> I've seen code with so much mocked that many unit tests failed to test anything other than behaviour of mocks. One example of this was a test that passed bec

> I've seen code with so much mocked that many unit tests failed to test anything other than behaviour of mocks. One example of this was a test that passed because of the expected behavior as determined by a mock, but the code failed in the staging environment because the underlying library changed its method signature to take some parameters in a different order. To me, this basically was a signal that that particular test and tests like it were essentially useless in determining whether the code was really in a working state.