Sync two directories without inventing another watcher.

npm i sync-directory -g
syncdir ./src ./mirror -w

# or in a project
npm i sync-directory

Copy vs hardlink

copy is the default. It is slower, but the target files are real files, so most watchers fire.

hardlink is faster and uses almost no extra disk. Some watchers will not notice changes on the target side. Pick it when you control both trees.

See the comparison if you are coming from rsync or a homegrown fs-extra loop.

Watch

Pass watch: true (API) or -w (CLI). Under the hood this is chokidar. You get a watcher back from the sync API.

Filter

exclude skips paths. forceSync always wins, so you can keep node_modules out except one package.

Sync or async

syncDirectory.sync() blocks. syncDirectory.async() returns a Promise and can await afterEachSync.