I write contract tests in order to help with the drifting test doubles problem: how do I know that my stubs and expectations and spies and mocks behave “like the real thing”? I do this because contract tests run in less time than integrated tests, I feel more confident with passing contract tests than I do with integrated tests, and they help me document my understanding of the contracts of the code that I use. Unfortunately, it remains possible to write a contract test that contradicts a...
