Currently, I am working on a very complex product. Unit testing is something unknown to this product till date. Hence the code base is too complex to keep it compatible with unit tests. I am supposed to develop a TDD framework for this product so that at least the newly written code will be thoroughly tested by unittests.
I am a newbie to the world of TDD and unit testing as well. I am going bonkers trying to wrap my head around the testing frameworks and tools available. My current focus is on code coverage that generates a complete report about package level, function level, and branch level coverage. The code base is targeted to java or groovy. I was going through Cobertura and some other tools and frameworks but I hardly know the goods and bads of each, as I am a newbie. Please suggest a good framework/tool that is apt for my needs.