I see software as composed of: data (what) -> control (when) -> alg (how). And software should be designed in this order. Hence you should write tests only whe

I see software as composed of: data (what) -> control (when) -> alg (how). And software should be designed in this order. Hence you should write tests only when you want to freeze your design in a specific area. I.e. make sure that you got the domain model right, and freeze it via tests, etc. I found this book very valuable: https://www.manning.com/books/unit-testing https://www.manning.com/books/unit-testing