source: app/Http/Requests/Dashboard/FileTypeRequest.php

<?php

namespace App\Http\Requests\Dashboard;

use Illuminate\Foundation\Http\FormRequest;
use League\Flysystem\Util\MimeType;
use League\MimeTypeDetection\MimeTypeDetector;

class FileTypeRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            "mimes" => [
                "required",
//                function ($attribute, $value, $fail) {
//
//                    try {
//                        $mimeType = mimes;
//                        @dd($mimeType);
//                        $mimetypes = $guesser->guess($pubdir . $avatar);
////                        if ($mimetypes == null) {
////                            $validator->errors()->add('avatar', 'No valid Mime/Type');
////                            return $validator;
////                        }
////                    }
////
////$mime= explode ('/', $mimetypes);
////if ($mime[0] != 'image') {
////    $validator->errors()->add('avatar', 'Not a valid image');
////}
//
//                        if (empty($archNum)) {
//                            $fail("Please enter folders Archive ID");
//                        }
//
//                        if ($deptId !== Department::find($this->request->get('department'))->code) {
//                            $fail("Folder Archive ID field format is invalid");
//                        }
//                    } catch (\Exception $e) {
//                        $fail("Please enter folders Archive ID");
//                    }
//                }
            ],
            "max_size" => "required|integer",
        ];
    }
}