帶有@Mock 和 @InjectMock 的 Mockito 被通緝但未被調用：實際上，與此模擬的交互為零

Question

我有一個要測試的課程：

   public class DivisionCalculator {
    private final Validator validator;
    private final MathProvider mathProvider;
    private final ViewProvider viewProvider;

    public DivisionCalculator(Validator validator, MathProvider mathProvider, ViewProvider viewProvider) {
        this.validator = validator;
        this.mathProvider = mathProvider;
        this.viewProvider = viewProvider;
    }

    public String calculate(int dividend, int divisor) {
        validator.validate(dividend, divisor);

        List<DivisionStep> items = mathProvider.calculate(dividend, divisor);

        DivisionResult result = DivisionResult.builder()
                .dividend(dividend)
                .divisor(divisor)
                .finalResult(mathProvider.finalResult(items))
                .items(items)
                .build();

        return viewProvider.provideView(result);
    }
}

我有下一個以下測試類工作正常並使用Mockito.mock(dependency.class)通過測試

    public class DivisionCalculatorTest {

    private ViewProvider viewProvider = Mockito.mock(ViewProvider.class);
    private MathProvider mathProvider = Mockito.mock(MathProvider.class);
    private Validator validator = Mockito.mock(Validator.class);

    private DivisionCalculator divisionCalculator = new DivisionCalculator(validator, mathProvider, viewProvider);

    DivisionResult makeDivision(int dividend, int divisor) {
        List<DivisionStep> items = mathProvider.calculate(dividend, divisor);
        return DivisionResult.builder()
                .dividend(dividend)
                .divisor(divisor)
                .finalResult(mathProvider.finalResult(items))
                .items(items)
                .build();
    }

    @Test
    void divisionCalculatorShouldSuccessfullyCallHisComponents() {

        divisionCalculator.calculate(4, 2);

        Mockito.verify(validator).validate(Mockito.anyInt(), Mockito.anyInt());
        Mockito.verify(mathProvider).calculate(Mockito.anyInt(),Mockito.anyInt());
        Mockito.verify(viewProvider).provideView(refEq(makeDivision(4, 2)));

    }
}

但是為了遵循使用模擬的最佳實踐，我想用@Mock和@InjectMock注釋替換我的Mockito.mock(dependency.class)

public class DivisionTest {
    @Mock
    private Validator validator = new Validator();
    @Mock
    private ViewProvider viewProvider = new ViewProvider();
    @Mock
    private MathProvider mathProvider = new MathProvider();

    @BeforeEach
    void setup() {
        MockitoAnnotations.initMocks(this);
    }
    @InjectMocks
    private DivisionCalculator divisionCalculator = new DivisionCalculator(validator, mathProvider, viewProvider);

    DivisionResult makeDivision(int dividend, int divisor) {
        List<DivisionStep> items = mathProvider.calculate(dividend, divisor);
        return DivisionResult.builder()
                .dividend(dividend)
                .divisor(divisor)
                .finalResult(mathProvider.finalResult(items))
                .items(items)
                .build();
    }

    @Test
    void divisionCalculatorShouldSuccessfullyCallHisComponents() {

        divisionCalculator.calculate(4, 2);

        Mockito.verify(validator).validate(4, 2);
        Mockito.verify(mathProvider).calculate(4, 2);
        Mockito.verify(viewProvider).provideView(refEq(makeDivision(4, 2)));
    }
}

在執行以下步驟后，我收到錯誤：需要但未調用：實際上，與此模擬的交互為零。 我不明白我在這里錯過了什么。

Answer 1

如果您有@Mock和@InjectMocks類的注釋， @InjectMocks需要在 Junit 5 中使用特殊擴展名運行 Junit 測試：

@ExtendWith(MockitoExtension.class)
class MyTest {
    @Mock
    private Validator validator;
     ...
}

另請注意，此擴展為您創建模擬並將值注入帶注釋的數據字段。 因此，從技術上講，像您在問題中顯示的那樣創建真實對象是錯誤的：

public class DivisionTest {
    @Mock
    private Validator validator = new Validator();  // this is wrong, don't use "new"
    @Mock
    private ViewProvider viewProvider = new ViewProvider(); // this is wrong, don't use "new"
    @Mock
    private MathProvider mathProvider = new MathProvider(); // this is wrong, don't use "new"

您可以按照本教程獲取更深入的示例和解釋。

為了完整起見，如果您使用的是 Junit 4，您可以使用：

@RunWith(MockitoJUnitRunner.class)
public class DivisionTest {...}