java - 如果不匹配，Powermockito whenNew 返回 null

Question

我不知道它是否应该这样做，但我想不会。看看下面我的代码。

File mocked = PowerMockito.mock(File.class);    
PowerMockito.whenNew(File.class).withParameterTypes(String.class).withArguments(eq(THE_TARGET_PATH)).thenReturn(mocked);
File normalFile = new File(WORKING_PATH);
File mockedFile = new File(THE_TARGET_PATH);

我确实期望 normalFile 会正常创建，但它实际上是 null。顺便说一句，mockedFile 被正确模拟了。

我也在使用 @RunWith(PowerMockRunner.class) 和 @PrepareForTest({ClassWhereInstanceIsCreated.class, File.class})

我正在使用:

<dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-module-junit4</artifactId>
        <version>1.7.4</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-api-mockito</artifactId>
        <version>1.7.4</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.powermock</groupId>
        <artifactId>powermock-core</artifactId>
        <version>1.7.4</version>
        <scope>test</scope>
    </dependency>

Answer 1

我的发现表明，没有好的方法可以使用 PowerMockito/PowerMockito 2 进行部分构造函数模拟。按照逻辑，您应该能够做类似的事情

PowerMockito.whenNew(File.class).withParameterTypes(String.class)
                                .withArguments(eq(WORKING_PATH)).thenCallRealMethod();

但是这会在 PowerMockito 中触发类似于此的内部异常

org.mockito.exceptions.base.MockitoException: Cannot call abstract real method on java object! Calling real methods is only possible when mocking non abstract method. //correct example: when(mockOfConcreteClass.nonAbstractMethod()).thenCallRealMethod();

因此，我能看到的唯一方法就是重新编写测试。在模拟构造函数之前，您应该首先构造所有需要的 File 对象，并给出在每个特定情况下返回的 PowerMockito 规则。

File mocked = Mockito.mock(File.class);
// create file as you want
File realFile = new File(WORKING_PATH);
// tell PowerMockito to return it
PowerMockito.whenNew(File.class).withParameterTypes(String.class)
            .withArguments(Mockito.eq(WORKING_PATH)).thenReturn(realFile);
// tell PowerMockito to return mock if other argument passed
PowerMockito.whenNew(File.class).withParameterTypes(String.class)
            .withArguments(Mockito.eq(THE_TARGET_PATH)).thenReturn(mocked);

File normalFile = new File(WORKING_PATH);
File mockedFile = new File(THE_TARGET_PATH);

这是不受欢迎的解决方案，但我无法提供更好的解决方案。

希望对您有所帮助!