Small module to mirror a folder to another folder. Supports live mode as well.
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Latest commit afd82e5 Apr 24, 2018


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Small module to mirror a folder to another folder.

Supports watch mode as well where it will continuously watch the src folder and mirror new entries as they are created/removed.

npm install mirror-folder


var mirror = require('mirror-folder')

mirror('/Users/maf/cool-stuff', '/Users/maf/cool-stuff-mirror', function (err) {
  if (err) throw err
  console.log('Folder was mirrored')


var progress = mirror(src, dst, [options], [callback])

Mirror src to dst. Returns a progress event emitter.

Options include:

  watch: false, // keep watching the src and mirror new entries,
  dereference: false, // dereference any symlinks
  equals: fun, // optional function to determine if two entries are the same, see below
  ignore: null, // optional function to ignore file paths on src or dest
  dryRun: false, // emit all events but don't write/del files,
  keepExisting: false, // whether to delete extra files in the destination that are not present in the source
  skipSpecial: true // skip any files that are not regular files

The equals function looks like this:

function equals (src, dst, cb) {
  console.log('src.stat', src.stat)
  console.log('dst.stat', dst.stat)
  cb(null, true) // callback with true if they are the same or false if not

Per default the equals function will check if mtime is larger on the src entry or if the size is different

The ignore function looks like this:

function ignore (file) {
  // ignore any files with secret in them
  if (file.indexOf('secret') > -1) return true
  return false

If you are using a custom fs module (like graceful-fs) you can pass that in with the src or dst like this:

mirror({name: '/Users/maf/cool-stuff', fs: customFs}, {name: '/Users/maf/cool-stuff-mirror', fs: anotherFs})

progress.on('pending', {name, live})

Emitted when file/dir added to pending queue.


Array of items pending to be processed.

progress.on('put', src, dst)

Emitted when a file/folder is copied from the src to the dst folder.

progress.on('put-data', data)

Emitted when a file chunk is read from the src.

progress.on('put-end', src, dst)

Emitted at the end of a write stream (files only).

progress.on('del', dst)

Emitted when a file/folder is deleted from the dst folder.

progress.on('ignore', src, dst)

Emitted when a file/folder is ignored (either src or dst).

progress.on('skip', src, dst)

Emitted when a file/folder is skipped. Either src file already is equal to dst file or file does not exist in either place.


Emitted when the mirror ends (not emitted in watch mode). The mirror callback is called when this event is emitted as well

progress.on('error', err)

Emitted when a critical error happens. If you pass a mirror callback you don't need to listen for this.


Stop mirroring files. If using watch mode, close the file watcher.