Mockito verify(...) 失败 - "Actually, there were zero interactions with this mock." 在多个测试中依次运行

Question

我有一个 Wrapper class 导致在包装对象上调用 equalsWithoutId 方法而不是 equals 方法。此处实现：

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，可确保存在所需的方法

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

然后我有一些应该测试的单元测试，如果 equals() 委托给 wrapped#equalsWithoutId() 方法并且 hashCode() 委托给 wrapped#hashCodeWithoutId。

现在我尝试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，我只是创建了包装模拟并测试了 equals 和 hashcode 是否委托了功能。

如果我运行单独测试，一切正常，但如果我运行顺序测试，第二个测试失败并显示此消息

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.

为什么会这样？

Answer 1

实际上，这里发生的是 @InjectMocks 无法正确注入构造函数参数 wrapped。根据 Javadoc for @InjectMocks，这是当前的行为。所以除非你想使用 setter 注入，否则你需要删除 @InjectMocks 注释。查看修改后的代码：

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
  }
}

当我运行以上代码时，两个测试运行一起按顺序通过。

Mockito verify(...) 失败 - "Actually, there were zero interactions with this mock." 在多个测试中依次 运行

Mockito verify(...) fails - "Actually, there were zero interactions with this mock." in more than one test run sequentially

java

testng

mockito

Mockito verify(...) 失败 - "Actually, there were zero interactions with this mock." 在多个测试中依次运行