I have a love-hate relationship with unit tests. They are great in theory but in practice not enough people do it to reach that "critical-mass". By that I mean

I have a love-hate relationship with unit tests. They are great in theory but in practice not enough people do it to reach that "critical-mass". By that I mean very few projects you pick up (especially in the maintenance phase) will have tests. And writing good tests is HARD. If you think it is easy then you are testing the wrong thing. A lot of people say refactoring without tests is pure danger. I disagree. Sometimes you don't know enough about the problem space to write good tests. However, refactoring forces you to understand the "micro" world of the code. And this gives you a leg up in order to understand what tests are actually needed.