https://github.com/twharmon/govalid

Struct validation using tags
https://github.com/twharmon/govalid

go validation

Last synced: about 1 month ago
JSON representation

Struct validation using tags

• Host: GitHub
• URL: https://github.com/twharmon/govalid
• Owner: twharmon
• License: mit
• Created: 2019-02-17T23:25:43.000Z (almost 6 years ago)
• Default Branch: master
• Last Pushed: 2024-11-14T22:45:16.000Z (about 1 month ago)
• Last Synced: 2024-11-14T23:29:50.901Z (about 1 month ago)
• Topics: go, validation
• Language: Go
• Homepage:
• Size: 129 KB
• Stars: 46
• Watchers: 7
• Forks: 7
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-go-extra - govalid - 02-17T23:25:43Z|2021-10-14T17:46:17Z| (Validation / Fail injection)

README

        
# Govalid

[![](https://goreportcard.com/badge/github.com/twharmon/govalid)](https://goreportcard.com/report/github.com/twharmon/govalid)

Use Govalid to validate structs.

## Documentation

For full documentation see [pkg.go.dev](https://pkg.go.dev/github.com/twharmon/govalid).

## Todo

Document use of `dive`. Rules are now ordered.

- pointers: dereference and check remaining rules

- slices / arrays: check each item with remaining rules

- structs: validates the struct according to its own field tags (remaining rules have no meaning)

## Example

```go

package main

import (

	"errors"

	"fmt"

	"log"

	"strings"

	"unicode/utf8"

	"github.com/twharmon/govalid"

)

type Post struct {

	// ID has no constraints

	ID int

	// Title is required, must be at least 3 characters long, and

	// cannot be more than 20 characters long

	Title string `valid:"req|min:3|max:20"`

	// Body is not required, cannot be more than 10000 charachers,

	// and must be "fun" (a custom rule defined below).

	Body string `valid:"max:10000|fun"`

}

func main() {

	// Add custom string rule "fun" that can be used on any string field

	// in any struct.

	govalid.Rule("fun", func(v any) error {

		switch tv := v.(type) {

		case string:

			if float64(strings.Count(tv, "!"))/float64(utf8.RuneCountInString(tv)) > 0.001 {

				return nil

			}

			return errors.New("must contain more exclamation marks")

		default:

			return errors.New("fun constraint must be applied to string only")

		}

	})

	fmt.Println(govalid.Validate(&Post{

		ID:    5,

		Title: "Hi",

		Body:  "Hello world!",

	}))

}

```

## Contribute

Make a pull request.