feat: add audio validation

[dapzthelegend]

Fixes Or Enhances

Adds built-in audio validation tag support via a new isAudio validator.

isAudio implementation

// isAudio is the validation function for validating if the current field's value contains the path to a valid audio file
func isAudio(fl FieldLevel) bool {
	mime, ok := detectFileMIMEType(fl.Field())
	if !ok {
		return false
	}

	return strings.HasPrefix(mime, "audio/")
}

Example Usage

package main

import (
	"fmt"

	"github.com/go-playground/validator/v10"
)

type Upload struct {
	AudioPath string `validate:"required,audio"`
}

func main() {
	validate := validator.New()

	u := Upload{AudioPath: "testdata/music.mp3"}
	if err := validate.Struct(u); err != nil {
		fmt.Println("validation failed:", err)
		return
	}

	fmt.Println("validation passed")
}

Make sure that you've checked the boxes below before you submit PR:

• Tests exist or have been written that cover this particular change.

@go-playground/validator-maintainers

[dapzthelegend]

@the-fanan

[the-fanan]

Looks good to me. Let's ship this please!

[zemzale]

One small thing that could be changed, but other than that don't see an issue with this. Is 90% the same thing as isImage.

There is an idea maybe that we can just have a generic mimetype or smth validator, but that is besides this PR.

[dapzthelegend]

Hi @zemzale — rebased feature/audio-validation on latest master (7 commits, same upstream changes as #1544). The only conflict was translations/it/it.go (new bcp47_strict_language_tag entry vs. mimetype/audio entries) — resolved by keeping all three tags.

Branch is now conflict-free. Noted that the review decision still shows REVIEW_REQUIRED since @zemzale's earlier review was dismissed after subsequent commits. If the implementation looks good, a fresh approval would unblock merge. Happy to address any remaining concerns.

[zemzale]

Looks great