laravel_sketch/app/Base/BaseController.php

<?php

namespace App\Base;

use App\Http\Controllers\Controller;

class BaseController extends Controller
{
    public function ok($data = null)
    {
        return [
            "data" => $data,
        ];
    }

    public function error(string $msg)
    {
        return [
            "error" => $msg,
        ];
    }
}