Default Mock Expectations

Often in unit testing, we end up with sets of tests which use the same object dependency over and over again. Rather than mocking this class/object within every single unit test (requiring a mountain of duplicate code), we can instead define reusable default mocks within the test case’s setup() method. This even works where unit tests use varying expectations on the same or similar mock object.

How this works, is that you can define mocks with default expectations. Then, in a later unit test, you can add or fine-tune expectations for that specific test. Any expectation can be set as a default using the byDefault() declaration.