iluminar/goodwork

use Exception;

class UserIsAlreadyMember extends Exception
{
    public function render()
    {
        return response()->json([
            'status'   => 'error',
            'message'  => 'User is already a member',
        ], 409);
    }
}

use App\Base\Models\User;
use App\Base\Exceptions\UserIsNotMember;

class MemberController extends Controller
{
    public function store()
    {
        $this->authorize('add', User::class);
        // Get model of team/project/office depending on request
        $group = $this->getGroupModel();
        if ($this->userIsAlreadyMember($group, request('user_id'))) {
            throw new UserIsAlreadyMember;
        }
        //
    }
    //
    private function userIsAlreadyMember($group, $userId)
    {
        return $group->members()->where('user_id', $userId)->exists();
    }
    //
}