java - 使用所述类的抽象版本模拟通用类

Question

我正在尝试模拟一个抽象类，但据我所见，我认为这是不可能的。我们有一些使用泛型的类，它们必须扩展一个特定的抽象类。有一整群人，他们被 mock 成功了。抽象类有一个处理返回泛型的方法，看起来像这样:

public abstract class ChildPresenter <T extends ChildView> {
    private T view;
    
    public abstract T getView();
}

我们正在测试的类中包含以下内容:

public class ParentPresenter {
    private ConcreteChildPresenter1 childPresenter1;
    private ConcreteChildPresenter2 childPresenter2;
    private ConcreteChildPresenter3 childPresenter3;
    private ConcreteChildPresenter4 childPresenter4;
    List<ChildPresenter> childPresenters;
}

在构造函数中，使用 Google Guice 注入(inject)这些类，设置为变量，并添加到子演示者列表中。

被测方法是迭代所有 childPresenters 对象并运行方法 getView()。

我在测试课上尝试过这种方式:

public class ParentPresenterTest {
    private ConcreteChildPresenter1 childPresenter1;
    private ConcreteChildPresenter2 childPresenter2;
    private ConcreteChildPresenter3 childPresenter3;
    private ConcreteChildPresenter4 childPresenter4;
    private List<ChildPresenter> childPresenters;

    //This is an abstract class 
    private ChildView childView;

    @BeforeTest
    public void createInjector() {
        Guice.createInjector(...//Creates a fake module and does binding for the variables mentioned earlier
            //e.g.
            childPresenter1 = mock(ConcreteChildPresenter1.class);
            binder.bind(ConcreteChildPresenter1.class).toInstance(childPresenter1);
            //e.t.c for other variables
            
            //Same for child view
            childView = mock(ChildView.class);
            binder.bind(ChildView.class).toInstance(childView);
        }

        childPresenters = new ArrayList<ChildPresenter>();
        childPresenters.add(childPresenter1);
        //Add all child presenters
        
        for(ChildPresenter childPresenter : childPresenters) {
            when(childPresenter.getView()).thenReturn(childView);
        }
    }
}

问题发生在 when(childPresenter.getView()).thenReturn(childView); 行，因为 Mockito 提示以下消息:

org.mockito.exceptions.misusing.WrongTypeOfReturnValue:

ChildView$$EnhancerByMockitoWithCGLIB$$2f6a4bd5

cannot be returned by getView() getView() should return ConcreteChildView1

*** If you're unsure why you're getting above error read on. Due to the nature of the syntax above problem might occur because:

1. This exception might occur in wrongly written multi-threaded tests. Please refer to Mockito FAQ on limitations of concurrency testing.

2. A spy is stubbed using when(spy.foo()).then() syntax. It is safer to stub spies with doReturn|Throw() family of methods. More in javadocs for Mockito.spy() method.

我能理解，但是模拟每个具体的 ChildView 似乎是一种浪费，而我只想确认模拟的 ChildView 使用以下:

verify(childView, atLeast(childPresenters.size())).getView();

还有其他方法吗？我能否以某种方式使用模拟抽象类来代替具体类？

编辑 下面是如何实现 getView() 方法的具体版本:

public ConcreteChildPresenter1<ConreteChildView1> {
    
    @Override
    public ConreteChildView1 getView() {
        view.buildView();
        return view;
    }
}

以及所有 subview 扩展的抽象 ChildView 类:

public abstract ChildView {

    public abstract void buildView();
}

Answer 1

由于每个子演示者都返回一个特定类型的 View ，正如您已经了解的那样，您不能将它们替换为抽象类 ChildView 的模拟。

有一种方法可以在运行时获取 ChildView 的具体类型，前提是您提供了正确的实现，如下所述:Get generic type of class at runtime

然后你可以用这种方式初始化演示者的模拟:

for(ChildPresenter childPresenter : childPresenters) {
    //this getter returns the needed runtime class
    when(childPresenter.getView()).thenReturn(mock(childPresenter.getViewType())); 
}