不可在package裡, 同時使用module.exports和exports.xxx

util = require 'util'

Q = require 'q'

randomInteger = (base) ->

  Math.floor Math.random() * base

class People

  constructor: (@name) ->

  do: (telephone, callback) ->

    util.debug "==> #{@name} #{@type}.do, #{telephone}"

    deferred = Q.defer()

    timer = setTimeout =>

      console.log 'do a long study task'

      deferred.resolve telephone;

      util.debug "<== #{@name} #{@type}.do"

    , randomInteger 3000

    deferred.promise

class Student extends People

  constructor: (name) ->

    super name

    @type = 'Student'

 class Worker extends People

  constructor: (name) ->

    super name

    @type = 'Worker'

exports.Student = Student

exports.module = Worker # 錯誤寫法

====================

上述exports.modules = Worker宣告當初始該package時, 對外使用介面為Worker function

Worker = require './school'

結果將沒有任何方式可以取得Student function

所以應該要改寫成

exports.Student = Student
exports.Worker = Worker

使用方式如下:
Student = require('school').Student
Worker = require('school').Worker

student = new Student("baby")
worker = new Worker("Rick")