1.Mockオブジェクトの確認

1-1. 特定のメソッドの動作と呼び出し回数の決定

public class StudyService {

		public Study createNewStudy(Long memberId, Study study) {
        Optional<Member> member = memberService.findById(memberId);
        study.setOwnerId(memberId);

        Study newStudy = repository.save(study);
        //memberService.notify(newStudy);
        return repository.save(study);
    }

		...
}

@ExtendWith(MockitoExtension.class)
class StudyServiceTest {

		@Test
    void stubbing(@Mock MemberService memberService, @Mock StudyRepository studyRepository) {
        StudyService studyService = new StudyService(memberService, studyRepository);
        assertNotNull(studyService);

        Member member = new Member();
        member.setId(1L);
        member.setEmail("[email protected]");

        Study study = new Study(10, "테스트");

        Mockito.when(memberService.findById(1L)).thenReturn(Optional.of(member));
        Mockito.when(studyRepository.save(study)).thenReturn(study);

        studyService.createNewStudy(1L, study);

        assertNotNull(study.getOwnerId());
        assertEquals(member.getId(), study.getOwnerId());

        Mockito.verify(memberService, Mockito.times(1)).notify(study); // notify 메서드가 한번 호출하기를 기대
        Mockito.verify(memberService, Mockito.never()).validate(Mockito.any()); // validate 메서드는 호출되지 않길 기대
    }
}

1-2. コール順序の確認

public class StudyService {
    private final MemberService memberService;
    private final StudyRepository repository;

    ...

    public Study createNewStudy(Long memberId, Study study) {
        Optional<Member> member = memberService.findById(memberId);
        study.setOwnerId(memberId);

        Study newStudy = repository.save(study);
        memberService.notify(newStudy);
        memberService.notify(member.get());
        return repository.save(study);
    }
}

@ExtendWith(MockitoExtension.class)
class StudyServiceTest {
		@Test
    void stubbing(@Mock MemberService memberService, @Mock StudyRepository studyRepository) {
        ...

        InOrder inOrder = Mockito.inOrder(memberService);

	//성공
        inOrder.verify(memberService).notify(study);
        inOrder.verify(memberService).notify(member);

	//실패
	inOrder.verify(memberService).notify(member);
        inOrder.verify(memberService).notify(study);
    }

}

1-3. ある時点で何も起こらなかったことを確認します

public class StudyService {
    private final MemberService memberService;
    private final StudyRepository repository;

		...

    public Study createNewStudy(Long memberId, Study study) {
        Optional<Member> member = memberService.findById(memberId);
        study.setOwnerId(memberId);

        Study newStudy = repository.save(study);
        memberService.notify(newStudy);
        memberService.notify(member.get());
        return repository.save(study);
    }
}

@ExtendWith(MockitoExtension.class)
class StudyServiceTest {
		@Test
    void stubbing(@Mock MemberService memberService, @Mock StudyRepository studyRepository) {
        ...

	//실패
        Mockito.verify(memberService, Mockito.times(1)).notify(study); // notify 메서드가 한번 호출하기를 기대
	Mockito.verifyNoMoreInteractions(memberService); // 실패 아래 notify()메서드가 동작하므로
        Mockito.verify(memberService, Mockito.times(1)).notify(member); // notify 메서드가 한번 호출하기를 기대
        
	//성공
	Mockito.verify(memberService, Mockito.times(1)).notify(study); // notify 메서드가 한번 호출하기를 기대
        Mockito.verify(memberService, Mockito.times(1)).notify(member); // notify 메서드가 한번 호출하기를 기대
	Mockito.verifyNoMoreInteractions(memberService);
    }

}

2.Mockito BDDスタイルAPI

2-1. BDD

2-2. BDDスタイルAPIの適用

@ExtendWith(MockitoExtension.class)
class StudyServiceTest {
		@Test
    void stubbing(@Mock MemberService memberService, @Mock StudyRepository studyRepository) {
        //Given
        StudyService studyService = new StudyService(memberService, studyRepository);
        assertNotNull(studyService);

        Member member = new Member();
        member.setId(1L);
        member.setEmail("[email protected]");

        Study study = new Study(10, "테스트");

        Mockito.when(memberService.findById(1L)).thenReturn(Optional.of(member));
        Mockito.when(studyRepository.save(study)).thenReturn(study);

        //when
        studyService.createNewStudy(1L, study);

        //then
        Mockito.verify(memberService, Mockito.times(1)).notify(study); // notify 메서드가 한번 호출하기를 기대
        Mockito.verify(memberService, Mockito.times(1)).notify(member); // notify 메서드가 한번 호출하기를 기대
        Mockito.verify(memberService, Mockito.never()).validate(Mockito.any()); // validate 메서드는 호출되지 않길 기대

        Mockito.verifyNoMoreInteractions(memberService);
    }
}

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