If you've started with advanced template, please refer to ["testing" guide](https://github.com/yiisoft/yii2-app-advanced/blob/master/docs/guide/start-testing.md)
for more details about running tests.
If you've started with basic template, check its [README "testing" section](https://github.com/yiisoft/yii2-app-basic/blob/master/README.md#testing).