class TeamRepositoryTest extends ExperimentalTest{
    @Test
    @DisplayName("[CASE-1] 팀만 멤버를 가지고 있을 경우")
    void func1(){

        // given
        Member member = Member.builder().name("Andy").build();
        Team team = Team.builder().name("FOXEE").build();
        team.add(member);

        // when
        Team savedTeam = teamRepository.save(team);

        // then
        assertThat(memberRepository.findById(member.getMemberId())
                .orElseThrow(RuntimeException::new)
                .getTeam().getName()
        ).isEqualTo("FOXEE");
    }

    @Test
    @DisplayName("[CASE-2] 멤버만 팀을 가지고 있을 경우")
    void func2(){

        // given
        Team team = Team.builder().name("FOXEE").build();
        Member member = Member.builder().name("Andy").team(team).build();

        // when
        memberRepository.save(member);

        // then
        assertThat(teamRepository.findById(member.getMemberId())
                .orElseThrow(RuntimeException::new)
                .getName()
        ).isEqualTo("FOXEE");
    }

    @Test
    @DisplayName("[CASE-3] 멤버와 팀 둘 다 서로 가지고 있을 경우")
    void func3(){

        // given
        Team team = Team.builder().name("FOXEE").build();
        Member member = Member.builder().name("Andy").team(team).build();
        team.add(member);

        // when
        teamRepository.save(team);

        // then
        assertThat(memberRepository.findById(member.getMemberId())
                .orElseThrow(RuntimeException::new)
                .getName()
        ).isEqualTo("Andy");
    }
}

public class Team {
    @Id
    @GeneratedValue
    private Long teamId;
    private String name;

    @OneToMany(mappedBy="team", cascade = PERSIST)
    private List<Member> members;

    public void add(Member member){
        member.setTeam(this);
        this.members.add(member);
    }

    @Builder
    public Team(Long teamId, String name) {
        this.members = new ArrayList<>();
        this.teamId = teamId;
        this.name = name;
    }
}

public class Member {
    @Id
    @GeneratedValue
    private Long memberId;
    private String name;

    @ManyToOne(cascade = PERSIST)
    @JoinColumn(name="teamId")
    private Team team;

    @Builder
    public Member(Long memberId, String name, Team team) {
        this.memberId = memberId;
        this.name = name;
        this.team = team;
    }
}