mock file upload

UserTest.php

<?php

        $list = [];
        $fp = new \SplFileObject('php://temp', 'rw');
        foreach ($list as $fields) {
            $fp->fputcsv($fields);
        }

        $uploadedFile = \Mockery::mock(
            '\Symfony\Component\HttpFoundation\File\UploadedFile',
            [
                'getClientOriginalName'      => 'users.csv',
                'getClientOriginalExtension' => 'csv',
                'openFile'                   => $fp,
            ]
        );

        $response = $this->action(
            'POST',
            'AdminPanel\UserController@bulkRegister',
            [],
            [],
            [],
            ['list' => $uploadedFile]
        );