PowerMock和Mockito不起作用的静态嘲讽

Question

我正在尝试验证Collections.shuffle（）方法是否在我的一个类中被调用。我用Mockito通读了PowerMock上的（小）文档，并通读了处理这个问题的其他SO问题，但没有得到解决。

@RunWith(PowerMockRunner.class)
@PrepareForTest(Collections.class)
public class MyTest {
    @Test
    public void testShuffle() {
        PowerMockito.mockStatic(Collections.class);
        PowerMockito.doCallRealMethod().when(Collections.class);
        Collections.shuffle(Mockito.anyListOf(Something.class));
        ClassToTest test = new ClassToTest();
        test.doSomething();
        PowerMockito.verifyStatic(); // Verify shuffle was called exactly once
        Collections.shuffle(Mockito.anyListOf(Something.class));
    }
}
public class ClassToTest {
    private final List<Something> list;
    // ...
    public void doSomething() {
        Collections.shuffle(list);
        // do more stuff
    }
}

给定上面的代码，我希望单元测试通过。然而，单元测试失败如下：

Wanted but not invoked java.util.Collections.shuffle([]);
Actually, there were zero interactions with this mock.

我做错了什么？

感谢

编辑：根据下面的建议，我尝试了以下操作，但我得到了相同的错误。

@RunWith(PowerMockRunner.class)
@PrepareForTest(Collections.class)
public class MyTest {
    @Test
    public void testShuffle() {
        PowerMockito.mockStatic(Collections.class);
        ClassToTest test = new ClassToTest();
        test.doSomething();
        PowerMockito.verifyStatic(); // Verify shuffle was called exactly once
        Collections.shuffle(Mockito.anyListOf(Something.class));
    }
}

Answer 1

这是一个相当古老的问题，但我仍然想澄清的是，公认的答案实际上是不正确的。通过执行以下代码，

PowerMockito.mockStatic(Collections.class);
Collections.shuffle(Mockito.anyListOf(Something.class));

所有验证都将在之后通过：

PowerMockito.verifyStatic(); // Verify shuffle was called exactly once
Collections.shuffle(Mockito.anyListOf(Something.class));

即使你不调用test.doSomething();，答案中提供的测试仍然会通过。正确的测试方法是实际检查列表中的项目是否正确排序。

Answer 2

您可以模拟/验证java.util.Collections.shuffle（[]）方法，也可以调用实际实现（使用PowerMockito.doCallRealMethod（））。但不能同时执行这两种操作。

如果删除

PowerMockito.doCallRealMethod().when(Collections.class);

呼叫将被验证，测试将通过。

https://powermock.googlecode.com/svn/docs/powermock-1.4.7/apidocs/org/powermock/api/mockito/PowerMockito.html#doCallRealMethod%28%29

这个代码对我有效：

package test;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
@RunWith(PowerMockRunner.class)
@PrepareForTest(Collections.class)
public class MyTest {
    @Test
    public void testShuffle() {
        PowerMockito.mockStatic(Collections.class);
/*        PowerMockito.doCallRealMethod().when(Collections.class);  remove this line */
        Collections.shuffle(Mockito.anyListOf(Something.class));
        ClassToTest test = new ClassToTest();
        test.doSomething();
        PowerMockito.verifyStatic(); // Verify shuffle was called exactly once
        Collections.shuffle(Mockito.anyListOf(Something.class));
    }
}
class ClassToTest {
    private List<Something> list = new LinkedList<Something>();
    // ...
    public void doSomething() {
        Collections.shuffle(list);
        // do more stuff
    }
}
class Something {
}