Following up to my previous post, I'm really regretting the lack of general testing facilities in Joomla.
Curiously, the Joomla MVC framework doesn't seem to help as much as hurt. Unlike Rails/Grails/Cake etc the framework doesn't do code generation and doesn't speak to clean coding idioms. So you end up with the worst of both worlds: the constraints of a framework with the productivity of from-the-ground-up work.
It isn't that testing in the framework is poorly framed -- it is simply absent from the picture. The developer shouldn't really be "rolling his own" when it comes to extending and integrating with a content management system. An active Joomla contributor could speak better to the test coverage and soundness of their PHP tool chain and technology stack, but I've seen little evidence that testing is handled with any rigor in the Joomla community at large.
Why do I bring it up? It costs a lot of time to fix stuff that other people broke, and I cannot afford to do that. I don't like doing it either. Foundations should be demonstrably sound and stable. If you cannot demonstrate soundness and stability with rigorous tests, your are living in a magical pixie dust land where everything flies because you wave your hands and say it is so.