Lots of ways to interpret it, but stripping back the story, it's showing a technique to sharpen your skills and looking at a problem in different ways. As you

Lots of ways to interpret it, but stripping back the story, it's showing a technique to sharpen your skills and looking at a problem in different ways. As you say there are definitely better ways to test the actual wrapper class in a real life situation, but showing the test suites one by one gives the reader a chance to see how the narrator approaches the problem and various situations are word-wrap class would face. If you were set your own 'katas' and reproduce similar code from scratch or a framework, I can see it helping some people look at various problems in different ways and look objectively at how they solve them. Every person has their own methods all the same.