Unit testing is a very important task of professional, scalable software development. Many tools exist to support unit testing in one or another way. All tools come with advantages and drawbacks. One of the best known test frameworks in the PHP world is PHPUnit. With the release of symfony, Fabien Potencier released another new testing framework for PHP: lime.

He compares them both, talking about where they came from and what sort of features they have included. He also gives some sample code for each of the frameworks and shows how a simple test would look in each.

From the first moment I was introduced to the concept of continuous integration I have been really interested in this. I've been playing with several packages for CI and set them up for fun. One thing that kept bothering me was that I could not test my own symfony projects with it. I started working on the symfonyUnderControlPlugin a few months ago, and quickly had a working proof of concept. It wasn't perfect, but it did the job.

Strapped for time, he didn't get much chance to work on it until the company he works for (Ibuildings) gave them time to work on Open Source projects. The results is his preview release, version 0.0.1.

If you keep an eye on the timeline, you probably saw that the symfony unit tests have been completely reworked lately. This is because we switched from simpletest, which was fine but had side effects when functional tests were executed all at once, to our own testing framework, lime.

Lime is more lighweight than PHPUnit or simpletest and has several advantages. First, it launches test files in a sandbox to avoid strange effects between each test file run (one of the reasons we were unable to fix the old symfony core tests). It also introduces a new sfBrowser, sfTestBrowser and more importantly sfDomCssSelectorBrowser that allow you to write functionnal tests with ease. It is not backward compatible but is a lot more powerful than the old system. Oh, and it holds in a single file, lime.php, without any dependence.

They show some examples of its usage (and a note on which tests will need to be updated) as well as the output that would come of it. They've also included some sample tests (in the "test/" folder of the release) if you'd like to check it out more throughly.