dump in case of Cmp*
	// failure.
	//
	// It defaults to 10 except if the environment variable
	// TESTDEEP_MAX_ERRORS is set. In this latter case, the
	// TESTDEEP_MAX_ERRORS value is converted to an int and used as is.
	//
	// Setting it to 0 has the same effect as 1: only the first error
	// will be dumped without the "Too many errors" error.
	//
	// Setting it to a negative number means no limit: all errors
	// will be dumped.
	MaxErrors int

	// FailureIsFatal allows to Fatal() (instead of Error()) when a test
	// fails. Using *testing.T or *testing.B instance as t.TB value, FailNow()
	// is called behind the scenes when Fatal() is called. See testing
	// documentation for details.
	FailureIsFatal bool
	// UseEqual allows to use the Equal method on got (if it exists) or
	// on any of its component to compare got and expected values.
	//
	// The signature of the Equal method should be:
	//   (A) Equal(B) bool
	// with B assignable to A.
	//
	// See time.Time as an example of accepted Equal() method.
	UseEqual bool
	// BeLax allows to compare different but convertible types. If set
	// to false (default), got and expected types must be the same. If
	// set to true and expected type is convertible to got one, expected
	// is first converted to go type before its comparison. See CmpLax
	// function/method and Lax operator to set this flag without
	// providing a specific configuration.
	BeLax bool
	// contains filtered or unexported fields
}

ContextConfig allows to configure finely how tests failures are rendered.

See NewT function to use it.

func (ContextConfig) Equal 

func (c ContextConfig) Equal(o ContextConfig) bool

Equal returns true if both ContextConfig are equal. Only public fields are taken into account to check equality.

type MapEntries 

type MapEntries map[interface{}]interface{}

MapEntries allows to pass map entries to check in function Map. It is a map whose each key is the expected entry key and the corresponding value the expected entry value (which can be a TestDeep operator as well as a zero value.)

type SmuggledGot 

type SmuggledGot struct {
	Name string
	Got  interface{}
}

SmuggledGot can be returned by a Smuggle function to name the transformed / returned value.

type StructFields 

type StructFields map[string]interface{}

StructFields allows to pass struct fields to check in functions Struct and SStruct. It is a map whose each key is the expected field name and the corresponding value the expected field value (which can be a TestDeep operator as well as a zero value.)

type T 

type T struct {
	testing.TB
	Config ContextConfig // defaults to DefaultContextConfig
}

T is a type that encapsulates testing.TB interface (which is implemented by *testing.T and *testing.B) allowing to easily use *testing.T methods as well as T ones.

func Assert 

func Assert(t testing.TB, config ...ContextConfig) *T

Assert return a new *T instance with FailureIsFatal flag set to false. 

assert := Assert(t)

is roughly equivalent to: 

assert := NewT(t).FailureIsFatal(false)

See NewT documentation for usefulness of "config" optional parameter.

func NewT 

func NewT(t testing.TB, config ...ContextConfig) *T

NewT returns a new *T instance. Typically used as: 

import (
  "testing"

  "github.com/maxatome/go-testdeep/td"
)

type Record struct {
  Id        uint64
  Name      string
  Age       int
  CreatedAt time.Time
}

func TestCreateRecord(tt *testing.T) {
  t := NewT(tt, ContextConfig{
    MaxErrors: 3, // in case of failure, will dump up to 3 errors
  })

  before := time.Now()
  record, err := CreateRecord()

  if t.CmpNoError(err) {
    t.Log("No error, can now check struct contents")

    ok := t.Struct(record,
      &Record{
        Name: "Bob",
        Age:  23,
      },
      td.StructFields{
        "Id":        td.NotZero(),
        "CreatedAt": td.Between(before, time.Now()),
      },
      "Newly created record")
    if ok {
      t.Log(Record created successfully!")
    }
  }
}

"config" is an optional argument and, if passed, must be unique. It allows to configure how failures will be rendered during the lifetime of the returned instance. 

t := NewT(tt)
t.Cmp(
  Record{Age: 12, Name: "Bob", Id: 12},  // got
  Record{Age: 21, Name: "John", Id: 28}) // expected

will produce: 

=== RUN   TestFoobar
--- FAIL: TestFoobar (0.00s)
        foobar_test.go:88: Failed test
                DATA.Id: values differ
                             got: (uint64) 12
                        expected: (uint64) 28
                DATA.Name: values differ
                             got: "Bob"
                        expected: "John"
                DATA.Age: values differ
                             got: 12
                        expected: 28
FAIL

Now with a special configuration: 

t := NewT(tt, ContextConfig{
    RootName:  "RECORD", // got data named "RECORD" instead of "DATA"
    MaxErrors: 2,        // stops after 2 errors instead of default 10
  })
t.Cmp(
  Record{Age: 12, Name: "Bob", Id: 12},  // got
  Record{Age: 21, Name: "John", Id: 28}, // expected
)

will produce: 

=== RUN   TestFoobar
--- FAIL: TestFoobar (0.00s)
        foobar_test.go:96: Failed test
                RECORD.Id: values differ
                             got: (uint64) 12
                        expected: (uint64) 28
                RECORD.Name: values differ
                             got: "Bob"
                        expected: "John"
                Too many errors (use TESTDEEP_MAX_ERRORS=-1 to see all)
FAIL

See RootName method to configure RootName in a more specific fashion.

Note that setting MaxErrors to a negative value produces a dump with all errors.

If MaxErrors is not set (or set to 0), it is set to DefaultContextConfig.MaxErrors which is potentially dependent from the TESTDEEP_MAX_ERRORS environment variable (else defaults to 10.) See ContextConfig documentation for details.

Of course "t" can already be a *T, in this special case if "config" is omitted, the Config of the new instance is a copy of the "t" Config, including hooks.

func Require 

func Require(t testing.TB, config ...ContextConfig) *T

Require return a new *T instance with FailureIsFatal flag set to true. 

require := Require(t)

is roughly equivalent to: 

require := NewT(t).FailureIsFatal(true)

See NewT documentation for usefulness of "config" optional parameter.

func (*T) A 

func (t *T) A(operator TestDeep, model ...interface{}) interface{}

A is a synonym for Anchor. 

import (
  "testing"

  "github.com/maxatome/go-testdeep/td"
)

func TestFunc(tt *testing.T) {
  got := Func()

  t := td.NewT(tt)
  t.Cmp(got, &MyStruct{
    Name:    "Bob",
    Details: &MyDetails{
      Nick: t.A(td.HasPrefix("Bobby"), "").(string),
      Age:  t.A(td.Between(40, 50)).(int),
    },
  })
}

func (*T) All 

func (t *T) All(got interface{}, expectedValues []interface{}, args ...interface{}) bool

All is a shortcut for: 

t.Cmp(got, td.All(expectedValues...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#All for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foo/bar"

	// Checks got string against:
	//   "o/b" regexp *AND* "bar" suffix *AND* exact "foo/bar" string
	ok := t.All(got, []interface{}{td.Re("o/b"), td.HasSuffix("bar"), "foo/bar"},
		"checks value %s", got)
	fmt.Println(ok)

	// Checks got string against:
	//   "o/b" regexp *AND* "bar" suffix *AND* exact "fooX/Ybar" string
	ok = t.All(got, []interface{}{td.Re("o/b"), td.HasSuffix("bar"), "fooX/Ybar"},
		"checks value %s", got)
	fmt.Println(ok)

	// When some operators or values have to be reused and mixed between
	// several calls, Flatten can be used to avoid boring and
	// inefficient []interface{} copies:
	regOps := td.Flatten([]td.TestDeep{td.Re("o/b"), td.Re(`^fo`), td.Re(`ar$`)})
	ok = t.All(got, []interface{}{td.HasPrefix("foo"), regOps, td.HasSuffix("bar")},
		"checks all operators against value %s", got)
	fmt.Println(ok)

}

Output:

true
false
true

func (*T) Anchor 

func (t *T) Anchor(operator TestDeep, model ...interface{}) interface{}

Anchor returns a typed value allowing to anchor the TestDeep operator "operator" in a go classic litteral like a struct, slice, array or map value.

If the TypeBehind method of "operator" returns non-nil, "model" can be omitted (like with Between operator in the example below). Otherwise, "model" should contain only one value corresponding to the returning type. It can be:

  • a go value: returning type is the type of the value, whatever the value is
  • a reflect.Type

It returns a typed value ready to be embed in a go data structure to be compared using T.Cmp or T.CmpLax: 

import (
  "testing"

  "github.com/maxatome/go-testdeep/td"
)

func TestFunc(tt *testing.T) {
  got := Func()

  t := td.NewT(tt)
  t.Cmp(got, &MyStruct{
    Name:    "Bob",
    Details: &MyDetails{
      Nick: t.Anchor(td.HasPrefix("Bobby"), "").(string),
      Age:  t.Anchor(td.Between(40, 50)).(int),
    },
  })
}

In this example:

HasPrefix operates on several input types (string, fmt.Stringer, error, …), so its TypeBehind method returns always nil as it can not guess in advance on which type it operates. In this case, we must pass "" as "model" parameter in order to tell it to return the string type. Note that the .(string) type assertion is then mandatory to conform to the strict type checking.

Between, on its side, knows the type on which it operates, as it is the same as the one of its parameters. So its TypeBehind method returns the right type, and so no need to pass it as "model" parameter. Note that the .(int) type assertion is still mandatory to conform to the strict type checking.

Without operator anchoring feature, the previous example would have been: 

import (
  "testing"

  "github.com/maxatome/go-testdeep/td"
)

func TestFunc(tt *testing.T) {
  got := Func()

  t := td.NewT(tt)
  t.Cmp(got, td.Struct(&MyStruct{Name: "Bob"},
    td.StructFields{
    "Details": td.Struct(&MyDetails{},
      td.StructFields{
        "Nick": td.HasPrefix("Bobby"),
        "Age":  td.Between(40, 50),
      }),
  }))
}

using two times the Struct operator to work around the strict type checking of golang.

By default, the value returned by Anchor can only be used in the next T.Cmp or T.CmpLax call. To make it persistent across calls, see SetAnchorsPersist and AnchorsPersistTemporarily methods.

See A method for a shorter synonym of Anchor.

func (*T) AnchorsPersistTemporarily 

func (t *T) AnchorsPersistTemporarily() func()

AnchorsPersistTemporarily is used by helpers to temporarily enable anchors persistence. See tdhttp package for an example of use. It returns a function to be deferred, to restore the normal behavior (clear anchored operators if persistence was false, do nothing otherwise).

Typically used as: 

defer t.AnchorsPersistTemporarily()()

func (*T) Any 

func (t *T) Any(got interface{}, expectedValues []interface{}, args ...interface{}) bool

Any is a shortcut for: 

t.Cmp(got, td.Any(expectedValues...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Any for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foo/bar"

	// Checks got string against:
	//   "zip" regexp *OR* "bar" suffix
	ok := t.Any(got, []interface{}{td.Re("zip"), td.HasSuffix("bar")},
		"checks value %s", got)
	fmt.Println(ok)

	// Checks got string against:
	//   "zip" regexp *OR* "foo" suffix
	ok = t.Any(got, []interface{}{td.Re("zip"), td.HasSuffix("foo")},
		"checks value %s", got)
	fmt.Println(ok)

	// When some operators or values have to be reused and mixed between
	// several calls, Flatten can be used to avoid boring and
	// inefficient []interface{} copies:
	regOps := td.Flatten([]td.TestDeep{td.Re("a/c"), td.Re(`^xx`), td.Re(`ar$`)})
	ok = t.Any(got, []interface{}{td.HasPrefix("xxx"), regOps, td.HasSuffix("zip")},
		"check at least one operator matches value %s", got)
	fmt.Println(ok)

}

Output:

true
false
true

func (*T) Array 

func (t *T) Array(got, model interface{}, expectedEntries ArrayEntries, args ...interface{}) bool

Array is a shortcut for: 

t.Cmp(got, td.Array(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Array for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Array) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := [3]int{42, 58, 26}

	ok := t.Array(got, [3]int{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks array %v", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedArray) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MyArray [3]int

	got := MyArray{42, 58, 26}

	ok := t.Array(got, MyArray{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks typed array %v", got)
	fmt.Println(ok)

	ok = t.Array(&got, &MyArray{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

	ok = t.Array(&got, &MyArray{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

	ok = t.Array(&got, (*MyArray)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func (*T) ArrayEach 

func (t *T) ArrayEach(got, expectedValue interface{}, args ...interface{}) bool

ArrayEach is a shortcut for: 

t.Cmp(got, td.ArrayEach(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#ArrayEach for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Array) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := [3]int{42, 58, 26}

	ok := t.ArrayEach(got, td.Between(25, 60),
		"checks each item of array %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{42, 58, 26}

	ok := t.ArrayEach(got, td.Between(25, 60),
		"checks each item of slice %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedArray) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MyArray [3]int

	got := MyArray{42, 58, 26}

	ok := t.ArrayEach(got, td.Between(25, 60),
		"checks each item of typed array %v is in [25 .. 60]", got)
	fmt.Println(ok)

	ok = t.ArrayEach(&got, td.Between(25, 60),
		"checks each item of typed array pointer %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
true
Example (TypedSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MySlice []int

	got := MySlice{42, 58, 26}

	ok := t.ArrayEach(got, td.Between(25, 60),
		"checks each item of typed slice %v is in [25 .. 60]", got)
	fmt.Println(ok)

	ok = t.ArrayEach(&got, td.Between(25, 60),
		"checks each item of typed slice pointer %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
true

func (*T) Bag 

func (t *T) Bag(got interface{}, expectedItems []interface{}, args ...interface{}) bool

Bag is a shortcut for: 

t.Cmp(got, td.Bag(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Bag for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are present
	ok := t.Bag(got, []interface{}{1, 1, 2, 3, 5, 8, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Does not match as got contains 2 times 1 and 8, and these
	// duplicates are not expected
	ok = t.Bag(got, []interface{}{1, 2, 3, 5, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	got = []int{1, 3, 5, 8, 2}

	// Duplicates of 1 and 8 are expected but not present in got
	ok = t.Bag(got, []interface{}{1, 1, 2, 3, 5, 8, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Matches as all items are present
	ok = t.Bag(got, []interface{}{1, 2, 3, 5, td.Gt(7)},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5}
	ok = t.Bag(got, []interface{}{td.Flatten(expected), td.Gt(7)},
		"checks all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
false
false
true
true

func (*T) BeLax 

func (t *T) BeLax(enable ...bool) *T

BeLax allows to to compare different but convertible types. If set to false, got and expected types must be the same. If set to true and expected type is convertible to got one, expected is first converted to go type before its comparison. See CmpLax function/method and Lax operator to set this flag without providing a specific configuration.

It returns a new instance of *T so does not alter the original t.

Note that t.BeLax() acts as t.BeLax(true).

func (*T) Between 

func (t *T) Between(got, from, to interface{}, bounds BoundsKind, args ...interface{}) bool

Between is a shortcut for: 

t.Cmp(got, td.Between(from, to, bounds), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Between for details.

Between() optional parameter "bounds" is here mandatory. td.BoundsInIn value should be passed to mimic its absence in original Between() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 156

	ok := t.Between(got, 154, 156, td.BoundsInIn,
		"checks %v is in [154 .. 156]", got)
	fmt.Println(ok)

	// BoundsInIn is implicit
	ok = t.Between(got, 154, 156, td.BoundsInIn,
		"checks %v is in [154 .. 156]", got)
	fmt.Println(ok)

	ok = t.Between(got, 154, 156, td.BoundsInOut,
		"checks %v is in [154 .. 156[", got)
	fmt.Println(ok)

	ok = t.Between(got, 154, 156, td.BoundsOutIn,
		"checks %v is in ]154 .. 156]", got)
	fmt.Println(ok)

	ok = t.Between(got, 154, 156, td.BoundsOutOut,
		"checks %v is in ]154 .. 156[", got)
	fmt.Println(ok)

}

Output:

true
true
false
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "abc"

	ok := t.Between(got, "aaa", "abc", td.BoundsInIn,
		`checks "%v" is in ["aaa" .. "abc"]`, got)
	fmt.Println(ok)

	// BoundsInIn is implicit
	ok = t.Between(got, "aaa", "abc", td.BoundsInIn,
		`checks "%v" is in ["aaa" .. "abc"]`, got)
	fmt.Println(ok)

	ok = t.Between(got, "aaa", "abc", td.BoundsInOut,
		`checks "%v" is in ["aaa" .. "abc"[`, got)
	fmt.Println(ok)

	ok = t.Between(got, "aaa", "abc", td.BoundsOutIn,
		`checks "%v" is in ]"aaa" .. "abc"]`, got)
	fmt.Println(ok)

	ok = t.Between(got, "aaa", "abc", td.BoundsOutOut,
		`checks "%v" is in ]"aaa" .. "abc"[`, got)
	fmt.Println(ok)

}

Output:

true
true
false
true
false

func (*T) Cap 

func (t *T) Cap(got, expectedCap interface{}, args ...interface{}) bool

Cap is a shortcut for: 

t.Cmp(got, td.Cap(expectedCap), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Cap for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := make([]int, 0, 12)

	ok := t.Cap(got, 12, "checks %v capacity is 12", got)
	fmt.Println(ok)

	ok = t.Cap(got, 0, "checks %v capacity is 0", got)
	fmt.Println(ok)

	got = nil

	ok = t.Cap(got, 0, "checks %v capacity is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true
Example (Operator) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := make([]int, 0, 12)

	ok := t.Cap(got, td.Between(10, 12),
		"checks %v capacity is in [10 .. 12]", got)
	fmt.Println(ok)

	ok = t.Cap(got, td.Gt(10),
		"checks %v capacity is in [10 .. 12]", got)
	fmt.Println(ok)

}

Output:

true
true

func (*T) Cmp 

func (t *T) Cmp(got, expected interface{}, args ...interface{}) bool

Cmp is mostly a shortcut for: 

Cmp(t.TB, got, expected, args...)

with the exception that t.Config is used to configure the test Context.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

func (*T) CmpDeeply 

func (t *T) CmpDeeply(got, expected interface{}, args ...interface{}) bool

CmpDeeply works the same as Cmp and is still available for compatibility purpose. Use shorter Cmp in new code.

func (*T) CmpError 

func (t *T) CmpError(got error, args ...interface{}) bool

CmpError checks that "got" is non-nil error. 

_, err := MyFunction(1, 2, 3)
t.CmpError(err, "MyFunction(1, 2, 3) should return an error")

CmpError and not Error to avoid collision with t.TB.Error method.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := fmt.Errorf("Error #%d", 42)
	ok := t.CmpError(got, "An error occurred")
	fmt.Println(ok)

	got = nil
	ok = t.CmpError(got, "An error occurred") // fails
	fmt.Println(ok)

}

Output:

true
false

func (*T) CmpLax 

func (t *T) CmpLax(got, expectedValue interface{}, args ...interface{}) bool

CmpLax is a shortcut for: 

t.Cmp(got, td.Lax(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Lax for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	gotInt64 := int64(1234)
	gotInt32 := int32(1235)

	type myInt uint16
	gotMyInt := myInt(1236)

	expected := td.Between(1230, 1240) // int type here

	ok := t.CmpLax(gotInt64, expected)
	fmt.Println("int64 got between ints [1230 .. 1240]:", ok)

	ok = t.CmpLax(gotInt32, expected)
	fmt.Println("int32 got between ints [1230 .. 1240]:", ok)

	ok = t.CmpLax(gotMyInt, expected)
	fmt.Println("myInt got between ints [1230 .. 1240]:", ok)

}

Output:

int64 got between ints [1230 .. 1240]: true
int32 got between ints [1230 .. 1240]: true
myInt got between ints [1230 .. 1240]: true

func (*T) CmpNoError 

func (t *T) CmpNoError(got error, args ...interface{}) bool

CmpNoError checks that "got" is nil error. 

value, err := MyFunction(1, 2, 3)
if t.CmpNoError(err) {
  // one can now check value...
}

CmpNoError and not NoError to be consistent with CmpError method.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := fmt.Errorf("Error #%d", 42)
	ok := t.CmpNoError(got, "An error occurred") // fails
	fmt.Println(ok)

	got = nil
	ok = t.CmpNoError(got, "An error occurred")
	fmt.Println(ok)

}

Output:

false
true

func (*T) CmpNotPanic 

func (t *T) CmpNotPanic(fn func(), args ...interface{}) bool

CmpNotPanic calls "fn" and checks no panic() occurred. If a panic() occurred false is returned then the panic() parameter and the stack trace appear in the test report.

Note that calling panic(nil) in "fn" body is detected as a panic. 

t.CmpNotPanic(func() {}) // succeeds as function does not panic

t.CmpNotPanic(func() { panic("I am panicking!") }) // fails
t.CmpNotPanic(func() { panic(nil) })               // fails too

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.CmpNotPanic(func() {}, nil)
	fmt.Println("checks a panic DID NOT occur:", ok)

	// Classic panic
	ok = t.CmpNotPanic(func() { panic("I am panicking!") },
		"Hope it does not panic!")
	fmt.Println("still no panic?", ok)

	// Can detect panic(nil)
	ok = t.CmpNotPanic(func() { panic(nil) }, "Checks for panic(nil)")
	fmt.Println("last no panic?", ok)

}

Output:

checks a panic DID NOT occur: true
still no panic? false
last no panic? false

func (*T) CmpPanic 

func (t *T) CmpPanic(fn func(), expected interface{}, args ...interface{}) bool

CmpPanic calls "fn" and checks a panic() occurred with the "expectedPanic" parameter. It returns true only if both conditions are fulfilled.

Note that calling panic(nil) in "fn" body is detected as a panic (in this case "expectedPanic" has to be nil). 

t.CmpPanic(func() { panic("I am panicking!") },
  "I am panicking!",
  "The function should panic with the right string")

t.CmpPanic(func() { panic("I am panicking!") },
  Contains("panicking!"),
  "The function should panic with a string containing `panicking!`")

t.CmpPanic(t, func() { panic(nil) }, nil, "Checks for panic(nil)")

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.CmpPanic(func() { panic("I am panicking!") }, "I am panicking!",
		"Checks for panic")
	fmt.Println("checks exact panic() string:", ok)

	// Can use TestDeep operator too
	ok = t.CmpPanic(
		func() { panic("I am panicking!") },
		td.Contains("panicking!"),
		"Checks for panic")
	fmt.Println("checks panic() sub-string:", ok)

	// Can detect panic(nil)
	ok = t.CmpPanic(func() { panic(nil) }, nil, "Checks for panic(nil)")
	fmt.Println("checks for panic(nil):", ok)

	// As well as structured data panic
	type PanicStruct struct {
		Error string
		Code  int
	}

	ok = t.CmpPanic(
		func() {
			panic(PanicStruct{Error: "Memory violation", Code: 11})
		},
		PanicStruct{
			Error: "Memory violation",
			Code:  11,
		})
	fmt.Println("checks exact panic() struct:", ok)

	// or combined with TestDeep operators too
	ok = t.CmpPanic(
		func() {
			panic(PanicStruct{Error: "Memory violation", Code: 11})
		},
		td.Struct(PanicStruct{}, td.StructFields{
			"Code": td.Between(10, 20),
		}))
	fmt.Println("checks panic() struct against TestDeep operators:", ok)

	// Of course, do not panic = test failure, even for expected nil
	// panic parameter
	ok = t.CmpPanic(func() {}, nil)
	fmt.Println("checks a panic occurred:", ok)

}

Output:

checks exact panic() string: true
checks panic() sub-string: true
checks for panic(nil): true
checks exact panic() struct: true
checks panic() struct against TestDeep operators: true
checks a panic occurred: false

func (*T) Code 

func (t *T) Code(got, fn interface{}, args ...interface{}) bool

Code is a shortcut for: 

t.Cmp(got, td.Code(fn), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Code for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "12"

	ok := t.Code(got, func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 10 && n < 100
	},
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

	// Same with failure reason
	ok = t.Code(got, func(num string) (bool, string) {
		n, err := strconv.Atoi(num)
		if err != nil {
			return false, "not a number"
		}
		if n > 10 && n < 100 {
			return true, ""
		}
		return false, "not in ]10 .. 100["
	},
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

	// Same with failure reason thanks to error
	ok = t.Code(got, func(num string) error {
		n, err := strconv.Atoi(num)
		if err != nil {
			return err
		}
		if n > 10 && n < 100 {
			return nil
		}
		return fmt.Errorf("%d not in ]10 .. 100[", n)
	},
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

}

Output:

true
true
true

func (*T) Contains 

func (t *T) Contains(got, expectedValue interface{}, args ...interface{}) bool

Contains is a shortcut for: 

t.Cmp(got, td.Contains(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Contains for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (ArraySlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.Contains([...]int{11, 22, 33, 44}, 22)
	fmt.Println("array contains 22:", ok)

	ok = t.Contains([...]int{11, 22, 33, 44}, td.Between(20, 25))
	fmt.Println("array contains at least one item in [20 .. 25]:", ok)

	ok = t.Contains([]int{11, 22, 33, 44}, 22)
	fmt.Println("slice contains 22:", ok)

	ok = t.Contains([]int{11, 22, 33, 44}, td.Between(20, 25))
	fmt.Println("slice contains at least one item in [20 .. 25]:", ok)

	ok = t.Contains([]int{11, 22, 33, 44}, []int{22, 33})
	fmt.Println("slice contains the sub-slice [22, 33]:", ok)

}

Output:

array contains 22: true
array contains at least one item in [20 .. 25]: true
slice contains 22: true
slice contains at least one item in [20 .. 25]: true
slice contains the sub-slice [22, 33]: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := errors.New("foobar")

	ok := t.Contains(got, "oob", "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = t.Contains(got, 'b', "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = t.Contains(got, byte('a'), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = t.Contains(got, td.Between('n', 'p'), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true
Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.Contains(map[string]int{"foo": 11, "bar": 22, "zip": 33}, 22)
	fmt.Println("map contains value 22:", ok)

	ok = t.Contains(map[string]int{"foo": 11, "bar": 22, "zip": 33}, td.Between(20, 25))
	fmt.Println("map contains at least one value in [20 .. 25]:", ok)

}

Output:

map contains value 22: true
map contains at least one value in [20 .. 25]: true
Example (Nil) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	num := 123
	got := [...]*int{&num, nil}

	ok := t.Contains(got, nil)
	fmt.Println("array contains untyped nil:", ok)

	ok = t.Contains(got, (*int)(nil))
	fmt.Println("array contains *int nil:", ok)

	ok = t.Contains(got, td.Nil())
	fmt.Println("array contains Nil():", ok)

	ok = t.Contains(got, (*byte)(nil))
	fmt.Println("array contains *byte nil:", ok) // types differ: *byte ≠ *int

}

Output:

array contains untyped nil: true
array contains *int nil: true
array contains Nil(): true
array contains *byte nil: false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foobar"

	ok := t.Contains(got, "oob", "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = t.Contains(got, []byte("oob"), "checks %s", got)
	fmt.Println("contains `oob` []byte:", ok)

	ok = t.Contains(got, 'b', "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = t.Contains(got, byte('a'), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = t.Contains(got, td.Between('n', 'p'), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains `oob` []byte: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := t.Contains(got, "oob", "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = t.Contains(got, 'b', "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = t.Contains(got, byte('a'), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = t.Contains(got, td.Between('n', 'p'), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true

func (*T) ContainsKey 

func (t *T) ContainsKey(got, expectedValue interface{}, args ...interface{}) bool

ContainsKey is a shortcut for: 

t.Cmp(got, td.ContainsKey(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#ContainsKey for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"strings"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.ContainsKey(map[string]int{"foo": 11, "bar": 22, "zip": 33}, "foo")
	fmt.Println(`map contains key "foo":`, ok)

	ok = t.ContainsKey(map[int]bool{12: true, 24: false, 42: true, 51: false}, td.Between(40, 50))
	fmt.Println("map contains at least a key in [40 .. 50]:", ok)

	ok = t.ContainsKey(map[string]int{"FOO": 11, "bar": 22, "zip": 33}, td.Smuggle(strings.ToLower, "foo"))
	fmt.Println(`map contains key "foo" without taking case into account:`, ok)

}

Output:

map contains key "foo": true
map contains at least a key in [40 .. 50]: true
map contains key "foo" without taking case into account: true
Example (Nil) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	num := 1234
	got := map[*int]bool{&num: false, nil: true}

	ok := t.ContainsKey(got, nil)
	fmt.Println("map contains untyped nil key:", ok)

	ok = t.ContainsKey(got, (*int)(nil))
	fmt.Println("map contains *int nil key:", ok)

	ok = t.ContainsKey(got, td.Nil())
	fmt.Println("map contains Nil() key:", ok)

	ok = t.ContainsKey(got, (*byte)(nil))
	fmt.Println("map contains *byte nil key:", ok) // types differ: *byte ≠ *int

}

Output:

map contains untyped nil key: true
map contains *int nil key: true
map contains Nil() key: true
map contains *byte nil key: false

func (*T) DoAnchorsPersist 

func (t *T) DoAnchorsPersist() bool

DoAnchorsPersist returns true if anchors persistence is enabled, false otherwise.

func (*T) Empty 

func (t *T) Empty(got interface{}, args ...interface{}) bool

Empty is a shortcut for: 

t.Cmp(got, td.Empty(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Empty for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.Empty(nil) // special case: nil is considered empty
	fmt.Println(ok)

	// fails, typed nil is not empty (expect for channel, map, slice or
	// pointers on array, channel, map slice and strings)
	ok = t.Empty((*int)(nil))
	fmt.Println(ok)

	ok = t.Empty("")
	fmt.Println(ok)

	// Fails as 0 is a number, so not empty. Use Zero() instead
	ok = t.Empty(0)
	fmt.Println(ok)

	ok = t.Empty((map[string]int)(nil))
	fmt.Println(ok)

	ok = t.Empty(map[string]int{})
	fmt.Println(ok)

	ok = t.Empty(([]int)(nil))
	fmt.Println(ok)

	ok = t.Empty([]int{})
	fmt.Println(ok)

	ok = t.Empty([]int{3}) // fails, as not empty
	fmt.Println(ok)

	ok = t.Empty([3]int{}) // fails, Empty() is not Zero()!
	fmt.Println(ok)

}

Output:

true
false
true
false
true
true
true
true
false
false
Example (Pointers) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MySlice []int

	ok := t.Empty(MySlice{}) // Ptr() not needed
	fmt.Println(ok)

	ok = t.Empty(&MySlice{})
	fmt.Println(ok)

	l1 := &MySlice{}
	l2 := &l1
	l3 := &l2
	ok = t.Empty(&l3)
	fmt.Println(ok)

	// Works the same for array, map, channel and string

	// But not for others types as:
	type MyStruct struct {
		Value int
	}

	ok = t.Empty(&MyStruct{}) // fails, use Zero() instead
	fmt.Println(ok)

}

Output:

true
true
true
false

func (*T) FailureIsFatal 

func (t *T) FailureIsFatal(enable ...bool) *T

FailureIsFatal allows to choose whether t.TB.Fatal() or t.TB.Error() will be used to print the next failure reports. When "enable" is true (or missing) testing.Fatal() will be called, else testing.Error(). Using *testing.T or *testing.B instance as t.TB value, FailNow() is called behind the scenes when Fatal() is called. See testing documentation for details.

It returns a new instance of *T so does not alter the original t and used as follows: 

// Following t.Cmp() will call Fatal() if failure
t = t.FailureIsFatal()
t.Cmp(...)
t.Cmp(...)
// Following t.Cmp() won't call Fatal() if failure
t = t.FailureIsFatal(false)
t.Cmp(...)

or, if only one call is critic: 

// This Cmp() call will call Fatal() if failure
t.FailureIsFatal().Cmp(...)
// Following t.Cmp() won't call Fatal() if failure
t.Cmp(...)
t.Cmp(...)

Note that t.FailureIsFatal() acts as t.FailureIsFatal(true).

func (*T) False 

func (t *T) False(got interface{}, args ...interface{}) bool

False is shortcut for: 

t.Cmp(got, false, args...)

Returns true if the test is OK, false if it fails. 

t.False(IsAvailable(x), "x should not be available")

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := false
	ok := t.False(got, "check that got is false!")
	fmt.Println(ok)

	got = true
	ok = t.False(got, "check that got is false!")
	fmt.Println(ok)

}

Output:

true
false

func (*T) Gt 

func (t *T) Gt(got, minExpectedValue interface{}, args ...interface{}) bool

Gt is a shortcut for: 

t.Cmp(got, td.Gt(minExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Gt for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 156

	ok := t.Gt(got, 155, "checks %v is > 155", got)
	fmt.Println(ok)

	ok = t.Gt(got, 156, "checks %v is > 156", got)
	fmt.Println(ok)

}

Output:

true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "abc"

	ok := t.Gt(got, "abb", `checks "%v" is > "abb"`, got)
	fmt.Println(ok)

	ok = t.Gt(got, "abc", `checks "%v" is > "abc"`, got)
	fmt.Println(ok)

}

Output:

true
false

func (*T) Gte 

func (t *T) Gte(got, minExpectedValue interface{}, args ...interface{}) bool

Gte is a shortcut for: 

t.Cmp(got, td.Gte(minExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Gte for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 156

	ok := t.Gte(got, 156, "checks %v is ≥ 156", got)
	fmt.Println(ok)

	ok = t.Gte(got, 155, "checks %v is ≥ 155", got)
	fmt.Println(ok)

	ok = t.Gte(got, 157, "checks %v is ≥ 157", got)
	fmt.Println(ok)

}

Output:

true
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "abc"

	ok := t.Gte(got, "abc", `checks "%v" is ≥ "abc"`, got)
	fmt.Println(ok)

	ok = t.Gte(got, "abb", `checks "%v" is ≥ "abb"`, got)
	fmt.Println(ok)

	ok = t.Gte(got, "abd", `checks "%v" is ≥ "abd"`, got)
	fmt.Println(ok)

}

Output:

true
true
false

func (*T) HasPrefix 

func (t *T) HasPrefix(got interface{}, expected string, args ...interface{}) bool

HasPrefix is a shortcut for: 

t.Cmp(got, td.HasPrefix(expected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#HasPrefix for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foobar"

	ok := t.HasPrefix(got, "foo", "checks %s", got)
	fmt.Println("using string:", ok)

	ok = t.Cmp([]byte(got), td.HasPrefix("foo"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := errors.New("foobar")

	ok := t.HasPrefix(got, "foo", "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := t.HasPrefix(got, "foo", "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func (*T) HasSuffix 

func (t *T) HasSuffix(got interface{}, expected string, args ...interface{}) bool

HasSuffix is a shortcut for: 

t.Cmp(got, td.HasSuffix(expected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#HasSuffix for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foobar"

	ok := t.HasSuffix(got, "bar", "checks %s", got)
	fmt.Println("using string:", ok)

	ok = t.Cmp([]byte(got), td.HasSuffix("bar"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := errors.New("foobar")

	ok := t.HasSuffix(got, "bar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := t.HasSuffix(got, "bar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func (*T) Isa 

func (t *T) Isa(got, model interface{}, args ...interface{}) bool

Isa is a shortcut for: 

t.Cmp(got, td.Isa(model), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Isa for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type TstStruct struct {
		Field int
	}

	got := TstStruct{Field: 1}

	ok := t.Isa(got, TstStruct{}, "checks got is a TstStruct")
	fmt.Println(ok)

	ok = t.Isa(got, &TstStruct{},
		"checks got is a pointer on a TstStruct")
	fmt.Println(ok)

	ok = t.Isa(&got, &TstStruct{},
		"checks &got is a pointer on a TstStruct")
	fmt.Println(ok)

}

Output:

true
false
true
Example (Interface) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := bytes.NewBufferString("foobar")

	ok := t.Isa(got, (*fmt.Stringer)(nil),
		"checks got implements fmt.Stringer interface")
	fmt.Println(ok)

	errGot := fmt.Errorf("An error #%d occurred", 123)

	ok = t.Isa(errGot, (*error)(nil),
		"checks errGot is a *error or implements error interface")
	fmt.Println(ok)

	// As nil, is passed below, it is not an interface but nil… So it
	// does not match
	errGot = nil

	ok = t.Isa(errGot, (*error)(nil),
		"checks errGot is a *error or implements error interface")
	fmt.Println(ok)

	// BUT if its address is passed, now it is OK as the types match
	ok = t.Isa(&errGot, (*error)(nil),
		"checks &errGot is a *error or implements error interface")
	fmt.Println(ok)

}

Output:

true
true
false
true

func (*T) JSON 

func (t *T) JSON(got, expectedJSON interface{}, params []interface{}, args ...interface{}) bool

JSON is a shortcut for: 

t.Cmp(got, td.JSON(expectedJSON, params...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#JSON for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob",
		Age:      42,
	}

	ok := t.JSON(got, `{"age":42,"fullname":"Bob"}`, nil)
	fmt.Println("check got with age then fullname:", ok)

	ok = t.JSON(got, `{"fullname":"Bob","age":42}`, nil)
	fmt.Println("check got with fullname then age:", ok)

	ok = t.JSON(got, `
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42     /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
}`, nil)
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = t.JSON(got, `{"fullname":"Bob","age":42,"gender":"male"}`, nil)
	fmt.Println("check got with gender field:", ok)

	ok = t.JSON(got, `{"fullname":"Bob"}`, nil)
	fmt.Println("check got with fullname only:", ok)

	ok = t.JSON(true, `true`, nil)
	fmt.Println("check boolean got is true:", ok)

	ok = t.JSON(42, `42`, nil)
	fmt.Println("check numeric got is 42:", ok)

	got = nil
	ok = t.JSON(got, `null`, nil)
	fmt.Println("check nil got is null:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got with gender field: false
check got with fullname only: false
check boolean got is true: true
check numeric got is 42: true
check nil got is null: true
Example (Embedding) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := t.JSON(got, `{"age": NotZero(), "fullname": NotEmpty()}`, nil)
	fmt.Println("check got with simple operators:", ok)

	ok = t.JSON(got, `{"age": $^NotZero, "fullname": $^NotEmpty}`, nil)
	fmt.Println("check got with operator shortcuts:", ok)

	ok = t.JSON(got, `
{
  "age":      Between(40, 42, "]]"), // in ]40; 42]
  "fullname": All(
    HasPrefix("Bob"),
    HasSuffix("bar")  // ← comma is optional here
  )
}`, nil)
	fmt.Println("check got with complex operators:", ok)

	ok = t.JSON(got, `
{
  "age":      Between(40, 42, "]["), // in ]40; 42[ → 42 excluded
  "fullname": All(
    HasPrefix("Bob"),
    HasSuffix("bar"),
  )
}`, nil)
	fmt.Println("check got with complex operators:", ok)

}

Output:

check got with simple operators: true
check got with operator shortcuts: true
check got with complex operators: true
check got with complex operators: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender"
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := t.JSON(got, filename, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = t.JSON(got, file, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := t.JSON(got, `{"age": $1, "fullname": $2}`, []interface{}{42, "Bob Foobar"})
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = t.JSON(got, `{"age": $1, "fullname": $2}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar")})
	fmt.Println("check got with numeric placeholders:", ok)

	ok = t.JSON(got, `{"age": "$1", "fullname": "$2"}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar")})
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = t.JSON(got, `{"age": $age, "fullname": $name}`, []interface{}{td.Tag("age", td.Between(40, 45)), td.Tag("name", td.HasSuffix("Foobar"))})
	fmt.Println("check got with named placeholders:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true

func (*T) JSONPointer added in v1.8.0 

func (t *T) JSONPointer(got interface{}, pointer string, expectedValue interface{}, args ...interface{}) bool

JSONPointer is a shortcut for: 

t.Cmp(got, td.JSONPointer(pointer, expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#JSONPointer for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Has_hasnt) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := json.RawMessage(`
{
  "name": "Bob",
  "age": 42,
  "children": [
    {
      "name": "Alice",
      "age": 16
    },
    {
      "name": "Britt",
      "age": 21,
      "children": [
        {
          "name": "John",
          "age": 1
        }
      ]
    }
  ]
}`)

	// Has Bob some children?
	ok := t.JSONPointer(got, "/children", td.Len(td.Gt(0)))
	fmt.Println("Bob has at least one child:", ok)

	// But checking "children" exists is enough here
	ok = t.JSONPointer(got, "/children/0/children", td.Ignore())
	fmt.Println("Alice has children:", ok)

	ok = t.JSONPointer(got, "/children/1/children", td.Ignore())
	fmt.Println("Britt has children:", ok)

	// The reverse can be checked too
	ok = t.Cmp(got, td.Not(td.JSONPointer("/children/0/children", td.Ignore())))
	fmt.Println("Alice hasn't children:", ok)

	ok = t.Cmp(got, td.Not(td.JSONPointer("/children/1/children", td.Ignore())))
	fmt.Println("Britt hasn't children:", ok)

}

Output:

Bob has at least one child: true
Alice has children: false
Britt has children: true
Alice hasn't children: true
Britt hasn't children: false
Example (Rfc6901) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := json.RawMessage(`
{
   "foo":  ["bar", "baz"],
   "":     0,
   "a/b":  1,
   "c%d":  2,
   "e^f":  3,
   "g|h":  4,
   "i\\j": 5,
   "k\"l": 6,
   " ":    7,
   "m~n":  8
}`)

	expected := map[string]interface{}{
		"foo": []interface{}{"bar", "baz"},
		"":    0,
		"a/b": 1,
		"c%d": 2,
		"e^f": 3,
		"g|h": 4,
		`i\j`: 5,
		`k"l`: 6,
		" ":   7,
		"m~n": 8,
	}
	ok := t.JSONPointer(got, "", expected)
	fmt.Println("Empty JSON pointer means all:", ok)

	ok = t.JSONPointer(got, `/foo`, []interface{}{"bar", "baz"})
	fmt.Println("Extract `foo` key:", ok)

	ok = t.JSONPointer(got, `/foo/0`, "bar")
	fmt.Println("First item of `foo` key slice:", ok)

	ok = t.JSONPointer(got, `/`, 0)
	fmt.Println("Empty key:", ok)

	ok = t.JSONPointer(got, `/a~1b`, 1)
	fmt.Println("Slash has to be escaped using `~1`:", ok)

	ok = t.JSONPointer(got, `/c%d`, 2)
	fmt.Println("% in key:", ok)

	ok = t.JSONPointer(got, `/e^f`, 3)
	fmt.Println("^ in key:", ok)

	ok = t.JSONPointer(got, `/g|h`, 4)
	fmt.Println("| in key:", ok)

	ok = t.JSONPointer(got, `/i\j`, 5)
	fmt.Println("Backslash in key:", ok)

	ok = t.JSONPointer(got, `/k"l`, 6)
	fmt.Println("Double-quote in key:", ok)

	ok = t.JSONPointer(got, `/ `, 7)
	fmt.Println("Space key:", ok)

	ok = t.JSONPointer(got, `/m~0n`, 8)
	fmt.Println("Tilde has to be escaped using `~0`:", ok)

}

Output:

Empty JSON pointer means all: true
Extract `foo` key: true
First item of `foo` key slice: true
Empty key: true
Slash has to be escaped using `~1`: true
% in key: true
^ in key: true
| in key: true
Backslash in key: true
Double-quote in key: true
Space key: true
Tilde has to be escaped using `~0`: true
Example (Struct) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// Without json tags, encoding/json uses public fields name
	type Item struct {
		Name  string
		Value int64
		Next  *Item
	}

	got := Item{
		Name:  "first",
		Value: 1,
		Next: &Item{
			Name:  "second",
			Value: 2,
			Next: &Item{
				Name:  "third",
				Value: 3,
			},
		},
	}

	ok := t.JSONPointer(got, "/Next/Next/Name", "third")
	fmt.Println("3rd item name is `third`:", ok)

	ok = t.JSONPointer(got, "/Next/Next/Value", td.Gte(int64(3)))
	fmt.Println("3rd item value is greater or equal than 3:", ok)

	ok = t.JSONPointer(got, "/Next", td.JSONPointer("/Next",
		td.JSONPointer("/Value", td.Gte(int64(3)))))
	fmt.Println("3rd item value is still greater or equal than 3:", ok)

	ok = t.JSONPointer(got, "/Next/Next/Next/Name", td.Ignore())
	fmt.Println("4th item exists and has a name:", ok)

	// Struct comparison work with or without pointer: &Item{…} works too
	ok = t.JSONPointer(got, "/Next/Next", Item{
		Name:  "third",
		Value: 3,
	})
	fmt.Println("3rd item full comparison:", ok)

}

Output:

3rd item name is `third`: true
3rd item value is greater or equal than 3: true
3rd item value is still greater or equal than 3: true
4th item exists and has a name: false
3rd item full comparison: true

func (*T) Keys 

func (t *T) Keys(got, val interface{}, args ...interface{}) bool

Keys is a shortcut for: 

t.Cmp(got, td.Keys(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Keys for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[string]int{"foo": 1, "bar": 2, "zip": 3}

	// Keys tests keys in an ordered manner
	ok := t.Keys(got, []string{"bar", "foo", "zip"})
	fmt.Println("All sorted keys are found:", ok)

	// If the expected keys are not ordered, it fails
	ok = t.Keys(got, []string{"zip", "bar", "foo"})
	fmt.Println("All unsorted keys are found:", ok)

	// To circumvent that, one can use Bag operator
	ok = t.Keys(got, td.Bag("zip", "bar", "foo"))
	fmt.Println("All unsorted keys are found, with the help of Bag operator:", ok)

	// Check that each key is 3 bytes long
	ok = t.Keys(got, td.ArrayEach(td.Len(3)))
	fmt.Println("Each key is 3 bytes long:", ok)

}

Output:

All sorted keys are found: true
All unsorted keys are found: false
All unsorted keys are found, with the help of Bag operator: true
Each key is 3 bytes long: true

func (*T) Len 

func (t *T) Len(got, expectedLen interface{}, args ...interface{}) bool

Len is a shortcut for: 

t.Cmp(got, td.Len(expectedLen), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Len for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[int]bool{11: true, 22: false, 33: false}

	ok := t.Len(got, 3, "checks %v len is 3", got)
	fmt.Println(ok)

	ok = t.Len(got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

	got = nil

	ok = t.Len(got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true
Example (OperatorMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[int]bool{11: true, 22: false, 33: false}

	ok := t.Len(got, td.Between(3, 8),
		"checks %v len is in [3 .. 8]", got)
	fmt.Println(ok)

	ok = t.Len(got, td.Gte(3), "checks %v len is ≥ 3", got)
	fmt.Println(ok)

}

Output:

true
true
Example (OperatorSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{11, 22, 33}

	ok := t.Len(got, td.Between(3, 8),
		"checks %v len is in [3 .. 8]", got)
	fmt.Println(ok)

	ok = t.Len(got, td.Lt(5), "checks %v len is < 5", got)
	fmt.Println(ok)

}

Output:

true
true
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{11, 22, 33}

	ok := t.Len(got, 3, "checks %v len is 3", got)
	fmt.Println(ok)

	ok = t.Len(got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

	got = nil

	ok = t.Len(got, 0, "checks %v len is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true

func (*T) Lt 

func (t *T) Lt(got, maxExpectedValue interface{}, args ...interface{}) bool

Lt is a shortcut for: 

t.Cmp(got, td.Lt(maxExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Lt for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 156

	ok := t.Lt(got, 157, "checks %v is < 157", got)
	fmt.Println(ok)

	ok = t.Lt(got, 156, "checks %v is < 156", got)
	fmt.Println(ok)

}

Output:

true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "abc"

	ok := t.Lt(got, "abd", `checks "%v" is < "abd"`, got)
	fmt.Println(ok)

	ok = t.Lt(got, "abc", `checks "%v" is < "abc"`, got)
	fmt.Println(ok)

}

Output:

true
false

func (*T) Lte 

func (t *T) Lte(got, maxExpectedValue interface{}, args ...interface{}) bool

Lte is a shortcut for: 

t.Cmp(got, td.Lte(maxExpectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Lte for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 156

	ok := t.Lte(got, 156, "checks %v is ≤ 156", got)
	fmt.Println(ok)

	ok = t.Lte(got, 157, "checks %v is ≤ 157", got)
	fmt.Println(ok)

	ok = t.Lte(got, 155, "checks %v is ≤ 155", got)
	fmt.Println(ok)

}

Output:

true
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "abc"

	ok := t.Lte(got, "abc", `checks "%v" is ≤ "abc"`, got)
	fmt.Println(ok)

	ok = t.Lte(got, "abd", `checks "%v" is ≤ "abd"`, got)
	fmt.Println(ok)

	ok = t.Lte(got, "abb", `checks "%v" is ≤ "abb"`, got)
	fmt.Println(ok)

}

Output:

true
true
false

func (*T) Map 

func (t *T) Map(got, model interface{}, expectedEntries MapEntries, args ...interface{}) bool

Map is a shortcut for: 

t.Cmp(got, td.Map(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Map for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := t.Map(got, map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()},
		"checks map %v", got)
	fmt.Println(ok)

	ok = t.Map(got, map[string]int{}, td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks map %v", got)
	fmt.Println(ok)

	ok = t.Map(got, (map[string]int)(nil), td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks map %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := t.Map(got, MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()},
		"checks typed map %v", got)
	fmt.Println(ok)

	ok = t.Map(&got, &MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()},
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

	ok = t.Map(&got, &MyMap{}, td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

	ok = t.Map(&got, (*MyMap)(nil), td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()},
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func (*T) MapEach 

func (t *T) MapEach(got, expectedValue interface{}, args ...interface{}) bool

MapEach is a shortcut for: 

t.Cmp(got, td.MapEach(expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#MapEach for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := t.MapEach(got, td.Between(10, 90),
		"checks each value of map %v is in [10 .. 90]", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := t.MapEach(got, td.Between(10, 90),
		"checks each value of typed map %v is in [10 .. 90]", got)
	fmt.Println(ok)

	ok = t.MapEach(&got, td.Between(10, 90),
		"checks each value of typed map pointer %v is in [10 .. 90]", got)
	fmt.Println(ok)

}

Output:

true
true

func (*T) N 

func (t *T) N(got, num, tolerance interface{}, args ...interface{}) bool

N is a shortcut for: 

t.Cmp(got, td.N(num, tolerance), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#N for details.

N() optional parameter "tolerance" is here mandatory. 0 value should be passed to mimic its absence in original N() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 1.12345

	ok := t.N(got, 1.1234, 0.00006,
		"checks %v = 1.1234 ± 0.00006", got)
	fmt.Println(ok)

}

Output:

true

func (*T) NaN 

func (t *T) NaN(got interface{}, args ...interface{}) bool

NaN is a shortcut for: 

t.Cmp(got, td.NaN(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NaN for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Float32) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := float32(math.NaN())

	ok := t.NaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(math.NaN()) is float32 not-a-number:", ok)

	got = 12

	ok = t.NaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(12) is float32 not-a-number:", ok)

}

Output:

float32(math.NaN()) is float32 not-a-number: true
float32(12) is float32 not-a-number: false
Example (Float64) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := math.NaN()

	ok := t.NaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("math.NaN() is not-a-number:", ok)

	got = 12

	ok = t.NaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("float64(12) is not-a-number:", ok)

	// math.NaN() is not-a-number: true
	// float64(12) is not-a-number: false
}

Output:

func (*T) Nil 

func (t *T) Nil(got interface{}, args ...interface{}) bool

Nil is a shortcut for: 

t.Cmp(got, td.Nil(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Nil for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	var got fmt.Stringer // interface

	// nil value can be compared directly with nil, no need of Nil() here
	ok := t.Cmp(got, nil)
	fmt.Println(ok)

	// But it works with Nil() anyway
	ok = t.Nil(got)
	fmt.Println(ok)

	got = (*bytes.Buffer)(nil)

	// In the case of an interface containing a nil pointer, comparing
	// with nil fails, as the interface is not nil
	ok = t.Cmp(got, nil)
	fmt.Println(ok)

	// In this case Nil() succeed
	ok = t.Nil(got)
	fmt.Println(ok)

}

Output:

true
true
false
true

func (*T) None 

func (t *T) None(got interface{}, notExpectedValues []interface{}, args ...interface{}) bool

None is a shortcut for: 

t.Cmp(got, td.None(notExpectedValues...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#None for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 18

	ok := t.None(got, []interface{}{0, 10, 20, 30, td.Between(100, 199)},
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	got = 20

	ok = t.None(got, []interface{}{0, 10, 20, 30, td.Between(100, 199)},
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	got = 142

	ok = t.None(got, []interface{}{0, 10, 20, 30, td.Between(100, 199)},
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	prime := td.Flatten([]int{1, 2, 3, 5, 7, 11, 13})
	even := td.Flatten([]int{2, 4, 6, 8, 10, 12, 14})
	for _, got := range [...]int{9, 3, 8, 15} {
		ok = t.None(got, []interface{}{prime, even, td.Gt(14)},
			"checks %v is not prime number, nor an even number and not > 14")
		fmt.Printf("%d → %t\n", got, ok)
	}

}

Output:

true
false
false
9 → true
3 → false
8 → false
15 → false

func (*T) Not 

func (t *T) Not(got, notExpected interface{}, args ...interface{}) bool

Not is a shortcut for: 

t.Cmp(got, td.Not(notExpected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Not for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 42

	ok := t.Not(got, 0, "checks %v is non-null", got)
	fmt.Println(ok)

	ok = t.Not(got, td.Between(10, 30),
		"checks %v is not in [10 .. 30]", got)
	fmt.Println(ok)

	got = 0

	ok = t.Not(got, 0, "checks %v is non-null", got)
	fmt.Println(ok)

}

Output:

true
true
false

func (*T) NotAny 

func (t *T) NotAny(got interface{}, notExpectedItems []interface{}, args ...interface{}) bool

NotAny is a shortcut for: 

t.Cmp(got, td.NotAny(notExpectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotAny for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{4, 5, 9, 42}

	ok := t.NotAny(got, []interface{}{3, 6, 8, 41, 43},
		"checks %v contains no item listed in NotAny()", got)
	fmt.Println(ok)

	ok = t.NotAny(got, []interface{}{3, 6, 8, 42, 43},
		"checks %v contains no item listed in NotAny()", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using notExpected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	notExpected := []int{3, 6, 8, 41, 43}
	ok = t.NotAny(got, []interface{}{td.Flatten(notExpected)},
		"checks %v contains no item listed in notExpected", got)
	fmt.Println(ok)

}

Output:

true
false
true

func (*T) NotEmpty 

func (t *T) NotEmpty(got interface{}, args ...interface{}) bool

NotEmpty is a shortcut for: 

t.Cmp(got, td.NotEmpty(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotEmpty for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.NotEmpty(nil) // fails, as nil is considered empty
	fmt.Println(ok)

	ok = t.NotEmpty("foobar")
	fmt.Println(ok)

	// Fails as 0 is a number, so not empty. Use NotZero() instead
	ok = t.NotEmpty(0)
	fmt.Println(ok)

	ok = t.NotEmpty(map[string]int{"foobar": 42})
	fmt.Println(ok)

	ok = t.NotEmpty([]int{1})
	fmt.Println(ok)

	ok = t.NotEmpty([3]int{}) // succeeds, NotEmpty() is not NotZero()!
	fmt.Println(ok)

}

Output:

false
true
false
true
true
true
Example (Pointers) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MySlice []int

	ok := t.NotEmpty(MySlice{12})
	fmt.Println(ok)

	ok = t.NotEmpty(&MySlice{12}) // Ptr() not needed
	fmt.Println(ok)

	l1 := &MySlice{12}
	l2 := &l1
	l3 := &l2
	ok = t.NotEmpty(&l3)
	fmt.Println(ok)

	// Works the same for array, map, channel and string

	// But not for others types as:
	type MyStruct struct {
		Value int
	}

	ok = t.NotEmpty(&MyStruct{}) // fails, use NotZero() instead
	fmt.Println(ok)

}

Output:

true
true
true
false

func (*T) NotNaN 

func (t *T) NotNaN(got interface{}, args ...interface{}) bool

NotNaN is a shortcut for: 

t.Cmp(got, td.NotNaN(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotNaN for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Float32) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := float32(math.NaN())

	ok := t.NotNaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(math.NaN()) is NOT float32 not-a-number:", ok)

	got = 12

	ok = t.NotNaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("float32(12) is NOT float32 not-a-number:", ok)

}

Output:

float32(math.NaN()) is NOT float32 not-a-number: false
float32(12) is NOT float32 not-a-number: true
Example (Float64) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := math.NaN()

	ok := t.NotNaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("math.NaN() is not-a-number:", ok)

	got = 12

	ok = t.NotNaN(got,
		"checks %v is not-a-number", got)

	fmt.Println("float64(12) is not-a-number:", ok)

	// math.NaN() is NOT not-a-number: false
	// float64(12) is NOT not-a-number: true
}

Output:

func (*T) NotNil 

func (t *T) NotNil(got interface{}, args ...interface{}) bool

NotNil is a shortcut for: 

t.Cmp(got, td.NotNil(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotNil for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	var got fmt.Stringer = &bytes.Buffer{}

	// nil value can be compared directly with Not(nil), no need of NotNil() here
	ok := t.Cmp(got, td.Not(nil))
	fmt.Println(ok)

	// But it works with NotNil() anyway
	ok = t.NotNil(got)
	fmt.Println(ok)

	got = (*bytes.Buffer)(nil)

	// In the case of an interface containing a nil pointer, comparing
	// with Not(nil) succeeds, as the interface is not nil
	ok = t.Cmp(got, td.Not(nil))
	fmt.Println(ok)

	// In this case NotNil() fails
	ok = t.NotNil(got)
	fmt.Println(ok)

}

Output:

true
true
true
false

func (*T) NotZero 

func (t *T) NotZero(got interface{}, args ...interface{}) bool

NotZero is a shortcut for: 

t.Cmp(got, td.NotZero(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#NotZero for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.NotZero(0) // fails
	fmt.Println(ok)

	ok = t.NotZero(float64(0)) // fails
	fmt.Println(ok)

	ok = t.NotZero(12)
	fmt.Println(ok)

	ok = t.NotZero((map[string]int)(nil)) // fails, as nil
	fmt.Println(ok)

	ok = t.NotZero(map[string]int{}) // succeeds, as not nil
	fmt.Println(ok)

	ok = t.NotZero(([]int)(nil)) // fails, as nil
	fmt.Println(ok)

	ok = t.NotZero([]int{}) // succeeds, as not nil
	fmt.Println(ok)

	ok = t.NotZero([3]int{}) // fails
	fmt.Println(ok)

	ok = t.NotZero([3]int{0, 1}) // succeeds, DATA[1] is not 0
	fmt.Println(ok)

	ok = t.NotZero(bytes.Buffer{}) // fails
	fmt.Println(ok)

	ok = t.NotZero(&bytes.Buffer{}) // succeeds, as pointer not nil
	fmt.Println(ok)

	ok = t.Cmp(&bytes.Buffer{}, td.Ptr(td.NotZero())) // fails as deref by Ptr()
	fmt.Println(ok)

}

Output:

false
false
true
false
true
false
true
false
true
false
true
false

func (*T) PPtr 

func (t *T) PPtr(got, val interface{}, args ...interface{}) bool

PPtr is a shortcut for: 

t.Cmp(got, td.PPtr(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#PPtr for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	num := 12
	got := &num

	ok := t.PPtr(&got, 12)
	fmt.Println(ok)

	ok = t.PPtr(&got, td.Between(4, 15))
	fmt.Println(ok)

}

Output:

true
true

func (*T) Ptr 

func (t *T) Ptr(got, val interface{}, args ...interface{}) bool

Ptr is a shortcut for: 

t.Cmp(got, td.Ptr(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Ptr for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := 12

	ok := t.Ptr(&got, 12)
	fmt.Println(ok)

	ok = t.Ptr(&got, td.Between(4, 15))
	fmt.Println(ok)

}

Output:

true
true

func (*T) Re 

func (t *T) Re(got, reg, capture interface{}, args ...interface{}) bool

Re is a shortcut for: 

t.Cmp(got, td.Re(reg, capture), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Re for details.

Re() optional parameter "capture" is here mandatory. nil value should be passed to mimic its absence in original Re() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foo bar"
	ok := t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (Capture) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foo bar biz"
	ok := t.Re(got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = t.Re(got, `^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (Compiled) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile("(zip|bar)$")

	got := "foo bar"
	ok := t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCapture) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile(`^(\w+) (\w+) (\w+)$`)

	got := "foo bar biz"
	ok := t.Re(got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = t.Re(got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledError) 
package main

import (
	"errors"
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile("(zip|bar)$")

	got := errors.New("foo bar")
	ok := t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (CompiledStringer) 
package main

import (
	"bytes"
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile("(zip|bar)$")

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := t.Re(got, expected, nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := errors.New("foo bar")
	ok := t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := t.Re(got, "(zip|bar)$", nil, "checks value %s", got)
	fmt.Println(ok)

}

Output:

true

func (*T) ReAll 

func (t *T) ReAll(got, reg, capture interface{}, args ...interface{}) bool

ReAll is a shortcut for: 

t.Cmp(got, td.ReAll(reg, capture), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#ReAll for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Capture) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foo bar biz"
	ok := t.ReAll(got, `(\w+)`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but all catured groups do not match Set
	got = "foo BAR biz"
	ok = t.ReAll(got, `(\w+)`, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CaptureComplex) 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "11 45 23 56 85 96"
	ok := t.ReAll(got, `(\d+)`, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 10 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but 11 is not greater than 20
	ok = t.ReAll(got, `(\d+)`, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 20 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCapture) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile(`(\w+)`)

	got := "foo bar biz"
	ok := t.ReAll(got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but all catured groups do not match Set
	got = "foo BAR biz"
	ok = t.ReAll(got, expected, td.Set("biz", "foo", "bar"),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCaptureComplex) 
package main

import (
	"fmt"
	"regexp"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	expected := regexp.MustCompile(`(\d+)`)

	got := "11 45 23 56 85 96"
	ok := t.ReAll(got, expected, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 10 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but 11 is not greater than 20
	ok = t.ReAll(got, expected, td.ArrayEach(td.Code(func(num string) bool {
		n, err := strconv.Atoi(num)
		return err == nil && n > 20 && n < 100
	})),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false

func (*T) ResetAnchors 

func (t *T) ResetAnchors()

ResetAnchors frees all operators anchored with Anchor method. Unless operators anchoring persistence has been enabled with SetAnchorsPersist, there is no need to call this method. Anchored operators are automatically freed after each Cmp, CmpDeeply and CmpPanic call (or others methods calling them behind the scene).

func (*T) RootName 

func (t *T) RootName(rootName string) *T

RootName changes the name of the got data. By default it is "DATA". For an HTTP response body, it could be "BODY" for example.

It returns a new instance of *T so does not alter the original t and used as follows: 

t.RootName("RECORD").
  Struct(record,
    &Record{
      Name: "Bob",
      Age:  23,
    },
    td.StructFields{
      "Id":        td.NotZero(),
      "CreatedAt": td.Between(before, time.Now()),
    },
    "Newly created record")

In case of error for the field Age, the failure message will contain: 

RECORD.Age: values differ

Which is more readable than the generic: 

DATA.Age: values differ

If "" is passed the name is set to "DATA", the default value.

func (*T) Run added in v1.6.0 

func (t *T) Run(name string, f func(t *T)) bool

Run runs "f" as a subtest of t called "name".

If t.TB implement a method with the following signature: 

(X) Run(string, func(X)) bool

it calls it with a function of its own in which it creates a new instance of *T on the fly before calling "f" with it.

So if t.TB is a *testing.T or a *testing.B (which is in normal cases), let's quote the testing.T.Run() & testing.B.Run() documentation: "f" is called in a separate goroutine and blocks until "f" returns or calls t.Parallel to become a parallel test. Run reports whether "f" succeeded (or at least did not fail before calling t.Parallel). Run may be called simultaneously from multiple goroutines, but all such calls must return before the outer test function for t returns.

If this Run() method is not found, it simply logs "name" then executes "f" using a new *T instance in the current goroutine. Note that it is only done for convenience.

The "t" param of "f" inherits the configuration of the self-reference.

func (*T) RunAssertRequire added in v1.7.0 

func (t *T) RunAssertRequire(name string, f func(assert, require *T)) bool

RunAssertRequire runs "f" as a subtest of t called "name".

If t.TB implement a method with the following signature: 

(X) Run(string, func(X)) bool

it calls it with a function of its own in which it creates two new instances of *T using AssertRequire() on the fly before calling "f" with them.

So if t.TB is a *testing.T or a *testing.B (which is in normal cases), let's quote the testing.T.Run() & testing.B.Run() documentation: "f" is called in a separate goroutine and blocks until "f" returns or calls t.Parallel to become a parallel test. Run reports whether "f" succeeded (or at least did not fail before calling t.Parallel). Run may be called simultaneously from multiple goroutines, but all such calls must return before the outer test function for t returns.

If this Run() method is not found, it simply logs "name" then executes "f" using two new instances of *T (built with AssertRequire()) in the current goroutine. Note that it is only done for convenience.

The "assert" and "require" params of "f" inherit the configuration of the self-reference, except that a failure is never fatal using "assert" and always fatal using "require".

func (*T) RunT deprecated 

func (t *T) RunT(name string, f func(t *T)) bool

RunT runs "f" as a subtest of t called "name".

Deprecated: RunT has been superseded by Run() method. It is kept for compatibility.

func (*T) SStruct 

func (t *T) SStruct(got, model interface{}, expectedFields StructFields, args ...interface{}) bool

SStruct is a shortcut for: 

t.Cmp(got, td.SStruct(model, expectedFields), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SStruct for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type Person struct {
		Name        string
		Age         int
		NumChildren int
	}

	got := Person{
		Name:        "Foobar",
		Age:         42,
		NumChildren: 0,
	}

	// NumChildren is not listed in expected fields so it must be zero
	ok := t.SStruct(got, Person{Name: "Foobar"}, td.StructFields{
		"Age": td.Between(40, 50),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model can be empty
	got.NumChildren = 3
	ok = t.SStruct(got, Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Works with pointers too
	ok = t.SStruct(&got, &Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model does not need to be instanciated
	ok = t.SStruct(&got, (*Person)(nil), td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

}

Output:

true
true
true
true

func (*T) Set 

func (t *T) Set(got interface{}, expectedItems []interface{}, args ...interface{}) bool

Set is a shortcut for: 

t.Cmp(got, td.Set(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Set for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are present, ignoring duplicates
	ok := t.Set(got, []interface{}{1, 2, 3, 5, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Duplicates are ignored in a Set
	ok = t.Set(got, []interface{}{1, 2, 2, 2, 2, 2, 3, 5, 8},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Tries its best to not raise an error when a value can be matched
	// by several Set entries
	ok = t.Set(got, []interface{}{td.Between(1, 4), 3, td.Between(2, 10)},
		"checks all items are present, in any order")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5, 8}
	ok = t.Set(got, []interface{}{td.Flatten(expected)},
		"checks all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
true
true
true

func (*T) SetAnchorsPersist 

func (t *T) SetAnchorsPersist(persist bool)

SetAnchorsPersist allows to enable or disable anchors persistence.

func (*T) Shallow 

func (t *T) Shallow(got, expectedPtr interface{}, args ...interface{}) bool

Shallow is a shortcut for: 

t.Cmp(got, td.Shallow(expectedPtr), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Shallow for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MyStruct struct {
		Value int
	}
	data := MyStruct{Value: 12}
	got := &data

	ok := t.Shallow(got, &data,
		"checks pointers only, not contents")
	fmt.Println(ok)

	// Same contents, but not same pointer
	ok = t.Shallow(got, &MyStruct{Value: 12},
		"checks pointers only, not contents")
	fmt.Println(ok)

}

Output:

true
false
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	back := []int{1, 2, 3, 1, 2, 3}
	a := back[:3]
	b := back[3:]

	ok := t.Shallow(a, back)
	fmt.Println("are ≠ but share the same area:", ok)

	ok = t.Shallow(b, back)
	fmt.Println("are = but do not point to same area:", ok)

}

Output:

are ≠ but share the same area: true
are = but do not point to same area: false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	back := "foobarfoobar"
	a := back[:6]
	b := back[6:]

	ok := t.Shallow(a, back)
	fmt.Println("are ≠ but share the same area:", ok)

	ok = t.Shallow(b, a)
	fmt.Println("are = but do not point to same area:", ok)

}

Output:

are ≠ but share the same area: true
are = but do not point to same area: false

func (*T) Slice 

func (t *T) Slice(got, model interface{}, expectedEntries ArrayEntries, args ...interface{}) bool

Slice is a shortcut for: 

t.Cmp(got, td.Slice(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Slice for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{42, 58, 26}

	ok := t.Slice(got, []int{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks slice %v", got)
	fmt.Println(ok)

	ok = t.Slice(got, []int{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks slice %v", got)
	fmt.Println(ok)

	ok = t.Slice(got, ([]int)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks slice %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
Example (TypedSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MySlice []int

	got := MySlice{42, 58, 26}

	ok := t.Slice(got, MySlice{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks typed slice %v", got)
	fmt.Println(ok)

	ok = t.Slice(&got, &MySlice{42}, td.ArrayEntries{1: 58, 2: td.Ignore()},
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

	ok = t.Slice(&got, &MySlice{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

	ok = t.Slice(&got, (*MySlice)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()},
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func (*T) Smuggle 

func (t *T) Smuggle(got, fn, expectedValue interface{}, args ...interface{}) bool

Smuggle is a shortcut for: 

t.Cmp(got, td.Smuggle(fn, expectedValue), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Smuggle for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Auto_unmarshal) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// Automatically json.Unmarshal to compare
	got := []byte(`{"a":1,"b":2}`)

	ok := t.Smuggle(got, func(b json.RawMessage) (r map[string]int, err error) {
		err = json.Unmarshal(b, &r)
		return
	}, map[string]int{
		"a": 1,
		"b": 2,
	})
	fmt.Println("JSON contents is OK:", ok)

}

Output:

JSON contents is OK: true
Example (Complex) 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// No end date but a start date and a duration
	type StartDuration struct {
		StartDate time.Time
		Duration  time.Duration
	}

	// Checks that end date is between 17th and 19th February both at 0h
	// for each of these durations in hours

	for _, duration := range []time.Duration{48, 72, 96} {
		got := StartDuration{
			StartDate: time.Date(2018, time.February, 14, 12, 13, 14, 0, time.UTC),
			Duration:  duration * time.Hour,
		}

		// Simplest way, but in case of Between() failure, error will be bound
		// to DATA<smuggled>, not very clear...
		ok := t.Smuggle(got, func(sd StartDuration) time.Time {
			return sd.StartDate.Add(sd.Duration)
		}, td.Between(
			time.Date(2018, time.February, 17, 0, 0, 0, 0, time.UTC),
			time.Date(2018, time.February, 19, 0, 0, 0, 0, time.UTC)))
		fmt.Println(ok)

		// Name the computed value "ComputedEndDate" to render a Between() failure
		// more understandable, so error will be bound to DATA.ComputedEndDate
		ok = t.Smuggle(got, func(sd StartDuration) td.SmuggledGot {
			return td.SmuggledGot{
				Name: "ComputedEndDate",
				Got:  sd.StartDate.Add(sd.Duration),
			}
		}, td.Between(
			time.Date(2018, time.February, 17, 0, 0, 0, 0, time.UTC),
			time.Date(2018, time.February, 19, 0, 0, 0, 0, time.UTC)))
		fmt.Println(ok)
	}

}

Output:

false
false
true
true
true
true
Example (Convert) 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := int64(123)

	ok := t.Smuggle(got, func(n int64) int { return int(n) }, 123,
		"checks int64 got against an int value")
	fmt.Println(ok)

	ok = t.Smuggle("123", func(numStr string) (int, bool) {
		n, err := strconv.Atoi(numStr)
		return n, err == nil
	}, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	ok = t.Smuggle("123", func(numStr string) (int, bool, string) {
		n, err := strconv.Atoi(numStr)
		if err != nil {
			return 0, false, "string must contain a number"
		}
		return n, true, ""
	}, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	ok = t.Smuggle("123", func(numStr string) (int, error) { // nolint: gocritic
		return strconv.Atoi(numStr)
	}, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	// Short version :)
	ok = t.Smuggle("123", strconv.Atoi, td.Between(120, 130),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

}

Output:

true
true
true
true
true
Example (Field_path) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type Body struct {
		Name  string
		Value interface{}
	}
	type Request struct {
		Body *Body
	}
	type Transaction struct {
		Request
	}
	type ValueNum struct {
		Num int
	}

	got := &Transaction{
		Request: Request{
			Body: &Body{
				Name:  "test",
				Value: &ValueNum{Num: 123},
			},
		},
	}

	// Want to check whether Num is between 100 and 200?
	ok := t.Smuggle(got, func(t *Transaction) (int, error) {
		if t.Request.Body == nil ||
			t.Request.Body.Value == nil {
			return 0, errors.New("Request.Body or Request.Body.Value is nil")
		}
		if v, ok := t.Request.Body.Value.(*ValueNum); ok && v != nil {
			return v.Num, nil
		}
		return 0, errors.New("Request.Body.Value isn't *ValueNum or nil")
	}, td.Between(100, 200))
	fmt.Println("check Num by hand:", ok)

	// Same, but automagically generated...
	ok = t.Smuggle(got, "Request.Body.Value.Num", td.Between(100, 200))
	fmt.Println("check Num using a fields-path:", ok)

	// And as Request is an anonymous field, can be simplified further
	// as it can be omitted
	ok = t.Smuggle(got, "Body.Value.Num", td.Between(100, 200))
	fmt.Println("check Num using an other fields-path:", ok)

}

Output:

check Num by hand: true
check Num using a fields-path: true
check Num using an other fields-path: true
Example (Interface) 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	gotTime, err := time.Parse(time.RFC3339, "2018-05-23T12:13:14Z")
	if err != nil {
		t.Fatal(err)
	}

	// Do not check the struct itself, but its stringified form
	ok := t.Smuggle(gotTime, func(s fmt.Stringer) string {
		return s.String()
	}, "2018-05-23 12:13:14 +0000 UTC")
	fmt.Println("stringified time.Time OK:", ok)

	// If got does not implement the fmt.Stringer interface, it fails
	// without calling the Smuggle func
	type MyTime time.Time
	ok = t.Smuggle(MyTime(gotTime), func(s fmt.Stringer) string {
		fmt.Println("Smuggle func called!")
		return s.String()
	}, "2018-05-23 12:13:14 +0000 UTC")
	fmt.Println("stringified MyTime OK:", ok)

	// Output
	// stringified time.Time OK: true
	// stringified MyTime OK: false
}

Output:
Example (Lax) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// got is an int16 and Smuggle func input is an int64: it is OK
	got := int(123)

	ok := t.Smuggle(got, func(n int64) uint32 { return uint32(n) }, uint32(123))
	fmt.Println("got int16(123) → smuggle via int64 → uint32(123):", ok)

}

Output:

got int16(123) → smuggle via int64 → uint32(123): true

func (*T) String 

func (t *T) String(got interface{}, expected string, args ...interface{}) bool

String is a shortcut for: 

t.Cmp(got, td.String(expected), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#String for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := "foobar"

	ok := t.String(got, "foobar", "checks %s", got)
	fmt.Println("using string:", ok)

	ok = t.Cmp([]byte(got), td.String("foobar"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := errors.New("foobar")

	ok := t.String(got, "foobar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := t.String(got, "foobar", "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func (*T) Struct 

func (t *T) Struct(got, model interface{}, expectedFields StructFields, args ...interface{}) bool

Struct is a shortcut for: 

t.Cmp(got, td.Struct(model, expectedFields), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Struct for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type Person struct {
		Name        string
		Age         int
		NumChildren int
	}

	got := Person{
		Name:        "Foobar",
		Age:         42,
		NumChildren: 3,
	}

	// As NumChildren is zero in Struct() call, it is not checked
	ok := t.Struct(got, Person{Name: "Foobar"}, td.StructFields{
		"Age": td.Between(40, 50),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model can be empty
	ok = t.Struct(got, Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Works with pointers too
	ok = t.Struct(&got, &Person{}, td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model does not need to be instanciated
	ok = t.Struct(&got, (*Person)(nil), td.StructFields{
		"Name":        "Foobar",
		"Age":         td.Between(40, 50),
		"NumChildren": td.Not(0),
	},
		"checks %v is the right Person")
	fmt.Println(ok)

}

Output:

true
true
true
true

func (*T) SubBagOf 

func (t *T) SubBagOf(got interface{}, expectedItems []interface{}, args ...interface{}) bool

SubBagOf is a shortcut for: 

t.Cmp(got, td.SubBagOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubBagOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := t.SubBagOf(got, []interface{}{0, 0, 1, 1, 2, 2, 3, 3, 5, 5, 8, 8, 9, 9},
		"checks at least all items are present, in any order")
	fmt.Println(ok)

	// got contains one 8 too many
	ok = t.SubBagOf(got, []interface{}{0, 0, 1, 1, 2, 2, 3, 3, 5, 5, 8, 9, 9},
		"checks at least all items are present, in any order")
	fmt.Println(ok)

	got = []int{1, 3, 5, 2}

	ok = t.SubBagOf(got, []interface{}{td.Between(0, 3), td.Between(0, 3), td.Between(0, 3), td.Between(0, 3), td.Gt(4), td.Gt(4)},
		"checks at least all items match, in any order with TestDeep operators")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5, 9, 8}
	ok = t.SubBagOf(got, []interface{}{td.Flatten(expected)},
		"checks at least all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
false
true
true

func (*T) SubJSONOf 

func (t *T) SubJSONOf(got, expectedJSON interface{}, params []interface{}, args ...interface{}) bool

SubJSONOf is a shortcut for: 

t.Cmp(got, td.SubJSONOf(expectedJSON, params...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubJSONOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob",
		Age:      42,
	}

	ok := t.SubJSONOf(got, `{"age":42,"fullname":"Bob","gender":"male"}`, nil)
	fmt.Println("check got with age then fullname:", ok)

	ok = t.SubJSONOf(got, `{"fullname":"Bob","age":42,"gender":"male"}`, nil)
	fmt.Println("check got with fullname then age:", ok)

	ok = t.SubJSONOf(got, `
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42,    /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
  "gender":   "male" // This field is ignored as SubJSONOf
}`, nil)
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = t.SubJSONOf(got, `{"fullname":"Bob","gender":"male"}`, nil)
	fmt.Println("check got without age field:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got without age field: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender",
  "details":  {
    "city": "TestCity",
    "zip":  666
  }
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := t.SubJSONOf(got, filename, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = t.SubJSONOf(got, file, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := t.SubJSONOf(got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{42, "Bob Foobar", "male"})
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = t.SubJSONOf(got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with numeric placeholders:", ok)

	ok = t.SubJSONOf(got, `{"age": "$1", "fullname": "$2", "gender": "$3"}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = t.SubJSONOf(got, `{"age": $age, "fullname": $name, "gender": $gender}`, []interface{}{td.Tag("age", td.Between(40, 45)), td.Tag("name", td.HasSuffix("Foobar")), td.Tag("gender", td.NotEmpty())})
	fmt.Println("check got with named placeholders:", ok)

	ok = t.SubJSONOf(got, `{"age": $^NotZero, "fullname": $^NotEmpty, "gender": $^NotEmpty}`, nil)
	fmt.Println("check got with operator shortcuts:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true
check got with operator shortcuts: true

func (*T) SubMapOf 

func (t *T) SubMapOf(got, model interface{}, expectedEntries MapEntries, args ...interface{}) bool

SubMapOf is a shortcut for: 

t.Cmp(got, td.SubMapOf(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubMapOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[string]int{"foo": 12, "bar": 42}

	ok := t.SubMapOf(got, map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666},
		"checks map %v is included in expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42}

	ok := t.SubMapOf(got, MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666},
		"checks typed map %v is included in expected keys/values", got)
	fmt.Println(ok)

	ok = t.SubMapOf(&got, &MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666},
		"checks pointed typed map %v is included in expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
true

func (*T) SubSetOf 

func (t *T) SubSetOf(got interface{}, expectedItems []interface{}, args ...interface{}) bool

SubSetOf is a shortcut for: 

t.Cmp(got, td.SubSetOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SubSetOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are expected, ignoring duplicates
	ok := t.SubSetOf(got, []interface{}{1, 2, 3, 4, 5, 6, 7, 8},
		"checks at least all items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

	// Tries its best to not raise an error when a value can be matched
	// by several SubSetOf entries
	ok = t.SubSetOf(got, []interface{}{td.Between(1, 4), 3, td.Between(2, 10), td.Gt(100)},
		"checks at least all items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 4, 5, 6, 7, 8}
	ok = t.SubSetOf(got, []interface{}{td.Flatten(expected)},
		"checks at least all expected items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

}

Output:

true
true
true

func (*T) SuperBagOf 

func (t *T) SuperBagOf(got interface{}, expectedItems []interface{}, args ...interface{}) bool

SuperBagOf is a shortcut for: 

t.Cmp(got, td.SuperBagOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperBagOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := t.SuperBagOf(got, []interface{}{8, 5, 8},
		"checks the items are present, in any order")
	fmt.Println(ok)

	ok = t.SuperBagOf(got, []interface{}{td.Gt(5), td.Lte(2)},
		"checks at least 2 items of %v match", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{8, 5, 8}
	ok = t.SuperBagOf(got, []interface{}{td.Flatten(expected)},
		"checks the expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
true
true

func (*T) SuperJSONOf 

func (t *T) SuperJSONOf(got, expectedJSON interface{}, params []interface{}, args ...interface{}) bool

SuperJSONOf is a shortcut for: 

t.Cmp(got, td.SuperJSONOf(expectedJSON, params...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperJSONOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	ok := t.SuperJSONOf(got, `{"age":42,"fullname":"Bob","gender":"male"}`, nil)
	fmt.Println("check got with age then fullname:", ok)

	ok = t.SuperJSONOf(got, `{"fullname":"Bob","age":42,"gender":"male"}`, nil)
	fmt.Println("check got with fullname then age:", ok)

	ok = t.SuperJSONOf(got, `
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42,    /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
  "gender":   "male" // The gender!
}`, nil)
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = t.SuperJSONOf(got, `{"fullname":"Bob","gender":"male","details":{}}`, nil)
	fmt.Println("check got with details field:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got with details field: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender"
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := t.SuperJSONOf(got, filename, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = t.SuperJSONOf(got, file, []interface{}{td.Tag("name", td.HasPrefix("Bob")), td.Tag("age", td.Between(40, 45)), td.Tag("gender", td.Re(`^(male|female)\z`))})
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	ok := t.SuperJSONOf(got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{42, "Bob Foobar", "male"})
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = t.SuperJSONOf(got, `{"age": $1, "fullname": $2, "gender": $3}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with numeric placeholders:", ok)

	ok = t.SuperJSONOf(got, `{"age": "$1", "fullname": "$2", "gender": "$3"}`, []interface{}{td.Between(40, 45), td.HasSuffix("Foobar"), td.NotEmpty()})
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = t.SuperJSONOf(got, `{"age": $age, "fullname": $name, "gender": $gender}`, []interface{}{td.Tag("age", td.Between(40, 45)), td.Tag("name", td.HasSuffix("Foobar")), td.Tag("gender", td.NotEmpty())})
	fmt.Println("check got with named placeholders:", ok)

	ok = t.SuperJSONOf(got, `{"age": $^NotZero, "fullname": $^NotEmpty, "gender": $^NotEmpty}`, nil)
	fmt.Println("check got with operator shortcuts:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true
check got with operator shortcuts: true

func (*T) SuperMapOf 

func (t *T) SuperMapOf(got, model interface{}, expectedEntries MapEntries, args ...interface{}) bool

SuperMapOf is a shortcut for: 

t.Cmp(got, td.SuperMapOf(model, expectedEntries), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperMapOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := t.SuperMapOf(got, map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15)},
		"checks map %v contains at leat all expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := t.SuperMapOf(got, MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15)},
		"checks typed map %v contains at leat all expected keys/values", got)
	fmt.Println(ok)

	ok = t.SuperMapOf(&got, &MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15)},
		"checks pointed typed map %v contains at leat all expected keys/values",
		got)
	fmt.Println(ok)

}

Output:

true
true

func (*T) SuperSetOf 

func (t *T) SuperSetOf(got interface{}, expectedItems []interface{}, args ...interface{}) bool

SuperSetOf is a shortcut for: 

t.Cmp(got, td.SuperSetOf(expectedItems...), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#SuperSetOf for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := t.SuperSetOf(got, []interface{}{1, 2, 3},
		"checks the items are present, in any order and ignoring duplicates")
	fmt.Println(ok)

	ok = t.SuperSetOf(got, []interface{}{td.Gt(5), td.Lte(2)},
		"checks at least 2 items of %v match ignoring duplicates", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3}
	ok = t.SuperSetOf(got, []interface{}{td.Flatten(expected)},
		"checks the expected items are present, in any order and ignoring duplicates")
	fmt.Println(ok)

}

Output:

true
true
true

func (*T) True 

func (t *T) True(got interface{}, args ...interface{}) bool

True is shortcut for: 

t.Cmp(got, true, args...)

Returns true if the test is OK, false if it fails. 

t.True(IsAvailable(x), "x should be available")

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := true
	ok := t.True(got, "check that got is true!")
	fmt.Println(ok)

	got = false
	ok = t.True(got, "check that got is true!")
	fmt.Println(ok)

}

Output:

true
false

func (*T) TruncTime 

func (t *T) TruncTime(got, expectedTime interface{}, trunc time.Duration, args ...interface{}) bool

TruncTime is a shortcut for: 

t.Cmp(got, td.TruncTime(expectedTime, trunc), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#TruncTime for details.

TruncTime() optional parameter "trunc" is here mandatory. 0 value should be passed to mimic its absence in original TruncTime() call.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	dateToTime := func(str string) time.Time {
		t, err := time.Parse(time.RFC3339Nano, str)
		if err != nil {
			panic(err)
		}
		return t
	}

	got := dateToTime("2018-05-01T12:45:53.123456789Z")

	// Compare dates ignoring nanoseconds and monotonic parts
	expected := dateToTime("2018-05-01T12:45:53Z")
	ok := t.TruncTime(got, expected, time.Second,
		"checks date %v, truncated to the second", got)
	fmt.Println(ok)

	// Compare dates ignoring time and so monotonic parts
	expected = dateToTime("2018-05-01T11:22:33.444444444Z")
	ok = t.TruncTime(got, expected, 24*time.Hour,
		"checks date %v, truncated to the day", got)
	fmt.Println(ok)

	// Compare dates exactly but ignoring monotonic part
	expected = dateToTime("2018-05-01T12:45:53.123456789Z")
	ok = t.TruncTime(got, expected, 0,
		"checks date %v ignoring monotonic part", got)
	fmt.Println(ok)

}

Output:

true
true
true

func (*T) UseEqual 

func (t *T) UseEqual(enable ...bool) *T

UseEqual allows to use the Equal method on got (if it exists) or on any of its component to compare got and expected values.

The signature should be: 

(A) Equal(B) bool

with B assignable to A.

See time.Time as an example of accepted Equal() method.

It returns a new instance of *T so does not alter the original t.

Note that t.UseEqual() acts as t.UseEqual(true).

func (*T) Values 

func (t *T) Values(got, val interface{}, args ...interface{}) bool

Values is a shortcut for: 

t.Cmp(got, td.Values(val), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Values for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	got := map[string]int{"foo": 1, "bar": 2, "zip": 3}

	// Values tests values in an ordered manner
	ok := t.Values(got, []int{1, 2, 3})
	fmt.Println("All sorted values are found:", ok)

	// If the expected values are not ordered, it fails
	ok = t.Values(got, []int{3, 1, 2})
	fmt.Println("All unsorted values are found:", ok)

	// To circumvent that, one can use Bag operator
	ok = t.Values(got, td.Bag(3, 1, 2))
	fmt.Println("All unsorted values are found, with the help of Bag operator:", ok)

	// Check that each value is between 1 and 3
	ok = t.Values(got, td.ArrayEach(td.Between(1, 3)))
	fmt.Println("Each value is between 1 and 3:", ok)

}

Output:

All sorted values are found: true
All unsorted values are found: false
All unsorted values are found, with the help of Bag operator: true
Each value is between 1 and 3: true

func (*T) WithCmpHooks added in v1.8.0 

func (t *T) WithCmpHooks(fns ...interface{}) *T

WithCmpHooks returns a new *T instance with new Cmp hooks recorded using functions passed in "fns".

Each function in "fns" has to be a function with the following possible signatures: 

func (A, A) bool
func (A, A) error

First arg is always "got", and second is always "expected".

A cannot be an interface. This retriction can be removed in the future, if really needed.

This function is called as soon as possible each time the type A is encountered for "got" while "expected" type is assignable to A.

When it returns a bool, false means A is not equal to B.

When it returns a non-nil error (meaning "got" ≠ "expected"), its contents is used to tell the reason of the failure.

Cmp hooks are checked before UseEqual feature. 

func TestCmpHook(tt *testing.T) {
  t := td.NewT(tt)

  // Test reflect.Value contents instead of default field/field
  t = t.WithCmpHooks(func (got, expected reflect.Value) bool {
    return td.EqDeeply(got.Interface(), expected.Interface())
  })
  a, b := 1, 1
  t.Cmp(reflect.ValueOf(&a), relect.ValueOf(&b)) // succeeds

  // Test reflect.Type correctly instead of default field/field
  t = t.WithCmpHooks(func (got, expected reflect.Type) bool {
    return got == expected
  })

  // Test time.Time via its Equal() method instead of default
  // field/field (note it bypasses the UseEqual flag)
  t = t.WithCmpHooks((time.Time).Equal)
  date, _ := time.Parse(time.RFC3339, "2020-09-08T22:13:54+02:00")
  t.Cmp(date, date.UTC()) // succeeds

  // Several hooks can be declared at once
  t = t.WithCmpHooks(
    func (got, expected reflect.Value) bool {
      return td.EqDeeply(got.Interface(), expected.Interface())
    },
    func (got, expected reflect.Type) bool {
      return got == expected
    },
    (time.Time).Equal,
  )
}

There is no way to add or remove hooks of an existing *T instance, only create a new one with this method or WithSmuggleHooks to add some.

WithCmpHooks panics if an item of "fns" is not a function or if its signature does not match the expected ones.

func (*T) WithSmuggleHooks added in v1.8.0 

func (t *T) WithSmuggleHooks(fns ...interface{}) *T

WithSmuggleHooks returns a new *T instance with new Smuggle hooks recorded using functions passed in "fns".

Each function in "fns" has to be a function with the following possible signatures: 

func (A) B
func (A) (B, error)

A cannot be an interface. This retriction can be removed in the future, if really needed.

B cannot be an interface. If you have a use case, we can talk about it.

This function is called as soon as possible each time the type A is encountered for "got".

The B value returned replaces the "got" value for subsequent tests. Smuggle hooks are NOT run again for this returned value to avoid easy infinite loop recursion.

When it returns non-nil error (meaning something wrong happened during the conversion of A to B), it raises a global error and its contents is used to tell the reason of the failure.

Smuggle hooks are run just before Cmp hooks. 

func TestSmuggleHook(tt *testing.T) {
  t := td.NewT(tt)

  // Each encountered int is changed to a bool
  t = t.WithSmuggleHooks(func (got int) bool {
    return got != 0
  })
  t.Cmp(map[string]int{"ok": 1, "no": 0},
    map[string]bool{"ok", true, "no", false}) // succeeds

  // Each encountered string is converted to int
  t = t.WithSmuggleHooks(strconv.Atoi)
  t.Cmp("123", 123) // succeeds

  // Several hooks can be declared at once
  t = t.WithSmuggleHooks(
    func (got int) bool { return got != 0 },
    strconv.Atoi,
  )
}

There is no way to add or remove hooks of an existing *T instance, only create a new one with this method or WithCmpHooks to add some.

WithSmuggleHooks panics if an item of "fns" is not a function or if its signature does not match the expected ones.

func (*T) Zero 

func (t *T) Zero(got interface{}, args ...interface{}) bool

Zero is a shortcut for: 

t.Cmp(got, td.Zero(), args...)

See https://pkg.go.dev/github.com/maxatome/go-testdeep/td#Zero for details.

Returns true if the test is OK, false if it fails.

"args..." are optional and allow to name the test. This name is used in case of failure to qualify the test. If len(args) > 1 and the first item of "args" is a string and contains a '%' rune then fmt.Fprintf is used to compose the name, else "args" are passed to fmt.Fprint. Do not forget it is the name of the test, not the reason of a potential failure.

Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := td.NewT(&testing.T{})

	ok := t.Zero(0)
	fmt.Println(ok)

	ok = t.Zero(float64(0))
	fmt.Println(ok)

	ok = t.Zero(12) // fails, as 12 is not 0 :)
	fmt.Println(ok)

	ok = t.Zero((map[string]int)(nil))
	fmt.Println(ok)

	ok = t.Zero(map[string]int{}) // fails, as not nil
	fmt.Println(ok)

	ok = t.Zero(([]int)(nil))
	fmt.Println(ok)

	ok = t.Zero([]int{}) // fails, as not nil
	fmt.Println(ok)

	ok = t.Zero([3]int{})
	fmt.Println(ok)

	ok = t.Zero([3]int{0, 1}) // fails, DATA[1] is not 0
	fmt.Println(ok)

	ok = t.Zero(bytes.Buffer{})
	fmt.Println(ok)

	ok = t.Zero(&bytes.Buffer{}) // fails, as pointer not nil
	fmt.Println(ok)

	ok = t.Cmp(&bytes.Buffer{}, td.Ptr(td.Zero())) // OK with the help of Ptr()
	fmt.Println(ok)

}

Output:

true
true
false
true
false
true
false
true
false
true
false
true

type TestDeep 

type TestDeep interface {
	types.TestDeepStringer
	location.GetLocationer
	// Match checks "got" against the operator. It returns nil if it matches.
	Match(ctx ctxerr.Context, got reflect.Value) *ctxerr.Error

	// HandleInvalid returns true if the operator is able to handle
	// untyped nil value. Otherwise the untyped nil value is handled
	// generically.
	HandleInvalid() bool
	// TypeBehind returns the type handled by the operator or nil if it
	// is not known. tdhttp helper uses it to know how to unmarshal HTTP
	// responses bodies before comparing them using the operator.
	TypeBehind() reflect.Type
	// contains filtered or unexported methods
}

TestDeep is the representation of a go-testdeep operator. It is not intended to be used directly, but through Cmp* functions.

func All 

func All(expectedValues ...interface{}) TestDeep

All operator compares data against several expected values. During a match, all of them have to match to succeed. Consider it as a "AND" logical operator. 

td.Cmp(t, "foobar", td.All(
  td.Len(6),
  td.HasPrefix("fo"),
  td.HasSuffix("ar"),
)) // succeeds

Note Flatten function can be used to group or reuse some values or operators and so avoid boring and inefficient copies: 

stringOps := td.Flatten([]td.TestDeep{td.HasPrefix("fo"), td.HasSuffix("ar")})
td.Cmp(t, "foobar", td.All(
  td.Len(6),
  stringOps,
)) // succeeds

One can do the same with All operator itself: 

stringOps := td.All(td.HasPrefix("fo"), td.HasSuffix("ar"))
td.Cmp(t, "foobar", td.All(
  td.Len(6),
  stringOps,
)) // succeeds

but if an error occurs in the nested All, the report is a bit more complex to read due to the nested level. Flatten does not create a new level, its slice is just flattened in the All parameters.

TypeBehind method can return a non-nil reflect.Type if all items known non-interface types are equal, or if only interface types are found (mostly issued from Isa()) and they are equal.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo/bar"

	// Checks got string against:
	//   "o/b" regexp *AND* "bar" suffix *AND* exact "foo/bar" string
	ok := td.Cmp(t,
		got,
		td.All(td.Re("o/b"), td.HasSuffix("bar"), "foo/bar"),
		"checks value %s", got)
	fmt.Println(ok)

	// Checks got string against:
	//   "o/b" regexp *AND* "bar" suffix *AND* exact "fooX/Ybar" string
	ok = td.Cmp(t,
		got,
		td.All(td.Re("o/b"), td.HasSuffix("bar"), "fooX/Ybar"),
		"checks value %s", got)
	fmt.Println(ok)

	// When some operators or values have to be reused and mixed between
	// several calls, Flatten can be used to avoid boring and
	// inefficient []interface{} copies:
	regOps := td.Flatten([]td.TestDeep{td.Re("o/b"), td.Re(`^fo`), td.Re(`ar$`)})
	ok = td.Cmp(t,
		got,
		td.All(td.HasPrefix("foo"), regOps, td.HasSuffix("bar")),
		"checks all operators against value %s", got)
	fmt.Println(ok)

}

Output:

true
false
true

func Any 

func Any(expectedValues ...interface{}) TestDeep

Any operator compares data against several expected values. During a match, at least one of them has to match to succeed. Consider it as a "OR" logical operator. 

td.Cmp(t, "foo", td.Any("bar", "foo", "zip")) // succeeds
td.Cmp(t, "foo", td.Any(
  td.Len(4),
  td.HasPrefix("f"),
  td.HasSuffix("z"),
)) // succeeds coz "f" prefix

Note Flatten function can be used to group or reuse some values or operators and so avoid boring and inefficient copies: 

stringOps := td.Flatten([]td.TestDeep{td.HasPrefix("f"), td.HasSuffix("z")})
td.Cmp(t, "foobar", td.All(
  td.Len(4),
  stringOps,
)) // succeeds coz "f" prefix

TypeBehind method can return a non-nil reflect.Type if all items known non-interface types are equal, or if only interface types are found (mostly issued from Isa()) and they are equal.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo/bar"

	// Checks got string against:
	//   "zip" regexp *OR* "bar" suffix
	ok := td.Cmp(t, got, td.Any(td.Re("zip"), td.HasSuffix("bar")),
		"checks value %s", got)
	fmt.Println(ok)

	// Checks got string against:
	//   "zip" regexp *OR* "foo" suffix
	ok = td.Cmp(t, got, td.Any(td.Re("zip"), td.HasSuffix("foo")),
		"checks value %s", got)
	fmt.Println(ok)

	// When some operators or values have to be reused and mixed between
	// several calls, Flatten can be used to avoid boring and
	// inefficient []interface{} copies:
	regOps := td.Flatten([]td.TestDeep{td.Re("a/c"), td.Re(`^xx`), td.Re(`ar$`)})
	ok = td.Cmp(t,
		got,
		td.Any(td.HasPrefix("xxx"), regOps, td.HasSuffix("zip")),
		"check at least one operator matches value %s", got)
	fmt.Println(ok)

}

Output:

true
false
true

func Array 

func Array(model interface{}, expectedEntries ArrayEntries) TestDeep

Array operator compares the contents of an array or a pointer on an array against the non-zero values of "model" (if any) and the values of "expectedEntries".

"model" must be the same type as compared data.

"expectedEntries" can be nil, if no zero entries are expected and no TestDeep operator are involved. 

got := [3]int{12, 14, 17}
td.Cmp(t, got, td.Array([3]int{0, 14}, td.ArrayEntries{0: 12, 2: 17})) // succeeds
td.Cmp(t, got,
  td.Array([3]int{0, 14}, td.ArrayEntries{0: td.Gt(10), 2: td.Gt(15)})) // succeeds

TypeBehind method returns the reflect.Type of "model".

Example (Array) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := [3]int{42, 58, 26}

	ok := td.Cmp(t, got,
		td.Array([3]int{42}, td.ArrayEntries{1: 58, 2: td.Ignore()}),
		"checks array %v", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedArray) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyArray [3]int

	got := MyArray{42, 58, 26}

	ok := td.Cmp(t, got,
		td.Array(MyArray{42}, td.ArrayEntries{1: 58, 2: td.Ignore()}),
		"checks typed array %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Array(&MyArray{42}, td.ArrayEntries{1: 58, 2: td.Ignore()}),
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Array(&MyArray{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()}),
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Array((*MyArray)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()}),
		"checks pointer on typed array %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func ArrayEach 

func ArrayEach(expectedValue interface{}) TestDeep

ArrayEach operator has to be applied on arrays or slices or on pointers on array/slice. It compares each item of data array/slice against "expectedValue". During a match, all items have to match to succeed. 

got := [3]string{"foo", "bar", "biz"}
td.Cmp(t, got, td.ArrayEach(td.Len(3)))         // succeeds
td.Cmp(t, got, td.ArrayEach(td.HasPrefix("b"))) // fails coz "foo"

Works on slices as well: 

got := []Person{
  {Name: "Bob", Age: 42},
  {Name: "Alice", Age: 24},
}
td.Cmp(t, got, td.ArrayEach(
  td.Struct(Person{}, td.StructFields{
    Age: td.Between(20, 45),
  })),
) // succeeds, each Person has Age field between 20 and 45
Example (Array) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := [3]int{42, 58, 26}

	ok := td.Cmp(t, got, td.ArrayEach(td.Between(25, 60)),
		"checks each item of array %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{42, 58, 26}

	ok := td.Cmp(t, got, td.ArrayEach(td.Between(25, 60)),
		"checks each item of slice %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedArray) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyArray [3]int

	got := MyArray{42, 58, 26}

	ok := td.Cmp(t, got, td.ArrayEach(td.Between(25, 60)),
		"checks each item of typed array %v is in [25 .. 60]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got, td.ArrayEach(td.Between(25, 60)),
		"checks each item of typed array pointer %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
true
Example (TypedSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	got := MySlice{42, 58, 26}

	ok := td.Cmp(t, got, td.ArrayEach(td.Between(25, 60)),
		"checks each item of typed slice %v is in [25 .. 60]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got, td.ArrayEach(td.Between(25, 60)),
		"checks each item of typed slice pointer %v is in [25 .. 60]", got)
	fmt.Println(ok)

}

Output:

true
true

func Bag 

func Bag(expectedItems ...interface{}) TestDeep

Bag operator compares the contents of an array or a slice (or a pointer on array/slice) without taking care of the order of items.

During a match, each expected item should match in the compared array/slice, and each array/slice item should be matched by an expected item to succeed. 

td.Cmp(t, []int{1, 1, 2}, td.Bag(1, 1, 2))    // succeeds
td.Cmp(t, []int{1, 1, 2}, td.Bag(1, 2, 1))    // succeeds
td.Cmp(t, []int{1, 1, 2}, td.Bag(2, 1, 1))    // succeeds
td.Cmp(t, []int{1, 1, 2}, td.Bag(1, 2))       // fails, one 1 is missing
td.Cmp(t, []int{1, 1, 2}, td.Bag(1, 2, 1, 3)) // fails, 3 is missing

// works with slices/arrays of any type
td.Cmp(t, personSlice, td.Bag(
  Person{Name: "Bob", Age: 32},
  Person{Name: "Alice", Age: 26},
))

To flatten a non-[]interface{} slice/array, use Flatten function and so avoid boring and inefficient copies: 

expected := []int{1, 2, 1}
td.Cmp(t, []int{1, 1, 2}, td.Bag(td.Flatten(expected))) // succeeds
// = td.Cmp(t, []int{1, 1, 2}, td.Bag(1, 2, 1))

exp1 := []int{5, 1, 1}
exp2 := []int{8, 42, 3}
td.Cmp(t, []int{1, 5, 1, 8, 42, 3, 3},
  td.Bag(td.Flatten(exp1), 3, td.Flatten(exp2))) // succeeds
// = td.Cmp(t, []int{1, 5, 1, 8, 42, 3, 3}, td.Bag(5, 1, 1, 3, 8, 42, 3))
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are present
	ok := td.Cmp(t, got, td.Bag(1, 1, 2, 3, 5, 8, 8),
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Does not match as got contains 2 times 1 and 8, and these
	// duplicates are not expected
	ok = td.Cmp(t, got, td.Bag(1, 2, 3, 5, 8),
		"checks all items are present, in any order")
	fmt.Println(ok)

	got = []int{1, 3, 5, 8, 2}

	// Duplicates of 1 and 8 are expected but not present in got
	ok = td.Cmp(t, got, td.Bag(1, 1, 2, 3, 5, 8, 8),
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Matches as all items are present
	ok = td.Cmp(t, got, td.Bag(1, 2, 3, 5, td.Gt(7)),
		"checks all items are present, in any order")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5}
	ok = td.Cmp(t, got, td.Bag(td.Flatten(expected), td.Gt(7)),
		"checks all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
false
false
true
true

func Between 

func Between(from, to interface{}, bounds ...BoundsKind) TestDeep

Between operator checks that data is between "from" and "to". "from" and "to" can be any numeric, string or time.Time (or assignable) value. "from" and "to" must be the same kind as the compared value if numeric, and the same type if string or time.Time (or assignable). "bounds" allows to specify whether bounds are included or not:

  • BoundsInIn (default): between "from" and "to" both included
  • BoundsInOut: between "from" included and "to" excluded
  • BoundsOutIn: between "from" excluded and "to" included
  • BoundsOutOut: between "from" and "to" both excluded

If "bounds" is missing, it defaults to BoundsInIn. 

tc.Cmp(t, 17, td.Between(17, 20))               // succeeds, BoundsInIn by default
tc.Cmp(t, 17, td.Between(10, 17, BoundsInOut))  // fails
tc.Cmp(t, 17, td.Between(10, 17, BoundsOutIn))  // succeeds
tc.Cmp(t, 17, td.Between(17, 20, BoundsOutOut)) // fails

TypeBehind method returns the reflect.Type of "from" (same as the "to" one.)

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.Cmp(t, got, td.Between(154, 156),
		"checks %v is in [154 .. 156]", got)
	fmt.Println(ok)

	// BoundsInIn is implicit
	ok = td.Cmp(t, got, td.Between(154, 156, td.BoundsInIn),
		"checks %v is in [154 .. 156]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Between(154, 156, td.BoundsInOut),
		"checks %v is in [154 .. 156[", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Between(154, 156, td.BoundsOutIn),
		"checks %v is in ]154 .. 156]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Between(154, 156, td.BoundsOutOut),
		"checks %v is in ]154 .. 156[", got)
	fmt.Println(ok)

}

Output:

true
true
false
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.Cmp(t, got, td.Between("aaa", "abc"),
		`checks "%v" is in ["aaa" .. "abc"]`, got)
	fmt.Println(ok)

	// BoundsInIn is implicit
	ok = td.Cmp(t, got, td.Between("aaa", "abc", td.BoundsInIn),
		`checks "%v" is in ["aaa" .. "abc"]`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Between("aaa", "abc", td.BoundsInOut),
		`checks "%v" is in ["aaa" .. "abc"[`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Between("aaa", "abc", td.BoundsOutIn),
		`checks "%v" is in ]"aaa" .. "abc"]`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Between("aaa", "abc", td.BoundsOutOut),
		`checks "%v" is in ]"aaa" .. "abc"[`, got)
	fmt.Println(ok)

}

Output:

true
true
false
true
false

func Cap 

func Cap(expectedCap interface{}) TestDeep

Cap is a smuggler operator. It takes data, applies cap() function on it and compares its result to "expectedCap". Of course, the compared value must be an array, a channel or a slice.

"expectedCap" can be an int value: 

td.Cmp(t, gotSlice, td.Cap(12))

as well as an other operator: 

td.Cmp(t, gotSlice, td.Cap(td.Between(3, 4)))
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := make([]int, 0, 12)

	ok := td.Cmp(t, got, td.Cap(12), "checks %v capacity is 12", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Cap(0), "checks %v capacity is 0", got)
	fmt.Println(ok)

	got = nil

	ok = td.Cmp(t, got, td.Cap(0), "checks %v capacity is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true
Example (Operator) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := make([]int, 0, 12)

	ok := td.Cmp(t, got, td.Cap(td.Between(10, 12)),
		"checks %v capacity is in [10 .. 12]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Cap(td.Gt(10)),
		"checks %v capacity is in [10 .. 12]", got)
	fmt.Println(ok)

}

Output:

true
true

func Catch 

func Catch(target, expectedValue interface{}) TestDeep

Catch is a smuggler operator. It allows to copy data in "target" on the fly before comparing it as usual against "expectedValue".

"target" must be a non-nil pointer and data should be assignable to its pointed type. If BeLax config flag is true or called under Lax (and so JSON) operator, data should be convertible to its pointer type. 

var id int64
if td.Cmp(t, CreateRecord("test"),
  td.JSON(`{"id": $1, "name": "test"}`, td.Catch(&id, td.NotZero()))) {
  t.Logf("Created record ID is %d", id)
}

It is really useful when used with JSON operator and/or tdhttp helper. 

var id int64
ta := tdhttp.NewTestAPI(t, api.Handler).
  PostJSON("/item", `{"name":"foo"}`).
  CmpStatus(http.StatusCreated).
  CmpJSONBody(td.JSON(`{"id": $1, "name": "foo"}`, td.Catch(&id, td.Gt(0))))
if !ta.Failed() {
  t.Logf("Created record ID is %d", id)
}

If you need to only catch data without comparing it, use Ignore operator as "expectedValue" as in: 

var id int64
if td.Cmp(t, CreateRecord("test"),
  td.JSON(`{"id": $1, "name": "test"}`, td.Catch(&id, td.Ignore()))) {
  t.Logf("Created record ID is %d", id)
}
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob",
		Age:      42,
	}

	var age int
	ok := td.Cmp(t, got,
		td.JSON(`{"age":$1,"fullname":"Bob"}`,
			td.Catch(&age, td.Between(40, 45))))
	fmt.Println("check got age+fullname:", ok)
	fmt.Println("caught age:", age)

}

Output:

check got age+fullname: true
caught age: 42

func Code 

func Code(fn interface{}) TestDeep

Code operator allows to check data using a custom function. So "fn" is a function that must take one parameter whose type must be the same as the type of the compared value.

"fn" can return a single bool kind value, telling that yes or no the custom test is successful: 

td.Cmp(t, gotTime,
  td.Code(func(date time.Time) bool {
    return date.Year() == 2018
  }))

or two values (bool, string) kinds. The bool value has the same meaning as above, and the string value is used to describe the test when it fails: 

td.Cmp(t, gotTime,
  td.Code(func(date time.Time) (bool, string) {
    if date.Year() == 2018 {
      return true, ""
    }
    return false, "year must be 2018"
  }))

or a single error value. If the returned error is nil, the test succeeded, else the error contains the reason of failure: 

td.Cmp(t, gotJsonRawMesg,
  td.Code(func(b json.RawMessage) error {
    var c map[string]int
    err := json.Unmarshal(b, &c)
    if err != nil {
      return err
    }
    if c["test"] != 42 {
      return fmt.Errorf(`key "test" does not match 42`)
    }
    return nil
  }))

This operator allows to handle any specific comparison not handled by standard operators.

It is not recommended to call Cmp (or any other Cmp* functions or *T methods) inside the body of "fn", because of confusion produced by output in case of failure. When the data needs to be transformed before being compared again, Smuggle operator should be used instead.

TypeBehind method returns the reflect.Type of only parameter of "fn".

Example 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "12"

	ok := td.Cmp(t, got,
		td.Code(func(num string) bool {
			n, err := strconv.Atoi(num)
			return err == nil && n > 10 && n < 100
		}),
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

	// Same with failure reason
	ok = td.Cmp(t, got,
		td.Code(func(num string) (bool, string) {
			n, err := strconv.Atoi(num)
			if err != nil {
				return false, "not a number"
			}
			if n > 10 && n < 100 {
				return true, ""
			}
			return false, "not in ]10 .. 100["
		}),
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

	// Same with failure reason thanks to error
	ok = td.Cmp(t, got,
		td.Code(func(num string) error {
			n, err := strconv.Atoi(num)
			if err != nil {
				return err
			}
			if n > 10 && n < 100 {
				return nil
			}
			return fmt.Errorf("%d not in ]10 .. 100[", n)
		}),
		"checks string `%s` contains a number and this number is in ]10 .. 100[",
		got)
	fmt.Println(ok)

}

Output:

true
true
true

func Contains 

func Contains(expectedValue interface{}) TestDeep

Contains is a smuggler operator to check if something is contained in another thing. Contains has to be applied on arrays, slices, maps or strings. It tries to be as smarter as possible.

If "expectedValue" is a TestDeep operator, each item of data array/slice/map/string (rune for strings) is compared to it. The use of a TestDeep operator as "expectedValue" works only in this way: item per item.

If data is a slice, and "expectedValue" has the same type, then "expectedValue" is searched as a sub-slice, otherwise "expectedValue" is compared to each slice value. 

list := []int{12, 34, 28}
td.Cmp(t, list, td.Contains(34))                 // succeeds
td.Cmp(t, list, td.Contains(td.Between(30, 35))) // succeeds too
td.Cmp(t, list, td.Contains(35))                 // fails
td.Cmp(t, list, td.Contains([]int{34, 28}))      // succeeds

If data is an array or a map, each value is compared to "expectedValue". Map keys are not checked: see ContainsKey to check map keys existence. 

hash := map[string]int{"foo": 12, "bar": 34, "zip": 28}
td.Cmp(t, hash, td.Contains(34))                 // succeeds
td.Cmp(t, hash, td.Contains(td.Between(30, 35))) // succeeds too
td.Cmp(t, hash, td.Contains(35))                 // fails

array := [...]int{12, 34, 28}
td.Cmp(t, array, td.Contains(34))                 // succeeds
td.Cmp(t, array, td.Contains(td.Between(30, 35))) // succeeds too
td.Cmp(t, array, td.Contains(35))                 // fails

If data is a string (or convertible), []byte (or convertible), error or fmt.Stringer interface (error interface is tested before fmt.Stringer), "expectedValue" can be a string, a []byte, a rune or a byte. In this case, it tests if the got string contains this expected string, []byte, rune or byte. 

got := "foo bar"
td.Cmp(t, got, td.Contains('o'))                  // succeeds
td.Cmp(t, got, td.Contains(rune('o')))            // succeeds
td.Cmp(t, got, td.Contains(td.Between('n', 'p'))) // succeeds
td.Cmp(t, got, td.Contains("bar"))                // succeeds
td.Cmp(t, got, td.Contains([]byte("bar")))        // succeeds

td.Cmp(t, []byte("foobar"), td.Contains("ooba")) // succeeds

type Foobar string
td.Cmp(t, Foobar("foobar"), td.Contains("ooba")) // succeeds

err := errors.New("error!")
td.Cmp(t, err, td.Contains("ror")) // succeeds

bstr := bytes.NewBufferString("fmt.Stringer!")
td.Cmp(t, bstr, td.Contains("String")) // succeeds

Pitfall: if you want to check if 2 words are contained in got, don't do: 

td.Cmp(t, "foobar", td.Contains(td.All("foo", "bar"))) // Bad!

as TestDeep operator All in Contains operates on each rune, so it does not work as expected, but do:: 

td.Cmp(t, "foobar", td.All(td.Contains("foo"), td.Contains("bar")))

When Contains(nil) is used, nil is automatically converted to a typed nil on the fly to avoid confusion (if the array/slice/map item type allows it of course.) So all following Cmp calls are equivalent (except the (*byte)(nil) one): 

num := 123
list := []*int{&num, nil}
td.Cmp(t, list, td.Contains(nil))         // succeeds → (*int)(nil)
td.Cmp(t, list, td.Contains((*int)(nil))) // succeeds
td.Cmp(t, list, td.Contains(td.Nil()))    // succeeds
// But...
td.Cmp(t, list, td.Contains((*byte)(nil))) // fails: (*byte)(nil) ≠ (*int)(nil)

As well as these ones: 

hash := map[string]*int{"foo": nil, "bar": &num}
td.Cmp(t, hash, td.Contains(nil))         // succeeds → (*int)(nil)
td.Cmp(t, hash, td.Contains((*int)(nil))) // succeeds
td.Cmp(t, hash, td.Contains(td.Nil()))    // succeeds
Example (ArraySlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t, [...]int{11, 22, 33, 44}, td.Contains(22))
	fmt.Println("array contains 22:", ok)

	ok = td.Cmp(t, [...]int{11, 22, 33, 44}, td.Contains(td.Between(20, 25)))
	fmt.Println("array contains at least one item in [20 .. 25]:", ok)

	ok = td.Cmp(t, []int{11, 22, 33, 44}, td.Contains(22))
	fmt.Println("slice contains 22:", ok)

	ok = td.Cmp(t, []int{11, 22, 33, 44}, td.Contains(td.Between(20, 25)))
	fmt.Println("slice contains at least one item in [20 .. 25]:", ok)

	ok = td.Cmp(t, []int{11, 22, 33, 44}, td.Contains([]int{22, 33}))
	fmt.Println("slice contains the sub-slice [22, 33]:", ok)

}

Output:

array contains 22: true
array contains at least one item in [20 .. 25]: true
slice contains 22: true
slice contains at least one item in [20 .. 25]: true
slice contains the sub-slice [22, 33]: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.Cmp(t, got, td.Contains("oob"), "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = td.Cmp(t, got, td.Contains('b'), "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = td.Cmp(t, got, td.Contains(byte('a')), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = td.Cmp(t, got, td.Contains(td.Between('n', 'p')), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true
Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t,
		map[string]int{"foo": 11, "bar": 22, "zip": 33}, td.Contains(22))
	fmt.Println("map contains value 22:", ok)

	ok = td.Cmp(t,
		map[string]int{"foo": 11, "bar": 22, "zip": 33},
		td.Contains(td.Between(20, 25)))
	fmt.Println("map contains at least one value in [20 .. 25]:", ok)

}

Output:

map contains value 22: true
map contains at least one value in [20 .. 25]: true
Example (Nil) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	num := 123
	got := [...]*int{&num, nil}

	ok := td.Cmp(t, got, td.Contains(nil))
	fmt.Println("array contains untyped nil:", ok)

	ok = td.Cmp(t, got, td.Contains((*int)(nil)))
	fmt.Println("array contains *int nil:", ok)

	ok = td.Cmp(t, got, td.Contains(td.Nil()))
	fmt.Println("array contains Nil():", ok)

	ok = td.Cmp(t, got, td.Contains((*byte)(nil)))
	fmt.Println("array contains *byte nil:", ok) // types differ: *byte ≠ *int

}

Output:

array contains untyped nil: true
array contains *int nil: true
array contains Nil(): true
array contains *byte nil: false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.Cmp(t, got, td.Contains("oob"), "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = td.Cmp(t, got, td.Contains([]byte("oob")), "checks %s", got)
	fmt.Println("contains `oob` []byte:", ok)

	ok = td.Cmp(t, got, td.Contains('b'), "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = td.Cmp(t, got, td.Contains(byte('a')), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = td.Cmp(t, got, td.Contains(td.Between('n', 'p')), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains `oob` []byte: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.Cmp(t, got, td.Contains("oob"), "checks %s", got)
	fmt.Println("contains `oob` string:", ok)

	ok = td.Cmp(t, got, td.Contains('b'), "checks %s", got)
	fmt.Println("contains 'b' rune:", ok)

	ok = td.Cmp(t, got, td.Contains(byte('a')), "checks %s", got)
	fmt.Println("contains 'a' byte:", ok)

	ok = td.Cmp(t, got, td.Contains(td.Between('n', 'p')), "checks %s", got)
	fmt.Println("contains at least one character ['n' .. 'p']:", ok)

}

Output:

contains `oob` string: true
contains 'b' rune: true
contains 'a' byte: true
contains at least one character ['n' .. 'p']: true

func ContainsKey 

func ContainsKey(expectedValue interface{}) TestDeep

ContainsKey is a smuggler operator and works on maps only. It compares each key of map against "expectedValue". 

hash := map[string]int{"foo": 12, "bar": 34, "zip": 28}
td.Cmp(t, hash, td.ContainsKey("foo"))             // succeeds
td.Cmp(t, hash, td.ContainsKey(td.HasPrefix("z"))) // succeeds
td.Cmp(t, hash, td.ContainsKey(td.HasPrefix("x"))) // fails

hnum := map[int]string{1: "foo", 42: "bar"}
td.Cmp(t, hash, td.ContainsKey(42))                 // succeeds
td.Cmp(t, hash, td.ContainsKey(td.Between(40, 45))) // succeeds

When ContainsKey(nil) is used, nil is automatically converted to a typed nil on the fly to avoid confusion (if the map key type allows it of course.) So all following Cmp calls are equivalent (except the (*byte)(nil) one): 

num := 123
hnum := map[*int]bool{&num: true, nil: true}
td.Cmp(t, hnum, td.ContainsKey(nil))         // succeeds → (*int)(nil)
td.Cmp(t, hnum, td.ContainsKey((*int)(nil))) // succeeds
td.Cmp(t, hnum, td.ContainsKey(td.Nil()))    // succeeds
// But...
td.Cmp(t, hnum, td.ContainsKey((*byte)(nil))) // fails: (*byte)(nil) ≠ (*int)(nil)
Example 
package main

import (
	"fmt"
	"strings"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t,
		map[string]int{"foo": 11, "bar": 22, "zip": 33}, td.ContainsKey("foo"))
	fmt.Println(`map contains key "foo":`, ok)

	ok = td.Cmp(t,
		map[int]bool{12: true, 24: false, 42: true, 51: false},
		td.ContainsKey(td.Between(40, 50)))
	fmt.Println("map contains at least a key in [40 .. 50]:", ok)

	ok = td.Cmp(t,
		map[string]int{"FOO": 11, "bar": 22, "zip": 33},
		td.ContainsKey(td.Smuggle(strings.ToLower, "foo")))
	fmt.Println(`map contains key "foo" without taking case into account:`, ok)

}

Output:

map contains key "foo": true
map contains at least a key in [40 .. 50]: true
map contains key "foo" without taking case into account: true
Example (Nil) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	num := 1234
	got := map[*int]bool{&num: false, nil: true}

	ok := td.Cmp(t, got, td.ContainsKey(nil))
	fmt.Println("map contains untyped nil key:", ok)

	ok = td.Cmp(t, got, td.ContainsKey((*int)(nil)))
	fmt.Println("map contains *int nil key:", ok)

	ok = td.Cmp(t, got, td.ContainsKey(td.Nil()))
	fmt.Println("map contains Nil() key:", ok)

	ok = td.Cmp(t, got, td.ContainsKey((*byte)(nil)))
	fmt.Println("map contains *byte nil key:", ok) // types differ: *byte ≠ *int

}

Output:

map contains untyped nil key: true
map contains *int nil key: true
map contains Nil() key: true
map contains *byte nil key: false

func Delay added in v1.4.0 

func Delay(delayed func() TestDeep) TestDeep

Delay operator allows to delay the construction of an operator to the time it is used for the first time. Most of the time, it is used with helpers. See the example for a very simple use case.

Example 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	cmpNow := func(expected td.TestDeep) bool {
		time.Sleep(time.Microsecond) // imagine a DB insert returning a CreatedAt
		return td.Cmp(t, time.Now(), expected)
	}

	before := time.Now()

	ok := cmpNow(td.Between(before, time.Now()))
	fmt.Println("Between called before compare:", ok)

	ok = cmpNow(td.Delay(func() td.TestDeep {
		return td.Between(before, time.Now())
	}))
	fmt.Println("Between delayed until compare:", ok)

}

Output:

Between called before compare: false
Between delayed until compare: true

func Empty 

func Empty() TestDeep

Empty operator checks that an array, a channel, a map, a slice or a string is empty. As a special case (non-typed) nil, as well as nil channel, map or slice are considered empty.

Note that the compared data can be a pointer (of pointer of pointer etc.) on an array, a channel, a map, a slice or a string. 

td.Cmp(t, "", td.Empty())                // succeeds
td.Cmp(t, map[string]bool{}, td.Empty()) // succeeds
td.Cmp(t, []string{"foo"}, td.Empty())   // fails
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t, nil, td.Empty()) // special case: nil is considered empty
	fmt.Println(ok)

	// fails, typed nil is not empty (expect for channel, map, slice or
	// pointers on array, channel, map slice and strings)
	ok = td.Cmp(t, (*int)(nil), td.Empty())
	fmt.Println(ok)

	ok = td.Cmp(t, "", td.Empty())
	fmt.Println(ok)

	// Fails as 0 is a number, so not empty. Use Zero() instead
	ok = td.Cmp(t, 0, td.Empty())
	fmt.Println(ok)

	ok = td.Cmp(t, (map[string]int)(nil), td.Empty())
	fmt.Println(ok)

	ok = td.Cmp(t, map[string]int{}, td.Empty())
	fmt.Println(ok)

	ok = td.Cmp(t, ([]int)(nil), td.Empty())
	fmt.Println(ok)

	ok = td.Cmp(t, []int{}, td.Empty())
	fmt.Println(ok)

	ok = td.Cmp(t, []int{3}, td.Empty()) // fails, as not empty
	fmt.Println(ok)

	ok = td.Cmp(t, [3]int{}, td.Empty()) // fails, Empty() is not Zero()!
	fmt.Println(ok)

}

Output:

true
false
true
false
true
true
true
true
false
false
Example (Pointers) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	ok := td.Cmp(t, MySlice{}, td.Empty()) // Ptr() not needed
	fmt.Println(ok)

	ok = td.Cmp(t, &MySlice{}, td.Empty())
	fmt.Println(ok)

	l1 := &MySlice{}
	l2 := &l1
	l3 := &l2
	ok = td.Cmp(t, &l3, td.Empty())
	fmt.Println(ok)

	// Works the same for array, map, channel and string

	// But not for others types as:
	type MyStruct struct {
		Value int
	}

	ok = td.Cmp(t, &MyStruct{}, td.Empty()) // fails, use Zero() instead
	fmt.Println(ok)

}

Output:

true
true
true
false

func Gt 

func Gt(minExpectedValue interface{}) TestDeep

Gt operator checks that data is greater than "minExpectedValue". "minExpectedValue" can be any numeric or time.Time (or assignable) value. "minExpectedValue" must be the same kind as the compared value if numeric, and the same type if time.Time (or assignable). 

td.Cmp(t, 17, td.Gt(15))
before := time.Now()
td.Cmp(t, time.Now(), td.Gt(before))

TypeBehind method returns the reflect.Type of "minExpectedValue".

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.Cmp(t, got, td.Gt(155), "checks %v is > 155", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Gt(156), "checks %v is > 156", got)
	fmt.Println(ok)

}

Output:

true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.Cmp(t, got, td.Gt("abb"), `checks "%v" is > "abb"`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Gt("abc"), `checks "%v" is > "abc"`, got)
	fmt.Println(ok)

}

Output:

true
false

func Gte 

func Gte(minExpectedValue interface{}) TestDeep

Gte operator checks that data is greater or equal than "minExpectedValue". "minExpectedValue" can be any numeric or time.Time (or assignable) value. "minExpectedValue" must be the same kind as the compared value if numeric, and the same type if time.Time (or assignable). 

td.Cmp(t, 17, td.Gte(17))
before := time.Now()
td.Cmp(t, time.Now(), td.Gte(before))

TypeBehind method returns the reflect.Type of "minExpectedValue".

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.Cmp(t, got, td.Gte(156), "checks %v is ≥ 156", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Gte(155), "checks %v is ≥ 155", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Gte(157), "checks %v is ≥ 157", got)
	fmt.Println(ok)

}

Output:

true
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.Cmp(t, got, td.Gte("abc"), `checks "%v" is ≥ "abc"`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Gte("abb"), `checks "%v" is ≥ "abb"`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Gte("abd"), `checks "%v" is ≥ "abd"`, got)
	fmt.Println(ok)

}

Output:

true
true
false

func HasPrefix 

func HasPrefix(expected string) TestDeep

HasPrefix operator allows to compare the prefix of a string (or convertible), []byte (or convertible), error or fmt.Stringer interface (error interface is tested before fmt.Stringer). 

td.Cmp(t, []byte("foobar"), td.HasPrefix("foo")) // succeeds

type Foobar string
td.Cmp(t, Foobar("foobar"), td.HasPrefix("foo")) // succeeds

err := errors.New("error!")
td.Cmp(t, err, td.HasPrefix("err")) // succeeds

bstr := bytes.NewBufferString("fmt.Stringer!")
td.Cmp(t, bstr, td.HasPrefix("fmt")) // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.Cmp(t, got, td.HasPrefix("foo"), "checks %s", got)
	fmt.Println("using string:", ok)

	ok = td.Cmp(t, []byte(got), td.HasPrefix("foo"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.Cmp(t, got, td.HasPrefix("foo"), "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.Cmp(t, got, td.HasPrefix("foo"), "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func HasSuffix 

func HasSuffix(expected string) TestDeep

HasSuffix operator allows to compare the suffix of a string (or convertible), []byte (or convertible), error or fmt.Stringer interface (error interface is tested before fmt.Stringer). 

td.Cmp(t, []byte("foobar"), td.HasSuffix("bar")) // succeeds

type Foobar string
td.Cmp(t, Foobar("foobar"), td.HasSuffix("bar")) // succeeds

err := errors.New("error!")
td.Cmp(t, err, td.HasSuffix("!")) // succeeds

bstr := bytes.NewBufferString("fmt.Stringer!")
td.Cmp(t, bstr, td.HasSuffix("!")) // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.Cmp(t, got, td.HasSuffix("bar"), "checks %s", got)
	fmt.Println("using string:", ok)

	ok = td.Cmp(t, []byte(got), td.HasSuffix("bar"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.Cmp(t, got, td.HasSuffix("bar"), "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.Cmp(t, got, td.HasSuffix("bar"), "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func Ignore 

func Ignore() TestDeep

Ignore operator is always true, whatever data is. It is useful when comparing a slice with Slice and wanting to ignore some indexes, for example. Or comparing a struct with SStruct and wanting to ignore some fields: 

td.Cmp(t, td.SStruct(
  Person{
    Name: "John Doe",
  },
  td.StructFields{
    Age:      td.Between(40, 45),
    Children: td.Ignore(),
  }),
)
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t, []int{1, 2, 3},
		td.Slice([]int{}, td.ArrayEntries{
			0: 1,
			1: td.Ignore(), // do not care about this entry
			2: 3,
		}))
	fmt.Println(ok)

}

Output:

true

func Isa 

func Isa(model interface{}) TestDeep

Isa operator checks the data type or whether data implements an interface or not.

Typical type checks: 

td.Cmp(t, time.Now(), td.Isa(time.Time{}))  // succeeds
td.Cmp(t, time.Now(), td.Isa(&time.Time{})) // fails, as not a *time.Time
td.Cmp(t, got, td.Isa(map[string]time.Time{}))

For interfaces, it is a bit more complicated, as: 

fmt.Stringer(nil)

is not an interface, but just nil… To bypass this golang limitation, Isa accepts pointers on interfaces. So checking that data implements fmt.Stringer interface should be written as: 

td.Cmp(t, bytes.Buffer{}, td.Isa((*fmt.Stringer)(nil))) // succeeds

Of course, in the latter case, if checked data type is *fmt.Stringer, Isa will match too (in fact before checking whether it implements fmt.Stringer or not).

TypeBehind method returns the reflect.Type of "model".

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type TstStruct struct {
		Field int
	}

	got := TstStruct{Field: 1}

	ok := td.Cmp(t, got, td.Isa(TstStruct{}), "checks got is a TstStruct")
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Isa(&TstStruct{}),
		"checks got is a pointer on a TstStruct")
	fmt.Println(ok)

	ok = td.Cmp(t, &got, td.Isa(&TstStruct{}),
		"checks &got is a pointer on a TstStruct")
	fmt.Println(ok)

}

Output:

true
false
true
Example (Interface) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := bytes.NewBufferString("foobar")

	ok := td.Cmp(t, got, td.Isa((*fmt.Stringer)(nil)),
		"checks got implements fmt.Stringer interface")
	fmt.Println(ok)

	errGot := fmt.Errorf("An error #%d occurred", 123)

	ok = td.Cmp(t, errGot, td.Isa((*error)(nil)),
		"checks errGot is a *error or implements error interface")
	fmt.Println(ok)

	// As nil, is passed below, it is not an interface but nil… So it
	// does not match
	errGot = nil

	ok = td.Cmp(t, errGot, td.Isa((*error)(nil)),
		"checks errGot is a *error or implements error interface")
	fmt.Println(ok)

	// BUT if its address is passed, now it is OK as the types match
	ok = td.Cmp(t, &errGot, td.Isa((*error)(nil)),
		"checks &errGot is a *error or implements error interface")
	fmt.Println(ok)

}

Output:

true
true
false
true

func JSON 

func JSON(expectedJSON interface{}, params ...interface{}) TestDeep

JSON operator allows to compare the JSON representation of data against "expectedJSON". "expectedJSON" can be a:

  • string containing JSON data like `{"fullname":"Bob","age":42}`
  • string containing a JSON filename, ending with ".json" (its content is ioutil.ReadFile before unmarshaling)
  • []byte containing JSON data
  • io.Reader stream containing JSON data (is ioutil.ReadAll before unmarshaling)

"expectedJSON" JSON value can contain placeholders. The "params" are for any placeholder parameters in "expectedJSON". "params" can contain TestDeep operators as well as raw values. Raw values, that do not contain TestDeep operators deeply nested, are first json.Marshal'ed then json.Unmarshal'ed in an interface{}. A placeholder can be numeric like $2 or named like $name and always references an item in "params".

Numeric placeholders reference the n'th "operators" item (starting at 1). Named placeholders are used with Tag operator as follows: 

td.Cmp(t, gotValue,
  td.JSON(`{"fullname": $name, "age": $2, "gender": $3}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43),                  // matches only $2
    "male"))                             // matches only $3

Note that placeholders can be double-quoted as in: 

td.Cmp(t, gotValue,
  td.JSON(`{"fullname": "$name", "age": "$2", "gender": "$3"}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43),                  // matches only $2
    "male"))                             // matches only $3

It makes no difference whatever the underlying type of the replaced item is (= double quoting a placeholder matching a number is not a problem). It is just a matter of taste, double-quoting placeholders can be preferred when the JSON data has to conform to the JSON specification, like when used in a ".json" file.

Note "expectedJSON" can be a []byte, JSON filename or io.Reader: 

td.Cmp(t, gotValue, td.JSON("file.json", td.Between(12, 34)))
td.Cmp(t, gotValue, td.JSON([]byte(`[1, $1, 3]`), td.Between(12, 34)))
td.Cmp(t, gotValue, td.JSON(osFile, td.Between(12, 34)))

A JSON filename ends with ".json".

To avoid a legit "$" string prefix causes a bad placeholder error, just double it to escape it. Note it is only needed when the "$" is the first character of a string: 

td.Cmp(t, gotValue,
  td.JSON(`{"fullname": "$name", "details": "$$info", "age": $2}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43)))                 // matches only $2

For the "details" key, the raw value "$info" is expected, no placeholders are involved here.

Note that Lax mode is automatically enabled by JSON operator to simplify numeric tests.

Comments can be embedded in JSON data: 

td.Cmp(t, gotValue,
  td.JSON(`
{
  // A guy properties:
  "fullname": "$name",  // The full name of the guy
  "details":  "$$info", // Literally "$info", thanks to "$" escape
  "age":      $2        /* The age of the guy:
                           - placeholder unquoted, but could be without
                             any change
                           - to demonstrate a multi-lines comment */
}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43)))                 // matches only $2

Comments, like in go, have 2 forms. To quote the Go language specification:

  • line comments start with the character sequence // and stop at the end of the line.
  • multi-lines comments start with the character sequence /* and stop with the first subsequent character sequence */.

Most operators can be directly embedded in JSON without requiring any placeholder. 

td.Cmp(t, gotValue,
  td.JSON(`
{
  "fullname": HasPrefix("Foo"),
  "age":      Between(41, 43),
  "details":  SuperMapOf({
    "address": NotEmpty(),
    "car":     Any("Peugeot", "Tesla", "Jeep") // any of these
  })
}`))

Placeholders can be used anywhere, even in operators parameters as in: 

td.Cmp(t, gotValue, td.JSON(`{"fullname": HasPrefix($1)}`, "Zip"))

A few notes about operators embedding:

  • SubMapOf and SuperMapOf take only one parameter, a JSON object;
  • the optional 3rd parameter of Between has to be specified as a string and can be: "[]" or "BoundsInIn" (default), "[[" or "BoundsInOut", "]]" or "BoundsOutIn", "][" or "BoundsOutOut";
  • not all operators are embeddable only the following are;
  • All, Any, ArrayEach, Bag, Between, Contains, ContainsKey, Empty, Gt, Gte, HasPrefix, HasSuffix, Ignore, JSONPointer, Keys, Len, Lt, Lte, MapEach, N, NaN, Nil, None, Not, NotAny, NotEmpty, NotNaN, NotNil, NotZero, Re, ReAll, Set, SubBagOf, SubMapOf, SubSetOf, SuperBagOf, SuperMapOf, SuperSetOf, Values and Zero.

Operators taking no parameters can also be directly embedded in JSON data using $^OperatorName or "$^OperatorName" notation. They are named shortcut operators (they predate the above operators embedding but they subsist for compatibility): 

td.Cmp(t, gotValue, td.JSON(`{"id": $1}`, td.NotZero()))

can be written as: 

td.Cmp(t, gotValue, td.JSON(`{"id": $^NotZero}`))

or 

td.Cmp(t, gotValue, td.JSON(`{"id": "$^NotZero"}`))

As for placeholders, there is no differences between $^NotZero and "$^NotZero".

The allowed shortcut operators follow:

  • Empty → $^Empty
  • Ignore → $^Ignore
  • NaN → $^NaN
  • Nil → $^Nil
  • NotEmpty → $^NotEmpty
  • NotNaN → $^NotNaN
  • NotNil → $^NotNil
  • NotZero → $^NotZero
  • Zero → $^Zero

TypeBehind method returns the reflect.Type of the "expectedJSON" json.Unmarshal'ed. So it can be bool, string, float64, []interface{}, map[string]interface{} or interface{} in case "expectedJSON" is "null".

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob",
		Age:      42,
	}

	ok := td.Cmp(t, got, td.JSON(`{"age":42,"fullname":"Bob"}`))
	fmt.Println("check got with age then fullname:", ok)

	ok = td.Cmp(t, got, td.JSON(`{"fullname":"Bob","age":42}`))
	fmt.Println("check got with fullname then age:", ok)

	ok = td.Cmp(t, got, td.JSON(`
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42     /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
}`))
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = td.Cmp(t, got, td.JSON(`{"fullname":"Bob","age":42,"gender":"male"}`))
	fmt.Println("check got with gender field:", ok)

	ok = td.Cmp(t, got, td.JSON(`{"fullname":"Bob"}`))
	fmt.Println("check got with fullname only:", ok)

	ok = td.Cmp(t, true, td.JSON(`true`))
	fmt.Println("check boolean got is true:", ok)

	ok = td.Cmp(t, 42, td.JSON(`42`))
	fmt.Println("check numeric got is 42:", ok)

	got = nil
	ok = td.Cmp(t, got, td.JSON(`null`))
	fmt.Println("check nil got is null:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got with gender field: false
check got with fullname only: false
check boolean got is true: true
check numeric got is 42: true
check nil got is null: true
Example (Embedding) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := td.Cmp(t, got, td.JSON(`{"age": NotZero(), "fullname": NotEmpty()}`))
	fmt.Println("check got with simple operators:", ok)

	ok = td.Cmp(t, got, td.JSON(`{"age": $^NotZero, "fullname": $^NotEmpty}`))
	fmt.Println("check got with operator shortcuts:", ok)

	ok = td.Cmp(t, got, td.JSON(`
{
  "age":      Between(40, 42, "]]"), // in ]40; 42]
  "fullname": All(
    HasPrefix("Bob"),
    HasSuffix("bar")  // ← comma is optional here
  )
}`))
	fmt.Println("check got with complex operators:", ok)

	ok = td.Cmp(t, got, td.JSON(`
{
  "age":      Between(40, 42, "]["), // in ]40; 42[ → 42 excluded
  "fullname": All(
    HasPrefix("Bob"),
    HasSuffix("bar"),
  )
}`))
	fmt.Println("check got with complex operators:", ok)

}

Output:

check got with simple operators: true
check got with operator shortcuts: true
check got with complex operators: true
check got with complex operators: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender"
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := td.Cmp(t, got,
		td.JSON(filename,
			td.Tag("name", td.HasPrefix("Bob")),
			td.Tag("age", td.Between(40, 45)),
			td.Tag("gender", td.Re(`^(male|female)\z`))))
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = td.Cmp(t, got,
		td.JSON(file,
			td.Tag("name", td.HasPrefix("Bob")),
			td.Tag("age", td.Between(40, 45)),
			td.Tag("gender", td.Re(`^(male|female)\z`))))
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := td.Cmp(t, got, td.JSON(`{"age": $1, "fullname": $2}`, 42, "Bob Foobar"))
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = td.Cmp(t, got,
		td.JSON(`{"age": $1, "fullname": $2}`,
			td.Between(40, 45),
			td.HasSuffix("Foobar")))
	fmt.Println("check got with numeric placeholders:", ok)

	ok = td.Cmp(t, got,
		td.JSON(`{"age": "$1", "fullname": "$2"}`,
			td.Between(40, 45),
			td.HasSuffix("Foobar")))
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = td.Cmp(t, got,
		td.JSON(`{"age": $age, "fullname": $name}`,
			td.Tag("age", td.Between(40, 45)),
			td.Tag("name", td.HasSuffix("Foobar"))))
	fmt.Println("check got with named placeholders:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true

func JSONPointer added in v1.8.0 

func JSONPointer(pointer string, expectedValue interface{}) TestDeep

JSONPointer is a smuggler operator. It takes the JSON representation of data, gets the value corresponding to the JSON pointer "pointer" (as RFC 6901 specifies it) and compares it to "expectedValue".

JSONPointer does its best to convert back the JSON pointed data to the type of "expectedValue" or to the type behind the "expectedValue" operator, if it is an operator. Allowing to do things like: 

type Item struct {
  Val  int   `json:"val"`
  Next *Item `json:"next"`
}
got := Item{Val: 1, Next: &Item{Val: 2, Next: &Item{Val: 3}}}

td.Cmp(t, got, td.JSONPointer("/next/next", Item{Val: 3}))
td.Cmp(t, got, td.JSONPointer("/next/next", &Item{Val: 3}))
td.Cmp(t,
  got,
  td.JSONPointer("/next/next",
    td.Struct(Item{}, td.StructFields{"Val": td.Gte(3)})),
)

It does this conversion only if the expected type is a struct, a struct pointer or implements the encoding/json.Unmarshaler interface. In the case the conversion does not occur, the Lax mode is automatically enabled to simplify numeric tests. 

got := map[string]int64{"zzz": 42} // 42 is int64 here
td.Cmp(t, got, td.JSONPointer("/zzz", 42))
td.Cmp(t, got, td.JSONPointer("/zzz", td.Between(40, 45)))

Note that as any TestDeep operator can be used as "expectedValue", JSON operator works out of the box: 

got := json.RawMessage(`{"foo":{"bar": {"zip": true}}}`)
td.Cmp(t, got, td.JSONPointer("/foo/bar", td.JSON(`{"zip": true}`)))

It can be used with structs lacking json tags. In this case, fields names have to be used in JSON pointer: 

type Item struct {
  Val  int
  Next *Item
}
got := Item{Val: 1, Next: &Item{Val: 2, Next: &Item{Val: 3}}}

td.Cmp(t, got, td.JSONPointer("/Next/Next", Item{Val: 3}))

Contrary to Smuggle operator and its field-path feature, only public fields can be followed, as private ones are never (un)marshalled.

There is no JSONHas nor JSONHasnt operators to only check a JSON pointer exists or not, but they can easily be emulated: 

JSONHas := func(pointer string) td.TestDeep {
  return td.JSONPointer(pointer, td.Ignore())
}

JSONHasnt := func(pointer string) td.TestDeep {
  return td.Not(td.JSONPointer(pointer, td.Ignore()))
}

TypeBehind method always returns nil as the expected type cannot be guessed from a JSON pointer.

Example (Has_hasnt) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := json.RawMessage(`
{
  "name": "Bob",
  "age": 42,
  "children": [
    {
      "name": "Alice",
      "age": 16
    },
    {
      "name": "Britt",
      "age": 21,
      "children": [
        {
          "name": "John",
          "age": 1
        }
      ]
    }
  ]
}`)

	// Has Bob some children?
	ok := td.Cmp(t, got, td.JSONPointer("/children", td.Len(td.Gt(0))))
	fmt.Println("Bob has at least one child:", ok)

	// But checking "children" exists is enough here
	ok = td.Cmp(t, got, td.JSONPointer("/children/0/children", td.Ignore()))
	fmt.Println("Alice has children:", ok)

	ok = td.Cmp(t, got, td.JSONPointer("/children/1/children", td.Ignore()))
	fmt.Println("Britt has children:", ok)

	// The reverse can be checked too
	ok = td.Cmp(t, got, td.Not(td.JSONPointer("/children/0/children", td.Ignore())))
	fmt.Println("Alice hasn't children:", ok)

	ok = td.Cmp(t, got, td.Not(td.JSONPointer("/children/1/children", td.Ignore())))
	fmt.Println("Britt hasn't children:", ok)

}

Output:

Bob has at least one child: true
Alice has children: false
Britt has children: true
Alice hasn't children: true
Britt hasn't children: false
Example (Rfc6901) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := json.RawMessage(`
{
   "foo":  ["bar", "baz"],
   "":     0,
   "a/b":  1,
   "c%d":  2,
   "e^f":  3,
   "g|h":  4,
   "i\\j": 5,
   "k\"l": 6,
   " ":    7,
   "m~n":  8
}`)

	expected := map[string]interface{}{
		"foo": []interface{}{"bar", "baz"},
		"":    0,
		"a/b": 1,
		"c%d": 2,
		"e^f": 3,
		"g|h": 4,
		`i\j`: 5,
		`k"l`: 6,
		" ":   7,
		"m~n": 8,
	}
	ok := td.Cmp(t, got, td.JSONPointer("", expected))
	fmt.Println("Empty JSON pointer means all:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/foo`, []interface{}{"bar", "baz"}))
	fmt.Println("Extract `foo` key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/foo/0`, "bar"))
	fmt.Println("First item of `foo` key slice:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/`, 0))
	fmt.Println("Empty key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/a~1b`, 1))
	fmt.Println("Slash has to be escaped using `~1`:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/c%d`, 2))
	fmt.Println("% in key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/e^f`, 3))
	fmt.Println("^ in key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/g|h`, 4))
	fmt.Println("| in key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/i\j`, 5))
	fmt.Println("Backslash in key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/k"l`, 6))
	fmt.Println("Double-quote in key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/ `, 7))
	fmt.Println("Space key:", ok)

	ok = td.Cmp(t, got, td.JSONPointer(`/m~0n`, 8))
	fmt.Println("Tilde has to be escaped using `~0`:", ok)

}

Output:

Empty JSON pointer means all: true
Extract `foo` key: true
First item of `foo` key slice: true
Empty key: true
Slash has to be escaped using `~1`: true
% in key: true
^ in key: true
| in key: true
Backslash in key: true
Double-quote in key: true
Space key: true
Tilde has to be escaped using `~0`: true
Example (Struct) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// Without json tags, encoding/json uses public fields name
	type Item struct {
		Name  string
		Value int64
		Next  *Item
	}

	got := Item{
		Name:  "first",
		Value: 1,
		Next: &Item{
			Name:  "second",
			Value: 2,
			Next: &Item{
				Name:  "third",
				Value: 3,
			},
		},
	}

	ok := td.Cmp(t, got, td.JSONPointer("/Next/Next/Name", "third"))
	fmt.Println("3rd item name is `third`:", ok)

	ok = td.Cmp(t, got, td.JSONPointer("/Next/Next/Value", td.Gte(int64(3))))
	fmt.Println("3rd item value is greater or equal than 3:", ok)

	ok = td.Cmp(t, got,
		td.JSONPointer("/Next",
			td.JSONPointer("/Next",
				td.JSONPointer("/Value", td.Gte(int64(3))))))
	fmt.Println("3rd item value is still greater or equal than 3:", ok)

	ok = td.Cmp(t, got, td.JSONPointer("/Next/Next/Next/Name", td.Ignore()))
	fmt.Println("4th item exists and has a name:", ok)

	// Struct comparison work with or without pointer: &Item{…} works too
	ok = td.Cmp(t, got, td.JSONPointer("/Next/Next", Item{
		Name:  "third",
		Value: 3,
	}))
	fmt.Println("3rd item full comparison:", ok)

}

Output:

3rd item name is `third`: true
3rd item value is greater or equal than 3: true
3rd item value is still greater or equal than 3: true
4th item exists and has a name: false
3rd item full comparison: true

func Keys 

func Keys(val interface{}) TestDeep

Keys is a smuggler operator. It takes a map and compares its ordered keys to "val".

"val" can be a slice of items of the same type as the map keys: 

got := map[string]bool{"c": true, "a": false, "b": true}
td.Cmp(t, got, td.Keys([]string{"a", "b", "c"})) // succeeds, keys sorted
td.Cmp(t, got, td.Keys([]string{"c", "a", "b"})) // fails as not sorted

as well as an other operator as Bag, for example, to test keys in an unsorted manner: 

got := map[string]bool{"c": true, "a": false, "b": true}
td.Cmp(t, got, td.Keys(td.Bag("c", "a", "b"))) // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 1, "bar": 2, "zip": 3}

	// Keys tests keys in an ordered manner
	ok := td.Cmp(t, got, td.Keys([]string{"bar", "foo", "zip"}))
	fmt.Println("All sorted keys are found:", ok)

	// If the expected keys are not ordered, it fails
	ok = td.Cmp(t, got, td.Keys([]string{"zip", "bar", "foo"}))
	fmt.Println("All unsorted keys are found:", ok)

	// To circumvent that, one can use Bag operator
	ok = td.Cmp(t, got, td.Keys(td.Bag("zip", "bar", "foo")))
	fmt.Println("All unsorted keys are found, with the help of Bag operator:", ok)

	// Check that each key is 3 bytes long
	ok = td.Cmp(t, got, td.Keys(td.ArrayEach(td.Len(3))))
	fmt.Println("Each key is 3 bytes long:", ok)

}

Output:

All sorted keys are found: true
All unsorted keys are found: false
All unsorted keys are found, with the help of Bag operator: true
Each key is 3 bytes long: true

func Lax 

func Lax(expectedValue interface{}) TestDeep

Lax is a smuggler operator, it temporarily enables the BeLax config flag before letting the comparison process continue its course.

It is more commonly used as CmpLax function than as an operator. It could be used when, for example, an operator is constructed once but applied to different, but compatible types as in: 

bw := td.Between(20, 30)
intValue := 21
floatValue := 21.89
td.Cmp(t, intValue, bw)           // no need to be lax here: same int types
td.Cmp(t, floatValue, td.Lax(bw)) // be lax please, as float64 ≠ int

Note that in the latter case, CmpLax() could be used as well: 

td.CmpLax(t, floatValue, bw)

TypeBehind method returns the greatest convertible or more common reflect.Type of "expectedValue" if it is a base type (bool, int*, uint*, float*, complex*, string), the reflect.Type of "expectedValue" otherwise, except if "expectedValue" is a TestDeep operator. In this case, it delegates TypeBehind() to the operator.

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	gotInt64 := int64(1234)
	gotInt32 := int32(1235)

	type myInt uint16
	gotMyInt := myInt(1236)

	expected := td.Between(1230, 1240) // int type here

	ok := td.Cmp(t, gotInt64, td.Lax(expected))
	fmt.Println("int64 got between ints [1230 .. 1240]:", ok)

	ok = td.Cmp(t, gotInt32, td.Lax(expected))
	fmt.Println("int32 got between ints [1230 .. 1240]:", ok)

	ok = td.Cmp(t, gotMyInt, td.Lax(expected))
	fmt.Println("myInt got between ints [1230 .. 1240]:", ok)

}

Output:

int64 got between ints [1230 .. 1240]: true
int32 got between ints [1230 .. 1240]: true
myInt got between ints [1230 .. 1240]: true

func Len 

func Len(expectedLen interface{}) TestDeep

Len is a smuggler operator. It takes data, applies len() function on it and compares its result to "expectedLen". Of course, the compared value must be an array, a channel, a map, a slice or a string.

"expectedLen" can be an int value: 

td.Cmp(t, gotSlice, td.Len(12))

as well as an other operator: 

td.Cmp(t, gotSlice, td.Len(td.Between(3, 4)))
Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[int]bool{11: true, 22: false, 33: false}

	ok := td.Cmp(t, got, td.Len(3), "checks %v len is 3", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
	fmt.Println(ok)

	got = nil

	ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true
Example (OperatorMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[int]bool{11: true, 22: false, 33: false}

	ok := td.Cmp(t, got, td.Len(td.Between(3, 8)),
		"checks %v len is in [3 .. 8]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Len(td.Gte(3)), "checks %v len is ≥ 3", got)
	fmt.Println(ok)

}

Output:

true
true
Example (OperatorSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{11, 22, 33}

	ok := td.Cmp(t, got, td.Len(td.Between(3, 8)),
		"checks %v len is in [3 .. 8]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Len(td.Lt(5)), "checks %v len is < 5", got)
	fmt.Println(ok)

}

Output:

true
true
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{11, 22, 33}

	ok := td.Cmp(t, got, td.Len(3), "checks %v len is 3", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
	fmt.Println(ok)

	got = nil

	ok = td.Cmp(t, got, td.Len(0), "checks %v len is 0", got)
	fmt.Println(ok)

}

Output:

true
false
true

func Lt 

func Lt(maxExpectedValue interface{}) TestDeep

Lt operator checks that data is lesser than "maxExpectedValue". "maxExpectedValue" can be any numeric or time.Time (or assignable) value. "maxExpectedValue" must be the same kind as the compared value if numeric, and the same type if time.Time (or assignable). 

td.Cmp(t, 17, td.Lt(19))
before := time.Now()
td.Cmp(t, before, td.Lt(time.Now()))

TypeBehind method returns the reflect.Type of "maxExpectedValue".

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.Cmp(t, got, td.Lt(157), "checks %v is < 157", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Lt(156), "checks %v is < 156", got)
	fmt.Println(ok)

}

Output:

true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.Cmp(t, got, td.Lt("abd"), `checks "%v" is < "abd"`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Lt("abc"), `checks "%v" is < "abc"`, got)
	fmt.Println(ok)

}

Output:

true
false

func Lte 

func Lte(maxExpectedValue interface{}) TestDeep

Lte operator checks that data is lesser or equal than "maxExpectedValue". "maxExpectedValue" can be any numeric or time.Time (or assignable) value. "maxExpectedValue" must be the same kind as the compared value if numeric, and the same type if time.Time (or assignable). 

td.Cmp(t, 17, td.Lte(17))
before := time.Now()
td.Cmp(t, before, td.Lt(time.Now()))

TypeBehind method returns the reflect.Type of "maxExpectedValue".

Example (Int) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 156

	ok := td.Cmp(t, got, td.Lte(156), "checks %v is ≤ 156", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Lte(157), "checks %v is ≤ 157", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Lte(155), "checks %v is ≤ 155", got)
	fmt.Println(ok)

}

Output:

true
true
false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "abc"

	ok := td.Cmp(t, got, td.Lte("abc"), `checks "%v" is ≤ "abc"`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Lte("abd"), `checks "%v" is ≤ "abd"`, got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Lte("abb"), `checks "%v" is ≤ "abb"`, got)
	fmt.Println(ok)

}

Output:

true
true
false

func Map 

func Map(model interface{}, expectedEntries MapEntries) TestDeep

Map operator compares the contents of a map against the non-zero values of "model" (if any) and the values of "expectedEntries".

"model" must be the same type as compared data.

"expectedEntries" can be nil, if no zero entries are expected and no TestDeep operator are involved.

During a match, all expected entries must be found and all data entries must be expected to succeed. 

got := map[string]string{
  "foo": "test",
  "bar": "wizz",
  "zip": "buzz",
}
td.Cmp(t, got, td.Map(
  map[string]string{
    "foo": "test",
    "bar": "wizz",
  },
  td.MapEntries{
    "zip": td.HasSuffix("zz"),
  }),
) // succeeds

TypeBehind method returns the reflect.Type of "model".

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := td.Cmp(t, got,
		td.Map(map[string]int{"bar": 42},
			td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()}),
		"checks map %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got,
		td.Map(map[string]int{},
			td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()}),
		"checks map %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got,
		td.Map((map[string]int)(nil),
			td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()}),
		"checks map %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := td.Cmp(t, got,
		td.Map(MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()}),
		"checks typed map %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Map(&MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": td.Ignore()}),
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Map(&MyMap{}, td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()}),
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Map((*MyMap)(nil), td.MapEntries{"bar": 42, "foo": td.Lt(15), "zip": td.Ignore()}),
		"checks pointer on typed map %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func MapEach 

func MapEach(expectedValue interface{}) TestDeep

MapEach operator has to be applied on maps. It compares each value of data map against expected value. During a match, all values have to match to succeed. 

got := map[string]string{"test": "foo", "buzz": "bar"}
td.Cmp(t, got, td.MapEach("bar"))     // fails, coz "foo" ≠ "bar"
td.Cmp(t, got, td.MapEach(td.Len(3))) // succeeds as values are 3 chars long
Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := td.Cmp(t, got, td.MapEach(td.Between(10, 90)),
		"checks each value of map %v is in [10 .. 90]", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := td.Cmp(t, got, td.MapEach(td.Between(10, 90)),
		"checks each value of typed map %v is in [10 .. 90]", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got, td.MapEach(td.Between(10, 90)),
		"checks each value of typed map pointer %v is in [10 .. 90]", got)
	fmt.Println(ok)

}

Output:

true
true

func N 

func N(num interface{}, tolerance ...interface{}) TestDeep

N operator compares a numeric data against "num" ± "tolerance". If "tolerance" is missing, it defaults to 0. "num" and "tolerance" must be the same kind as the compared value. 

td.Cmp(t, 12.2, td.N(12., 0.3)) // succeeds
td.Cmp(t, 12.2, td.N(12., 0.1)) // fails

TypeBehind method returns the reflect.Type of "num".

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 1.12345

	ok := td.Cmp(t, got, td.N(1.1234, 0.00006),
		"checks %v = 1.1234 ± 0.00006", got)
	fmt.Println(ok)

}

Output:

true

func NaN 

func NaN() TestDeep

NaN operator checks that data is a float and is not-a-number. 

got := math.NaN()
td.Cmp(t, got, td.NaN()) // succeeds
td.Cmp(t, 4.2, td.NaN()) // fails
Example (Float32) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := float32(math.NaN())

	ok := td.Cmp(t, got, td.NaN(),
		"checks %v is not-a-number", got)

	fmt.Println("float32(math.NaN()) is float32 not-a-number:", ok)

	got = 12

	ok = td.Cmp(t, got, td.NaN(),
		"checks %v is not-a-number", got)

	fmt.Println("float32(12) is float32 not-a-number:", ok)

}

Output:

float32(math.NaN()) is float32 not-a-number: true
float32(12) is float32 not-a-number: false
Example (Float64) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := math.NaN()

	ok := td.Cmp(t, got, td.NaN(),
		"checks %v is not-a-number", got)

	fmt.Println("math.NaN() is not-a-number:", ok)

	got = 12

	ok = td.Cmp(t, got, td.NaN(),
		"checks %v is not-a-number", got)

	fmt.Println("float64(12) is not-a-number:", ok)

	// math.NaN() is not-a-number: true
	// float64(12) is not-a-number: false
}

Output:

func Nil 

func Nil() TestDeep

Nil operator checks that data is nil (or is a non-nil interface, but containing a nil pointer.) 

var got *int
td.Cmp(t, got, td.Nil())    // succeeds
td.Cmp(t, got, nil)         // fails as (*int)(nil) ≠ untyped nil
td.Cmp(t, got, (*int)(nil)) // succeeds

but: 

var got fmt.Stringer = (*bytes.Buffer)(nil)
td.Cmp(t, got, td.Nil()) // succeeds
td.Cmp(t, got, nil)      // fails, as the interface is not nil
got = nil
td.Cmp(t, got, nil) // succeeds
Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	var got fmt.Stringer // interface

	// nil value can be compared directly with nil, no need of Nil() here
	ok := td.Cmp(t, got, nil)
	fmt.Println(ok)

	// But it works with Nil() anyway
	ok = td.Cmp(t, got, td.Nil())
	fmt.Println(ok)

	got = (*bytes.Buffer)(nil)

	// In the case of an interface containing a nil pointer, comparing
	// with nil fails, as the interface is not nil
	ok = td.Cmp(t, got, nil)
	fmt.Println(ok)

	// In this case Nil() succeed
	ok = td.Cmp(t, got, td.Nil())
	fmt.Println(ok)

}

Output:

true
true
false
true

func None 

func None(notExpectedValues ...interface{}) TestDeep

None operator compares data against several not expected values. During a match, none of them have to match to succeed. 

td.Cmp(t, 12, td.None(8, 10, 14))     // succeeds
td.Cmp(t, 12, td.None(8, 10, 12, 14)) // fails

Note Flatten function can be used to group or reuse some values or operators and so avoid boring and inefficient copies: 

prime := td.Flatten([]int{1, 2, 3, 5, 7, 11, 13})
even := td.Flatten([]int{2, 4, 6, 8, 10, 12, 14})
td.Cmp(t, 9, td.None(prime, even)) // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 18

	ok := td.Cmp(t, got, td.None(0, 10, 20, 30, td.Between(100, 199)),
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	got = 20

	ok = td.Cmp(t, got, td.None(0, 10, 20, 30, td.Between(100, 199)),
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	got = 142

	ok = td.Cmp(t, got, td.None(0, 10, 20, 30, td.Between(100, 199)),
		"checks %v is non-null, and ≠ 10, 20 & 30, and not in [100-199]", got)
	fmt.Println(ok)

	prime := td.Flatten([]int{1, 2, 3, 5, 7, 11, 13})
	even := td.Flatten([]int{2, 4, 6, 8, 10, 12, 14})
	for _, got := range [...]int{9, 3, 8, 15} {
		ok = td.Cmp(t, got, td.None(prime, even, td.Gt(14)),
			"checks %v is not prime number, nor an even number and not > 14")
		fmt.Printf("%d → %t\n", got, ok)
	}

}

Output:

true
false
false
9 → true
3 → false
8 → false
15 → false

func Not 

func Not(notExpected interface{}) TestDeep

Not operator compares data against the not expected value. During a match, it must not match to succeed.

Not is the same operator as None() with only one argument. It is provided as a more readable function when only one argument is needed. 

td.Cmp(t, 12, td.Not(10)) // succeeds
td.Cmp(t, 12, td.Not(12)) // fails
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 42

	ok := td.Cmp(t, got, td.Not(0), "checks %v is non-null", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.Not(td.Between(10, 30)),
		"checks %v is not in [10 .. 30]", got)
	fmt.Println(ok)

	got = 0

	ok = td.Cmp(t, got, td.Not(0), "checks %v is non-null", got)
	fmt.Println(ok)

}

Output:

true
true
false

func NotAny 

func NotAny(notExpectedItems ...interface{}) TestDeep

NotAny operator checks that the contents of an array or a slice (or a pointer on array/slice) does not contain any of "notExpectedItems". 

td.Cmp(t, []int{1}, td.NotAny(1, 2, 3)) // fails
td.Cmp(t, []int{5}, td.NotAny(1, 2, 3)) // succeeds

// works with slices/arrays of any type
td.Cmp(t, personSlice, td.NotAny(
  Person{Name: "Bob", Age: 32},
  Person{Name: "Alice", Age: 26},
))

To flatten a non-[]interface{} slice/array, use Flatten function and so avoid boring and inefficient copies: 

notExpected := []int{2, 1}
td.Cmp(t, []int{4, 4, 3, 8}, td.NotAny(td.Flatten(notExpected))) // succeeds
// = td.Cmp(t, []int{4, 4, 3, 8}, td.NotAny(2, 1))

notExp1 := []int{2, 1}
notExp2 := []int{5, 8}
td.Cmp(t, []int{4, 4, 42, 8},
  td.NotAny(td.Flatten(notExp1), 3, td.Flatten(notExp2))) // succeeds
// = td.Cmp(t, []int{4, 4, 42, 8}, td.NotAny(2, 1, 3, 5, 8))

Beware that NotAny(…) is not equivalent to Not(Any(…)) but is like Not(SuperSet(…)).

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{4, 5, 9, 42}

	ok := td.Cmp(t, got, td.NotAny(3, 6, 8, 41, 43),
		"checks %v contains no item listed in NotAny()", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.NotAny(3, 6, 8, 42, 43),
		"checks %v contains no item listed in NotAny()", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using notExpected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	notExpected := []int{3, 6, 8, 41, 43}
	ok = td.Cmp(t, got, td.NotAny(td.Flatten(notExpected)),
		"checks %v contains no item listed in notExpected", got)
	fmt.Println(ok)

}

Output:

true
false
true

func NotEmpty 

func NotEmpty() TestDeep

NotEmpty operator checks that an array, a channel, a map, a slice or a string is not empty. As a special case (non-typed) nil, as well as nil channel, map or slice are considered empty.

Note that the compared data can be a pointer (of pointer of pointer etc.) on an array, a channel, a map, a slice or a string. 

td.Cmp(t, "", td.NotEmpty())                // fails
td.Cmp(t, map[string]bool{}, td.NotEmpty()) // fails
td.Cmp(t, []string{"foo"}, td.NotEmpty())   // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t, nil, td.NotEmpty()) // fails, as nil is considered empty
	fmt.Println(ok)

	ok = td.Cmp(t, "foobar", td.NotEmpty())
	fmt.Println(ok)

	// Fails as 0 is a number, so not empty. Use NotZero() instead
	ok = td.Cmp(t, 0, td.NotEmpty())
	fmt.Println(ok)

	ok = td.Cmp(t, map[string]int{"foobar": 42}, td.NotEmpty())
	fmt.Println(ok)

	ok = td.Cmp(t, []int{1}, td.NotEmpty())
	fmt.Println(ok)

	ok = td.Cmp(t, [3]int{}, td.NotEmpty()) // succeeds, NotEmpty() is not NotZero()!
	fmt.Println(ok)

}

Output:

false
true
false
true
true
true
Example (Pointers) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	ok := td.Cmp(t, MySlice{12}, td.NotEmpty())
	fmt.Println(ok)

	ok = td.Cmp(t, &MySlice{12}, td.NotEmpty()) // Ptr() not needed
	fmt.Println(ok)

	l1 := &MySlice{12}
	l2 := &l1
	l3 := &l2
	ok = td.Cmp(t, &l3, td.NotEmpty())
	fmt.Println(ok)

	// Works the same for array, map, channel and string

	// But not for others types as:
	type MyStruct struct {
		Value int
	}

	ok = td.Cmp(t, &MyStruct{}, td.NotEmpty()) // fails, use NotZero() instead
	fmt.Println(ok)

}

Output:

true
true
true
false

func NotNaN 

func NotNaN() TestDeep

NotNaN operator checks that data is a float and is not not-a-number. 

got := math.NaN()
td.Cmp(t, got, td.NotNaN()) // fails
td.Cmp(t, 4.2, td.NotNaN()) // succeeds
td.Cmp(t, 4, td.NotNaN())   // fails, as 4 is not a float
Example (Float32) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := float32(math.NaN())

	ok := td.Cmp(t, got, td.NotNaN(),
		"checks %v is not-a-number", got)

	fmt.Println("float32(math.NaN()) is NOT float32 not-a-number:", ok)

	got = 12

	ok = td.Cmp(t, got, td.NotNaN(),
		"checks %v is not-a-number", got)

	fmt.Println("float32(12) is NOT float32 not-a-number:", ok)

}

Output:

float32(math.NaN()) is NOT float32 not-a-number: false
float32(12) is NOT float32 not-a-number: true
Example (Float64) 
package main

import (
	"fmt"
	"math"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := math.NaN()

	ok := td.Cmp(t, got, td.NotNaN(),
		"checks %v is not-a-number", got)

	fmt.Println("math.NaN() is not-a-number:", ok)

	got = 12

	ok = td.Cmp(t, got, td.NotNaN(),
		"checks %v is not-a-number", got)

	fmt.Println("float64(12) is not-a-number:", ok)

	// math.NaN() is NOT not-a-number: false
	// float64(12) is NOT not-a-number: true
}

Output:

func NotNil 

func NotNil() TestDeep

NotNil operator checks that data is not nil (or is a non-nil interface, containing a non-nil pointer.) 

got := &Person{}
td.Cmp(t, got, td.NotNil()) // succeeds
td.Cmp(t, got, td.Not(nil)) // succeeds too, but be careful it is first
// because of got type *Person ≠ untyped nil so prefer NotNil()

but: 

var got fmt.Stringer = (*bytes.Buffer)(nil)
td.Cmp(t, got, td.NotNil()) // fails
td.Cmp(t, got, td.Not(nil)) // succeeds, as the interface is not nil
Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	var got fmt.Stringer = &bytes.Buffer{}

	// nil value can be compared directly with Not(nil), no need of NotNil() here
	ok := td.Cmp(t, got, td.Not(nil))
	fmt.Println(ok)

	// But it works with NotNil() anyway
	ok = td.Cmp(t, got, td.NotNil())
	fmt.Println(ok)

	got = (*bytes.Buffer)(nil)

	// In the case of an interface containing a nil pointer, comparing
	// with Not(nil) succeeds, as the interface is not nil
	ok = td.Cmp(t, got, td.Not(nil))
	fmt.Println(ok)

	// In this case NotNil() fails
	ok = td.Cmp(t, got, td.NotNil())
	fmt.Println(ok)

}

Output:

true
true
true
false

func NotZero 

func NotZero() TestDeep

NotZero operator checks that data is not zero regarding its type.

  • nil is the zero value of pointers, maps, slices, channels and functions;
  • 0 is the zero value of numbers;
  • "" is the 0 value of strings;
  • false is the zero value of booleans;
  • zero value of structs is the struct with no fields initialized.

Beware that: 

td.Cmp(t, AnyStruct{}, td.NotZero())          // is false
td.Cmp(t, &AnyStruct{}, td.NotZero())         // is true, coz pointer ≠ nil
td.Cmp(t, &AnyStruct{}, td.Ptr(td.NotZero())) // is false
Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t, 0, td.NotZero()) // fails
	fmt.Println(ok)

	ok = td.Cmp(t, float64(0), td.NotZero()) // fails
	fmt.Println(ok)

	ok = td.Cmp(t, 12, td.NotZero())
	fmt.Println(ok)

	ok = td.Cmp(t, (map[string]int)(nil), td.NotZero()) // fails, as nil
	fmt.Println(ok)

	ok = td.Cmp(t, map[string]int{}, td.NotZero()) // succeeds, as not nil
	fmt.Println(ok)

	ok = td.Cmp(t, ([]int)(nil), td.NotZero()) // fails, as nil
	fmt.Println(ok)

	ok = td.Cmp(t, []int{}, td.NotZero()) // succeeds, as not nil
	fmt.Println(ok)

	ok = td.Cmp(t, [3]int{}, td.NotZero()) // fails
	fmt.Println(ok)

	ok = td.Cmp(t, [3]int{0, 1}, td.NotZero()) // succeeds, DATA[1] is not 0
	fmt.Println(ok)

	ok = td.Cmp(t, bytes.Buffer{}, td.NotZero()) // fails
	fmt.Println(ok)

	ok = td.Cmp(t, &bytes.Buffer{}, td.NotZero()) // succeeds, as pointer not nil
	fmt.Println(ok)

	ok = td.Cmp(t, &bytes.Buffer{}, td.Ptr(td.NotZero())) // fails as deref by Ptr()
	fmt.Println(ok)

}

Output:

false
false
true
false
true
false
true
false
true
false
true
false

func PPtr 

func PPtr(val interface{}) TestDeep

PPtr is a smuggler operator. It takes the address of the address of data and compares it to "val".

"val" depends on data type. For example, if the compared data is an **int, one can have: 

num := 12
pnum = &num
td.Cmp(t, &pnum, td.PPtr(12)) // succeeds

as well as an other operator: 

num := 3
pnum = &num
td.Cmp(t, &pnum, td.PPtr(td.Between(3, 4))) // succeeds

It is more efficient and shorter to write than: 

td.Cmp(t, &pnum, td.Ptr(td.Ptr(val))) // succeeds too

TypeBehind method returns the reflect.Type of a pointer on a pointer on "val", except if "val" is a TestDeep operator. In this case, it delegates TypeBehind() to the operator and returns the reflect.Type of a pointer on a pointer on the returned value (if non-nil of course).

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	num := 12
	got := &num

	ok := td.Cmp(t, &got, td.PPtr(12))
	fmt.Println(ok)

	ok = td.Cmp(t, &got, td.PPtr(td.Between(4, 15)))
	fmt.Println(ok)

}

Output:

true
true

func Ptr 

func Ptr(val interface{}) TestDeep

Ptr is a smuggler operator. It takes the address of data and compares it to "val".

"val" depends on data type. For example, if the compared data is an *int, one can have: 

num := 12
td.Cmp(t, &num, td.Ptr(12)) // succeeds

as well as an other operator: 

num := 3
td.Cmp(t, &num, td.Ptr(td.Between(3, 4)))

TypeBehind method returns the reflect.Type of a pointer on "val", except if "val" is a TestDeep operator. In this case, it delegates TypeBehind() to the operator and returns the reflect.Type of a pointer on the returned value (if non-nil of course).

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := 12

	ok := td.Cmp(t, &got, td.Ptr(12))
	fmt.Println(ok)

	ok = td.Cmp(t, &got, td.Ptr(td.Between(4, 15)))
	fmt.Println(ok)

}

Output:

true
true

func Re 

func Re(reg interface{}, capture ...interface{}) TestDeep

Re operator allows to apply a regexp on a string (or convertible), []byte, error or fmt.Stringer interface (error interface is tested before fmt.Stringer.)

"reg" is the regexp. It can be a string that is automatically compiled using regexp.MustCompile, or a *regexp.Regexp.

Optional "capture" parameter can be used to match the contents of regexp groups. Groups are presented as a []string or [][]byte depending the original matched data. Note that an other operator can be used here. 

td.Cmp(t, "foobar zip!", td.Re(`^foobar`)) // succeeds
td.Cmp(t, "John Doe",
  td.Re(`^(\w+) (\w+)`, []string{"John", "Doe"})) // succeeds
td.Cmp(t, "John Doe",
  td.Re(`^(\w+) (\w+)`, td.Bag("Doe", "John"))) // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo bar"
	ok := td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (Capture) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo bar biz"
	ok := td.Cmp(t, got, td.Re(`^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.Cmp(t, got, td.Re(`^(\w+) (\w+) (\w+)$`, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (Compiled) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := "foo bar"
	ok := td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

	got = "bar foo"
	ok = td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCapture) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile(`^(\w+) (\w+) (\w+)$`)

	got := "foo bar biz"
	ok := td.Cmp(t, got, td.Re(expected, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	got = "foo bar! biz"
	ok = td.Cmp(t, got, td.Re(expected, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledError) 
package main

import (
	"errors"
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	got := errors.New("foo bar")
	ok := td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (CompiledStringer) 
package main

import (
	"bytes"
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile("(zip|bar)$")

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.Cmp(t, got, td.Re(expected), "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foo bar")
	ok := td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foo bar")
	ok := td.Cmp(t, got, td.Re("(zip|bar)$"), "checks value %s", got)
	fmt.Println(ok)

}

Output:

true

func ReAll 

func ReAll(reg, capture interface{}) TestDeep

ReAll operator allows to successively apply a regexp on a string (or convertible), []byte, error or fmt.Stringer interface (error interface is tested before fmt.Stringer) and to match its groups contents.

"reg" is the regexp. It can be a string that is automatically compiled using regexp.MustCompile, or a *regexp.Regexp.

"capture" is used to match the contents of regexp groups. Groups are presented as a []string or [][]byte depending the original matched data. Note that an other operator can be used here. 

td.Cmp(t, "John Doe",
  td.ReAll(`(\w+)(?: |\z)`, []string{"John", "Doe"})) // succeeds
td.Cmp(t, "John Doe",
  td.ReAll(`(\w+)(?: |\z)`, td.Bag("Doe", "John"))) // succeeds
Example (Capture) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foo bar biz"
	ok := td.Cmp(t, got, td.ReAll(`(\w+)`, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but all catured groups do not match Set
	got = "foo BAR biz"
	ok = td.Cmp(t, got, td.ReAll(`(\w+)`, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CaptureComplex) 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "11 45 23 56 85 96"
	ok := td.Cmp(t, got,
		td.ReAll(`(\d+)`, td.ArrayEach(td.Code(func(num string) bool {
			n, err := strconv.Atoi(num)
			return err == nil && n > 10 && n < 100
		}))),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but 11 is not greater than 20
	ok = td.Cmp(t, got,
		td.ReAll(`(\d+)`, td.ArrayEach(td.Code(func(num string) bool {
			n, err := strconv.Atoi(num)
			return err == nil && n > 20 && n < 100
		}))),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCapture) 
package main

import (
	"fmt"
	"regexp"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile(`(\w+)`)

	got := "foo bar biz"
	ok := td.Cmp(t, got, td.ReAll(expected, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but all catured groups do not match Set
	got = "foo BAR biz"
	ok = td.Cmp(t, got, td.ReAll(expected, td.Set("biz", "foo", "bar")),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false
Example (CompiledCaptureComplex) 
package main

import (
	"fmt"
	"regexp"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	expected := regexp.MustCompile(`(\d+)`)

	got := "11 45 23 56 85 96"
	ok := td.Cmp(t, got,
		td.ReAll(expected, td.ArrayEach(td.Code(func(num string) bool {
			n, err := strconv.Atoi(num)
			return err == nil && n > 10 && n < 100
		}))),
		"checks value %s", got)
	fmt.Println(ok)

	// Matches, but 11 is not greater than 20
	ok = td.Cmp(t, got,
		td.ReAll(expected, td.ArrayEach(td.Code(func(num string) bool {
			n, err := strconv.Atoi(num)
			return err == nil && n > 20 && n < 100
		}))),
		"checks value %s", got)
	fmt.Println(ok)

}

Output:

true
false

func SStruct 

func SStruct(model interface{}, expectedFields StructFields) TestDeep

SStruct operator (aka strict-Struct) compares the contents of a struct or a pointer on a struct against values of "model" (if any) and the values of "expectedFields". The zero values are compared too even if they are omitted from "expectedFields": that is the difference with Struct operator.

"model" must be the same type as compared data.

"expectedFields" can be nil, if no TestDeep operators are involved.

To ignore a field, one has to specify it in "expectedFields" and use the Ignore operator. 

td.Cmp(t, td.SStruct(
  Person{
    Name: "John Doe",
  },
  td.StructFields{
    "Age":      td.Between(40, 45),
    "Children": td.Ignore(),
  }),
)

During a match, all expected and zero fields must be found to succeed.

TypeBehind method returns the reflect.Type of "model".

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type Person struct {
		Name        string
		Age         int
		NumChildren int
	}

	got := Person{
		Name:        "Foobar",
		Age:         42,
		NumChildren: 0,
	}

	// NumChildren is not listed in expected fields so it must be zero
	ok := td.Cmp(t, got,
		td.SStruct(Person{Name: "Foobar"}, td.StructFields{
			"Age": td.Between(40, 50),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model can be empty
	got.NumChildren = 3
	ok = td.Cmp(t, got,
		td.SStruct(Person{}, td.StructFields{
			"Name":        "Foobar",
			"Age":         td.Between(40, 50),
			"NumChildren": td.Not(0),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

	// Works with pointers too
	ok = td.Cmp(t, &got,
		td.SStruct(&Person{}, td.StructFields{
			"Name":        "Foobar",
			"Age":         td.Between(40, 50),
			"NumChildren": td.Not(0),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model does not need to be instanciated
	ok = td.Cmp(t, &got,
		td.SStruct((*Person)(nil), td.StructFields{
			"Name":        "Foobar",
			"Age":         td.Between(40, 50),
			"NumChildren": td.Not(0),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

}

Output:

true
true
true
true

func Set 

func Set(expectedItems ...interface{}) TestDeep

Set operator compares the contents of an array or a slice (or a pointer on array/slice) ignoring duplicates and without taking care of the order of items.

During a match, each expected item should match in the compared array/slice, and each array/slice item should be matched by an expected item to succeed. 

td.Cmp(t, []int{1, 1, 2}, td.Set(1, 2))    // succeeds
td.Cmp(t, []int{1, 1, 2}, td.Set(2, 1))    // succeeds
td.Cmp(t, []int{1, 1, 2}, td.Set(1, 2, 3)) // fails, 3 is missing

// works with slices/arrays of any type
td.Cmp(t, personSlice, td.Set(
  Person{Name: "Bob", Age: 32},
  Person{Name: "Alice", Age: 26},
))

To flatten a non-[]interface{} slice/array, use Flatten function and so avoid boring and inefficient copies: 

expected := []int{2, 1}
td.Cmp(t, []int{1, 1, 2}, td.Set(td.Flatten(expected))) // succeeds
// = td.Cmp(t, []int{1, 1, 2}, td.Set(2, 1))

exp1 := []int{2, 1}
exp2 := []int{5, 8}
td.Cmp(t, []int{1, 5, 1, 2, 8, 3, 3},
  td.Set(td.Flatten(exp1), 3, td.Flatten(exp2))) // succeeds
// = td.Cmp(t, []int{1, 5, 1, 2, 8, 3, 3}, td.Set(2, 1, 3, 5, 8))
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are present, ignoring duplicates
	ok := td.Cmp(t, got, td.Set(1, 2, 3, 5, 8),
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Duplicates are ignored in a Set
	ok = td.Cmp(t, got, td.Set(1, 2, 2, 2, 2, 2, 3, 5, 8),
		"checks all items are present, in any order")
	fmt.Println(ok)

	// Tries its best to not raise an error when a value can be matched
	// by several Set entries
	ok = td.Cmp(t, got, td.Set(td.Between(1, 4), 3, td.Between(2, 10)),
		"checks all items are present, in any order")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5, 8}
	ok = td.Cmp(t, got, td.Set(td.Flatten(expected)),
		"checks all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
true
true
true

func Shallow 

func Shallow(expectedPtr interface{}) TestDeep

Shallow operator compares pointers only, not their contents. It applies on channels, functions (with some restrictions), maps, pointers, slices and strings.

During a match, the compared data must be the same as "expectedPtr" to succeed. 

a, b := 123, 123
td.Cmp(t, &a, td.Shallow(&a)) // succeeds
td.Cmp(t, &a, td.Shallow(&b)) // fails even if a == b as &a != &b

back := "foobarfoobar"
a, b := back[:6], back[6:]
// a == b but...
td.Cmp(t, &a, td.Shallow(&b)) // fails

Be careful for slices and strings! Shallow can succeed but the slices/strings not be identical because of their different lengths. For example: 

a := "foobar yes!"
b := a[:1]                    // aka "f"
td.Cmp(t, &a, td.Shallow(&b)) // succeeds as both strings point to the same area, even if len() differ

The same behavior occurs for slices: 

a := []int{1, 2, 3, 4, 5, 6}
b := a[:2]                    // aka []int{1, 2}
td.Cmp(t, &a, td.Shallow(&b)) // succeeds as both slices point to the same area, even if len() differ
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyStruct struct {
		Value int
	}
	data := MyStruct{Value: 12}
	got := &data

	ok := td.Cmp(t, got, td.Shallow(&data),
		"checks pointers only, not contents")
	fmt.Println(ok)

	// Same contents, but not same pointer
	ok = td.Cmp(t, got, td.Shallow(&MyStruct{Value: 12}),
		"checks pointers only, not contents")
	fmt.Println(ok)

}

Output:

true
false
Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	back := []int{1, 2, 3, 1, 2, 3}
	a := back[:3]
	b := back[3:]

	ok := td.Cmp(t, a, td.Shallow(back))
	fmt.Println("are ≠ but share the same area:", ok)

	ok = td.Cmp(t, b, td.Shallow(back))
	fmt.Println("are = but do not point to same area:", ok)

}

Output:

are ≠ but share the same area: true
are = but do not point to same area: false
Example (String) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	back := "foobarfoobar"
	a := back[:6]
	b := back[6:]

	ok := td.Cmp(t, a, td.Shallow(back))
	fmt.Println("are ≠ but share the same area:", ok)

	ok = td.Cmp(t, b, td.Shallow(a))
	fmt.Println("are = but do not point to same area:", ok)

}

Output:

are ≠ but share the same area: true
are = but do not point to same area: false

func Slice 

func Slice(model interface{}, expectedEntries ArrayEntries) TestDeep

Slice operator compares the contents of a slice or a pointer on a slice against the non-zero values of "model" (if any) and the values of "expectedEntries".

"model" must be the same type as compared data.

"expectedEntries" can be nil, if no zero entries are expected and no TestDeep operator are involved. 

got := []int{12, 14, 17}
td.Cmp(t, got, td.Slice([]int{0, 14}, td.ArrayEntries{0: 12, 2: 17})) // succeeds
td.Cmp(t, got,
  td.Slice([]int{0, 14}, td.ArrayEntries{0: td.Gt(10), 2: td.Gt(15)})) // succeeds

TypeBehind method returns the reflect.Type of "model".

Example (Slice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{42, 58, 26}

	ok := td.Cmp(t, got, td.Slice([]int{42}, td.ArrayEntries{1: 58, 2: td.Ignore()}),
		"checks slice %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got,
		td.Slice([]int{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()}),
		"checks slice %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, got,
		td.Slice(([]int)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()}),
		"checks slice %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
Example (TypedSlice) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MySlice []int

	got := MySlice{42, 58, 26}

	ok := td.Cmp(t, got, td.Slice(MySlice{42}, td.ArrayEntries{1: 58, 2: td.Ignore()}),
		"checks typed slice %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got, td.Slice(&MySlice{42}, td.ArrayEntries{1: 58, 2: td.Ignore()}),
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Slice(&MySlice{}, td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()}),
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.Slice((*MySlice)(nil), td.ArrayEntries{0: 42, 1: 58, 2: td.Ignore()}),
		"checks pointer on typed slice %v", got)
	fmt.Println(ok)

}

Output:

true
true
true
true

func Smuggle 

func Smuggle(fn, expectedValue interface{}) TestDeep

Smuggle operator allows to change data contents or mutate it into another type before stepping down in favor of generic comparison process. Of course it is a smuggler operator. So "fn" is a function that must take one parameter whose type must be convertible to the type of the compared value (as a convenient shortcut, "fn" can be a string specifying a fields-path through structs, see below for details).

"fn" must return at least one value. These value will be compared as is to "expectedValue", here integer 28: 

td.Cmp(t, "0028",
  td.Smuggle(func(value string) int {
    num, _ := strconv.Atoi(value)
    return num
  }, 28),
)

or using an other TestDeep operator, here Between(28, 30): 

td.Cmp(t, "0029",
  td.Smuggle(func(value string) int {
    num, _ := strconv.Atoi(value)
    return num
  }, td.Between(28, 30)),
)

"fn" can return a second boolean value, used to tell that a problem occurred and so stop the comparison: 

td.Cmp(t, "0029",
  td.Smuggle(func(value string) (int, bool) {
    num, err := strconv.Atoi(value)
    return num, err == nil
  }, td.Between(28, 30)),
)

"fn" can return a third string value which is used to describe the test when a problem occurred (false second boolean value): 

td.Cmp(t, "0029",
  td.Smuggle(func(value string) (int, bool, string) {
    num, err := strconv.Atoi(value)
    if err != nil {
      return 0, false, "string must contain a number"
    }
    return num, true, ""
  }, td.Between(28, 30)),
)

Instead of returning (X, bool) or (X, bool, string), "fn" can return (X, error). When a problem occurs, the returned error is non-nil, as in: 

td.Cmp(t, "0029",
  td.Smuggle(func(value string) (int, error) {
    num, err := strconv.Atoi(value)
    return num, err
  }, td.Between(28, 30)),
)

Which can be simplified to: 

td.Cmp(t, "0029", td.Smuggle(strconv.Atoi, td.Between(28, 30)))

Imagine you want to compare that the Year of a date is between 2010 and 2020: 

td.Cmp(t, time.Date(2015, time.May, 1, 1, 2, 3, 0, time.UTC),
  td.Smuggle(func(date time.Time) int { return date.Year() },
    td.Between(2010, 2020)),
)

In this case the data location forwarded to next test will be something like "DATA.MyTimeField<smuggled>", but you can act on it too by returning a SmuggledGot struct (by value or by address): 

td.Cmp(t, time.Date(2015, time.May, 1, 1, 2, 3, 0, time.UTC),
  td.Smuggle(func(date time.Time) SmuggledGot {
    return SmuggledGot{
      Name: "Year",
      Got:  date.Year(),
    }
  }, td.Between(2010, 2020)),
)

then the data location forwarded to next test will be something like "DATA.MyTimeField.Year". The "." between the current path (here "DATA.MyTimeField") and the returned Name "Year" is automatically added when Name starts with a Letter.

Note that SmuggledGot and *SmuggledGot returns are treated equally, and they are only used when "fn" has only one returned value or when the second boolean returned value is true.

Of course, all cases can go together: 

// Accepts a "YYYY/mm/DD HH:MM:SS" string to produce a time.Time and tests
// whether this date is contained between 2 hours before now and now.
td.Cmp(t, "2020-01-25 12:13:14",
  td.Smuggle(func(date string) (*SmuggledGot, bool, string) {
    date, err := time.Parse("2006/01/02 15:04:05", date)
    if err != nil {
      return nil, false, `date must conform to "YYYY/mm/DD HH:MM:SS" format`
    }
    return &SmuggledGot{
      Name: "Date",
      Got:  date,
    }, true, ""
  }, td.Between(time.Now().Add(-2*time.Hour), time.Now())),
)

or: 

// Accepts a "YYYY/mm/DD HH:MM:SS" string to produce a time.Time and tests
// whether this date is contained between 2 hours before now and now.
td.Cmp(t, "2020-01-25 12:13:14",
  td.Smuggle(func(date string) (*SmuggledGot, error) {
    date, err := time.Parse("2006/01/02 15:04:05", date)
    if err != nil {
      return nil, err
    }
    return &SmuggledGot{
      Name: "Date",
      Got:  date,
    }, nil
  }, td.Between(time.Now().Add(-2*time.Hour), time.Now())),
)

Smuggle can also be used to access a struct field embedded in several struct layers. 

type A struct{ Num int }
type B struct{ A *A }
type C struct{ B B }
got := C{B: B{A: &A{Num: 12}}}

// Tests that got.B.A.Num is 12
td.Cmp(t, got,
  td.Smuggle(func(c C) int {
    return c.B.A.Num
  }, 12))

As brought up above, a field-path can be passed as "fn" value instead of a function pointer. Using this feature, the Cmp call in the above example can be rewritten as follows: 

// Tests that got.B.A.Num is 12
td.Cmp(t, got, td.Smuggle("B.A.Num", 12))

Contrary to JSONPointer operator, private fields can be followed but not maps nor slices items.

Behind the scenes, a temporary function is automatically created to achieve the same goal, but add some checks against nil values and auto-dereference interfaces and pointers.

The difference between Smuggle and Code operators is that Code is used to do a final comparison while Smuggle transforms the data and then steps down in favor of generic comparison process. Moreover, the type accepted as input for the function is more lax to facilitate the tests writing (e.g. the function can accept a float64 and the got value be an int). See examples. On the other hand, the output type is strict and must match exactly the expected value type. The fields-path string "fn" shortcut is not available with Code operator.

TypeBehind method returns the reflect.Type of only parameter of "fn". For the case where "fn" is a fields-path, it is always interface{}, as the type can not be known in advance.

Example (Auto_unmarshal) 
package main

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// Automatically json.Unmarshal to compare
	got := []byte(`{"a":1,"b":2}`)

	ok := td.Cmp(t, got,
		td.Smuggle(
			func(b json.RawMessage) (r map[string]int, err error) {
				err = json.Unmarshal(b, &r)
				return
			},
			map[string]int{
				"a": 1,
				"b": 2,
			}))
	fmt.Println("JSON contents is OK:", ok)

}

Output:

JSON contents is OK: true
Example (Complex) 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// No end date but a start date and a duration
	type StartDuration struct {
		StartDate time.Time
		Duration  time.Duration
	}

	// Checks that end date is between 17th and 19th February both at 0h
	// for each of these durations in hours

	for _, duration := range []time.Duration{48, 72, 96} {
		got := StartDuration{
			StartDate: time.Date(2018, time.February, 14, 12, 13, 14, 0, time.UTC),
			Duration:  duration * time.Hour,
		}

		// Simplest way, but in case of Between() failure, error will be bound
		// to DATA<smuggled>, not very clear...
		ok := td.Cmp(t, got,
			td.Smuggle(
				func(sd StartDuration) time.Time {
					return sd.StartDate.Add(sd.Duration)
				},
				td.Between(
					time.Date(2018, time.February, 17, 0, 0, 0, 0, time.UTC),
					time.Date(2018, time.February, 19, 0, 0, 0, 0, time.UTC))))
		fmt.Println(ok)

		// Name the computed value "ComputedEndDate" to render a Between() failure
		// more understandable, so error will be bound to DATA.ComputedEndDate
		ok = td.Cmp(t, got,
			td.Smuggle(
				func(sd StartDuration) td.SmuggledGot {
					return td.SmuggledGot{
						Name: "ComputedEndDate",
						Got:  sd.StartDate.Add(sd.Duration),
					}
				},
				td.Between(
					time.Date(2018, time.February, 17, 0, 0, 0, 0, time.UTC),
					time.Date(2018, time.February, 19, 0, 0, 0, 0, time.UTC))))
		fmt.Println(ok)
	}

}

Output:

false
false
true
true
true
true
Example (Convert) 
package main

import (
	"fmt"
	"strconv"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := int64(123)

	ok := td.Cmp(t, got,
		td.Smuggle(func(n int64) int { return int(n) }, 123),
		"checks int64 got against an int value")
	fmt.Println(ok)

	ok = td.Cmp(t, "123",
		td.Smuggle(
			func(numStr string) (int, bool) {
				n, err := strconv.Atoi(numStr)
				return n, err == nil
			},
			td.Between(120, 130)),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	ok = td.Cmp(t, "123",
		td.Smuggle(
			func(numStr string) (int, bool, string) {
				n, err := strconv.Atoi(numStr)
				if err != nil {
					return 0, false, "string must contain a number"
				}
				return n, true, ""
			},
			td.Between(120, 130)),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	ok = td.Cmp(t, "123",
		td.Smuggle(
			func(numStr string) (int, error) { // nolint: gocritic
				return strconv.Atoi(numStr)
			},
			td.Between(120, 130)),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

	// Short version :)
	ok = td.Cmp(t, "123",
		td.Smuggle(strconv.Atoi, td.Between(120, 130)),
		"checks that number in %#v is in [120 .. 130]")
	fmt.Println(ok)

}

Output:

true
true
true
true
true
Example (Field_path) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type Body struct {
		Name  string
		Value interface{}
	}
	type Request struct {
		Body *Body
	}
	type Transaction struct {
		Request
	}
	type ValueNum struct {
		Num int
	}

	got := &Transaction{
		Request: Request{
			Body: &Body{
				Name:  "test",
				Value: &ValueNum{Num: 123},
			},
		},
	}

	// Want to check whether Num is between 100 and 200?
	ok := td.Cmp(t, got,
		td.Smuggle(
			func(t *Transaction) (int, error) {
				if t.Request.Body == nil ||
					t.Request.Body.Value == nil {
					return 0, errors.New("Request.Body or Request.Body.Value is nil")
				}
				if v, ok := t.Request.Body.Value.(*ValueNum); ok && v != nil {
					return v.Num, nil
				}
				return 0, errors.New("Request.Body.Value isn't *ValueNum or nil")
			},
			td.Between(100, 200)))
	fmt.Println("check Num by hand:", ok)

	// Same, but automagically generated...
	ok = td.Cmp(t, got, td.Smuggle("Request.Body.Value.Num", td.Between(100, 200)))
	fmt.Println("check Num using a fields-path:", ok)

	// And as Request is an anonymous field, can be simplified further
	// as it can be omitted
	ok = td.Cmp(t, got, td.Smuggle("Body.Value.Num", td.Between(100, 200)))
	fmt.Println("check Num using an other fields-path:", ok)

}

Output:

check Num by hand: true
check Num using a fields-path: true
check Num using an other fields-path: true
Example (Interface) 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	gotTime, err := time.Parse(time.RFC3339, "2018-05-23T12:13:14Z")
	if err != nil {
		t.Fatal(err)
	}

	// Do not check the struct itself, but its stringified form
	ok := td.Cmp(t, gotTime,
		td.Smuggle(func(s fmt.Stringer) string {
			return s.String()
		},
			"2018-05-23 12:13:14 +0000 UTC"))
	fmt.Println("stringified time.Time OK:", ok)

	// If got does not implement the fmt.Stringer interface, it fails
	// without calling the Smuggle func
	type MyTime time.Time
	ok = td.Cmp(t, MyTime(gotTime),
		td.Smuggle(func(s fmt.Stringer) string {
			fmt.Println("Smuggle func called!")
			return s.String()
		},
			"2018-05-23 12:13:14 +0000 UTC"))
	fmt.Println("stringified MyTime OK:", ok)

	// Output
	// stringified time.Time OK: true
	// stringified MyTime OK: false
}

Output:
Example (Lax) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// got is an int16 and Smuggle func input is an int64: it is OK
	got := int(123)

	ok := td.Cmp(t, got,
		td.Smuggle(func(n int64) uint32 { return uint32(n) }, uint32(123)))
	fmt.Println("got int16(123) → smuggle via int64 → uint32(123):", ok)

}

Output:

got int16(123) → smuggle via int64 → uint32(123): true

func String 

func String(expected string) TestDeep

String operator allows to compare a string (or convertible), []byte (or convertible), error or fmt.Stringer interface (error interface is tested before fmt.Stringer). 

err := errors.New("error!")
td.Cmp(t, err, td.String("error!")) // succeeds

bstr := bytes.NewBufferString("fmt.Stringer!")
td.Cmp(t, bstr, td.String("fmt.Stringer!")) // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := "foobar"

	ok := td.Cmp(t, got, td.String("foobar"), "checks %s", got)
	fmt.Println("using string:", ok)

	ok = td.Cmp(t, []byte(got), td.String("foobar"), "checks %s", got)
	fmt.Println("using []byte:", ok)

}

Output:

using string: true
using []byte: true
Example (Error) 
package main

import (
	"errors"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := errors.New("foobar")

	ok := td.Cmp(t, got, td.String("foobar"), "checks %s", got)
	fmt.Println(ok)

}

Output:

true
Example (Stringer) 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	// bytes.Buffer implements fmt.Stringer
	got := bytes.NewBufferString("foobar")

	ok := td.Cmp(t, got, td.String("foobar"), "checks %s", got)
	fmt.Println(ok)

}

Output:

true

func Struct 

func Struct(model interface{}, expectedFields StructFields) TestDeep

Struct operator compares the contents of a struct or a pointer on a struct against the non-zero values of "model" (if any) and the values of "expectedFields". See SStruct to compares against zero fields without specifying them in "expectedFields".

"model" must be the same type as compared data.

"expectedFields" can be nil, if no zero entries are expected and no TestDeep operators are involved. 

td.Cmp(t, td.Struct(
  Person{
    Name: "John Doe",
  },
  td.StructFields{
    "Age":      td.Between(40, 45),
    "Children": 0,
  }),
)

During a match, all expected fields must be found to succeed. Non-expected fields are ignored.

TypeBehind method returns the reflect.Type of "model".

Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type Person struct {
		Name        string
		Age         int
		NumChildren int
	}

	got := Person{
		Name:        "Foobar",
		Age:         42,
		NumChildren: 3,
	}

	// As NumChildren is zero in Struct() call, it is not checked
	ok := td.Cmp(t, got,
		td.Struct(Person{Name: "Foobar"}, td.StructFields{
			"Age": td.Between(40, 50),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model can be empty
	ok = td.Cmp(t, got,
		td.Struct(Person{}, td.StructFields{
			"Name":        "Foobar",
			"Age":         td.Between(40, 50),
			"NumChildren": td.Not(0),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

	// Works with pointers too
	ok = td.Cmp(t, &got,
		td.Struct(&Person{}, td.StructFields{
			"Name":        "Foobar",
			"Age":         td.Between(40, 50),
			"NumChildren": td.Not(0),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

	// Model does not need to be instanciated
	ok = td.Cmp(t, &got,
		td.Struct((*Person)(nil), td.StructFields{
			"Name":        "Foobar",
			"Age":         td.Between(40, 50),
			"NumChildren": td.Not(0),
		}),
		"checks %v is the right Person")
	fmt.Println(ok)

}

Output:

true
true
true
true

func SubBagOf 

func SubBagOf(expectedItems ...interface{}) TestDeep

SubBagOf operator compares the contents of an array or a slice (or a pointer on array/slice) without taking care of the order of items.

During a match, each array/slice item should be matched by an expected item to succeed. But some expected items can be missing from the compared array/slice. 

td.Cmp(t, []int{1}, td.SubBagOf(1, 1, 2))       // succeeds
td.Cmp(t, []int{1, 1, 1}, td.SubBagOf(1, 1, 2)) // fails, one 1 is an extra item

// works with slices/arrays of any type
td.Cmp(t, personSlice, td.SubBagOf(
  Person{Name: "Bob", Age: 32},
  Person{Name: "Alice", Age: 26},
))

To flatten a non-[]interface{} slice/array, use Flatten function and so avoid boring and inefficient copies: 

expected := []int{1, 2, 1}
td.Cmp(t, []int{1}, td.SubBagOf(td.Flatten(expected))) // succeeds
// = td.Cmp(t, []int{1}, td.SubBagOf(1, 2, 1))

exp1 := []int{5, 1, 1}
exp2 := []int{8, 42, 3}
td.Cmp(t, []int{1, 42, 3},
  td.SubBagOf(td.Flatten(exp1), 3, td.Flatten(exp2))) // succeeds
// = td.Cmp(t, []int{1, 42, 3}, td.SubBagOf(5, 1, 1, 3, 8, 42, 3))
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := td.Cmp(t, got, td.SubBagOf(0, 0, 1, 1, 2, 2, 3, 3, 5, 5, 8, 8, 9, 9),
		"checks at least all items are present, in any order")
	fmt.Println(ok)

	// got contains one 8 too many
	ok = td.Cmp(t, got, td.SubBagOf(0, 0, 1, 1, 2, 2, 3, 3, 5, 5, 8, 9, 9),
		"checks at least all items are present, in any order")
	fmt.Println(ok)

	got = []int{1, 3, 5, 2}

	ok = td.Cmp(t, got, td.SubBagOf(
		td.Between(0, 3),
		td.Between(0, 3),
		td.Between(0, 3),
		td.Between(0, 3),
		td.Gt(4),
		td.Gt(4)),
		"checks at least all items match, in any order with TestDeep operators")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 5, 9, 8}
	ok = td.Cmp(t, got, td.SubBagOf(td.Flatten(expected)),
		"checks at least all expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
false
true
true

func SubJSONOf 

func SubJSONOf(expectedJSON interface{}, params ...interface{}) TestDeep

SubJSONOf operator allows to compare the JSON representation of data against "expectedJSON". Unlike JSON operator, marshalled data must be a JSON object/map (aka {…}). "expectedJSON" can be a:

  • string containing JSON data like `{"fullname":"Bob","age":42}`
  • string containing a JSON filename, ending with ".json" (its content is ioutil.ReadFile before unmarshaling)
  • []byte containing JSON data
  • io.Reader stream containing JSON data (is ioutil.ReadAll before unmarshaling)

JSON data contained in "expectedJSON" must be a JSON object/map (aka {…}) too. During a match, each expected entry should match in the compared map. But some expected entries can be missing from the compared map. 

type MyStruct struct {
  Name string `json:"name"`
  Age  int    `json:"age"`
}
got := MyStruct{
  Name: "Bob",
  Age:  42,
}
td.Cmp(t, got, td.SubJSONOf(`{"name": "Bob", "age": 42, "city": "NY"}`)) // succeeds
td.Cmp(t, got, td.SubJSONOf(`{"name": "Bob", "zip": 666}`))              // fails, extra "age"

"expectedJSON" JSON value can contain placeholders. The "params" are for any placeholder parameters in "expectedJSON". "params" can contain TestDeep operators as well as raw values. A placeholder can be numeric like $2 or named like $name and always references an item in "params".

Numeric placeholders reference the n'th "operators" item (starting at 1). Named placeholders are used with Tag operator as follows: 

td.Cmp(t, gotValue,
  td.SubJSONOf(`{"fullname": $name, "age": $2, "gender": $3}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43),                  // matches only $2
    "male"))                             // matches only $3

Note that placeholders can be double-quoted as in: 

td.Cmp(t, gotValue,
  td.SubJSONOf(`{"fullname": "$name", "age": "$2", "gender": "$3"}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43),                  // matches only $2
    "male"))                             // matches only $3

It makes no difference whatever the underlying type of the replaced item is (= double quoting a placeholder matching a number is not a problem). It is just a matter of taste, double-quoting placeholders can be preferred when the JSON data has to conform to the JSON specification, like when used in a ".json" file.

Note "expectedJSON" can be a []byte, JSON filename or io.Reader: 

td.Cmp(t, gotValue, td.SubJSONOf("file.json", td.Between(12, 34)))
td.Cmp(t, gotValue, td.SubJSONOf([]byte(`[1, $1, 3]`), td.Between(12, 34)))
td.Cmp(t, gotValue, td.SubJSONOf(osFile, td.Between(12, 34)))

A JSON filename ends with ".json".

To avoid a legit "$" string prefix causes a bad placeholder error, just double it to escape it. Note it is only needed when the "$" is the first character of a string: 

td.Cmp(t, gotValue,
  td.SubJSONOf(`{"fullname": "$name", "details": "$$info", "age": $2}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43)))                 // matches only $2

For the "details" key, the raw value "$info" is expected, no placeholders are involved here.

Note that Lax mode is automatically enabled by SubJSONOf operator to simplify numeric tests.

Comments can be embedded in JSON data: 

td.Cmp(t, gotValue,
  SubJSONOf(`
{
  // A guy properties:
  "fullname": "$name",  // The full name of the guy
  "details":  "$$info", // Literally "$info", thanks to "$" escape
  "age":      $2        /* The age of the guy:
                           - placeholder unquoted, but could be without
                             any change
                           - to demonstrate a multi-lines comment */
}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43)))                 // matches only $2

Comments, like in go, have 2 forms. To quote the Go language specification:

  • line comments start with the character sequence // and stop at the end of the line.
  • multi-lines comments start with the character sequence /* and stop with the first subsequent character sequence */.

Last but not least, simple operators can be directly embedded in JSON data without requiring any placeholder but using directly $^OperatorName. They are operator shortcuts: 

td.Cmp(t, gotValue, td.SubJSONOf(`{"id": $1}`, td.NotZero()))

can be written as: 

td.Cmp(t, gotValue, td.SubJSONOf(`{"id": $^NotZero}`))

Unfortunately, only simple operators (in fact those which take no parameters) have shortcuts. They follow:

  • Empty → $^Empty
  • Ignore → $^Ignore
  • NaN → $^NaN
  • Nil → $^Nil
  • NotEmpty → $^NotEmpty
  • NotNaN → $^NotNaN
  • NotNil → $^NotNil
  • NotZero → $^NotZero
  • Zero → $^Zero

TypeBehind method returns the map[string]interface{} type.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob",
		Age:      42,
	}

	ok := td.Cmp(t, got, td.SubJSONOf(`{"age":42,"fullname":"Bob","gender":"male"}`))
	fmt.Println("check got with age then fullname:", ok)

	ok = td.Cmp(t, got, td.SubJSONOf(`{"fullname":"Bob","age":42,"gender":"male"}`))
	fmt.Println("check got with fullname then age:", ok)

	ok = td.Cmp(t, got, td.SubJSONOf(`
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42,    /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
  "gender":   "male" // This field is ignored as SubJSONOf
}`))
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = td.Cmp(t, got, td.SubJSONOf(`{"fullname":"Bob","gender":"male"}`))
	fmt.Println("check got without age field:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got without age field: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender",
  "details":  {
    "city": "TestCity",
    "zip":  666
  }
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := td.Cmp(t, got,
		td.SubJSONOf(filename,
			td.Tag("name", td.HasPrefix("Bob")),
			td.Tag("age", td.Between(40, 45)),
			td.Tag("gender", td.Re(`^(male|female)\z`))))
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = td.Cmp(t, got,
		td.SubJSONOf(file,
			td.Tag("name", td.HasPrefix("Bob")),
			td.Tag("age", td.Between(40, 45)),
			td.Tag("gender", td.Re(`^(male|female)\z`))))
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
	}

	ok := td.Cmp(t, got,
		td.SubJSONOf(`{"age": $1, "fullname": $2, "gender": $3}`,
			42, "Bob Foobar", "male"))
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = td.Cmp(t, got,
		td.SubJSONOf(`{"age": $1, "fullname": $2, "gender": $3}`,
			td.Between(40, 45),
			td.HasSuffix("Foobar"),
			td.NotEmpty()))
	fmt.Println("check got with numeric placeholders:", ok)

	ok = td.Cmp(t, got,
		td.SubJSONOf(`{"age": "$1", "fullname": "$2", "gender": "$3"}`,
			td.Between(40, 45),
			td.HasSuffix("Foobar"),
			td.NotEmpty()))
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = td.Cmp(t, got,
		td.SubJSONOf(`{"age": $age, "fullname": $name, "gender": $gender}`,
			td.Tag("age", td.Between(40, 45)),
			td.Tag("name", td.HasSuffix("Foobar")),
			td.Tag("gender", td.NotEmpty())))
	fmt.Println("check got with named placeholders:", ok)

	ok = td.Cmp(t, got,
		td.SubJSONOf(`{"age": $^NotZero, "fullname": $^NotEmpty, "gender": $^NotEmpty}`))
	fmt.Println("check got with operator shortcuts:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true
check got with operator shortcuts: true

func SubMapOf 

func SubMapOf(model interface{}, expectedEntries MapEntries) TestDeep

SubMapOf operator compares the contents of a map against the non-zero values of "model" (if any) and the values of "expectedEntries".

"model" must be the same type as compared data.

"expectedEntries" can be nil, if no zero entries are expected and no TestDeep operator are involved.

During a match, each map entry should be matched by an expected entry to succeed. But some expected entries can be missing from the compared map. 

got := map[string]string{
  "foo": "test",
  "zip": "buzz",
}
td.Cmp(t, got, td.SubMapOf(
  map[string]string{
    "foo": "test",
    "bar": "wizz",
  },
  td.MapEntries{
    "zip": td.HasSuffix("zz"),
  }),
) // succeeds

td.Cmp(t, got, td.SubMapOf(
  map[string]string{
    "bar": "wizz",
  },
  td.MapEntries{
    "zip": td.HasSuffix("zz"),
  }),
) // fails, extra {"foo": "test"} in got

TypeBehind method returns the reflect.Type of "model".

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42}

	ok := td.Cmp(t, got,
		td.SubMapOf(map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666}),
		"checks map %v is included in expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42}

	ok := td.Cmp(t, got,
		td.SubMapOf(MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666}),
		"checks typed map %v is included in expected keys/values", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.SubMapOf(&MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15), "zip": 666}),
		"checks pointed typed map %v is included in expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
true

func SubSetOf 

func SubSetOf(expectedItems ...interface{}) TestDeep

SubSetOf operator compares the contents of an array or a slice (or a pointer on array/slice) ignoring duplicates and without taking care of the order of items.

During a match, each array/slice item should be matched by an expected item to succeed. But some expected items can be missing from the compared array/slice. 

td.Cmp(t, []int{1, 1}, td.SubSetOf(1, 2))    // succeeds
td.Cmp(t, []int{1, 1, 2}, td.SubSetOf(1, 3)) // fails, 2 is an extra item

// works with slices/arrays of any type
td.Cmp(t, personSlice, td.SubSetOf(
  Person{Name: "Bob", Age: 32},
  Person{Name: "Alice", Age: 26},
))

To flatten a non-[]interface{} slice/array, use Flatten function and so avoid boring and inefficient copies: 

expected := []int{2, 1}
td.Cmp(t, []int{1, 1}, td.SubSetOf(td.Flatten(expected))) // succeeds
// = td.Cmp(t, []int{1, 1}, td.SubSetOf(2, 1))

exp1 := []int{2, 1}
exp2 := []int{5, 8}
td.Cmp(t, []int{1, 5, 1, 3, 3},
  td.SubSetOf(td.Flatten(exp1), 3, td.Flatten(exp2))) // succeeds
// = td.Cmp(t, []int{1, 5, 1, 3, 3}, td.SubSetOf(2, 1, 3, 5, 8))
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	// Matches as all items are expected, ignoring duplicates
	ok := td.Cmp(t, got, td.SubSetOf(1, 2, 3, 4, 5, 6, 7, 8),
		"checks at least all items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

	// Tries its best to not raise an error when a value can be matched
	// by several SubSetOf entries
	ok = td.Cmp(t, got, td.SubSetOf(td.Between(1, 4), 3, td.Between(2, 10), td.Gt(100)),
		"checks at least all items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3, 4, 5, 6, 7, 8}
	ok = td.Cmp(t, got, td.SubSetOf(td.Flatten(expected)),
		"checks at least all expected items are present, in any order, ignoring duplicates")
	fmt.Println(ok)

}

Output:

true
true
true

func SuperBagOf 

func SuperBagOf(expectedItems ...interface{}) TestDeep

SuperBagOf operator compares the contents of an array or a slice (or a pointer on array/slice) without taking care of the order of items.

During a match, each expected item should match in the compared array/slice. But some items in the compared array/slice may not be expected. 

td.Cmp(t, []int{1, 1, 2}, td.SuperBagOf(1))       // succeeds
td.Cmp(t, []int{1, 1, 2}, td.SuperBagOf(1, 1, 1)) // fails, one 1 is missing

// works with slices/arrays of any type
td.Cmp(t, personSlice, td.SuperBagOf(
  Person{Name: "Bob", Age: 32},
  Person{Name: "Alice", Age: 26},
))

To flatten a non-[]interface{} slice/array, use Flatten function and so avoid boring and inefficient copies: 

expected := []int{1, 2, 1}
td.Cmp(t, []int{1}, td.SuperBagOf(td.Flatten(expected))) // succeeds
// = td.Cmp(t, []int{1}, td.SuperBagOf(1, 2, 1))

exp1 := []int{5, 1, 1}
exp2 := []int{8, 42}
td.Cmp(t, []int{1, 5, 1, 8, 42, 3, 3, 6},
  td.SuperBagOf(td.Flatten(exp1), 3, td.Flatten(exp2))) // succeeds
// = td.Cmp(t, []int{1, 5, 1, 8, 42, 3, 3, 6}, td.SuperBagOf(5, 1, 1, 3, 8, 42))
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := td.Cmp(t, got, td.SuperBagOf(8, 5, 8),
		"checks the items are present, in any order")
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.SuperBagOf(td.Gt(5), td.Lte(2)),
		"checks at least 2 items of %v match", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{8, 5, 8}
	ok = td.Cmp(t, got, td.SuperBagOf(td.Flatten(expected)),
		"checks the expected items are present, in any order")
	fmt.Println(ok)

}

Output:

true
true
true

func SuperJSONOf 

func SuperJSONOf(expectedJSON interface{}, params ...interface{}) TestDeep

SuperJSONOf operator allows to compare the JSON representation of data against "expectedJSON". Unlike JSON operator, marshalled data must be a JSON object/map (aka {…}). "expectedJSON" can be a:

  • string containing JSON data like `{"fullname":"Bob","age":42}`
  • string containing a JSON filename, ending with ".json" (its content is ioutil.ReadFile before unmarshaling)
  • []byte containing JSON data
  • io.Reader stream containing JSON data (is ioutil.ReadAll before unmarshaling)

JSON data contained in "expectedJSON" must be a JSON object/map (aka {…}) too. During a match, each expected entry should match in the compared map. But some entries in the compared map may not be expected. 

type MyStruct struct {
  Name string `json:"name"`
  Age  int    `json:"age"`
  City string `json:"city"`
}
got := MyStruct{
  Name: "Bob",
  Age:  42,
  City: "TestCity",
}
td.Cmp(t, got, td.SuperJSONOf(`{"name": "Bob", "age": 42}`))  // succeeds
td.Cmp(t, got, td.SuperJSONOf(`{"name": "Bob", "zip": 666}`)) // fails, miss "zip"

"expectedJSON" JSON value can contain placeholders. The "params" are for any placeholder parameters in "expectedJSON". "params" can contain TestDeep operators as well as raw values. A placeholder can be numeric like $2 or named like $name and always references an item in "params".

Numeric placeholders reference the n'th "operators" item (starting at 1). Named placeholders are used with Tag operator as follows: 

td.Cmp(t, gotValue,
  SuperJSONOf(`{"fullname": $name, "age": $2, "gender": $3}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43),                  // matches only $2
    "male"))                             // matches only $3

Note that placeholders can be double-quoted as in: 

td.Cmp(t, gotValue,
  td.SuperJSONOf(`{"fullname": "$name", "age": "$2", "gender": "$3"}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43),                  // matches only $2
    "male"))                             // matches only $3

It makes no difference whatever the underlying type of the replaced item is (= double quoting a placeholder matching a number is not a problem). It is just a matter of taste, double-quoting placeholders can be preferred when the JSON data has to conform to the JSON specification, like when used in a ".json" file.

Note "expectedJSON" can be a []byte, JSON filename or io.Reader: 

td.Cmp(t, gotValue, td.SuperJSONOf("file.json", td.Between(12, 34)))
td.Cmp(t, gotValue, td.SuperJSONOf([]byte(`[1, $1, 3]`), td.Between(12, 34)))
td.Cmp(t, gotValue, td.SuperJSONOf(osFile, td.Between(12, 34)))

A JSON filename ends with ".json".

To avoid a legit "$" string prefix causes a bad placeholder error, just double it to escape it. Note it is only needed when the "$" is the first character of a string: 

td.Cmp(t, gotValue,
  td.SuperJSONOf(`{"fullname": "$name", "details": "$$info", "age": $2}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43)))                 // matches only $2

For the "details" key, the raw value "$info" is expected, no placeholders are involved here.

Note that Lax mode is automatically enabled by SuperJSONOf operator to simplify numeric tests.

Comments can be embedded in JSON data: 

td.Cmp(t, gotValue,
  td.SuperJSONOf(`
{
  // A guy properties:
  "fullname": "$name",  // The full name of the guy
  "details":  "$$info", // Literally "$info", thanks to "$" escape
  "age":      $2        /* The age of the guy:
                           - placeholder unquoted, but could be without
                             any change
                           - to demonstrate a multi-lines comment */
}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $1 and $name
    td.Between(41, 43)))                 // matches only $2

Comments, like in go, have 2 forms. To quote the Go language specification:

  • line comments start with the character sequence // and stop at the end of the line.
  • multi-lines comments start with the character sequence /* and stop with the first subsequent character sequence */.

Last but not least, simple operators can be directly embedded in JSON data without requiring any placeholder but using directly $^OperatorName. They are operator shortcuts: 

td.Cmp(t, gotValue, td.SuperJSONOf(`{"id": $1}`, td.NotZero()))

can be written as: 

td.Cmp(t, gotValue, td.SuperJSONOf(`{"id": $^NotZero}`))

Unfortunately, only simple operators (in fact those which take no parameters) have shortcuts. They follow:

  • Empty → $^Empty
  • Ignore → $^Ignore
  • NaN → $^NaN
  • Nil → $^Nil
  • NotEmpty → $^NotEmpty
  • NotNaN → $^NotNaN
  • NotNil → $^NotNil
  • NotZero → $^NotZero
  • Zero → $^Zero

TypeBehind method returns the map[string]interface{} type.

Example (Basic) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	ok := td.Cmp(t, got, td.SuperJSONOf(`{"age":42,"fullname":"Bob","gender":"male"}`))
	fmt.Println("check got with age then fullname:", ok)

	ok = td.Cmp(t, got, td.SuperJSONOf(`{"fullname":"Bob","age":42,"gender":"male"}`))
	fmt.Println("check got with fullname then age:", ok)

	ok = td.Cmp(t, got, td.SuperJSONOf(`
// This should be the JSON representation of a struct
{
  // A person:
  "fullname": "Bob", // The name of this person
  "age":      42,    /* The age of this person:
                        - 42 of course
                        - to demonstrate a multi-lines comment */
  "gender":   "male" // The gender!
}`))
	fmt.Println("check got with nicely formatted and commented JSON:", ok)

	ok = td.Cmp(t, got,
		td.SuperJSONOf(`{"fullname":"Bob","gender":"male","details":{}}`))
	fmt.Println("check got with details field:", ok)

}

Output:

check got with age then fullname: true
check got with fullname then age: true
check got with nicely formatted and commented JSON: true
check got with details field: false
Example (File) 
package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	tmpDir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir) // clean up

	filename := tmpDir + "/test.json"
	if err = ioutil.WriteFile(filename, []byte(`
{
  "fullname": "$name",
  "age":      "$age",
  "gender":   "$gender"
}`), 0644); err != nil {
		t.Fatal(err)
	}

	// OK let's test with this file
	ok := td.Cmp(t, got,
		td.SuperJSONOf(filename,
			td.Tag("name", td.HasPrefix("Bob")),
			td.Tag("age", td.Between(40, 45)),
			td.Tag("gender", td.Re(`^(male|female)\z`))))
	fmt.Println("Full match from file name:", ok)

	// When the file is already open
	file, err := os.Open(filename)
	if err != nil {
		t.Fatal(err)
	}
	ok = td.Cmp(t, got,
		td.SuperJSONOf(file,
			td.Tag("name", td.HasPrefix("Bob")),
			td.Tag("age", td.Between(40, 45)),
			td.Tag("gender", td.Re(`^(male|female)\z`))))
	fmt.Println("Full match from io.Reader:", ok)

}

Output:

Full match from file name: true
Full match from io.Reader: true
Example (Placeholders) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := &struct {
		Fullname string `json:"fullname"`
		Age      int    `json:"age"`
		Gender   string `json:"gender"`
		City     string `json:"city"`
		Zip      int    `json:"zip"`
	}{
		Fullname: "Bob Foobar",
		Age:      42,
		Gender:   "male",
		City:     "TestCity",
		Zip:      666,
	}

	ok := td.Cmp(t, got,
		td.SuperJSONOf(`{"age": $1, "fullname": $2, "gender": $3}`,
			42, "Bob Foobar", "male"))
	fmt.Println("check got with numeric placeholders without operators:", ok)

	ok = td.Cmp(t, got,
		td.SuperJSONOf(`{"age": $1, "fullname": $2, "gender": $3}`,
			td.Between(40, 45),
			td.HasSuffix("Foobar"),
			td.NotEmpty()))
	fmt.Println("check got with numeric placeholders:", ok)

	ok = td.Cmp(t, got,
		td.SuperJSONOf(`{"age": "$1", "fullname": "$2", "gender": "$3"}`,
			td.Between(40, 45),
			td.HasSuffix("Foobar"),
			td.NotEmpty()))
	fmt.Println("check got with double-quoted numeric placeholders:", ok)

	ok = td.Cmp(t, got,
		td.SuperJSONOf(`{"age": $age, "fullname": $name, "gender": $gender}`,
			td.Tag("age", td.Between(40, 45)),
			td.Tag("name", td.HasSuffix("Foobar")),
			td.Tag("gender", td.NotEmpty())))
	fmt.Println("check got with named placeholders:", ok)

	ok = td.Cmp(t, got,
		td.SuperJSONOf(`{"age": $^NotZero, "fullname": $^NotEmpty, "gender": $^NotEmpty}`))
	fmt.Println("check got with operator shortcuts:", ok)

}

Output:

check got with numeric placeholders without operators: true
check got with numeric placeholders: true
check got with double-quoted numeric placeholders: true
check got with named placeholders: true
check got with operator shortcuts: true

func SuperMapOf 

func SuperMapOf(model interface{}, expectedEntries MapEntries) TestDeep

SuperMapOf operator compares the contents of a map against the non-zero values of "model" (if any) and the values of "expectedEntries".

"model" must be the same type as compared data.

"expectedEntries" can be nil, if no zero entries are expected and no TestDeep operator are involved.

During a match, each expected entry should match in the compared map. But some entries in the compared map may not be expected. 

got := map[string]string{
  "foo": "test",
  "bar": "wizz",
  "zip": "buzz",
}
td.Cmp(t, got, td.SuperMapOf(
  map[string]string{
    "foo": "test",
  },
  td.MapEntries{
    "zip": td.HasSuffix("zz"),
  }),
) // succeeds

td.Cmp(t, got, td.SuperMapOf(
  map[string]string{
    "foo": "test",
  },
  td.MapEntries{
    "biz": td.HasSuffix("zz"),
  }),
) // fails, missing {"biz": …} in got

TypeBehind method returns the reflect.Type of "model".

Example (Map) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 12, "bar": 42, "zip": 89}

	ok := td.Cmp(t, got,
		td.SuperMapOf(map[string]int{"bar": 42}, td.MapEntries{"foo": td.Lt(15)}),
		"checks map %v contains at leat all expected keys/values", got)
	fmt.Println(ok)

}

Output:

true
Example (TypedMap) 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	type MyMap map[string]int

	got := MyMap{"foo": 12, "bar": 42, "zip": 89}

	ok := td.Cmp(t, got,
		td.SuperMapOf(MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15)}),
		"checks typed map %v contains at leat all expected keys/values", got)
	fmt.Println(ok)

	ok = td.Cmp(t, &got,
		td.SuperMapOf(&MyMap{"bar": 42}, td.MapEntries{"foo": td.Lt(15)}),
		"checks pointed typed map %v contains at leat all expected keys/values",
		got)
	fmt.Println(ok)

}

Output:

true
true

func SuperSetOf 

func SuperSetOf(expectedItems ...interface{}) TestDeep

SuperSetOf operator compares the contents of an array or a slice (or a pointer on array/slice) ignoring duplicates and without taking care of the order of items.

During a match, each expected item should match in the compared array/slice. But some items in the compared array/slice may not be expected. 

td.Cmp(t, []int{1, 1, 2}, td.SuperSetOf(1))    // succeeds
td.Cmp(t, []int{1, 1, 2}, td.SuperSetOf(1, 3)) // fails, 3 is missing

// works with slices/arrays of any type
td.Cmp(t, personSlice, td.SuperSetOf(
  Person{Name: "Bob", Age: 32},
  Person{Name: "Alice", Age: 26},
))

To flatten a non-[]interface{} slice/array, use Flatten function and so avoid boring and inefficient copies: 

expected := []int{2, 1}
td.Cmp(t, []int{1, 1, 2, 8}, td.SuperSetOf(td.Flatten(expected))) // succeeds
// = td.Cmp(t, []int{1, 1, 2, 8}, td.SubSetOf(2, 1))

exp1 := []int{2, 1}
exp2 := []int{5, 8}
td.Cmp(t, []int{1, 5, 1, 8, 42, 3, 3},
  td.SuperSetOf(td.Flatten(exp1), 3, td.Flatten(exp2))) // succeeds
// = td.Cmp(t, []int{1, 5, 1, 8, 42, 3, 3}, td.SuperSetOf(2, 1, 3, 5, 8))
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := []int{1, 3, 5, 8, 8, 1, 2}

	ok := td.Cmp(t, got, td.SuperSetOf(1, 2, 3),
		"checks the items are present, in any order and ignoring duplicates")
	fmt.Println(ok)

	ok = td.Cmp(t, got, td.SuperSetOf(td.Gt(5), td.Lte(2)),
		"checks at least 2 items of %v match ignoring duplicates", got)
	fmt.Println(ok)

	// When expected is already a non-[]interface{} slice, it cannot be
	// flattened directly using expected... without copying it to a new
	// []interface{} slice, then use td.Flatten!
	expected := []int{1, 2, 3}
	ok = td.Cmp(t, got, td.SuperSetOf(td.Flatten(expected)),
		"checks the expected items are present, in any order and ignoring duplicates")
	fmt.Println(ok)

}

Output:

true
true
true

func Tag 

func Tag(tag string, expectedValue interface{}) TestDeep

Tag is a smuggler operator. It only allows to name "expectedValue", which can be an operator or a value. The data is then compared against "expectedValue" as if Tag was never called. It is only useful as JSON operator parameter, to name placeholders. See JSON operator for more details. 

td.Cmp(t, gotValue,
  td.JSON(`{"fullname": $name, "age": $age, "gender": $gender}`,
    td.Tag("name", td.HasPrefix("Foo")), // matches $name
    td.Tag("age", td.Between(41, 43)),   // matches $age
    td.Tag("gender", "male")))           // matches $gender

TypeBehind method is delegated to "expectedValue" one if "expectedValue" is a TestDeep operator, otherwise it returns the type of "expectedValue" (or nil if it is originally untyped nil).

func TruncTime 

func TruncTime(expectedTime interface{}, trunc ...time.Duration) TestDeep

TruncTime operator compares time.Time (or assignable) values after truncating them to the optional "trunc" duration. See time.Truncate for details about the truncation.

If "trunc" is missing, it defaults to 0.

During comparison, location does not matter as time.Equal method is used behind the scenes: a time instant in two different locations is the same time instant.

Whatever the "trunc" value is, the monotonic clock is stripped before the comparison against "expectedTime". 

gotDate := time.Date(2018, time.March, 9, 1, 2, 3, 999999999, time.UTC).
  In(time.FixedZone("UTC+2", 2))

expected := time.Date(2018, time.March, 9, 1, 2, 3, 0, time.UTC)

td.Cmp(t, gotDate, td.TruncTime(expected))              // fails, ns differ
td.Cmp(t, gotDate, td.TruncTime(expected, time.Second)) // succeeds

TypeBehind method returns the reflect.Type of "expectedTime".

Example 
package main

import (
	"fmt"
	"testing"
	"time"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	dateToTime := func(str string) time.Time {
		t, err := time.Parse(time.RFC3339Nano, str)
		if err != nil {
			panic(err)
		}
		return t
	}

	got := dateToTime("2018-05-01T12:45:53.123456789Z")

	// Compare dates ignoring nanoseconds and monotonic parts
	expected := dateToTime("2018-05-01T12:45:53Z")
	ok := td.Cmp(t, got, td.TruncTime(expected, time.Second),
		"checks date %v, truncated to the second", got)
	fmt.Println(ok)

	// Compare dates ignoring time and so monotonic parts
	expected = dateToTime("2018-05-01T11:22:33.444444444Z")
	ok = td.Cmp(t, got, td.TruncTime(expected, 24*time.Hour),
		"checks date %v, truncated to the day", got)
	fmt.Println(ok)

	// Compare dates exactly but ignoring monotonic part
	expected = dateToTime("2018-05-01T12:45:53.123456789Z")
	ok = td.Cmp(t, got, td.TruncTime(expected),
		"checks date %v ignoring monotonic part", got)
	fmt.Println(ok)

}

Output:

true
true
true

func Values 

func Values(val interface{}) TestDeep

Values is a smuggler operator. It takes a map and compares its ordered values to "val".

"val" can be a slice of items of the same type as the map values: 

got := map[int]string{3: "c", 1: "a", 2: "b"}
td.Cmp(t, got, td.Values([]string{"a", "b", "c"})) // succeeds, values sorted
td.Cmp(t, got, td.Values([]string{"c", "a", "b"})) // fails as not sorted

as well as an other operator as Bag, for example, to test values in an unsorted manner: 

got := map[int]string{3: "c", 1: "a", 2: "b"}
td.Cmp(t, got, td.Values(td.Bag("c", "a", "b"))) // succeeds
Example 
package main

import (
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	got := map[string]int{"foo": 1, "bar": 2, "zip": 3}

	// Values tests values in an ordered manner
	ok := td.Cmp(t, got, td.Values([]int{1, 2, 3}))
	fmt.Println("All sorted values are found:", ok)

	// If the expected values are not ordered, it fails
	ok = td.Cmp(t, got, td.Values([]int{3, 1, 2}))
	fmt.Println("All unsorted values are found:", ok)

	// To circumvent that, one can use Bag operator
	ok = td.Cmp(t, got, td.Values(td.Bag(3, 1, 2)))
	fmt.Println("All unsorted values are found, with the help of Bag operator:", ok)

	// Check that each value is between 1 and 3
	ok = td.Cmp(t, got, td.Values(td.ArrayEach(td.Between(1, 3))))
	fmt.Println("Each value is between 1 and 3:", ok)

}

Output:

All sorted values are found: true
All unsorted values are found: false
All unsorted values are found, with the help of Bag operator: true
Each value is between 1 and 3: true

func Zero 

func Zero() TestDeep

Zero operator checks that data is zero regarding its type.

  • nil is the zero value of pointers, maps, slices, channels and functions;
  • 0 is the zero value of numbers;
  • "" is the 0 value of strings;
  • false is the zero value of booleans;
  • zero value of structs is the struct with no fields initialized.

Beware that: 

td.Cmp(t, AnyStruct{}, td.Zero())          // is true
td.Cmp(t, &AnyStruct{}, td.Zero())         // is false, coz pointer ≠ nil
td.Cmp(t, &AnyStruct{}, td.Ptr(td.Zero())) // is true
Example 
package main

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/maxatome/go-testdeep/td"
)

func main() {
	t := &testing.T{}

	ok := td.Cmp(t, 0, td.Zero())
	fmt.Println(ok)

	ok = td.Cmp(t, float64(0), td.Zero())
	fmt.Println(ok)

	ok = td.Cmp(t, 12, td.Zero()) // fails, as 12 is not 0 :)
	fmt.Println(ok)

	ok = td.Cmp(t, (map[string]int)(nil), td.Zero())
	fmt.Println(ok)

	ok = td.Cmp(t, map[string]int{}, td.Zero()) // fails, as not nil
	fmt.Println(ok)

	ok = td.Cmp(t, ([]int)(nil), td.Zero())
	fmt.Println(ok)

	ok = td.Cmp(t, []int{}, td.Zero()) // fails, as not nil
	fmt.Println(ok)

	ok = td.Cmp(t, [3]int{}, td.Zero())
	fmt.Println(ok)

	ok = td.Cmp(t, [3]int{0, 1}, td.Zero()) // fails, DATA[1] is not 0
	fmt.Println(ok)

	ok = td.Cmp(t, bytes.Buffer{}, td.Zero())
	fmt.Println(ok)

	ok = td.Cmp(t, &bytes.Buffer{}, td.Zero()) // fails, as pointer not nil
	fmt.Println(ok)

	ok = td.Cmp(t, &bytes.Buffer{}, td.Ptr(td.Zero())) // OK with the help of Ptr()
	fmt.Println(ok)

}

Output:

true
true
false
true
false
true
false
true
false
true
false
true

type TestingFT 

type TestingFT = testing.TB

TestingFT is a deprecated alias of testing.TB. Use testing.TB directly in new code.

type TestingT 

type TestingT interface {
	Error(args ...interface{})
	Fatal(args ...interface{})
	Helper()
}

TestingT is the minimal interface used by Cmp to report errors. It is commonly implemented by *testing.T and *testing.B.

type Tuple added in v1.8.0 

type Tuple interface {
	// Len returns t length, aka the number of items the tuple contains.
	Len() int
	// Index returns t's i'th element. It panics if i is out of range.
	Index(int) interface{}
}

A Tuple is an immutable container. It is used to easily compare several values at once, typically when a function returns several values: 

price := func(p float64) (float64, string, error) {
  if p < 0 {
    return 0, "", errors.New("negative price not supported")
  }
  return p * 1.2, "€", nil
}

td.Cmp(t,
  td.TupleFrom(price(10)),
  td.TupleFrom(float64(12), "€", nil),
)

td.Cmp(t,
  td.TupleFrom(price(-10)),
  td.TupleFrom(float64(0), "", td.Not(nil)),
)

Once initialized with TupleFrom, a Tuple is immutable.

func TupleFrom added in v1.8.0 

func TupleFrom(vals ...interface{}) Tuple

TupleFrom returns a new Tuple initialized to the values of "vals". 

td.TupleFrom(float64(0), "", td.Not(nil))

Flatten can be used to flatten non-[]interface{} slice/array into a new Tuple: 

ints := []int64{1, 2, 3}
td.TupleFrom(td.Flatten(ints), "OK", nil)

is the same as: 

td.TupleFrom(int64(1), int64(2), int64(3), "OK", nil)

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