用CoffeeScript代碼茉莉花測試的奇怪行爲

Question

我正在寫Jasmine測試，但它顯示奇怪的行爲。

這是我的代碼：

root = exports ? this 
class root.SomeClass 
    constructor: -> 
    @index = 0 
    incrementIndex: -> @index++ 
    decrementIndex: -> @index-- 

，這是我的測試代碼：

describe "Object", -> 
    object = new SomeClass 

    describe ".index", -> 
    describe "when index = 3", -> 
     object.index = 3 

     describe "when next button is clicked", -> 
     object.incrementIndex() 
     it "returns 4", -> 
      expect(object.index).toBe 4 

     describe "when previous button is clicked", -> 
     object.decrementIndex() 
     it "returns 3", -> 
      expect(object.index).toBe 2 

測試結果如下：

Failing 2 specs 

Photos initialized .index when index = 3 when next button is clicked returns 4. 
Expected 3 to be 4. 

Photos initialized .index when index = 3 when previous button is clicked returns 3. 
Expected 3 to be 2. 

而且很奇怪的是當我註釋掉了最後4行測試代碼，測試通過。我不明白髮生了什麼...> _ <

謝謝你的幫助。

Answer 1

您的測試會相互影響。 Do setup in beforeEach blocks。

 
describe "Object", -> 
    object = undefined 

    beforeEach -> 
    object = new SomeClass 

    describe ".index", -> 
    describe "when index = 3", -> 
     beforeEach -> 
     object.index = 3 

     describe "when next button is clicked", -> 
     beforeEach -> 
      object.incrementIndex() 

     it "returns 4", -> 
      expect(object.index).toBe 4 

     describe "when previous button is clicked", -> 
     beforeEach -> 
      object.decrementIndex() 

     it "returns 3", -> 
      expect(object.index).toBe 2 

未選中，如果這段代碼是有效的，但仍然展示了應該如何解決你的測試。注意2行中的object = undefined。您需要在此聲明變量，否則object將在每個beforeEach和it塊的本地。