validol

README

validol

Validation library for golang.

Content

• Install
• Usage
• Validators
• Combinators

Install

go get -u github.com/cospectrum/validol

Requires Go version 1.22.0 or greater.

Usage

import (
	"errors"
	vd "github.com/cospectrum/validol"
)

type Sex string

func (s Sex) Validate() error {
	return vd.OneOf[Sex]("male", "female", "other")(s)
}

type Email string

func (e Email) Validate() error {
	return vd.All(
		vd.Len[string](vd.Gt(5)),
		vd.Len[string](vd.Lte(100)),
		vd.Email,
	)(string(e))
}

type User struct {
	Email Email
	Sex   Sex
	age   int
}

func (u User) Validate() error {
	return errors.Join(
		vd.Gte(18)(u.age),
		vd.Walk(u),
	)
}

func main() {
	users := []User{
		{Email: "first_user@mail.com", age: 22},
		{Email: "second_user@mail.com", Sex: "male"},
	}
	if err := vd.Validate(users); err != nil {
		panic(err)
	}
}

Validators

Type Validator[T] is equivalent to func(T) error.
For validation during recursive Walk, you can implement Validatable interface, which requires a single Validate() error method.

Name	Input	Description
Validate	T	If T has Validate() error method, then it will call it, otherwise will call Walk
Walk	T	Recursively checks all descendants that have the Validate() error method. The descendants are public struct fields, slice/array elements, map keys/values
Required	T	Checks that the value is different from default
Empty	T	Checks that the value is initialized as default
NotNil	T	Checks that the value is different from nil
Nil	T	Checks that the value is nil
Email	string	Email string
UUID4	string	Universally Unique Identifier UUID v4

Combinators

Functions that create a Validator[T].

Name	Input	Output	Description
All	...Validator[T]	Validator[T]	Checks whether all validations have been completed successfully
Any	...Validator[T]	Validator[T]	Checks that at least one validation has been completed successfully
Not	Validator[T]	Validator[T]	Logical not
OneOf	...T	Validator[T]	Checks that the value is equal to one of the arguments
Eq	T comparable	Validator[T]	==
Ne	T comparable	Validator[T]	!=
Gt	T cmp.Ordered	Validator[T]	>
Gte	T cmp.Ordered	Validator[T]	>=
Lt	T cmp.Ordered	Validator[T]	<
Lte	T cmp.Ordered	Validator[T]	<=
Len	Validator[int]	Validator[T]	Checks whether the len of the object passes the specified Validator[int]
StartsWith	string	Validator[string]	Checks if the string starts with the specified prefix
EndsWith	string	Validator[string]	Checks whether the string ends with the specified suffix
Contains	string	Validator[string]	Checks whether the specified substr is within string
ContainsRune	rune	Validator[string]	Checks whether the specified Unicode code point is within string

Documentation

Index

• func Email(s string) error
• func Empty[T any](t T) error
• func Nil[T any](t T) error
• func NotNil[T any](t T) error
• func Required[T any](t T) error
• func UUID4(s string) error
• func Validate[T any](t T) error
• func Walk[T any](t T) error
• type Validatable
• type Validator
  • func All[T any](validators ...Validator[T]) Validator[T]
  • func Any[T any](validators ...Validator[T]) Validator[T]
  • func Contains(substr string) Validator[string]
  • func ContainsRune(r rune) Validator[string]
  • func EndsWith(suffix string) Validator[string]
  • func Eq[T comparable](val T) Validator[T]
  • func Gt[T cmp.Ordered](val T) Validator[T]
  • func Gte[T cmp.Ordered](val T) Validator[T]
  • func Len[T any](validateLen Validator[int]) Validator[T]
  • func Lt[T cmp.Ordered](val T) Validator[T]
  • func Lte[T cmp.Ordered](val T) Validator[T]
  • func Ne[T comparable](val T) Validator[T]
  • func Not[T any](fn Validator[T]) Validator[T]
  • func OneOf[T comparable](vals ...T) Validator[T]
  • func StartsWith(prefix string) Validator[string]

Functions

func Email

func Email(s string) error

func Empty

func Empty[T any](t T) error

func Nil

func Nil[T any](t T) error

func NotNil

func NotNil[T any](t T) error

func Required

func Required[T any](t T) error

func UUID4

func UUID4(s string) error

func Validate

func Validate[T any](t T) error

func Walk

func Walk[T any](t T) error

Types

type Validatable

type Validatable interface {
	Validate() error
}

type Validator

type Validator[Of any] func(Of) error

func All

func All[T any](validators ...Validator[T]) Validator[T]

func Any

func Any[T any](validators ...Validator[T]) Validator[T]

func Contains

func Contains(substr string) Validator[string]

func ContainsRune

func ContainsRune(r rune) Validator[string]

func EndsWith

func EndsWith(suffix string) Validator[string]

func Eq

func Eq[T comparable](val T) Validator[T]

func Gt

func Gt[T cmp.Ordered](val T) Validator[T]

func Gte

func Gte[T cmp.Ordered](val T) Validator[T]

func Len

func Len[T any](validateLen Validator[int]) Validator[T]

func Lt

func Lt[T cmp.Ordered](val T) Validator[T]

func Lte

func Lte[T cmp.Ordered](val T) Validator[T]

func Ne

func Ne[T comparable](val T) Validator[T]

func Not

func Not[T any](fn Validator[T]) Validator[T]

func OneOf

func OneOf[T comparable](vals ...T) Validator[T]

func StartsWith

func StartsWith(prefix string) Validator[string]