Question

这个代码可以用更多功能/下划线样式重构，主要是检查addedEvents中是否存在actualEvents的部分吗？

describe 'when removing', ->

  it 'should remove all bound events from the window', ->
    @view.remove()
    addedEvents = ['dragenter', 'drop', 'dragleave', 'register']
    actualEvents = _.keys $._data(window, 'events') #=> ['onload', 'drop', 'etc.']
    for event in addedEvents
      present = _.contains(actualEvents, event)
      expect(present).toBe(false)

Answer 1

如果您特别希望它使用下划线功能，则应执行以下操作。

addedEvents = ['dragenter', 'drop', 'dragleave', 'register']
actualEvents = _.keys $._data(window, 'events')
present = _.reduce addedEvents, ((prev, current) ->
  prev or _.contains actualEvents, current 
  ), false)
expect(present).toBe false

当然，您可以在没有下划线的情况下执行此操作，但它需要ES5函数：

addedEvents = ['dragenter', 'drop', 'dragleave', 'register']
actualEvents = Object.keys $._data(window, 'events')
present = addedEvents.reduce, ((prev, current) ->
  prev or actualEvents.indexOf(current) > -1
  ), false)
expect(present).toBe false

Answer 2

使用Coffee的postfix for和in运算符可以使代码更具可读性：

addedEvents = ['dragenter', 'drop', 'dragleave', 'register']
actualEvents = _.keys $._data(window, 'events') #=> ['onload', 'drop', 'etc.']
expect(event not in actualEvents).toBe(true) for event in addedEvents

如果你使用Jasmine作为测试库，你可以使用我认为更具可读性的toContain：）

expect(actualEvents).not.toContain(event) for event in addedEvents

最后，如果您想使用Underscore寻找更具功能性的风格，您可以将此断言视为检查addedEvents上是否存在actualEvents，换句话说，这两个数组的intersection为空：

expect(_.intersection(actualEvents, addedEvents).length).toBe(0)

如何使用underscore.js重构此数组比较？

2 个答案: