Thursday, 10 May 2007

Overview of Doing QA in PHP

"So what does PHP do QA'ing for our applications?" asks Lukas Kahwe Smith. He tries to give an overview of the present status of Quality Assurance (QA) in PHP.

He starts by saying that at the very basic level you have your unit tests using PHPUnit or phpt. Usually at least all your core components, like your db layer, mod_rewrite link generator and parser should be covered with unit tests.

He points out that when on getting the actual runtime modules, where unit tests become too troublesome to write especially if they are dependent on time of day or session variables like user rights and session specific states. He says, that at this point you probably want to move on to using things like Selenium or BadBoy.

The next critical area in QA he talks about is Application Programming Interface (API) documentation, which can be generated via PHPDocumentor or Doxygen. This helps you to analyze how many classes and methods are missing documentation. He adds that for core libraries in PEAR there are now even documentation coverage analysis scripts.

He also thinks its important that applications, or more specifically their underlying frameworks, provide debugging tools.

In the final level in terms of tools he refers to things like code analyzers that check CS violations, XSS or SQL injection attacks. However, he comments that the most important approach to QA'ing PHP applications is a commit mailing list and encouraging peer review. He initiates that committing some bogus code that doesn't break any unit tests to check if everybody is on their toes is necessary, if you see too few comments on people’s commits. In the same context things like paired programming and help improve the quality of code.

He concludes by saying that a checklist will also help to facilitate the process of QA.