Queenabby/tests/codeception/config/backend/unit.php

<?php

/**
 * Application configuration for backend unit tests.
 */
return yii\helpers\ArrayHelper::merge(
    require(YII_APP_BASE_PATH.'/common/config/main.php'),
    require(YII_APP_BASE_PATH.'/common/config/main-local.php'),
    require(YII_APP_BASE_PATH.'/backend/config/main.php'),
    require(YII_APP_BASE_PATH.'/backend/config/main-local.php'),
    require(dirname(__DIR__).'/config.php'),
    require(dirname(__DIR__).'/config-local.php'),
    require(dirname(__DIR__).'/unit.php'),
    require(__DIR__.'/config.php'),
    [
    ]
);