Hire/fire a webpack watcher after detecting new files in the file system

watch

#!/usr/bin/env coffee
os = require 'os'
chokidar = require './nosync/node_modules/chokidar'
spawn = require('child_process').spawn
watcher = null

debounce = (fn, delay=100) ->
  timer = null
  ->
    context = this
    args = arguments
    clearTimeout timer
    timer = setTimeout((->
      fn.apply context, args
    ), delay)

start = ->
  console.log "hiring new watcher"
  cmd = 'webpack'
  cmd += '.cmd' if ~['win32', 'win64'].indexOf os.platform()
  watcher = spawn cmd, ['--watch', '--watch-polling'], stdio: 'inherit'
  watcher.on 'close', (code, signal) ->
    console.log "child process terminated due to receipt of signal #{signal}"
    start()

restart =
  debounce ->
    if watcher
      console.log "firing #{watcher.pid}"
      watcher.kill()
    else
      start()

chokidar.watch('modules/versions').on 'add', (path) ->
  console.log "file #{path} has been added."
  restart()