Laravel Snippet: Custom Validation Rules

When Laravel's built-in validation rules aren't enough, don't stuff custom logic into your controllers. Instead, create an invokable Rule object.

Generating the Rule

php artisan make:rule Uppercase

The Snippet

namespace App\Rules;

use Closure;
use Illuminate\Contracts\Validation\ValidationRule;

class Uppercase implements ValidationRule
{
    /**
     * Run the validation rule.
     *
     * @param  \Closure(string): \Illuminate\Translation\PotentiallyTranslatedString  $fail
     */
    public function validate(string $attribute, mixed $value, Closure $fail): void
    {
        if (strtoupper($value) !== $value) {
            $fail('The :attribute must be completely uppercase.');
        }
    }
}

How to Use It

You can now use this rule inside any Form Request or Controller validation array.

use App\Rules\Uppercase;

$request->validate([
    'company_code' => ['required', 'string', 'size:6', new Uppercase],
]);