mockito使用

mockito学习资料:

http://docs.mockito.googlecode.com/hg/org/mockito/Mockito.html

http://blog.csdn.net/sdyy321/article/details/38757135

 

1、验证行为是否发生

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@Test
public void mockedList(){
    List mockedList = mock(List.class);
    mockedList.add("one");
    mockedList.clear();
    verify(mockedList).add("one");
    verify(mockedList).clear();
}

验证add和clear是否执行。

2、验证返回值

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@Test
    public void two(){
        //模拟创建一个List对象
        LinkedList mockLinkedList = mock(LinkedList.class);
 
        //打桩,当LinkedList调用get(0)方法时,第一次返回zero,第二次n次返回nnnn
        when(mockLinkedList.get(0)).thenReturn("zero").thenReturn("nnnn");
 
        //使用mock对象
        System.out.println(mockLinkedList.get(0));
        System.out.println(mockLinkedList.get(0));
        System.out.println(mockLinkedList.get(0));
 
        //验证行为get是否发生
        verify(mockLinkedList).get(0);
 
    }

这里注意所有的方法都会有返回值,如果没有设置返回值,那么就会返回null或者空集、适当的类型。 Stubbing可以被重写,也就是同一个参数方法可以放回不同的值,但是已最后一次设置的值为标准。一旦被 Stubbed,无论方法被调用多少次,都只会返回Stubbed value。最后一次最重要原则。

3、参数匹配

通过equals()来验证参数。

不同的参数返回不同的结果:

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when(comparable.compareTo("Test")).thenReturn(1); 
when(comparable.compareTo("Omg")).thenReturn(2);

一旦你使用了参数匹配器,那么所有的参数都必须由匹配器给出:

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//stubbing using built-in anyInt() argument matcher
 when(mockedList.get(anyInt())).thenReturn("element");
 
 //stubbing using hamcrest (let's say isValid() returns your own hamcrest matcher):
 when(mockedList.contains(argThat(isValid()))).thenReturn("element");
 
 //following prints "element"
 System.out.println(mockedList.get(999));
 
 //you can also verify using an argument matcher
 verify(mockedList).get(anyInt());
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verify(mock).someMethod(anyInt(), anyString(), eq("third argument"));
   //above is correct - eq() is also an argument matcher
 
   verify(mock).someMethod(anyInt(), anyString(), "third argument");
   //above is incorrect - exception will be thrown because third argument is given without an argument matcher.

4、验证调用次数

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@Test
    public void three(){
        List mockedList = mock(List.class);
        mockedList.add(1);
        mockedList.add(2);
        mockedList.add(2);
        mockedList.add(3);
        mockedList.add(3);
        mockedList.add(3);
        //验证是否被调用一次,等效于下面的times(1),默认的,可以不写
        verify(mockedList).add(1);
        verify(mockedList,times(1)).add(1);
        //验证是否被调用2次 
        verify(mockedList,times(2)).add(2);
        //验证是否被调用3次 
        verify(mockedList,times(3)).add(3);
        //验证是否从未被调用过
        verify(mockedList,never()).add(4);
        //验证至少调用一次
        verify(mockedList,atLeastOnce()).add(1);
        //验证至少调用2次
        verify(mockedList,atLeast(2)).add(2);
        //验证至多调用3次
        verify(mockedList,atMost(3)).add(3);
    }

add(1)这个方法被调用了1次,add(2)这个被调用了2次。add(3)这个方法被调用了3次,如果将verify(mockedList,times(1)).add(3);运行后那么就会出现错误:

5、模拟方法体抛出异常

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doThrow(new RuntimeException()).when(mockedList).clear(); 
  //following throws RuntimeException:
mockedList.clear();
 
doThrow(new RuntimeException()).when(list).add(1); 
list.add(1);

6、验证执行的顺序

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@Test
    public void four(){
        List firstList = mock(List.class);
        List secondList = mock(List.class);
        //using mocks
        firstList.add("was called first one mock");
        secondList.add("was called second one mock");
        //create inOrder object passing any mocks that need to be verified in order
        InOrder indOrder = inOrder(firstList,secondList);
 
        indOrder.verify(firstList).add("was called first one mock");
        indOrder.verify(secondList).add("was called second one mock");
 
 
    }

如果将11,12调换,

indOrder.verify(secondList).add("was called second one mock");

indOrder.verify(firstList).add("was called first one mock");

会出现如下错误:

可是如果顺序如下:

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firstList.add("was called first one mock");
secondList.add("was called second one mock");
InOrder indOrder = inOrder(secondList,firstList);
indOrder.verify(firstList).add("was called first one mock");
indOrder.verify(secondList).add("was called second one mock");

inorder中顺序调换后,上面程序居然没有出错?难道我理解错了。验证的顺序是按照inOrder中给出的,也就是second要在first前面,而在verify中明显second在first后验证了,应该出错啊。

7、模拟对象上没有相互关系

 

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//using mocks - only mockOne is interacted
 mockOne.add("one");
 
 //ordinary verification
 verify(mockOne).add("one");
 
 //verify that method was never called on a mock
 verify(mockOne, never()).add("two");
 
 //verify that other mocks were not interacted
 verifyZeroInteractions(mockTwo, mockThree);

8、找出多余的调用

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//using mocks
 mockedList.add("one");
 mockedList.add("two");
 
 verify(mockedList).add("one");
 
 //following verification will fail 检查是否有未被验证的行为
 verifyNoMoreInteractions(mockedList);
 
  verify(list,times(2)).add(anyInt()); 
//检查是否有未被验证的互动行为,因为add(1)和add(2)都会被上面的anyInt()验证到,所以下面的代码会通过 
   verifyNoMoreInteractions(list);

mockedList还有add("two")没有验证,所以出错。

9、使用注解来mock

这里注意要在构造函数中初试化mock对象,否则mock对象为null。

也可以通过在类上使用注解:@RunWith(MockitoJUnitRunner.class)  

这样就不需要初始化mock了。

10、连续调用

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@Test(expected = RuntimeException.class
    public void consecutive_calls(){ 
        List mockList = mock(List.class);
        //模拟连续调用返回期望值,如果分开,则只有最后一个有效 
        when(mockList.get(0)).thenReturn(0); 
        when(mockList.get(0)).thenReturn(1); 
        when(mockList.get(0)).thenReturn(2); 
        when(mockList.get(1)).thenReturn(0).thenReturn(1).thenThrow(new RuntimeException()); 
        assertEquals(2,mockList.get(0)); 
        assertEquals(2,mockList.get(0)); 
        assertEquals(0,mockList.get(1)); 
        assertEquals(1,mockList.get(1)); 
        //第三次或更多调用都会抛出异常 
        mockList.get(1); 
    }

11、使用回调来stub

通用:

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when(mock.someMethod(anyString())).thenAnswer(new Answer() {
     Object answer(InvocationOnMock invocation) {
         Object[] args = invocation.getArguments();
         Object mock = invocation.getMock();
         return "called with arguments: " + args;
     }
 });
  
 //Following prints "called with arguments: foo"
 System.out.println(mock.someMethod("foo"));

使用:

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@Test
    public void six(){
        List mockList = mock(List.class);
        when(mockList.get(anyInt())).thenAnswer(new Answer<Object>() {
            public Object answer(InvocationOnMock invocation) throws Throwable {
                Object[] args = invocation.getArguments();
                return "hi:"+args[0];
            }
        });
        assertEquals("hi:0",mockList.get(0));
        assertEquals("hi:1",mockList.get(1));
    }

12、对于void方法,有系列函数可以用来处理。

doThrow() doAnswer doNothing doReturn。当一个void的方法有异常抛出时可以使用doThrow()。

13、监控真实对象

当使用spy的时候真正的方法将会被调用,而不再是stub的对象了,这个和部分mock的思想是一样的。

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@Test
    public void seven(){
        List list = new LinkedList();
        List spy = spy(list);
          
        //optionally, you can stub out some methods:
        when(spy.size()).thenReturn(100);
          
        //using the spy calls real methods
        spy.add("one");
        spy.add("two");
          
        //prints "one" - the first element of a list
        System.out.println(spy.get(0));
          
        //size() method was stubbed - 100 is printed
         System.out.println(spy.size());
          
        //optionally, you can verify
        verify(spy).add("one");
        verify(spy).add("two");
    }

使用spy的时候需要注意一点:有时候是不能使用when语句的

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List list = new LinkedList();
   List spy = spy(list);
    
   //Impossible: real method is called so spy.get(0) throws IndexOutOfBoundsException (the list is yet empty)
   when(spy.get(0)).thenReturn("foo");
    
   //You have to use doReturn() for stubbing
   doReturn("foo").when(spy).get(0);

14、设置未stub的调用的默认值

对于没有stub方法的调用,我们一般返回null,或者是默认类型。也可以修改使其返回你指定的值。

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@Test 
    public void eight(){ 
        //mock对象使用Answer来对未预设的调用返回默认期望值 
        List mocklist = mock(List.class,new Answer(){ 
            public Object answer(InvocationOnMock invocation) throws Throwable { 
                return 999
            }
        }); 
        //下面的get(1)没有预设,通常情况下会返回NULL,但是使用了Answer改变了默认期望值 
        assertEquals(999, mocklist.get(1)); 
        //下面的size()没有预设,通常情况下会返回0,但是使用了Answer改变了默认期望值 
        assertEquals(999,mocklist.size()); 
    }

 

posted @ 2015-12-03 18:44  silenceer  阅读(602)  评论(0编辑  收藏  举报