Tests that help you fix failures are great - just be sure they're helping more than they're hurting.
Beyond that I think the key is to test the things you don't expect to change. The user always needs to be able to log in. But I expect developers will rearrange the private method boundaries.
Beyond that I think the key is to test the things you don't expect to change. The user always needs to be able to log in. But I expect developers will rearrange the private method boundaries.