Manually testing the functionality of your code takes time and is prone to error. The solution is to automate your tests! In a previous video, we took a look at Selenium and how you can use it to automate testing by using a real browser. In this video, we explain SimpleTest, which is both a module and a testing framework used throughout the Drupal world.

Using SimpleTest can save you hours, greatly reduce the number of oversights when doing testing, and it's much quicker to run numerous and complicated tests than Selenium. As a bonus, many modules come bundled with tests so you can insure that your code isn't causing problems outside of your module.