The more automated ones will separately write tests and code, and if the code doesn't compile or pass the test, give itself the error messages and update its code.

Code Interpreter does this a bit in Chat-GPT Plus with some success.

I don't think it needs much more than a GPT-4 level LLM, and a change in IDEs and code structure, to get this working well enough. Place it gets stuck it'll flag to a human to help.

We'll see though! Lots of startups and big tech companies are working on this.