Want to work both on node and in a browser. my problem was the scope of window and $

t.coffee

class Cursor
  constructor:  (dadDiv) ->
    dadDiv.append $ "<div class='cursor'></div>"
    @visible = false

  toggle : ->
     cursor.style.visibility =
      if @visible = !@visible then 'visible' else 'hidden'
      setTimeout toggle, 500


main = ->
   $ "body"
   c = new Cursor $ "body" 
   console.log ($ ".cursor").length

if window?
  main()
else
 { jsdom } = require 'jsdom'
 this.$ = require 'jquery'
 this.window = jsdom().createWindow()
 main.call(window)