I made this same mistake refactoring a function to not process duplicates that the original dev caught in code review. I argue that assumptions (intentionally r

I made this same mistake refactoring a function to not process duplicates that the original dev caught in code review. I argue that assumptions (intentionally re-processing duplicates) should be explicitly communicated through comments, unit tests, or assertions. In the article, author states that existing unit tests checked that two digit zip codes were invalid. The question remains how a refactor that fails unit tests was pushed to master.