Consider replacing chokidar with filespy

Is your feature request related to a problem? Please describe. Vite could take advantage of Watchman when installed and the other benefits of using filespy, like event throttling, native performance (powered by @parcel/watcher), and more.

Disclaimer: I haven’t compared chokidar and filespy in a benchmark yet. Should probably do that.

Describe the solution you’d like Replace chokidar with filespy.

[devongovett]

Since I was tagged… we replaced Chokidar in Parcel mainly because we ran into a lot of issues with it especially when building large projects, both on macOS and linux. Mainly this was due to running out of file descriptors due to watching individual files, and the slow crawl over the whole filesystem that chokidar does on startup. In addition, there were stability issues where the watcher would simply stop working after a while. This could have improved in the last couple years though, not sure.

That said, the main reason we wrote our own module wasn’t actually for watching but for caching. Parcel’s watcher can be used to efficiently detect changes in files even after a restart, which makes it work almost like watch mode after a restart. Not sure if this is a problem vite has though.

[aleclarson]

@dominikg Not a problem with filespy, since each file event provides a fs.Stats object whose isSymbolicLink method can be called to determine if fs.realpath should be used to resolve the symlink (if such behavior is desired).