Typical test using tesng with mockito

testng_mockito.java

public class SharePointStreamFetcherTest {


    @Mock(answer = Answers.RETURNS_DEEP_STUBS)
    SPDataLoaderManager spDataLoaderManager;

    SharePointStreamFetcher underTest;

    SoftAssertions softAssertions = new SoftAssertions();

    @BeforeMethod
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(spDataLoaderManager);

        underTest = new SharePointStreamFetcher(spDataLoaderManager, "siteUrl", "listId");
    }

    @AfterMethod
    public void tearDown() throws Exception {
        softAssertions.assertAll();
        // specifick mock to forget each previous stubbing.
        reset(spDataLoaderManager);
    }

    @Test
    public void should_do_some_testing() throws IOException, JAXBException {

        // given
        ItemIndex itemIndex = new ItemIndex();
        // ... setting some stuff
        when(spDataLoaderManager.getItemIndex(anyString(), anyString(), anyInt(), anyString())).thenReturn(itemIndex);


        // when
        Stream<ItemIndex> itemIndexStream = underTest.getItemIndexStream();
        List<ItemIndex> toTestValue = itemIndexStream.collect(Collectors.toList());

        // then
        softAssertions.assertThat(toTestValue).isNotEmpty().hasSize(42).contains(new ItemIndex());
        verify(spDataLoaderManager, atLeastOnce()).getItemIndex(anyString(), anyString(), anyInt(), anyString());
    }
}