스프링부트 단위테스트 어떻게 작성해야하는지 감이 안잡혀요.. 코드 리뷰 부탁립니다.

안녕하세요. 단위테스트라는 것을 처음 작성해보는데 어떻게 작성해야할지 감이 안잡히네요 ㅠㅠ
일단 꾸역꾸역 작성을 해봤는데 이렇게 하는 게 맞는지 의문입니다. 너무 구체적으로 작성한 것은 아닌 지 고칠 부분이 있다면 피드백 해주시면 정말 감사하겠습니다.

아래 코드는 아이디, 이메일 중복 체크 및 레디스에 저장 된 인증번호를 체크한 후 회원가입을 구현한 코드입니다.

@Service
@Transactional
@RequiredArgsConstructor
public class MemberServiceImpl implements MemberService{

    private final MemberRepository memberRepository;
    private final PasswordEncoder passwordEncoder;
    private final RedisService redisService;

    @Override
    public Member signUp(MemberRequest memberRequest) {
        // 회원가입 조건 검증
        verifySignUpCondition(memberRequest);

        Member member = memberRequest.toEntity();
        member.setPassword(passwordEncoder.encode(memberRequest.getPassword()));
        member.setRole(Role.MEMBER);
        member.setSns(Sns.NONE);

        memberRepository.save(member);

        // 회원가입 성공 시 레디스에서 관련 데이터 삭제
        redisService.deleteKey(memberRequest.getEmail());

        return member;
    }


    private void verifySignUpCondition(MemberRequest memberRequest) {
        checkLoginIdDuplicate(memberRequest.getLoginId());
        checkEmailDuplicate(memberRequest.getEmail());
        redisService.verifyAuthNum(memberRequest.getEmail(), memberRequest.getAuthNum());
    }

    private void checkLoginIdDuplicate(String loginId) {
        Optional<Member> findMember = memberRepository.findByLoginId(loginId);

        if(findMember.isPresent()) {
            throw new BusinessException(ErrorCode.LOGIN_ID_DUPLICATE);
        }
    }

    private void checkEmailDuplicate(String email) {
        Optional<Member> findMember = memberRepository.findByEmail(email);

        if(findMember.isPresent()) {
            throw new BusinessException(ErrorCode.EMAIL_DUPLICATE);
        }
    }
}

아래는 단위 테스트 코드입니다.

@ExtendWith(MockitoExtension.class)
class MemberServiceImplTest {

    @Mock
    private MemberRepository memberRepository;

    @Mock
    private PasswordEncoder passwordEncoder;

    @Mock
    private RedisService redisService;

    @InjectMocks
    private MemberServiceImpl memberService;

    @BeforeEach
    void setUp() {
        reset(memberRepository, passwordEncoder, redisService);
    }

    @Test
    @DisplayName("회원 가입 성공")
    void signUp_Success() {
        // given
        MemberRequest memberRequest = createMemberRequest();

        String encodedPassword = "encodedPassword";

        given(memberRepository.findByLoginId(memberRequest.getLoginId())).willReturn(Optional.empty());
        given(memberRepository.findByEmail(memberRequest.getEmail())).willReturn(Optional.empty());
        given(passwordEncoder.encode(memberRequest.getPassword())).willReturn(encodedPassword);

        willDoNothing().given(redisService).verifyAuthNum(memberRequest.getEmail(), memberRequest.getAuthNum());
        willDoNothing().given(redisService).deleteKey(memberRequest.getEmail());

        // when
        Member member = memberService.signUp(memberRequest);

        // then
        assertNotNull(member);
        assertEquals(member.getLoginId(), memberRequest.getLoginId());
        assertEquals(member.getEmail(), memberRequest.getEmail());
        assertEquals(member.getNickname(), memberRequest.getNickname());
        assertEquals(member.getPassword(), encodedPassword);
        assertEquals(member.getRole(), Role.MEMBER);
        assertEquals(member.getSns(), Sns.NONE);

        verify(memberRepository, times(1)).save(any(Member.class));
        verify(memberRepository, times(1)).findByLoginId(any());
        verify(memberRepository, times(1)).findByEmail(any());
        verify(passwordEncoder, times(1)).encode(any());
        verify(redisService, times(1)).verifyAuthNum(any(), any());
        verify(redisService, times(1)).deleteKey(any());
    }
}