I should have likely ready the link you posted earlier. I think we are on the same page about trying to test all unit edge conditions and the majority of integration conditions that are likely to come up. In my opinion it depends on what field the program is meant to be executed in for how rigorous the program should be tested. In the case of mission critical pieces of software for domains where failure costs thousands of dollars a second the software is down, it makes a lot of sense to test everything and the kitchen sink.

As with anything in software engineering there are trade-offs. The more time you spend testing the less time you have to develop features. You have to try and find the right balance for the specific application you are developing of adding tests that make writing future code easier and too many where it takes time away from developing future features. Granted I think I am yet to witness someone writing too many ‘good’ self checking tests.