Since Yum 0.8 a set of unit tests is being shipped to test portions of your
Application. The Unit-Tests are included in the tests/unit folder. 

In order to use them, simply copy them over to you application-specific
unit test folder (webroot/protected/tests/unit) and run them with phpunit. See 

http://www.yiiframework.com/doc/guide/1.1/en/test.overview
http://www.yiiframework.com/doc/guide/1.1/en/test.unit

on how unit test works.
