I sat down with David Chelimsky at Rubyconf today to talk about rSpec and an interesting topic came up.

In my mind, there are two reasons to use a mock object: first, when you’re developing TDD style, you physically don’t have the objects yet; and second, so that you can tightly focus your unit tests. Maybe, these two different purposes should use a different mechanism.

His question to me then was, “Do you replace your mocks with the real objects after you’ve implemented those objects?”. I guess I hadn’t thought about that before. Do you? If so, how do you handle the extra complexity, maintaining sane associations and valid data?