Инициализировано Yii2 приложение, выпилены лишние части, накинуты чуточку нужных

tests/codeception/config/functional.php

@@ -0,0 +1,18 @@
+<?php
+/**
+ * Application configuration shared by all applications functional tests
+ */
+return [
+    'components' => [
+        'request' => [
+            // it's not recommended to run functional tests with CSRF validation enabled
+            'enableCsrfValidation' => false,
+            // but if you absolutely need it set cookie domain to localhost
+            /*
+            'csrfCookie' => [
+                'domain' => 'localhost',
+            ],
+            */
+        ],
+    ],
+];