Continuing in their effort to help PHP developers keep their code bug-free, DevShed has posted part two of the series looking at unit testing your applications. Previously they had looked at the basics - of they work and what they're for. This time, they dig a little deeper, showing some of the additional features and conditions that PHPUnit has to offer.

This week, you will learn about running multiple tests simultaneously, creating more informative error messages, and more.

They get back into something they mentioned briefly before - packaging tests in a separate archive to keep it out of the main body of code (the same way separating content and display functionality is good). They also talk about how to run more than one test at the same time, a handy feature that lets you make regression tests.

They also show how to create more informative error messages and how to manually add more testing conditions for you to check custom bits of code that don't quite fit with the assertNull, assertEquals, and assertFalse crowd.

This article is an excerpt from the Sams Publishing book "Advanced PHP Programming" by George Schlossnagle.