Chapter 6. Quality and XP

It's impossible to talk about testing without mentioning quality, and vice versa. Testing is almost always performed with some implied level of quality in mind. While a 100% pass rate is required of unit tests, this is not necessarily the case for acceptance tests. It's up to the customer to decide whether all tests she defines are critical and must pass. Acceptance testing in XP requires some definition of quality levels and criteria. This is often an ongoing negotiation as the project proceeds.