주문과 할인 도메인 실행과 테스트

1. 주문과 할인 정책 실행
- src/main/java/hello/core/order/OrderApp.java

package hello.core.order;

import hello.core.member.Grade;
import hello.core.member.Member;
import hello.core.member.MemberService;
import hello.core.member.MemberServiceImpl;

public class OrderApp {

    public static void main(String[] args) {
        MemberService memberService = new MemberServiceImpl();
        OrderService orderService = new OrderServiceImpl();

        long memberId = 1L;
        Member member = new Member(memberId, "memberA", Grade.VIP);
        memberService.join(member);

        Order order = orderService.createOrder(memberId, "itemA", 10000);

        System.out.println("order = " + order); // toString() 호출됨
    }

}

- 결과

> Task :hello.core.order.OrderApp.main()
order = Order{memberId=1, itemName='itemA', itemPrice=10000, discountPrice=1000}
order.calculatePrice = 9000

할인 금액이 출력되는 것을 확인할 수 있다.
애플리케이션 로직으로 테스트 하는 것은 좋지 않으므로, JUnit 테스트를 사용


2. 주문과 할인 정책 테스트
- src/test/java/hello/core/order/OrderServiceTest.java

package hello.core.order;

import hello.core.member.Grade;
import hello.core.member.Member;
import hello.core.member.MemberService;
import hello.core.member.MemberServiceImpl;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;

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

public class OrderServiceTest {

    MemberService memberService = new MemberServiceImpl();
    OrderService orderService = new OrderServiceImpl();

    @Test
    void createOrder() {
        Long memberId = 1L; // 래퍼 클래스(Wrapper Class)
        Member member = new Member(memberId, "memberA", Grade.VIP);
        memberService.join(member);

        Order order = orderService.createOrder(memberId, "itemA", 10000);

        Assertions.assertThat(order.getDiscountPrice()).isEqualTo(1000);
    }

}

테스트가 성공했다.
순수하게 자바 코드로 하는 단위 테스트가 중요하다.


참고링크 : https://www.inflearn.com/course/%EC%8A%A4%ED%94%84%EB%A7%81-%ED%95%B5%EC%8B%AC-%EC%9B%90%EB%A6%AC-%EA%B8%B0%EB%B3%B8%ED%8E%B8?cid=325969

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