Most development happens on the `develop` branch, which is occasionally rebased + merged into `master` when it's not incredibly broken. When this happens, the `develop` branch is usually pruned until I feel like making 'unsafe' changes again.
Fuzzing can be useful. We don't have testing done inside the IRCd itself, but this fuzzer I've written works alright and has helped shake out various bugs: [irc_fuzz.py](https://gist.github.com/DanielOaks/63ae611039cdf591dfa4).
In addition, I've got the beginnings of a stress-tester here which is useful:
https://github.com/DanielOaks/irc-stress-test
As well, there's a decent set of 'tests' here, which I like to run Oragono through now and then: