There might even be a whole ladder going further down. You, something about the value of everything and the cost of nothing. I've seen tests with bugs in them,

There might even be a whole ladder going further down. You, something about the value of everything and the cost of nothing. I've seen tests with bugs in them, hiding bugs in the code and giving a false sense of robustness. because, you know, code coverage is 100% so we cannot have any bugs, right? I had to work with tests that test many trivial things, tightly coupled with implementation details. Those would discourage small refactorings, because it took a lot of time to understand and fix the failed tests as changes in details of implementation would lead to failures in unittests. It also slowed down the pace of development for no good reason. Unless a test has a value that exceeds the cost, it is a net negative.