KeyDirective.php

<?php

namespace App\Graphql\Directives;

use Nuwave\Lighthouse\Schema\Directives\BaseDirective;
use Nuwave\Lighthouse\Support\Contracts\DefinedDirective;

/**
 * Class KeyDirective
 *
 * @package App\Graphql\Directives
 */
class KeyDirective extends BaseDirective implements DefinedDirective
{
    /**
     * @return string
     */
    public function name(): string
    {
        return 'key';
    }

    /**
     * @return string
     */
    public static function definition(): string
    {
        return /* @lang GraphQL */
            <<<'SDL'
directive @key(
  fields: String!
) on OBJECT | INTERFACE
SDL;
    }
}