yii2-app-basic/tests/acceptance/_config.php

<?php

return yii\helpers\ArrayHelper::merge(
	require(__DIR__ . '/../../config/web.php'),
	require(__DIR__ . '/../_config.php'),
	[
		'components' => [
			'db' => [
				'dsn' => 'mysql:host=localhost;dbname=yii2_basic_acceptance',
			],
			'mail' => [
				'useFileTransport' => true,
			],
			'urlManager' => [
				'showScriptName' => true,
			],
		],
	]
);