I wish everyone would move away from code coverage as a metric and towards some kind of mutation framework.

There seem to be increasing numbers of devs getting themselves off on their "shiny 95% coverage" and patting themselves on the back for covering everything but the 5% of the codebase that actually needs thorough testing.

Oh, and that's ignoring the tests that just assert an exception isn't thrown, or don't assert anything at all. Completely bloody useless, but hey, you just carry on boasting how great all your tests are because you've got a higher coverage than the team next door 😤🙄