On: Things I learnt the hard way in thirty years of software development

[Nasrudith]

Reminds me of one unusual application of tests - working with inadequate or overadequate documentation (filled with many lines but difficult to find what you need) they work well as "scratch pads" for details which are unclear like "Does it return null or throw an exception when you attempt to remove something not in the collection?"

[pjc50 → Nasrudith]

Exactly. They can be a great form of "case analysis", and can also be translated back into business-analyst-speak or use cases.