I've got a big project written in PHP and Javascript. The problem is that it's become so big and unmaintainable that changing some little portion of the code will upset and probably break a whole lot of other portions.
I'm really bad at testing my own code (as a matter of fact, others point this out daily), which makes it even more difficult to maintain the project.
The project itself isn't that complicated or complex, it's more the way it's built that makes it complex: we don't have predefined rules or lists to follow when doing our testing. This often results in lots of bugs and unhappy customers.
We started discussing this at the office and came up with the idea of starting to use test driven development instead of the develop like hell and maybe test later (which almost always ends up being fix bugs all the time).
After that background, the things I need help with are the following:
How to implement a test framework into an already existing project? (3 years in the making and counting)
What kind of frameworks are there for testing? I figure I'll need one framework for Javascript and one for PHP.
Whats the best approach for testing the graphical user interface?
I've never used Unit Testing before so this is really uncharted territory for me.