Simple function finding all files of a given extension with EventEmitter

findFiles.js

// Give a list of files all of them which match an extension
function findFiles (files, extension) {
  const emitter = new EventEmitter()

  if (files.length === 0) {
    // yield an error
    emitter.emit('error', 'no files supplied')
  }

  // Check for matches
  function checkFiles () {
    files.forEach(file => {
      if (path.extname(file) === extension) {
        // yield a result
        emitter.emit('match', file)
      }
    })
  }

  // Ask the event loop to loop through our loop ...
  process.nextTick(checkFiles)

  // For chainability on on()
  return emitter
}