java Mockito验证（…）fails“实际上，与此模拟没有任何交互。”按顺序在多个测试运行中

Question

我有一个包装器类，它导致在包装对象上调用方法equalsWithoutId而不是equals方法。在这里实施：

import org.apache.commons.lang3.Validate;

public class IdAgnosticWrapper {

    private final IdAgnostic wrapped;

    public IdAgnosticWrapper(IdAgnostic wrapped) {
        Validate.notNull(wrapped, "wrapped must not be null");
        this.wrapped = wrapped;
    }

    @Override
    public int hashCode() {
        return wrapped.hashCodeWithoutId();
    }

    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof IdAgnosticWrapper)) {
            return false;
        }
        return wrapped.equalsWithoutId(((IdAgnosticWrapper) obj).getWrapped());
    }

    public IdAgnostic getWrapped() {
        return wrapped;
    }
}

IdAgnostic是一个简单的接口，它确保存在所需的方法

public interface IdAgnostic {
    int hashCodeWithoutId();
    boolean equalsWithoutId(Object o);
}

然后我有一些单元测试应该测试，如果equals（）委托给wrapped#equalsWithoutId（）方法，hashCode（）委托给wrapped#hashCodeWithoutId（）

现在我试着通过这些测试来测试它

import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import static org.mockito.Mockito.verify;

public class IdAgnosticWrapperTest {

    @Mock
    private IdAgnostic wrappedMock;

    @InjectMocks
    private IdAgnosticWrapper tested;


    @BeforeMethod
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void testEquals_EqualsWithoutIdIsCalledOnWrapped() throws Exception {
        tested.equals(tested);
        verify(wrappedMock).equalsWithoutId(tested.getWrapped());
    }

    @Test
    public void testHashCode_HashCodeWithoutIdIsCalledOnWrapped() throws Exception {
        tested.hashCode();
        verify(wrappedMock).hashCodeWithoutId(); //line 34
    }
}

如您所见，我只是创建了包装的mock，并测试equals和hashcode是否委托了功能

如果我单独运行测试，一切正常，但是如果我按顺序运行两个测试，第二个测试将失败，并显示以下消息

Wanted but not invoked:
wrappedMock.hashCodeWithoutId();
-> at com.my.app.utils.IdAgnosticWrapperTest.testHashCode_HashCodeWithoutIdIsCalledOnWrapped(IdAgnosticWrapperTest.java:34)
Actually, there were zero interactions with this mock.

为什么会发生这种情况

Answer 1

实际上，这里发生的事情是@InjectMocks无法正确地注入构造函数参数wrapped。根据Javadoc for ^{}，这是当前的行为。因此，除非您想使用setter注入，否则需要删除@InjectMocks注释。见修订后的守则：

public class IdAgnosticWrapperTest {

  @Mock
  private IdAgnostic wrappedMock;

  private IdAgnosticWrapper tested;

  @BeforeMethod
  public void setUp() throws Exception {
    MockitoAnnotations.initMocks(this);

    this.tested = new IdAgnosticWrapper(this.wrappedMock);
  }

  @Test
  public void testEquals_EqualsWithoutIdIsCalledOnWrapped()
      throws Exception {
    tested.equals(tested);
    verify(wrappedMock).equalsWithoutId(tested.getWrapped());
  }

  @Test
  public void testHashCode_HashCodeWithoutIdIsCalledOnWrapped()
      throws Exception {
    tested.hashCode();
    verify(wrappedMock).hashCodeWithoutId(); //line 34
  }
}

当我运行上述代码时，两个测试按顺序一起运行并通过