You are way off on what Unit Testing is, and how it works, and what you need to do to start applying it.
You could add your first simple test TODAY on any bit of code that you isolated into a testable unit. It takes a little bit of time to get the idea of, like anything else.
Furthermore, Unit Testing is more than simply catching bugs - it is also about confirming that the desired output is being returned. Unit Tests and other types of testing can handle receiving multiple "moving parts" and tell you what outcomes are happening. Far more complex code that BattleMaster relies on testing to stay online.
(BTW - it has nothing to do with Doctrine. If anything Doctrine can make it more difficult sometimes, as everything has to be mocked. I would recommend you skip the db areas for now and look for small bits of code that can be refactored to functions, then learn how to write a few tests on those until you get steadier on your feet with it. It takes time, but there's a huge Open Source community willing to help )
I highly recommend that you take a Sat. afternoon off and play with it for an hour or two and understand what it can do for you. It even the short-term, it can save you many hours of having to go back and constantly fix small things - so it adds up to a huge savings very quickly.
