Yes but it's not really fair to expect me to know how to do that. Just because I know how to do it for backend code, where it's often a lot easier to see those copies, doesn't mean I'm just a negligent asshole for not doing it on the frontend. I don't know how, it's a different skillset.
Nobody expects you to know that, but I'm curious to hear how do you know it for backend code but not frontend code. Have any examples?