Yeah, I guess I would make the distinction between simple stubs and heavyweight mocks and fakes. If you're using a lot of the latter in your unit tests, that's

Yeah, I guess I would make the distinction between simple stubs and heavyweight mocks and fakes. If you're using a lot of the latter in your unit tests, that's a code smell to me; unit tests should ideally not be concerned with the state of the world, which is where mocks (especially fakes) tend to come in. Obviously there are no absolutes, but that's my rule of thumb and it's served me well.