<?php namespace Codeception; class ApplicationTest extends \PHPUnit\Framework\TestCase { public static function setUpBeforeClass() { require_once \Codeception\Configuration::dataDir() . 'register_command/examples/MyCustomCommand.php'; } public function testRegisterCustomCommand() { \Codeception\Configuration::append(array('extensions' => array( 'commands' => array( 'Project\Command\MyCustomCommand')))); $application = new Application(); $application->registerCustomCommands(); try { $application->find('myProject:myCommand'); } catch (\Exception $e) { $this->fail($e->getMessage()); } } }