如何在coffeescript中的特定范围内声明一个变量？ [英] How do I declare a variable in a specific scope in coffeescript?

问题描述

我试图在coffeescript中写一个使用beforeEach块的茉莉花测试。这遇到一个问题coffeescript的变量范围。这里是我想写的：

I'm trying to write a jasmine test in coffeescript that uses a beforeEach block. This runs into a problem with coffeescript's variable scoping. Here's what I'd like to write:

describe 'PhoneDetailCtrl', () ->
  beforeEach () ->
    scope = angular.scope()
    $browser = scope.$service('$browser')

  it 'should fetch phone detail', () ->
    scope.params = {phoneId:'xyz'}
    $browser.xhr.expectGET('phones/xyz.json').respond({name:'phone xyz'})
    ctrl = scope.$new(PhoneDetailCtrl)

    expect(ctrl.phone).toEqualData({})
    $browser.xhr.flush()

    expect(ctrl.phone).toEqualData({name:'phone xyz'})

工作，因为 scope 和 $ browser 将声明与 var 在最深的范围。也就是说，一旦在 beforeEach ，然后再次在 it 块。我可以通过初始化它们来强制变量声明在正确的范围，但是这似乎很奇怪：

This doesn't work, though, because the scope and $browser will get declared with var in the innermost scope. That is, once in the beforeEach and then again in the it block. I can force the variables to be declared in the right scope by initializing them, but this seems very strange:

describe 'PhoneDetailCtrl', () ->
  $browser = {}
  scope = {}
  beforeEach () ->
    scope = angular.scope()
    $browser = scope.$service('$browser')

  it 'should fetch phone detail', () ->
    scope.params = {phoneId:'xyz'}
    ...

这个工程，但它编译的JavaScript实际上是

This works, but the javascript it compiles to is actually

describe('PhoneListCtrl', function() {
  var $browser, ctrl, scope;
  $browser = {};
  ctrl = {};
  scope = {};

其中所有我需要的是 var $ browser，ctrl，scope; 。 in coffeescript？

where all I need is the line var $browser, ctrl, scope;. Can I write this more concisely in coffeescript?

推荐答案

您正在以正确的方式做。

You are doing it the right way.

这在 CoffeeScript文档中有所描述，我不担心它创建的JS。 ，这是一个有点凌乱，如果你是自己写的，但这是你必须与当你使用一个重写作如CoffeeScript一样的东西。

This is described in the CoffeeScript documentation. I wouldn't worry about the JS that it creates. Yes, it is a bit messy if you were to write it yourself, but this is one of the things that you have to live with when you use a re-writer like CoffeeScript.

你可以把变量放在当前上下文中，如果你愿意的话jasmine.Spec对象的好奇，所以它是一个相对安全和适当的地方放置变量...只是不要覆盖上下文中现有的变量）：

You can put the variables in the current context if you wish (which happens to be your jasmine.Spec object for the curious, so it is a relatively safe and appropriate place to be putting variables... just don't overwrite existing vars in the context.):

describe 'PhoneDetailCtrl', () ->
  beforeEach () ->
    @scope = angular.scope()
    @$browser = @scope.$service('$browser')

it 'should fetch phone detail', () ->
  @scope.params = {phoneId:'xyz'}
  #... etc

$ b

You can also setup your own variable in which to store things

describe 'PhoneDetailCtrl', () ->
  setup = {}

  beforeEach () ->
    setup.scope = angular.scope()
    setup.$browser = setup.scope.$service('$browser')

  it 'should fetch phone detail', () ->
    setup.scope.params = {phoneId:'xyz'}
    #... etc

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