watch-and-sync

A script to watch a directory on your local machine and copy it to a remote when changes are detected

Usage

npx watch-and-sync --help

Notes and observations

The script uses Node's fs.watch API to handle the directory watching. There are a few third-party packages that do similar things that I considered but chose not too as I didn't encounter the problems they claim to solve.

chokidar, for example, claims that fs.watch:

• Doesn't report filenames on OS X
• Doesn't report events at all when using editors like Sublime on OS X
• Does not provide an easy way to recursively watch file trees
• Often reports events twice

I tested the first three points and found that they simply aren't the case; I assume they were problems that have since been fixed in later versions of Node.js. I did observe fs.watch reporting events twice (see debounce below).

Dependencies

rsync

• Widely-used and stable
• Used to do the actual syncing between local and remote
• Script assumes the executable is present in your PATH

debounce

• npm package
• fs.watch seems to often get called twice for the same file change
  • Not sure on the cause - initial investigation seems to point to it coming from the underlying FSEvents API