[orange_puff]

This seems really impressive. I am too lazy to replicate this, but I do wonder how important the test suite is for a a port that likely uses straight forward, dependency free python code https://github.com/EmilStenstrom/justhtml/tree/main/src/just...

It is enormously useful for the author to know that the code works, but my intuition is if you asked an agent to port files slowly, forming its own plan, making commits every feature, it would still get reasonably close, if not there.

Basically, I am guessing that this impressive output could have been achieved based on how good models are these days with large amounts of input tokens, without running the code against tests.

[EmilStenstrom]

I think the reason this was an evening project for Simon is based on both the code and the tests and conjunction. Removing one of them would at least 10x the effort is my guess.

[simonw]

The biggest value I got from JustHTML here was the API design.

I think that represents the bulk of the human work that went into JustHTML - it's really nice, and lifting that directly is the thing that let me build my library almost hands-off and end up with a good result.

Without that I would have had to think a whole lot more about what I was doing here!

[orange_puff]

Do you mind elaborating? By API design, do you mean how they structured their classes, methods, etc. or something else?

[simonw]

I mean the design of the user-facing API: https://github.com/EmilStenstrom/justhtml/blob/main/docs/api...

See also the demo app I vibe-coded against their library here: https://tools.simonwillison.net/justhtml - that's what initially convinced me that the API design was good.

I particularly liked the design of JustHTML's core DOM node: https://github.com/EmilStenstrom/justhtml/blob/main/docs/api... - and the design of the streaming API: https://github.com/EmilStenstrom/justhtml/blob/main/docs/api...