No, you are confusing unit testing with TDD. Unit testing is just testing units of code. TDD is the religious practice adhered to by some followers of Agile that is a "design tool" where you write tests first. http://en.wikipedia.org/wiki/Test-driven_development
>not for exposing nullpointer exceptions
If you are using a language primitive enough to have null pointer exceptions, then using unit tests to try to detect some of them is a perfectly reasonable thing.
>not for exposing nullpointer exceptions
If you are using a language primitive enough to have null pointer exceptions, then using unit tests to try to detect some of them is a perfectly reasonable thing.