The Asymmetry of Change: Why Your Tests Are Looking the Wrong Way

The Asymmetry of Change: Why Your Tests Are Looking the Wrong Way A passing build is often treated as a certificate of correctness. In reality, it's a narrow contract. It doesn't prove your code is right. It proves that the assertions you wrote in the past, against behaviors you anticipated back then, still hold true today. When you open a pull request, your unit tests ask: "Does the system still behave the way it used to?" The question you actually need to answer is different: "Is the new behav