shouldn't this be added to https://github.com/nodejs/node/blob/d3eb1cb3850b4194f652a07e74631788dc94e4c4/lib/internal/fs/recursive_watch.js instead?

I'm not familiar with that, are you suggesting that the change be made to the general recursive watch mechanism instead of the watch/restart functionality? Currently, on linux - the watch functionality isn't recursive at all, so I'm not sure how changes to the recursive mechanism would change the behaviour in watch mode?

I'm not familiar with that, are you suggesting that the change be made to the general recursive watch mechanism instead of the watch/restart functionality? Currently, on linux - the watch functionality isn't recursive at all, so I'm not sure how changes to the recursive mechanism would change the behaviour in watch mode?

Yes, that is my suggestion. that file is an implementation for environments where recursive watch isn't natively implemented via libuv, and it was added after the addition of watch mode.

my guess that file already handles this edge case, and if not it can be added there

I started working on usage of non native recursive watch at #45271 and there were some issues (in the CI if I recall), but I would be happy if you or someone else picked it up

what's the advantage of a recursive watch? Particularly in environments where it isn't natively supported, where it's still one watcher per file.

The nice thing about non recursive watch mode is it should have near perfect detection - no false positives where an unused file triggers a restart. It's possible I've missunderstood how the recursive watch works though.

A trivial limitation of the recursive watch implementation you linked is that it appears it doesn't follow symlinks, so changes to local NPM modules (installed via symlink) won't trigger a restart.

My goal with this PR is not that it implements (or fixes) recursive file watching, but that in non recursive mode it correctly detects changes to a single watched file

This pull request has been marked as stale due to 90 days of inactivity.
It will be automatically closed in 30 days if no further activity occurs. If this is still relevant, please leave a comment or update it to keep it open.