java如何用JUnit5模拟Spring依赖关系？

Question

我们必须测试类，见下文。我们的问题是如何填充依赖项，以便测试您在下面看到的原始类

public class FragenAntwortenDataprovider extends SortableDataProvider<FragenAntworten, String> {

    @SpringBean
    private IFragenAntwortenService service;

    private IModel<FragenAntworten> filter;


    public FragenAntwortenDataprovider(IModel<FragenAntworten> filter){
        this.filter = filter;
        Injector.get().inject(this);
        setSort("id", SortOrder.DESCENDING);  // absteigend sortieren
    }


    @Override
    public Iterator<? extends FragenAntworten> iterator(long first, long count){
        List<FragenAntworten> list = load();
        List<FragenAntworten> sublist = list.subList((int) first, (int) (first+count));
        return sublist.iterator();
    }

    @Override
    public long size() {return getListSize();}

    @Override
    public IModel<FragenAntworten> model(FragenAntworten object) {
        return Model.of(object);
    }

    private void sort(final List<FragenAntworten> list){

    }

    private long getListSize(){
        List<FragenAntworten> list = service.ladeAlle(filter.getObject().getSystem());
        return list.size();
    }


    private List<FragenAntworten> load(){
        List<FragenAntworten> list = service.ladeAlle(filter.getObject().getSystem());
        return list;
    }

}

Answer 1

因为您使用Spring，所以可以使用它的ReflectionUtils助手类来注入依赖项：

IFragenAntwortenService service = mock(IFragenAntwortenService.class);
IModel<FragenAntworten> model = ...;
FragenAntwortenDataprovider provider = new FragenAntwortenDataprovider(model);
Field serviceField = ReflectionUtils.findField("service", provider);
ReflectionUtils.setField(serviceField, provider, service);

另一个选项是为service字段引入包私有setter，并避免使用反射

Answer 2

您应该让原始类使用@Autowired或@Inject注入依赖项。实际上，不应该使用字段注入，而应该使用构造函数注入。然后，您应该对JUnit 5测试类使用@ExtendWith(MockitoExtension.class)。必须定义为@Mock的每个依赖项，对于要测试的类，使用@InjectMocks注释

这是要使用的构造函数注入：

public class FragenAntwortenDataprovider extends SortableDataProvider<FragenAntworten, String> {

    private IFragenAntwortenService service;

    private IModel<FragenAntworten> filter;

    @Inject
    public FragenAntwortenDataprovider(IFragenAntwortenService service, IModel<FragenAntworten> filter){
        this.service = service;
        this.filter = filter;
        //I guess you don't need the injector anymore
        //Injector.get().inject(this);
        setSort("id", SortOrder.DESCENDING);  // absteigend sortieren
    }
    //Rest of class
}

这是一个测试类：

@ExtendWith(MockitoExtension.class)
public class testClass() {
    @Mock
    private IFragenAntwortenService service;

    @Mock
    private IModel<FragenAntworten> filter;

    @InjectMocks
    FragenAntwortenDataprovider sut; //System under Test

    @Test
    void test() {
        //Testcode
        // Control the mock with 
        when(service.anymethod()).thenReturn(result);

        var result = sut.callMethodToTest();

        // verify all calls
        verify(service, times(1)).anymethod();

        // and assert
        assertNotNull(result);
    }
}