Wsrtjtyk

I'm trying to test the implementation class, in which I'm creating a constructor based autowiring for the Interface.
I'm not suppose to change this class or the way it's autowired.

While writing test cases for the implementation class I'm getting NullPointerException because the object created in Implementation class
has different object reference and the mock object has different reference value.

Could anyone please tell me how to mock the object.

Implementation class

public class ImplementationClass implements ClientClass {



private final RepositoryInterface repositoryInterface;

@Autowired

public ImplementationClass( RepositoryInterface repositoryInterface ) {

    this.repositoryInterface = repositoryInterface;

}

@Autowired

AAA aaa;



@Autowired

BBB bbb;



@Autowired

CCC ccc;



public DomainClass getDetails( String Id ) {

    // aaa, bbb, ccc usage

    DomainClass getDetDocument =

        repositoryInterface.findById( Id ).orElse( null );



}

Unit Test Class

@Mock

RepositoryInterface repositoryInterface;



@Mock

DomainClass DomainClass;



@Mock

AAA aaa;



@Mock

BBB bbb;



@Mock

CCC ccc;



@InjectMocks

ImplementationClass implementationClass;



@Before

public void setUp() {

    MockitoAnnotations.initMocks( this );

    }



 @Test

public void getDetTest() {

DomainClass dc = new DomainClass();

    dc.setId( "Id-123456789" );

    dc.setDetailsList( <Some list> );



    Optional<DomainClass> c1 = Optional.of( dc );

    // when().thenReturn(); // aaa, bbb, ccc usage

when( repositoryInterface.findById( "Id-123456789" )).thenReturn( c1 );

    DomainClass c2 = implementationClass.getDetails( "Id-123456789" );



    assertThat( c2.getDetailsList(), equalTo( c1.getDetailsList() ) );

}

UPDATE : While debugging the Test class, the object repositoryInterface when( repositoryInterface.findById( "Id-123456789" )).thenReturn( c1 );
creates a reference value (23425634534@2005) and when the
ImplementationClass is called the repositoryInterface DomainClass getDetDocument =repositoryInterface.findById( Id ).orElse( null );
in ImplementationClass has a reference value (23425634534@1879). Because of this I'm getting null for getDetDocument.

After all the research, got it working by changing the way the constructor was creating the object.

// @Mock //removed this annotation

   RepositoryInterface repositoryInterface;





@Before

   public void setUp() {

     repositoryInterface = mock(RepositoryInterface.class)

     ImplementationClass = new ImplementationClass(repositoryInterface);

     MockitoAnnotations.initMocks( this );

}

Reference : https://mhaligowski.github.io/blog/2014/05/30/mockito-with-both-constructor-and-field-injection.html