java - Powermock 在模拟静态对象时使用 spring 注入(inject)错误模拟对象

Question

我正在使用 PowerMock easy mock 来模拟类的静态方法。我写了两个测试用例，如果我独立运行，则运行良好，但同时运行时会出现错误。

汽车测试:

@RunWith(PowerMockRunner.class)
@PrepareForTest({ ServiceCaller.class })
public class CarTest {

  ServiceCaller           mockServiceCallerObjectToReturn;

  public CarTest() {
    PowerMock.mockStaticPartial(ServiceCaller.class, "getInstance");
    mockServiceCallerObjectToReturn = PowerMock.createMock(ServiceCaller.class);
    EasyMock.expect(ServiceCaller.getInstance()).andReturn(mockServiceCallerObjectToReturn);
  }

  @Test
  public void test1() throws IOException {
    PowerMock.reset(mockServiceCallerObjectToReturn);
    PowerMock.reset(ServiceCaller.class);

    EasyMock.expect(ServiceCaller.getInstance()).andReturn(mockServiceCallerObjectToReturn);

    EasyMock.expect(mockServiceCallerObjectToReturn.checkValidity("testDriver")).andReturn(false);

    PowerMock.replay(mockServiceCallerObjectToReturn);
    PowerMock.replay(ServiceCaller.class);

    Car car = CarFactory.getInstance().getCar();
    boolean canDrive = car.drive("testDriver");
    Assert.assertEquals(canDrive, false);

    PowerMock.verify(mockServiceCallerObjectToReturn);
    PowerMock.verify(ServiceCaller.class);
  }

  @Test
  public void test2() throws IOException {
    PowerMock.reset(mockServiceCallerObjectToReturn);
    PowerMock.reset(ServiceCaller.class);

    EasyMock.expect(ServiceCaller.getInstance()).andReturn(mockServiceCallerObjectToReturn);

    EasyMock.expect(mockServiceCallerObjectToReturn.checkValidity("testDriver")).andReturn(false);

    PowerMock.replay(mockServiceCallerObjectToReturn);
    PowerMock.replay(ServiceCaller.class);

    Car car = CarFactory.getInstance().getCar();
    boolean canDrive = car.drive("testDriver");
    Assert.assertEquals(canDrive, false);

    PowerMock.verify(mockServiceCallerObjectToReturn);
    PowerMock.verify(ServiceCaller.class);
  }
}

汽车工厂:

public class CarFactory {    
  private static final String               CAR_SPRING_CONTEXT_XML = "/com/archit/mock/spring-config/CarSpringContext.xml";    
  protected static final ApplicationContext CONTEXT                = new ClassPathXmlApplicationContext(new String[] { CAR_SPRING_CONTEXT_XML });    
  private static final CarFactory           INSTANCE               = new CarFactory();    
  public static CarFactory getInstance() {
    return INSTANCE;
  }    
  public Car getCar() {
    return CONTEXT.getBean("car", Car.class);
  }    
}

汽车:

package com.archit.mock;
public class Car {
  private final ServiceCaller        serviceCaller;
  public Car(final ServiceCallerFactory serviceCallerFactory) {
    this.serviceCaller = serviceCallerFactory.getServiceCaller();
  }
  public boolean drive(final String driver) {
    return (serviceCaller.checkValidity(driver));
  }
}

服务调用者:

package com.archit.mock;
public class ServiceCaller {
  private static class ServiceCallerHolder {
    private static ServiceCaller INSTANCE = new ServiceCaller();
  }
  public static ServiceCaller getInstance() {
    return ServiceCallerHolder.INSTANCE;
  }
  public boolean checkValidity(final String x) {
    // Do some call
    throw new IllegalStateException("This should have been mocked");
  }
}

服务调用者工厂:

package com.archit.mock;
public class ServiceCallerFactory {
  public ServiceCaller getServiceCaller() {
    return ServiceCaller.getInstance();
  }
}

Spring 配置:

<bean name="car" class="com.archit.mock.Car">
    <constructor-arg>
        <ref bean="serviceCallerFactory" />
    </constructor-arg>
</bean>

<bean name="serviceCallerFactory" class="com.archit.mock.ServiceCallerFactory" />

错误:

java.lang.AssertionError: 
  Unexpected method call ServiceCaller.checkValidity("testDriver"):
    ServiceCaller.checkValidity("testDriver"): expected: 1, actual: 2
  at org.easymock.internal.MockInvocationHandler.invoke(MockInvocationHandler.java:44)
  at org.easymock.internal.ObjectMethodsFilter.invoke(ObjectMethodsFilter.java:85)
  at org.easymock.internal.ClassProxyFactory$MockMethodInterceptor.intercept(ClassProxyFactory.java:94)
  at com.archit.mock.ServiceCaller$$EnhancerByCGLIB$$9848ad9e.checkValidity(<generated>)
  at com.archit.mock.Car.drive(Car.java:12)
  at com.archit.mock.CarTest.test2(CarTest.java:60)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:601)
  at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:66)
  at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:312)
  at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:86)
  at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:94)
  at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:296)
  at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:284)
  at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:84)
  at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)
  at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:209)
  at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:148)
  at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
  at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
  at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
  at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
  at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:102)
  at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
  at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:42)
  at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
  at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
  at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

其他观察结果:

• 在 Spring 配置中将对象范围设置为原型(prototype)可以正常工作。
• 这两个测试单独运行时都可以正常工作。
• 根据上面2，似乎是重新设置mocks的问题。

Answer 1

我发现使用模拟可以更轻松地在每次运行测试时将它们作为新对象启动。您可以通过使用 Mockito.Mock 注释将所有模拟对象放在顶部作为私有(private)变量来实现此目的:

@Mock
private MockOneClass mockOne;
...
@Mock
private MockNClass mockN;

然后使用 JUnit Before 注释，创建某种初始化所有模拟对象的设置函数:

@Before
public void setup() {
    // initialize all the @Mock objects
    MockitoAnnotations.initMocks(this);
}

这样，在每次测试运行之前，您都会创建一个新的模拟，然后您可以对其应用任意数量的期望和功能，而不必担心清除在测试中完成的任何旧模拟。之前的测试。如果您知道任何 Mock 将提供某些特定功能(例如静态单例模拟 getInstance 调用)，则可以在此 setup 函数中调用，以帮助保持测试更清晰模拟重置。

我有一些测试，其中有 10 多个测试都使用此框架连续运行。它不仅使它更容易阅读，而且使从头开始设置测试变得非常快。能够在测试中复制旧的模拟设置并删除/更改某些部分比每次测试都必须维护每个模拟对象要容易得多，一旦开始进行更多测试，这就无法很好地扩展。