laravel exists already validation rules code example

Example 1: custom rule laravel validation

public function store()
{
    $this->validate(request(), [
        'song' => [function ($attribute, $value, $fail) {
            if ($value <= 10) {
                $fail(':attribute needs more cowbell!');
            }
        }]
    ]);
}

Example 2: validation rule if row exist laravel

//update request 
return [
	'username' => 'unique:users,username,' . $this->route('internalUser')->id . ',id',
];

//create request
return [
	'username' => 'unique:users'
];