The Extreme Programming method rules that unit tests be done first, and any bug fixes be accompanied by a test. Whatever your experience or opinion on various formal methodologies, unit and regression tests are useful tools. They are especially useful when coding to a standard, helping to identify flaws and catch regressions in the code. Khtml uses regression testing, and when someone fixes a bug or merges some of the Apple WebCore code, reminders are made to update the Changelog and write a test.

It was of interest to see the Nikolas Zimmermann commit a KSVG test suite, in the ksvgtests module. The test module will compare the output with a baseline image. For more information see ksvgtests/HOWTO.