great article on how to layer your tests from ThoughtWorks
"I often hear opponents of unit testing (or TDD ) arguing that writing unit tests becomes pointless work where you have to test all your methods in order to come up with a high test coverage. They often cite scenarios where an overly eager team lead forced them to write unit tests for getters and setters and all other sorts of trivial code in order to come up with 100% test coverage.
There's so much wrong with that.
Yes, you should test the public interface. More importantly, however, you don't test trivial code. "
