Mockito 绕过静态方法进行测试

2022-01-14 00:00:00 mockito java junit

我需要使用 Mockito 测试 handleIn() 方法.

I need to test handleIn() method using Mockito.

但是代码需要调用这个遗留代码 Util.getContextPDO 这是一个静态方法.

However the code need to call this legacy code Util.getContextPDO which is a static method.

请注意，在测试环境中，这个 Util.getContextPDO 总是返回异常，我打算通过总是返回一个虚拟 IPDO 来绕过这个 Util.getContextPDO().

Note that in testing environment this Util.getContextPDO is always returns Exception, and I intend to bypass this Util.getContextPDO() by always return a dummy IPDO.

public class MyClass {
  public IPDO getIPDO() 
  {
    return Util.getContextPDO(); // note that Util.getContextPDO() is a static, not mockable.
  }

  public String handleIn(Object input) throws Throwable 
  {
    String result = "";
    IPDO pdo = getIPDO();

    // some important business logic.

    return result;
  } 
}

最初我认为这可以通过使用MyClass"类的 spy() 来实现，因此我可以模拟 getIPDO() 的返回值.下面是我使用 spy() 的初步尝试

Initially I thought this achieveable by using spy() of the class "MyClass", so I can mock the return value of getIPDO(). Below is my initial effort using spy ()

@Test
public void testHandleIn() throws Exception
{
    IPDO pdo = new PDODummy();


    MyClass handler = new MyClass ();
    MyClass handler2 = spy(handler);

    when(handler2.getIPDO()).thenReturn(pdo);
    PDOUtil.setPDO(pdo, LogicalFieldEnum.P_TX_CTGY, "test123");
    IPDO pdoNew = handler2.getIPDO();

    Assert.assertEquals("test123,(PDOUtil.getValueAsString(pdoNew, LogicalFieldEnum.P_TX_CTGY)));

}

但是 when(handler2.getIPDO()).thenReturn(pdo); 正在抛出我想避免的异常(因为 handler2.getIPDO() )似乎调用了真正的方法.

However the when(handler2.getIPDO()).thenReturn(pdo); is throwing the Exception that I want to avoid ( because handler2.getIPDO() ) seems to call the real method.

知道如何测试这部分代码吗?

Any idea on how to test this part of code?

推荐答案

将我的测试改为:

@Test
public void testHandleIn() throws Exception
{
  IPDO pdo = new PDODummy();


  MyClass handler = new MyClass ();
  MyClass handler2 = spy(handler);

  doReturn(pdo ).when( handler2 ).getIPDO();
  PDOUtil.setPDO(pdo, LogicalFieldEnum.P_TX_CTGY, "test123");
  IPDO pdoNew = handler2.getIPDO();

  Assert.assertEquals("test123,(PDOUtil.getValueAsString(pdoNew, LogicalFieldEnum.P_TX_CTGY)));

}

阅读Effective Mockito后解决.

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