On the Web Builder Zone (from DZone) Giorgio Sironi has posted a new article that talks about the different kinds of testing you can do on your application - both on the frontend and backend.

Automated testing supports your constant effort in design and refactoring, and besides that ensures that your application actually works in a reliable and repeatable way. [...] In this article I'll describe the different categories of testing, as applied to a Zend Framework 1 application, but this classification pertains to every web application based on object-oriented programming. Since this kind of applications is obviously PHP-based, PHPUnit will be the tool of choice along with some of its standard extensions.

He looks at five different types of testing you can do on your application:

• Unit testing
• Pragmatic unit testing
• Functional testing
• Integration testing
• Acceptance testing

Not all of these can be done with PHPUnit on the backend, but they (mostly) have automated tools of their own like Selenium for frontend interface testing.