I’ve found that golden master tests (aka snapshot testing) pair very well with fixtures. If I need to add to the fixtures for a new test, I regenerate the golden files for all the known good tests. I barely need to glance at these changes because, as I said, they are known good. Still I usually give them a brief once over to make sure I didn’t do something like add too many records to a response that’s supposed to be a partial page. Then I go about writing the new test and implementing the change I’m testing. After implementing the change, only the new test’s golden files should change.

They are also nice because I don’t have to think so much about assertions. They automatically assert the response is exactly the same as before.