Javascript 继承放置在另一个文件中的子类（CoffeeScript）

如何使用CoffeeScript在不同文件中正确组织子类？下面是代码问题的一个简单示例。Snake运行正常，但在尝试使用Dog类（因为它位于另一个类中）时，会出现以下错误：

TypeError:Dog不是构造函数

主文件：.test/Animals.coffee

#expect = require "expect.js"
Animal = require "../learning/Animals"
Snake = Animal.Snake
Dog = require "../learning/Dog"
#Dog = Animal.Dog #unresolved variable

describe 'animals', ->
  it 'test inheritance', ->
    sam = new Snake "Sammy the Python"
    peanut = new Dog "Peanut the Dog"

    sam.move()
    peanut.move()

class Animal
  constructor: (@name) ->

  move: (meters) ->
    console.log(@name + " moved #{meters}m.")

class Snake extends Animal
  move: ->
    console.log( "Slithering...")
    super 5

module.exports = { Animal, Snake }

家长班级：。学习/动物。咖啡

#expect = require "expect.js"
Animal = require "../learning/Animals"
Snake = Animal.Snake
Dog = require "../learning/Dog"
#Dog = Animal.Dog #unresolved variable

describe 'animals', ->
  it 'test inheritance', ->
    sam = new Snake "Sammy the Python"
    peanut = new Dog "Peanut the Dog"

    sam.move()
    peanut.move()

class Animal
  constructor: (@name) ->

  move: (meters) ->
    console.log(@name + " moved #{meters}m.")

class Snake extends Animal
  move: ->
    console.log( "Slithering...")
    super 5

module.exports = { Animal, Snake }

儿童班：。学习/狗。咖啡

Animal = require './Animals'

class Dog extends Animal
  move: ->
    console.log( "Runs...")
    super 15

module.exports = { Dog }

---

您正在导出包含类的对象：

module.exports = { Dog }

这相当于

module.exports = {
  Dog: Dog
}

您可以分解导入的对象：

{ Dog } = require('./Dog.coffee')

这类似于：

a = require('./Dog.coffee')
Dog = a.Dog

您应该保持一致，始终导出对象，并始终将导入的对象分解为您需要的部分

或者，我建议给每个类它自己的文件，以避免混淆