CODEWITHSUNDEEP
javajunitmockitojunit4
Amrmsmb
Amrmsmb

Reputation: 1

How to test a void method using Mockito

the below posted method in the code section returns void. I want to know how to test a method that returns void. I checked some answers but the use "doThrow()" with passing an exception, but in my case the method does not throw any exception

please let me know how can I test a method returns void?

code

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

testing:

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);
    }
}

Upvotes: 4

Views: 7598

Answers (2)

Sivaram Rasathurai
Sivaram Rasathurai

Reputation: 6333

If you want to verify a void method is not throwing anything, then you can use the assertDoesNotThrows method as follow

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"...));

If you have some dependencies in your class then you can use verify to check whether that dependency is invoked or not.

Upvotes: 1

Kevin Coppock
Kevin Coppock

Reputation: 134664

What exactly are you trying to test? Is that test that "when setImageOnImageView(RequestCreator, ImageView) is called, it invokes RequestCreator.into(ImageView)"?

If that's what you're trying to test, you aren't wanting to test that it "returns void". Rather, I would recommend something like:

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

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

Upvotes: 2

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