問題描述

我有如下測試方法:

MyClass myClass= Mockito.mock(MyClass.class);
Mockito.when(myClass.methodUsedInMethodBeingTested(Matchers.any(MyTypeParam.class))).thenReturn(Collections.<X, Y> emptyMap());

assertNull(myClass.methodToTest(myObject));
Mockito.verify(myClass).methodUsedInMethodBeingTested(Matchers.any(MyTypeParam.class));

methodUsedInMethodBeingTested 是一種我想模擬并返回空映射的方法.但我收到失敗消息說

The methodUsedInMethodBeingTested is a method that I want to mock and return an empty map. But I am getting the failure message saying

需要但未調用 myClass.methodUsedInMethodBeingTested()

Wanted but not invoked myClass.methodUsedInMethodBeingTested()

.

MyClass
{
   public XYZ methodToTest()
   {
    ....
    ....
    Map<X,Y> mp = methodUsedInMethodBeingTested(myTypeParam);
    .....
   }

   public Map<X,Y> methodUsedInMethodBeingTested(MyTypeParam myTypeParam)
   {
    .....
   }
}

推薦答案

你誤解了什么是 mock.當你在做的時候

You're misunderstanding what a mock is. When you're doing

MyClass myClass = Mockito.mock(MyClass.class);
// ...
assertNull(myClass.methodToTest(myObject));

您實際上并沒有在您的真實對象上調用 methodToTest.您正在模擬上調用 methodToTest，默認情況下，它什么也不做并返回 null，除非它被存根.引用 Mockito 文檔:

You're not actually invoking methodToTest on your real object. You're invoking methodToTest on the mock, which by default, does nothing and return null, unless it was stubbed. Quoting from Mockito docs:

默認情況下，對于所有返回值的方法，mock 返回 null、一個空集合或適當的原始/原始包裝值(例如:0、false、...對于 int/Integer、boolean/Boolean、...).

By default, for all methods that return value, mock returns null, an empty collection or appropriate primitive/primitive wrapper value (e.g: 0, false, ... for int/Integer, boolean/Boolean, ...).

這解釋了您隨后的錯誤:該方法實際上沒有在模擬上調用.

This explains your subsequent error: the method was really not invoked on the mock.

看來你想要的是 spy 改為:

It seems what you want here is a spy instead:

您可以創建真實對象的間諜.當您使用 spy 時，會調用 real 方法(除非方法被存根).

You can create spies of real objects. When you use the spy then the real methods are called (unless a method was stubbed).

警告說明:由于調用的是真正的方法，因此您不應該使用 Mockito.when 而是更喜歡 Mockito.doReturn(...).when，否則該方法將被真正調用一次.如果考慮表達式:

A note of warning though: since it is the real methods that are getting called, you should not use Mockito.when but prefer Mockito.doReturn(...).when, otherwise the method will be called once for real. If you consider the expression:

Mockito.when(myClass.methodUsedInMethodBeingTested(Matchers.any(MyTypeParam.class))).thenReturn(Collections.<X, Y> emptyMap());
             ^-----------------------------------^
                 this will be invoked by Java

方法 when 的參數必須被計算，但這意味著方法 methodUsedInMethodBeingTested 將被調用.因為我們有一個間諜，所以它是真正的方法將被調用.所以，改為使用:

the argument of the method when must be evaluated, but this means the method methodUsedInMethodBeingTested will be invoked. And since we have a spy, it is the real method that will be invoked. So, instead, use:

MyClass spy = Mockito.spy(new MyClass());
Mockito.doReturn(Collections.<X, Y> emptyMap()).when(spy).methodUsedInMethodBeingTested(Matchers.any(MyTypeParam.class));
assertNull(spy.methodToTest(myObject));
Mockito.verify(spy).methodUsedInMethodBeingTested(Matchers.any(MyTypeParam.class));

這篇關于Mockito:通緝但未調用的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！