Here's some of the code antirez described in the OP, if you want to see what expert usage of Claude Code looks like: https://github.com/antirez/linenoise/commit/c12b66d25508bd70... and https://github.com/antirez/linenoise/commit/a7b86c17444227aa...

This looks more worrying than impressive. It's long files of code with if-statements and flag-checking unicode bit patterns, with an enormous number of potential test-cases.

It's not conceptually challenging to understand, but time consuming to write, test, and trust. Having an LLM write these types of things can save time, but please don't trust it blindly.

I see dividing the tests and code into two different changes is pretty nice, In fact I have been using double agent thing where one is writing tests and other is writing the code, solves the attention issue also. Although the code itself looks harder to read, but that is probably more on me than Claude.