Go Validation

Easy Validation for Go.

Contents

• Installation
• Usage
• Hint
• Rules
• Dependencies

Installation

$ go get -u github.com/adnanbrq/validation

Usage

All you have to do is put the (valid) tag inside your structs
In order to use multiple rules you have to seperate them with the pipe symbol > | <

You can inspect the following code if you want to see how it can be used. https://github.com/adnanbrq/slugify/blob/main/internal/handler/link_handler.go#L20

package main

import (
  "github.com/adnanbrq/validation"
)

type MyStruct struct {
	Email                     string `valid:"email"`
	Age                       int    `valid:"int|between:18,26"`
	RegEx                     string `valid:"regex:^[0-9]$"`
	RegExExposePatternInError string `valid:"regex:^[0-9]$;expose"`
}

func main() {
  m := MyStruct{
		Email: "max@mustermann.de",
		Age: 18,
		RegEx: "123",
		RegExExposePatternInError: "ABC",
  }
  
  errors := validation.Validate(m)

  // error handling
  if len(errors) > 0 {
	  /*
		errors may look like this
		errors = [
			"age": [
				"must be between 1 and 4",
				"...",
			],
			"email": [
				"..."
			],
		]
	  */
  }

}

Hint

Go will always initialize all fields of a struct with a default value if it's a primitive type.
Because of that required or nullable will have no effect.

You can use required or nullable with fields whose type is interface{} as it will be initialized with nil by go.\

Rules

Name	Note
Required	Skips upcoming rules if the value is not present
Nullable	Skips upcoming rules if the value is not present
Between	Checks length of strings, size of ints, etc.
Bool	Checks if the value if either 0, 1 false, true
Default	Runs if given rule is not found.
Email	Same as RegEx
JSON	Tries to unmarshal the given json string.
JWT	Checks if given string matches a RegEx Pattern
Max	Checks length of strings, size of ints, etc.
Min	Checks length of strings, size of ints, etc.
Numeric	Checks if the value is of type int
RegEx	Might not work if using : in regex. (Used as delimiter in rules)
String	Checks if the value is of type string

Dependencies

• github.com/stretchr/testify - v1.6.1 Assertions