How to resolve Unneccessary Stubbing exception

Question

My Code is as below,

@RunWith(MockitoJUnitRunner.class)
public class MyClass {

    private static final String code =\"Test\";

    @Mock
     private MyCl         


        

Answer 1

This was already pointed out in this comment, but I think that's too easy to overlook: You may run into an UnnecessaryStubbingException if you simply convert a JUnit 4 test class to a JUnit 5 test class by replacing an existing @Before with @BeforeEach, and if you perform some stubbing in that setup method that is not realized by at least one of the test cases.

This Mockito thread has more information on that, basically there is a subtle difference in the test execution between @Before and @BeforeEach. With @Before, it was sufficient if any test case realized the stubbings, with @BeforeEach, all cases would have to.

If you don't want to break up the setup of @BeforeEach into many small bits (as the comment cited above rightly points out), there's another option still instead of activating the lenient mode for the whole test class: you can merely make those stubbings in the @BeforeEach method lenient individually using lenient().