Question

我是PowerMockito的新手，并且有一个我不明白的行为。以下代码解释了我的问题：

public class ClassOfInterest {

  private Object methodIWantToMock(String x) {

    String y = x.trim();

    //Do some other stuff;
  }

  public void methodUsingThePrivateMethod() {

    Object a = new Object();
    Object b = methodIWantToMock("some string");

    //Do some other stuff ...
  }
}

我有一个类，其中包含一个我要模拟的名为methodIWantToMock(String x)的私有方法。在我的测试代码中，我正在执行以下操作：

@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassOfInterest.class)
public class ClassOfInterestTest {

  @Test
  public void someTestMethod() {

  ClassOfInterest coiSpy = PowerMockito.spy(new ClassOfInterest());

  PowerMockito.doReturn(null).when(coiSpy, "methodIWantToMock", any(String.class));

  coiSpy.methodUsingThePrivateMethod();

  //Do some stuff ...

  }
}

根据上面的代码，当我运行上面的测试时，只要在methodIWantToMock内调用methodUsingThePrivateMethod()，PowerMockito就应该返回一个null。然而实际发生的是，当运行此命令时：PowerMockito.doReturn(...).when(...)， PowerMockito实际上正在调用methodIWantToMock然后就在那里!! 为什么这样做？在这个阶段，我只想说明在运行coiSpy.methodUsingThePrivateMethod();行时，如果最终被调用，它应该如何模拟私有方法。

Answer 1

So I figured out a solution that works for me. Instead of using a spy, I used a mock and then told PowerMockito to call the real method when methodUsingThePrivateMethod() is called inside my mocked object. It's essentially doing the same thing as before but just using a mock instead of a spy. This way, PowerMockito does NOT end up calling the private method whose behavior I'm trying to control using PowerMockito.doReturn(...).when(...). Here is my modified test code. The lines I changed/added are marked:

@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassOfInterest.class)
public class ClassOfInterestTest {

  @Test
  public void someTestMethod() {

  //Line changed:
  ClassOfInterest coiMock = PowerMockito.mock(new ClassOfInterest());

  //Line changed:
  PowerMockito.doReturn(null).when(coiMock, "methodIWantToMock", any(String.class));

  //Line added:
  PowerMockito.when(coiMock.methodUsingThePrivateMethod()).thenCallRealMethod();

  coiSpy.methodUsingThePrivateMethod();

  //Do some stuff ...

  }
}

当我使用doReturn（..）时，PowerMockito正在调用该方法。当（....）

1 个答案: