如何使用 Mockito 测试 void 方法

Question

下面在代码部分发布的方法 returns 无效。我想知道如何测试 returns 无效的方法。我检查了一些答案，但使用 "doThrow()" 传递异常，但在我的情况下，该方法不会抛出任何异常

请告诉我如何测试方法 returns 无效？

代码

public void setImageOnImageView(RequestCreator requestCreator, ImageView imgView) {
    requestCreator.into(imgView);
}

测试:

public class ValidationTest {
    @Mock
    private Context mCtx = null;
    @Rule
    public MockitoRule mockitoRule = MockitoJUnit.rule();

    @Before
    public void setUp() throws Exception {
        mCtx = Mockito.mock(Context.class);
        Assert.assertNotNull("Context is not null", mCtx);
    }

    @Test
    public void setImageOnImageView() throws Exception {
        Uri mockUri = mock(Uri.class);
        RequestCreator requestCreator = Picasso.with(mCtx).load(mockUri);
        RequestCreator spyRequestCreator = spy(requestCreator);
        ImageView imageView = new ImageView(mCtx);
        ImageView spyImageView = spy(imageView);

        doThrow().when(spyRequestCreator).into(spyImageView);
        //spyRequestCreator.into(spyImageView);
    }
}

Answer 1

您到底要测试什么？那个测试是 "when setImageOnImageView(RequestCreator, ImageView) is called, it invokes RequestCreator.into(ImageView)"?

如果这就是您要测试的内容，那么您不想测试它 "returns void"。相反，我会推荐这样的东西：

@Test
public void itInvokesRequestCreatorIntoOnProvidedImageView() {
    RequestCreator creator = mock(RequestCreator.class);
    ImageView imageView = mock(ImageView.class);

    setImageOnImageView(creator, imageView);
    verify(creator).into(imageView);
}

Answer 2

如果你想验证一个 void 方法没有抛出任何东西，那么你可以使用 assertDoesNotThrows 方法如下

Assert that execution of the supplied executable does not throw any kind of exception. Usage Note Although any exception thrown from a test method will cause the test to fail, there are certain use cases where it can be beneficial to explicitly assert that an exception is not thrown for a given code block within a test method.

 Assertions.assertDoesNotThrow(() -> testCl.voidM("test"...));

如果您的 class 中有一些依赖项，那么您可以使用验证来检查是否调用了该依赖项。

如何使用 Mockito 测试 void 方法

How to test a void method using Mockito

junit

junit4

mockito