[Spring Boot] Test 수행 시 NullPointerException 에러

에러 내용

1) 발생

에러 발생. NullPointerException

---

2) 원인

package jpabook.jpashop.service;

import jpabook.jpashop.domain.Address;
import jpabook.jpashop.domain.Member;
import jpabook.jpashop.domain.Order;
import jpabook.jpashop.domain.OrderStatus;
import jpabook.jpashop.domain.item.Book;
import jpabook.jpashop.repository.OrderRepository;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.EntityManager;

import static org.junit.Assert.*;

@SpringBootTest
@Transactional
public class OrderServiceTest {

    @Autowired
    EntityManager em;
    @Autowired
    OrderService orderService;
    @Autowired
    OrderRepository orderRepository;

    @Test
    public void 상품주문() throws Exception {
        //given
        Member member = new Member();
        member.setName("회원1");
        member.setAddress(new Address("서울","강가","123-123"));
        em.persist(member);

        Book book = new Book();
        book.setName("시골 JPA");
        book.setPrice(10000);
        book.setStockQuantity(10);
        em.persist(book);

        int orderCount = 2;

        //when
        Long orderId = orderService.order(member.getId(), book.getId(), orderCount);

        //then
        Order getOrder = orderRepository.findOne(orderId);

        assertEquals("상품 주문시 상태는 ORDER", OrderStatus.ORDER, getOrder.getStatus());
    }

    @Test
    public void 주문취소() throws Exception {
        //given

        //when

        //then
    }

    @Test
    public void 상품주문_재고수량초과() throws Exception {
        //given

        //when

        //then
    }
}

위 코드에서 import org.junit.Test; 이 부분이 에러의 원인이다.

위 코드 대신 import org.junit.jupiter.api.Test; 이 코드로 수정하면 제대로 동작한다.

---

3) 해결

package jpabook.jpashop.service;

import jpabook.jpashop.domain.Address;
import jpabook.jpashop.domain.Member;
import jpabook.jpashop.domain.Order;
import jpabook.jpashop.domain.OrderStatus;
import jpabook.jpashop.domain.item.Book;
import jpabook.jpashop.repository.OrderRepository;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.EntityManager;

import static org.junit.Assert.*;

@SpringBootTest
@Transactional
public class OrderServiceTest {

    @Autowired
    EntityManager em;
    @Autowired
    OrderService orderService;
    @Autowired
    OrderRepository orderRepository;

    @Test
    public void 상품주문() throws Exception {
        //given
        Member member = new Member();
        member.setName("회원1");
        member.setAddress(new Address("서울","강가","123-123"));
        em.persist(member);

        Book book = new Book();
        book.setName("시골 JPA");
        book.setPrice(10000);
        book.setStockQuantity(10);
        em.persist(book);

        int orderCount = 2;

        //when
        Long orderId = orderService.order(member.getId(), book.getId(), orderCount);

        //then
        Order getOrder = orderRepository.findOne(orderId);

        assertEquals("상품 주문시 상태는 ORDER", OrderStatus.ORDER, getOrder.getStatus());
    }

    @Test
    public void 주문취소() throws Exception {
        //given

        //when

        //then
    }

    @Test
    public void 상품주문_재고수량초과() throws Exception {
        //given

        //when

        //then
    }
}

에러없이 모든 테스트 케이스 정상 동작

코드를 변경 후 테스트가 모두 정상적으로 수행됨을 알 수 있다.