I’ve been playing around recently trying to do a bit of refactoring work with copy pasting in Claude and using Cursor. This week I tried a task where I had a small script that used jquery (one Ajax call and a bunch of dom manipulations).

I found that it was pretty easy to get cursor into a place where it had decimated the file and each tab complete suggestion became more and more broken.

Claude was given the task wholesale and did a reasonable job but introduced a subtle bug by moving a tracking call outside of the Ajax promise and I could not convince it to put it right. It kept apologising and then offering up more incorrect code.

I’d say that the original result was good enough that I could pretty much take it and fix it, but only because I knew all the code and libraries well enough. It was only about 150 lines of simple code and by the time I’d finished I was joking with the team that I could have spent all the time wrestling vim macros instead and come out about the same.

What’s your experience been with correctness?