Transaction - 적용 1

MemberServiceV1

package hello.jdbc.service;

import hello.jdbc.domain.Member;
import hello.jdbc.repository.MemberRepositoryV1;
import lombok.RequiredArgsConstructor;

import java.sql.SQLException;

@RequiredArgsConstructor
public class MemberServiceV1 {

    private final MemberRepositoryV1 memberRepository;

    private void accountTransfer(String fromId, String toId, int money) throws SQLException {
        Member fromMember = memberRepository.findById(fromId);
        Member toMember = memberRepository.findById(toId);

        memberRepository.update(fromId, fromMember.getMoney() - money);
        validation(toMember);
        memberRepository.update(toId, toMember.getMoney()+money);


    }

    private void validation(Member toMember) {
        if (toMember.getMemberId().equals("ex")){
            throw new IllegalStateException("이체중 예외 발생");
        }
    }
}

• formId 의 회원을 조회해서 toId 의 회원에게 money 만큼의 돈을 계좌이체 하는 로직이다.
• fromId 회원의 돈을 money 만큼 감소한다. UPDATE SQL 실행
• toId 회원의 돈을 money 만큼 증가한다. UPDATE SQL 실행
• 예외 상황을 테스트해보기 위해 toId 가 "ex" 인 경우 예외를 발생한다.

 

test : 정상 케이스

package hello.jdbc.service;

import hello.jdbc.connection.ConnectionConst;
import hello.jdbc.domain.Member;
import hello.jdbc.repository.MemberRepositoryV1;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.jdbc.datasource.DriverManagerDataSource;

import java.net.PortUnreachableException;
import java.sql.SQLException;

import static hello.jdbc.connection.ConnectionConst.*;
import static org.assertj.core.api.Assertions.*;
import static org.junit.jupiter.api.Assertions.*;

/**
 * 기본 동작, transaction이 없어서 문제 발생
 */
class MemberServiceV1Test {

    public static final String MEMBER_A = "memberA";
    public static final String MEMBER_B = "memberB";
    public static final String MEMBER_EX = "ex";

    private MemberRepositoryV1 memberRepository;
    private MemberServiceV1 memberService;

    @BeforeEach
    void before(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource(URL, USERNAME, PASSWORD);
        memberRepository = new MemberRepositoryV1(dataSource);
        memberService = new MemberServiceV1(memberRepository);
    }

    @Test
    @DisplayName("정상이체")
    void accountTransfer() throws SQLException {
        
        //given
        Member memberA = new Member(MEMBER_A, 10000);
        Member memberB = new Member(MEMBER_B, 10000);

        memberRepository.save(memberA);
        memberRepository.save(memberB);

        //when
        memberService.accountTransfer(memberA.getMemberId(), memberB.getMemberId(), 2000);

        //then
        Member findMemberA = memberRepository.findById(memberA.getMemberId());
        Member findMemberB = memberRepository.findById(memberB.getMemberId());

        assertThat(findMemberA.getMoney()).isEqualTo(8000);
        assertThat(findMemberB.getMoney()).isEqualTo(12000);

    }
}

 

 

test2 : transaction 없이 예외 발생

@Test
@DisplayName("이체중 예외 발생")
void accountTransferEX() throws SQLException {

    //given
    Member memberA = new Member(MEMBER_A, 10000);
    Member memberEx = new Member(MEMBER_EX, 10000);

    memberRepository.save(memberA);
    memberRepository.save(memberEx);

    //when - memberEx변경 중 예외.
    assertThatThrownBy(() ->
            memberService.accountTransfer(memberA.getMemberId(), memberEx.getMemberId(), 2000))
            .isInstanceOf(IllegalStateException.class);

    //then
    Member findMemberA = memberRepository.findById(memberA.getMemberId());
    Member findMemberEx = memberRepository.findById(memberEx.getMemberId());

    assertThat(findMemberA.getMoney()).isEqualTo(8000);
    assertThat(findMemberEx.getMoney()).isEqualTo(10000);

}

 

test: 종합

package hello.jdbc.service;

import hello.jdbc.connection.ConnectionConst;
import hello.jdbc.domain.Member;
import hello.jdbc.repository.MemberRepositoryV1;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.jdbc.datasource.DriverManagerDataSource;

import java.net.PortUnreachableException;
import java.sql.SQLException;

import static hello.jdbc.connection.ConnectionConst.*;
import static org.assertj.core.api.Assertions.*;
import static org.junit.jupiter.api.Assertions.*;

/**
 * 기본 동작, transaction이 없어서 문제 발생
 */
class MemberServiceV1Test {

    public static final String MEMBER_A = "memberA";
    public static final String MEMBER_B = "memberB";
    public static final String MEMBER_EX = "ex";

    private MemberRepositoryV1 memberRepository;
    private MemberServiceV1 memberService;

    @BeforeEach
    void before(){
        DriverManagerDataSource dataSource = new DriverManagerDataSource(URL, USERNAME, PASSWORD);
        memberRepository = new MemberRepositoryV1(dataSource);
        memberService = new MemberServiceV1(memberRepository);
    }

    @AfterEach
    void after() throws SQLException {
        memberRepository.delete(MEMBER_A);
        memberRepository.delete(MEMBER_B);
        memberRepository.delete(MEMBER_EX);
    }

    @Test
    @DisplayName("정상이체")
    void accountTransfer() throws SQLException {

        //given
        Member memberA = new Member(MEMBER_A, 10000);
        Member memberB = new Member(MEMBER_B, 10000);

        memberRepository.save(memberA);
        memberRepository.save(memberB);

        //when
        memberService.accountTransfer(memberA.getMemberId(), memberB.getMemberId(), 2000);

        //then
        Member findMemberA = memberRepository.findById(memberA.getMemberId());
        Member findMemberB = memberRepository.findById(memberB.getMemberId());

        assertThat(findMemberA.getMoney()).isEqualTo(8000);
        assertThat(findMemberB.getMoney()).isEqualTo(12000);

    }

    @Test
    @DisplayName("이체중 예외 발생")
    void accountTransferEX() throws SQLException {

        //given
        Member memberA = new Member(MEMBER_A, 10000);
        Member memberEx = new Member(MEMBER_EX, 10000);

        memberRepository.save(memberA);
        memberRepository.save(memberEx);

        //when - memberEx변경 중 예외.
        assertThatThrownBy(() ->
                memberService.accountTransfer(memberA.getMemberId(), memberEx.getMemberId(), 2000))
                .isInstanceOf(IllegalStateException.class);

        //then
        Member findMemberA = memberRepository.findById(memberA.getMemberId());
        Member findMemberEx = memberRepository.findById(memberEx.getMemberId());

        assertThat(findMemberA.getMoney()).isEqualTo(8000);
        assertThat(findMemberEx.getMoney()).isEqualTo(10000);

    }
}

 

테스트 데이터 제거

• 테스트가 끝나면 다음 테스트에 영향을 주지 않기 위해 
  @AfterEach 에서 테스트에 사용한 데이터를 모두 삭제한다.
• @BeforeEach : 각각의 테스트가 수행되기 전에 실행된다.
• @AfterEach : 각각의 테스트가 실행되고 난 이후에 실행된다.
• 테스트 데이터를 제거하는 과정이 불편하지만, 다음 테스트에 영향을 주지 않으려면 테스트에서 사용한
  데이터를 모두 제거해야 한다. 
• 그렇지 않으면 이번 테스트에서 사용한 데이터 때문에 다음 테스트에서 데이터 중복으로 오류가 발생할 수 있다.
• 테스트에서 사용한 데이터를 제거하는 더 나은 방법으로는 트랜잭션을 활용하면 된다. 
• 테스트 전에 트랜잭션을 시작하고, 테스트 이후에 트랜잭션을 롤백해버리면 데이터가 처음 상태로 돌아온다.