为演示者类写一个Mockito测试(Presenter First Pattern)

时间:2012-07-01 23:00:45

标签: java unit-testing design-patterns mockito presenter-first

我试图熟悉TDD和Presenter First Pattern。现在我为我的Presenter.class写了一个测试用例。我的目标是覆盖整个Presenter.class,包括动作事件,但我没有胶水如何使用Mockito。

Presenter.class:

public class Presenter {
IModel model;
IView view;

public Presenter(final IModel model, final IView view) {
    this.model = model;
    this.view = view;

    this.model.addModelChangesListener(new AbstractAction() {
        public void actionPerformed(ActionEvent arg0) {
            view.setText(model.getText());
        }
    });
}}

IView.class:

public interface IView {
    public void setText(String text);
}

IModel.class:

public interface IModel {
    public void setText();
    public String getText();
    public void whenModelChanges();
    public void addModelChangesListener(AbstractAction action);
}

PresenterTest.class:

@RunWith(MockitoJUnitRunner.class)
public class PresenterTest {

    @Mock
    IView view;
    @Mock
    IModel model;

    @Before
    public void setup() {
        new Presenter(model, view);
    }

    @Test
    public void test1() {
    }
}

提前致谢!

3 个答案:

答案 0 :(得分:1)

起初......谢谢你们!

过了一段时间我发现了这个解决方案并坚持下去,因为我不想在presenter类中实现任何接口,我也不想在我的测试中创建存根类。

IVIEW

public interface IView {
    public void setText(String text);
}

IModel

public interface IModel {
    public String getText();
    public void addModelChangeListener(Action a);
}

演示

public class Presenter {

    private IModel model;
    private IView view;

    public Presenter(final IModel model, final IView view) {
        this.model = model;
        this.view = view;

        model.addModelChangeListener(new AbstractAction() {
            public void actionPerformed(ActionEvent e) {
                view.setText(model.getText());
            }
        });
    }
}

PresenterTest

@RunWith(MockitoJUnitRunner.class)
public class PresenterTest {

    @Mock
    IView view;

    @Mock
    IModel model;

    @Test
    public void when_model_changes_presenter_should_update_view() {
        ArgumentCaptor<Action> event = ArgumentCaptor.forClass(Action.class);

        when(model.getText()).thenReturn("test-string");
        new Presenter(model, view);
        verify(model).addModelChangeListener(event.capture());
        event.getValue().actionPerformed(null);
        verify(view).setText("test-string");
    }
}

答案 1 :(得分:0)

在这种情况下,模型和演示者之间的连接足够松散(通过动作监听器进行通信),您可能最好不要使用模拟模型。

你可以使用一个真实的模型(如果真实的模型足够简单,我更喜欢它),或者正如我在下面的代码片段中所做的那样,在你的测试代码中创建一个存根。

@RunWith(MockitoJUnitRunner.class)
public class PresenterTest {

    @Mock
    IView view;

    IModel model;

    @Before
    public void setup() {
        model = new StubModel();
        new Presenter(model, view);
    }

    @Test
    public void presenterUpdatesViewWhenModelChanges() {
        model.setText("Test Text");
        verify(view).setText("Test Text");
    }

    private class StubModel implements IModel {
        private String text;
        private List<ActionListener> actionListeners;

        StubModel() {
            actionListeners = new ArrayList<ActionListener>();
        }

        @Override
        public void setText(String text) {
            this.text = text;
            whenModelChanges();
        }

        @Override
        public String getText() {
            return text;
        }

        @Override
        public void whenModelChanges() {
            for (ActionListener listener: actionListeners) {
                listener.actionPerformed(null);
            }
        }

        @Override
        public void addModelChangesListener(AbstractAction action) {
            actionListeners.add(action);
        }
    }
}

您可以使用模拟模型设置此测试,您可以在其上设置存根调用,但为了明智地执行此操作,您可能还需要模拟操作,这会使操作复杂化,因为操作由演示者创建。

这似乎是很多测试代码,用于在您的演示者类中测试基本上一行代码,但最大的块是存根模型,可能被实际模型替换或从此测试类中提取并与之共享其他测试。

答案 2 :(得分:0)

这种情况下,一点点重构可以走很长的路。学会“聆听”测试并让他们推动设计。 Model只需知道需要通知ActionListener,而不关心它是AbstractAction。使用类合同中可能的最小接口。以下是进行简单测试的重构(可能太简单了,不值得单元测试,但你明白了):

Presenter.class:

public class Presenter {
  public Presenter(final IModel model, final IView v) implements ActionListener {
    this.model = model;
    this.view = v;
    model.addModelChangesListener(this);
  }

  public void actionPerformed(ActionEvent arg0) {
    view.setText(model.getText());
  }
}

IModel.class:

public interface IModel {
    public void addModelChangesListener(ActionListener action);
}

PresenterTest.class:

@RunWith(MockitoJUnitRunner.class)
public class PresenterTest {
    @Mock IView view;
    @Mock IModel model;

    @Test
    public void when_model_changes_presenter_should_update_text() {
       when(model.getText()).thenReturn("Test Text");
       Presenter p = new Presenter(model, view);
       p.actionPerformed(null);
       verify(view).setText("Test Text");
    }
}