Custom Drupal Modules with SimpleTest Coverage

Recently I've been building custom Drupal modules with SimpleTest coverage. The modules use a web service API to transform data and bring it back into Drupal as custom entity types. The SimpleTest classes provide quality assurance through functional testing of the modules, forms, entities and API services. I've discovered I enjoy expanding the native capabilities of Drupal by integrating it with web services. SimpleTest is fun to work with once you get the hang of it. I feel better about applying frequent Drupal core updates knowing I can thoroughly test my modules on each new update.