| But that's tangential. Maintenance is tangential? Most of the work across all of the fields of programming is probably maintenance. If you are doing exploratory programming, what does unit testing get you? It gets you the ability to change your mind and do deep reworkings of very complicated systems with a higher degree of confidence. It's most valuable for maintenance, while duck typing, however. How can you write the tests before the code if you don't have a spec to work from in the first place? You end up doing better interface design at a finer granularity than you would have to otherwise. It slows you down, but requires greater discipline in terms of good architecture, so you end up saving time that way. Test first is really just design-up front, but with 3 or 4 orders of magnitude more iterations. This is best for duck typing languages. Would I unit test in Eiffel, which supports Design By Contract? Doubt it. you don't need to wait for the unit tests to run on your nightly build! In the original Extreme Programming, one ran unit tests before checking in any code! |