Identifying worse-case scenarios

To maximize the efficiency of your testing, identify the worst-case scenarios and just test them. If they work, then all simpler cases should be successful as well. Many tests will be a subset of complex tests, so it’s fastest just to perform the complex ones. For example, if your users can have multiple copies of many different relationships, add multiple instances of every kind of relationship. If that works, then having just one relationship should work, as well as having multiple copies of just one type because those are simpler cases.

One exception is with newly written code, where you can expect to find issues. Then, if you test the worst-case scenario, you’re likely to hit a problem and possibly several simultaneously. In that case, it’s faster to gradually build up to the most complex configuration. Then you can isolate and debug issues as they arise, and you know which step triggered them. However, once each aspect of...