I'm not sure I agree that the market makes a great test suite. It kinda hurts when you fail. But yeah, there's other things you can use, like - A/B testing (fo

I'm not sure I agree that the market makes a great test suite. It kinda hurts when you fail. But yeah, there's other things you can use, like - A/B testing (for web apps). You can automate "code smell" detectors, and get a continuous graph on how good your code seems to be. Of course, things like converters and math functions (anything non-GUI) can benefit from unit tests.