I'm not criticizing your comment, just adding a little bit to it. You're totally right, there's a lot of complexity when you're testing complex features in a hu

I'm not criticizing your comment, just adding a little bit to it. You're totally right, there's a lot of complexity when you're testing complex features in a huge app. Buuuuut, a huge complex app is probably not the right place to try learning any new technology. Do a few small things first, prototype something out, test it along the way. Then maybe something a little more complicated. Slowly expand your horizon of uncertainty. That way you only need to focus on learning one thing at a time. The assert() call that OP suggested is exactly enough to start thinking about testing simple code; once you're doing well at it, you can start noticing repetition and opportunities for abstraction (and finding existing libraries that have these abstractions already done for you); then, you start doing testing on more complex code and start learning about mocks to facilitate testing there. Some people do really well in a "big bang" kind of learning environment, but I definitely don't. For me, learning works best given: a rough map of where I'm trying to get (even just a mind map that gives me things to look up when I get stuck), and an opportunity to master each piece before expanding onto new topics.