Souke/tests/codeception/common/_bootstrap.php

<?php
defined('YII_DEBUG') or define('YII_DEBUG', true);
defined('YII_ENV') or define('YII_ENV', 'test');

defined('YII_APP_BASE_PATH') or define('YII_APP_BASE_PATH', dirname(dirname(dirname(__DIR__))));

require_once(YII_APP_BASE_PATH . '/vendor/autoload.php');
require_once(YII_APP_BASE_PATH . '/vendor/yiisoft/yii2/Yii.php');
require_once(YII_APP_BASE_PATH . '/common/config/bootstrap.php');

// set correct script paths
$_SERVER['SERVER_NAME'] = 'localhost';
$_SERVER['SERVER_PORT'] = '80';

Yii::setAlias('@tests', dirname(dirname(__DIR__)));