Question

After reading an interesting article about unit testing behavior instead of state, I came to realize that my unit tests often are tightly coupled to my code because I am using mocks.
I cannot image writing unit tests without mocks but the fact is that these mocks are coupling my unit test very much to my code because of the expect andReturn calls.

For example when I create a test that uses a mock, I record all calls to the specific mock and assign return values.
Now when I change the implementation of the actual code for whatever reason, a lot of tests break because that call was not expected by the mock, forcing me to update the unit test also, and effectively forcing me to implement every change twice…
This happens a lot.

Is this issue intrinsic to using mocks, and should I learn to live with it, or am I doing something fundamentally wrong?
Please enlighten me 🙂
Clear examples coming with the explanation are most welcome of course.

Answer 1

when I create a test that uses a mock,
I record all calls to the specific
mock and assign return values

It sounds like you may be over-specifying expectations.

Try to build as little setup code as possible into your tests: stub (rather than expect) all behavior that doesn’t pertain to the current test and only specify return values that are absolutely needed to make your test work.

This answer includes a concise example (as well as an alternative, more detailed explanation).