I feel like there's definitely an art to mocking. Rather than mocking out the module being called (A calls B, A_test mocks B), you want to mock out its dependen

I feel like there's definitely an art to mocking. Rather than mocking out the module being called (A calls B, A_test mocks B), you want to mock out its dependencies (A calls B calls C, A_test mocks C). But if you swap out said dependency, now you have to go update other modules' integration tests to mock out the new service.