"Otherwise you’re describing testing implementation rather than behavior, indicating you’re writing bad tests." Yeah, people have been threatening me for decad

"Otherwise you’re describing testing implementation rather than behavior, indicating you’re writing bad tests." Yeah, people have been threatening me for decades with the claim that if I write tests to test internals I'll have to refactor like crazy someday. I'm still waiting for someday to come. Meanwhile, it has caught a lot of bugs. I'm open to the possibility that there's something different about the way I write code that causes me to not have this problem. Stay tuned to my blog over the next couple of months if that intrigues you. In the meantime, as reality fails to correspond to theory, I go with reality.