The Drupal simpletest module is awesome! I discovered it while I was looking for a new GHOP task, and I loved the idea of it immediately. So, I claimed the task, and I'm writing now to share what I learned with you.
The simpletest module extends the php simpletest framework. Basically, it allows users to run a series of automated tests on a Drupal install.
Often, new code is entered into Drupal contributed modules, and even the Drupal core, without being thoroughly tested - or even tested at all, in some situations. With simpletest, tests become so easy (without having to manually try maybe hundreds of situations) that finding and fixing bugs becomes a breeze.
Just in the past few days, during my coding for simpletest,
two THREE FOUR critical core bugs for Drupal 6 have been found. This makes you wonder: is anyone actually bothering to test this stuff? And these weren't small issues; you'd think, if people were testing, they'd notice that node revisions were completely broken (they didn't WORK).
You can help by joining the simpletest revolution! Module maintainers, write simpletests for your modules by implementing hook_simpletest! See the article on how to write them. Other Drupal coders, write simpletests for portions of the Drupal core not covered by the current simpletest module. And people who know nothing about code, post issues to applicable modules' issue queues asking for simpletests to be included.
Spread the word! Join the simpletest revolution!