Ye at-least for projects with many developers involved. My experience is that tests that tests too much makes QA collapse when the original authors of the tests

Ye at-least for projects with many developers involved. My experience is that tests that tests too much makes QA collapse when the original authors of the tests are gone and no-one know what tests are actually testing implementation or spec. I use #ifdef:s to enable "intermediate state" and implementation asserts usually to mark them as development tests.