| Don't think in terms of tests -- think in terms of examples. Write examples of how you would like to be able to solve common cases and handle edge cases if you had the ideal interface based on what you know at the time, then use unit tests with stubbed out interfaces as a tool while trying to develop the implementation. Refine and even rewrite your examples as you learn about what works and what doesn't work. Recursively break down complex pieces into smaller modules as you learn what can be handled independently and composed with the other pieces. Break off independent examples depicting how you expect those modules to work and be used as new unit test suites for those new modules. Don't sweat testing the implementation details, especially when prototyping. What you want is to use tests as a way to speed up your development process and improve the quality of your design and architecture. Try to write tests that show off how nice your code is to use and how few edge cases you need to handle when calling it. It'll raise the bar for how your code interacts with the rest of the application or system and give you smaller pieces to work and focus on. Finally, for really green field stuff with a lot of unknown unknowns, you often have to write a lot of standalone, bottom-up throw-away prototypes for things. That doesn't invalidate the usefulness of tests, so don't be afraid to do that pretty regularly. |