I treat each unit test as an individual assertion on the logic of the program. I find using a <methodName>_<Conditions>_Expectations syntax documents the intent

I treat each unit test as an individual assertion on the logic of the program. I find using a <methodName>_<Conditions>_Expectations syntax documents the intent very well. E.g: testCalculateGrade_scoreOver85_returnsAnA() You're right that refactoring the code can break tests. That's when you have to ask if the original assertion still stands. It's OK to change them if your understand of the problem has changed also.