unassert

README

unassert - providing a lack of assertions

unassert is a library that provides assertions based on the provided build tags - unassert_panic or unassert_stderr.

By default assertions are disabled (NOP implementation) to provide zero overhead in performance. The Go compiler detects when the library is not enbled and completely removes any function calls to unassert, so it behaves as if it the library were not used at all. This can be very useful if you are in a high performance scenario where you want to do assertinons in tight loops and you are reasonably sure your test cases cover any realistic scenarios.

There are multiple implementations available that can be enabled to discover issues in automated test runs or in QA environments.

Go Get

go get -u github.com/markus-wa/go-unassert

Example

package main

import (
	"fmt"

	"github.com/markus-wa/go-unassert"
)

func main() {
	unassert.True(true)

	fmt.Println("Hello")

	unassert.Same("a", "b")

	fmt.Println("World")

	unassert.Error("you can also %s a string", "format")
	unassert.Nilf(new(struct{}), "you can also pass error messages to any other function")
	unassert.NotNilf(nil, "with or without %s", "formatting")

	lenLessThan10 := func(v interface{}) bool {
		return len(v.([]int)) < 10
	}
	unassert.Matches(lenLessThan10, []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10})

	complexEvaluation := func() bool {
		// add logic here
		return false
	}
	unassert.ReturnsTrue(complexEvaluation)
}

Assertions disabled

go run main.go

output:

Hello
World

unassert_panic

go run -tags unassert_panic main.go

output:

Hello
panic: UNASSERT: assertion failed: expected same values, got a != b

goroutine 1 [running]:
github.com/markus-wa/go-unassert.Same(...)
    C:/Users/mwalt/dev/go-unassert/panic.go:11
main.main()
    C:/Users/mwalt/dev/go-unassert/example/example.go:14 +0x1c3
exit status 2

unassert_stderr

go run -tags unassert_stderr example/example.go

output:

Hello
UNASSERT: assertion failed: expected same values, got a != b
goroutine 1 [running]:
runtime/debug.Stack(0x4ddcc0, 0xc00000e020, 0xc000084ea8)
    /opt/go/current/src/runtime/debug/stack.go:24 +0x9d
github.com/markus-wa/go-unassert/stderr.Stderr(0x4c8eef, 0x34, 0xc00000c060, 0x2, 0x2)
    /home/mark/dev/go-unassert/stderr/stderr.go:20 +0x1b3
github.com/markus-wa/go-unassert.Error(...)
    /home/mark/dev/go-unassert/unassert.go:18
github.com/markus-wa/go-unassert.Samef(...)
    /home/mark/dev/go-unassert/unassert.go:142
github.com/markus-wa/go-unassert.Same(...)
    /home/mark/dev/go-unassert/unassert.go:129
main.main()
    /home/mark/dev/go-unassert/example/example.go:14 +0x3c4
World
UNASSERT: you can also format a string
goroutine 1 [running]:
runtime/debug.Stack(0x4ddcc0, 0xc00000e020, 0xc000084ea8)
    /opt/go/current/src/runtime/debug/stack.go:24 +0x9d
github.com/markus-wa/go-unassert/stderr.Stderr(0x4c51f2, 0x18, 0xc000010210, 0x1, 0x1)
    /home/mark/dev/go-unassert/stderr/stderr.go:20 +0x1b3
github.com/markus-wa/go-unassert.Error(...)
    /home/mark/dev/go-unassert/unassert.go:18
main.main()
    /home/mark/dev/go-unassert/example/example.go:18 +0x18f
UNASSERT: you can also pass error messages to any other function
goroutine 1 [running]:
runtime/debug.Stack(0x4ddcc0, 0xc00000e020, 0xc000084ea8)
    /opt/go/current/src/runtime/debug/stack.go:24 +0x9d
github.com/markus-wa/go-unassert/stderr.Stderr(0x4c9136, 0x36, 0x0, 0x0, 0x0)
    /home/mark/dev/go-unassert/stderr/stderr.go:20 +0x1b3
github.com/markus-wa/go-unassert.Error(...)
    /home/mark/dev/go-unassert/unassert.go:18
github.com/markus-wa/go-unassert.Nilf(...)
    /home/mark/dev/go-unassert/unassert.go:92
main.main()
    /home/mark/dev/go-unassert/example/example.go:19 +0x1c2
UNASSERT: with or without formatting
goroutine 1 [running]:
runtime/debug.Stack(0x4ddcc0, 0xc00000e020, 0xc000084ea8)
    /opt/go/current/src/runtime/debug/stack.go:24 +0x9d
github.com/markus-wa/go-unassert/stderr.Stderr(0x4c3db5, 0x12, 0xc000010240, 0x1, 0x1)
    /home/mark/dev/go-unassert/stderr/stderr.go:20 +0x1b3
github.com/markus-wa/go-unassert.Error(...)
    /home/mark/dev/go-unassert/unassert.go:18
github.com/markus-wa/go-unassert.NotNilf(...)
    /home/mark/dev/go-unassert/unassert.go:117
main.main()
    /home/mark/dev/go-unassert/example/example.go:20 +0x224
UNASSERT: assertion failed: predicate(x) did not return true; x = [1 2 3 4 5 6 7 8 9 10]
goroutine 1 [running]:
runtime/debug.Stack(0x4ddcc0, 0xc00000e020, 0xc000084e70)
    /opt/go/current/src/runtime/debug/stack.go:24 +0x9d
github.com/markus-wa/go-unassert/stderr.Stderr(0x4c93d2, 0x3a, 0xc000010260, 0x1, 0x1)
    /home/mark/dev/go-unassert/stderr/stderr.go:20 +0x1b3
github.com/markus-wa/go-unassert.Error(...)
    /home/mark/dev/go-unassert/unassert.go:18
github.com/markus-wa/go-unassert.Matchesf(0x4c9920, 0x49fb40, 0xc00000c080, 0x4c93d2, 0x3a, 0xc000010260, 0x1, 0x1)
    /home/mark/dev/go-unassert/unassert.go:200 +0x88
github.com/markus-wa/go-unassert.Matches(...)
    /home/mark/dev/go-unassert/unassert.go:186
main.main()
    /home/mark/dev/go-unassert/example/example.go:25 +0x328
UNASSERT: assertion failed: evaluator() did not return true
goroutine 1 [running]:
runtime/debug.Stack(0x4ddcc0, 0xc00000e020, 0xc000084e70)
    /opt/go/current/src/runtime/debug/stack.go:24 +0x9d
github.com/markus-wa/go-unassert/stderr.Stderr(0x4c8c09, 0x31, 0x0, 0x0, 0x0)
    /home/mark/dev/go-unassert/stderr/stderr.go:20 +0x1b3
github.com/markus-wa/go-unassert.Error(...)
    /home/mark/dev/go-unassert/unassert.go:18
github.com/markus-wa/go-unassert.ReturnsTruef(0x4c9928, 0x4c8c09, 0x31, 0x0, 0x0, 0x0)
    /home/mark/dev/go-unassert/unassert.go:233 +0x74
github.com/markus-wa/go-unassert.ReturnsTrue(...)
    /home/mark/dev/go-unassert/unassert.go:219
main.main()
    /home/mark/dev/go-unassert/example/example.go:31 +0x35e

License

This project is licensed under the MIT license.

Documentation

Overview

Package unassert provides assertions based on the provided build tags. Using -tags unassert_panics panics if an assertion fails. Using -tags unassert_stderr prints an error to stdout if an assertion fails.

Index

• func Error(format string, v ...interface{})
• func False(b bool)
• func Falsef(b bool, format string, v ...interface{})
• func Matches(predicate Predicate, x interface{})
• func Matchesf(predicate Predicate, x interface{}, format string, v ...interface{})
• func Nil(o interface{})
• func Nilf(o interface{}, format string, v ...interface{})
• func NotNil(o interface{})
• func NotNilf(o interface{}, format string, v ...interface{})
• func NotSame(a interface{}, b interface{})
• func NotSamef(a interface{}, b interface{}, format string, v ...interface{})
• func ReturnsTrue(evaluator Evaluator)
• func ReturnsTruef(evaluator Evaluator, format string, v ...interface{})
• func Same(a interface{}, b interface{})
• func Samef(a interface{}, b interface{}, format string, v ...interface{})
• func True(b bool)
• func Truef(b bool, format string, v ...interface{})
• type ErrorHandler
• type Evaluator
• type Predicate

Functions

func Error

func Error(format string, v ...interface{})

Error promotes an error according to 'unassert_' build tags. Formats according to a format specifier.

func False

func False(b bool)

False checks if b is false. Behaves according to 'unassert_' build tags.

func Falsef

func Falsef(b bool, format string, v ...interface{})

Falsef checks if b is false. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func Matches

func Matches(predicate Predicate, x interface{})

Matches checks if predicate(v) is true. Useful for lazy evaluation of complex assertions. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func Matchesf

func Matchesf(predicate Predicate, x interface{}, format string, v ...interface{})

Matchesf checks if predicate(v) is true. Useful for lazy evaluation of complex assertions. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func Nil

func Nil(o interface{})

Nil checks if v is nil. Behaves according to 'unassert_' build tags.

func Nilf

func Nilf(o interface{}, format string, v ...interface{})

Nilf checks if v is nil. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func NotNil

func NotNil(o interface{})

NotNil checks if v is not nil. Behaves according to 'unassert_' build tags.

func NotNilf

func NotNilf(o interface{}, format string, v ...interface{})

NotNilf checks if v is not nil. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func NotSame

func NotSame(a interface{}, b interface{})

NotSame checks if a != b. Behaves according to 'unassert_' build tags.

func NotSamef

func NotSamef(a interface{}, b interface{}, format string, v ...interface{})

NotSamef checks if a != b. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func ReturnsTrue

func ReturnsTrue(evaluator Evaluator)

ReturnsTrue checks if evaluator() returns true. Useful for lazy evaluation of complex assertions. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func ReturnsTruef

func ReturnsTruef(evaluator Evaluator, format string, v ...interface{})

ReturnsTrue checks if evaluator() returns true. Useful for lazy evaluation of complex assertions. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func Same

func Same(a interface{}, b interface{})

Same checks if a == b. Behaves according to 'unassert_' build tags.

func Samef

func Samef(a interface{}, b interface{}, format string, v ...interface{})

Samef checks if a == b. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

func True

func True(b bool)

True checks if b is true. Behaves according to 'unassert_' build tags.

func Truef

func Truef(b bool, format string, v ...interface{})

Truef checks if b is true. Behaves according to 'unassert_' build tags. Formats according to a format specifier.

Types

type ErrorHandler

type ErrorHandler func(format string, v ...interface{})

ErrorHandler handles an error. See unassert_panic & unassert_stderr

type Evaluator

type Evaluator func() bool

Evaluator is a function type used for lazy evaluation in assertions. Mostly used for function closures. See ReturnsTrue().

type Predicate

type Predicate func(interface{}) bool

Predicate is a function type used for lazy evaluation in assertions. It takes one argument and returns true if that argument matches a given predicate. See Matches().