This is a super interesting approach to JS. Conceptually, it’s really cool. In practice, I don’t think I’d do it (at least for any projects I can think of) because explaining it to others would be difficult and representing complex logic as “commands” sounds a bit difficult.
In a weird way, it reminds me of actor frameworks though. The difference is of course the separation of effects.
One thing I wish the author would have done, though, is add some type hints. I know it’s about JS, but even some jsdoc types would have helped. It was a bit hard to know at first what the input types were to these functions.
Author here. In my experience, AI coding tools like Claude Code can write code in the Effect system style, and that could be a great starting point for getting developers not familiar with this approach on board.
I considered adding JSDoc type comments, but that would make the code a bit verbose.