회원 관리 예제 - 회원 서비스 개발 및 테스트

1)

MemberService

package hello.hellospring.service;

import hello.hellospring.domain.Member;
import hello.hellospring.repository.MemberRepository;
import hello.hellospring.repository.MemoryMemberRepository;

import java.util.List;
import java.util.Optional;

public class MemberService {

    private final MemberRepository memberRepository;
    public MemberService(MemberRepository memberRepository) {
        this.memberRepository = memberRepository;
    }

    /**회원가입**/
    public Long join(Member member){
        //같은 이름이 있는 중복 회원X
        validateDuplicateMember(member); //중복 회원 검증
        memberRepository.save(member);
        return member.getId();
    }

    private void validateDuplicateMember(Member member) {
        memberRepository.findByName(member.getName())
            .ifPresent(m -> {
                throw new IllegalStateException("이미 존재하는 회원입니다.");
            });
    }
    /**전체 회원 조회**/
    public List<Member> findMembers() {
        return memberRepository.findAll();
    }
    public Optional<Member> findOne(Long memberId) {
        return memberRepository.findById(memberId);
    }
}

2)

컨트롤+shift+T : 테스트 껍데기 자동 생성

MemberServiceTest

package hello.hellospring.service;

import hello.hellospring.domain.Member;
import hello.hellospring.repository.MemoryMemberRepository;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.*;
import static org.junit.jupiter.api.Assertions.*;

class MemberServiceTest {

    MemberService memberService;
    MemoryMemberRepository memberRepository;

    @BeforeEach
    public void beforeEach(){
        memberRepository = new MemoryMemberRepository();
        memberService = new MemberService(memberRepository);
    }

    @AfterEach
    public void afterEach(){
        memberRepository.clearStore();
    }

    @Test
    void 회원가입() {
        //given
        Member member = new Member();
        member.setName("hello");

        //when
        Long saveId = memberService.join(member);

        //then
        Member findMember = memberService.findOne(saveId).get();
        assertThat(member.getName()).isEqualTo(findMember.getName());
    }
    @Test
    void 중복_회원_예외(){
        //given
        Member member1 = new Member();
        member1.setName("spring");

        Member member2 = new Member();
        member2.setName("spring");

        //when
        memberService.join(member1);
        IllegalStateException e = assertThrows(IllegalStateException.class, () -> memberService.join(member2));
        assertThat(e.getMessage()).isEqualTo("이미 존재하는 회원입니다.");
//        try {
//            memberService.join(member2);
//            fail();
//        }catch(IllegalStateException e){
//            assertThat(e.getMessage()).isEqualTo("이미 존재하는 회원입니다.");
//        }

        //then
    }

    @Test
    void findMembers() {
        //given

        //when

        //then
    }

    @Test
    void findOne() {
    }
}

3)