springboot中的PowerMockito模拟私有方法

Question

我试图在测试的类中模拟一个私有方法，如下所示。

public String processPayment(...) {
    //some lines
    privateMethod(...);
    return "";
}

private Object privateMethod(...) {
    //some lines
    return someObject;
}

现在我需要测试ProcPayment方法和mockPrivate atemethod。

我尝试创建间谍的上述类，但该方法得到调用时，我这样做下面

final DeviceCheckoutServiceImpl spyDeviceCheckoutService = spy(injectedMockBeanOfAboveClass); //@InjectMock in test class
PowerMockito.doReturn(null).when(spyDeviceCheckoutService, "privateMethod", ArgumentMatchers.anyMap()); //method gets called here
spyDeviceCheckoutService.processPayment(...); //private method isn't mocked somehow, and gets called here too

privateMethod在第二行本身被调用。而且，私有方法不会被模仿。

也许我用错误的方式创建了间谍对象？无法执行spy（新设备checkoutserviceinpl（）） 因为它需要bean实例化。

Powermockito版本：

compile group: 'org.powermock', name: 'powermock-module-junit4', version: '2.0.0'
compile group: 'org.powermock', name: 'powermock-api-mockito2', version: '2.0.0'

让我知道我做错了什么。




Answer 1

Mockito引入了AdditionalAnswers.delegatesTo来支持监视Spring代理和其他类似的东西：

查看此问题：https://github.com/mockito/mockito/issues/529#issuecomment-239494581

因此，不要使用spy（proxy）而是使用mock（TestSubject.class，delegatesTo（springProxy））。

但是，如果需要阅读注释，那么您将需要mockito 2 beta。因为mockito 1. x使用CGLIB，它不会复制mockito子类上的注释。Mockito 2使用了伟大的字节伙伴。

Answer 2

问题解决了！忘记在测试类上添加@准备测试（DeviceCheckoutServiceImpl.class）。

Answer 3

在测试类中，我们将调用org的spy（）方法。powermock。应用程序编程接口。莫基托。PowerMockito通过将引用传递给需要测试的类：

MockPrivateMethodExample spy = PowerMockito.spy(mockPrivateMethodExample);

然后定义调用这个特定私有方法时要执行的操作。

PowerMockito.doReturn("Test").when(spy, {$methodName});

xample.java

public class MockPrivateMethodExample {

  public String getDetails() {
    return "Mock private method example: " + iAmPrivate();
  }

  private String iAmPrivate() {
    return new Date().toString();
  }
}

est.java

@RunWith(PowerMockRunner.class)
@PrepareForTest(MockPrivateMethodExample.class)
public class MockPrivateMethodTest {

  private MockPrivateMethodExample mockPrivateMethodExample;

  // This is the name of the private method which we want to mock
  private static final String METHOD = "iAmPrivate";

  @Test
  public void testPrivateMethod() throws Exception {
    mockPrivateMethodExample = new MockPrivateMethodExample();

    MockPrivateMethodExample spy = PowerMockito.spy(mockPrivateMethodExample);
    PowerMockito.doReturn("Test").when(spy, METHOD);
    String value = spy.getDetails();

    Assert.assertEquals(value, "Mock private method example: Test");
    PowerMockito.verifyPrivate(spy, Mockito.times(1)).invoke(METHOD);
  }
}

更多细节：https://examples.javacodegeeks.com/core-java/mockito/mockito-mock-private-method-example-with-powermock/