从mockito-all迁移至mockito-core后测试失败，如何修复？

问题背景 #

项目从mockito-all:1.9.5升级到mockito-core:2.28.2后，部分原有测试执行失败。以下是典型案例：

测试代码 #

@ExtendWith(CdiUnitExtension.class)
@AdditionalClasses({
    XmlMockUnmarshaller.class
})
public class FeaturesTest {

    @Produces
    @Mock
    private RefService refService;
    
    @Produces
    @Mock
    private PaymentService paymentService;
    
    private CacheData cacheData;
    
    @BeforeEach
    public void setUp() {
        this.cacheData = new CacheData();
        this.cacheData.setDateExecution("12/12/2015");
        when(refService.isDateAvailable(anyString())).thenReturn(true);
    }
    
    @Test
    public void shouldReturnErrorIfReasonHasInvalidChars() {
        // Given
        this.cacheData.setReason("qhsdlq$98%èd");
    
        // When
        List<Error> errors = paymentService.validatePayment(this.cacheData);
    
        // Then
        assertTrue(errors.size() == 1); // 测试失败：errors.size() = 2
        assertEquals(errors.get(0).getField(), "reason");
    }
}

对应的业务方法 #

@Inject
RefService refService;
...
public List<Error> validatePayment(CacheData cacheData) {
    ...
    if (!refService.isDateAvailable(cacheData.getExecutionDate())) {
        errors.add(new Error("executionDate"));
    }
    ...
    return errors;
}

问题现象 #

测试执行后错误列表包含2个错误，setUp中配置的refService.isDateAvailable()返回true的Mock逻辑完全没生效，导致多了一个executionDate字段的错误。

解决方法 #

方案1：改用Mockito原生扩展（推荐） #

放弃CDIUnitExtension，直接使用MockitoExtension来管理Mock和依赖注入，避免CDI上下文导致的实例不一致问题：

@ExtendWith(MockitoExtension.class)
public class FeaturesTest {

    @Mock
    private RefService refService;
    
    @InjectMocks
    private PaymentService paymentService;
    
    private CacheData cacheData;
    
    @BeforeEach
    public void setUp() {
        this.cacheData = new CacheData();
        this.cacheData.setDateExecution("12/12/2015");
        when(refService.isDateAvailable(anyString())).thenReturn(true);
    }
    
    @Test
    public void shouldReturnErrorIfReasonHasInvalidChars() {
        this.cacheData.setReason("qhsdlq$98%èd");
        
        List<Error> errors = paymentService.validatePayment(this.cacheData);
        
        assertTrue(errors.size() == 1);
        assertEquals(errors.get(0).getField(), "reason");
    }
}

方案2：保留CDIUnit并修正Mock实例一致性 #

如果必须依赖CDIUnitExtension，需要确保测试类中配置的Mock实例和CDI注入到PaymentService中的是同一个：

@ExtendWith(CdiUnitExtension.class)
@AdditionalClasses({
    XmlMockUnmarshaller.class
})
public class FeaturesTest {

    @Inject
    private PaymentService paymentService; // 直接从CDI上下文注入
    
    @Produces
    @Mock
    private RefService refService;
    
    private CacheData cacheData;
    
    @BeforeEach
    public void setUp() {
        this.cacheData = new CacheData();
        this.cacheData.setDateExecution("12/12/2015");
        // 显式初始化Mock，确保实例被CDI上下文正确识别
        MockitoAnnotations.openMocks(this);
        when(refService.isDateAvailable(anyString())).thenReturn(true);
    }
    
    @Test
    public void shouldReturnErrorIfReasonHasInvalidChars() {
        this.cacheData.setReason("qhsdlq$98%èd");
        
        List<Error> errors = paymentService.validatePayment(this.cacheData);
        
        assertTrue(errors.size() == 1);
        assertEquals(errors.get(0).getField(), "reason");
    }
}

原因分析 #

Mockito 2.x对@Mock注解的处理逻辑与1.x存在差异：在CDI环境下，@Produces生成的Mock实例，和测试类中直接持有的refService实例可能不是同一个对象。测试代码中配置的Mock行为只作用于测试类的实例，但PaymentService注入的是CDI上下文生成的另一个未配置的Mock（默认返回false），因此触发了executionDate的错误校验。

内容的提问来源于stack exchange，提问作者l0r3nz4cc10