OrderServiceTest 코드의 NullPointerException

[질문 내용]

(구글 드라이브에 업로드한 전체 프로젝트 링크 : https://drive.google.com/file/d/1rHbKUDz6JSdGbSuCNprE86n8_K0tP0Ls/view?usp=sharing)

OrderService 코드를 테스트 하기 위해 OrderServiceTest 파일을 만든 후, 해당 파일 아래에 상품주문 테스트 코드를 작성하여 실행했습니다

그 결과 다음과 같은 오류가 발생합니다

java.lang.NullPointerException: Cannot invoke "jpabook.jpashop.service.OrderService.order(java.lang.Long, java.lang.Long, int)" because "this.orderService" is null

아래의 Order, OrderRepository, OrderService 코드 모두 강사님의 코드와 비교해보았으나 딱히 다른점을 찾지 못했습니다. 왜 이런 일이 일어날까요?

OrderService 코드

package jpabook.jpashop.service;

import jpabook.jpashop.domain.*;
import jpabook.jpashop.domain.item.Item;
import jpabook.jpashop.repository.ItemRepository;
import jpabook.jpashop.repository.MemberRepository;
import jpabook.jpashop.repository.OrderRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
@Transactional(readOnly = true)
@RequiredArgsConstructor
public class OrderService {
    private final OrderRepository orderRepository;
    private final MemberRepository memberRepository;
    private final ItemRepository itemRepository;

    //주문
    @Transactional
    public Long order(Long memberId, Long itemId, int count) {
        //엔티티 조회
        Member member = memberRepository.findOne(memberId);
        Item item = itemRepository.findOne(itemId);

        //배송정보 생성
        Delivery delivery = new Delivery();
        delivery.setAddress(member.getAddress());
        delivery.setStatus(DeliveryStatus.READY);

        //주문상품 생성
        OrderItem orderItem = OrderItem.createOrderItem(item, item.getPrice(), count);

        //주문 생성
        Order order = Order.createOrder(member, delivery, orderItem);

        //주문 저장
        orderRepository.save(order);

        return order.getId();


    }


    //주문취소
//    @Transactional
//    public void cancelOrder(Long orderId) {
//        //엔티티 조회
//        Order order = orderRepository.findOne(orderId);
//        //주문 취소
//        order.cancel();
//
//    }

    //검색
//    public List<Order> findOrders(OrderSwarch orderSwarch) {
//        return orderRepository.findall(orderSwarch);
//    }

}

OrderRepository 코드

package jpabook.jpashop.repository;

import jpabook.jpashop.domain.Order;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Repository;

import javax.persistence.EntityManager;

@Repository
@RequiredArgsConstructor
public class OrderRepository {

    private final EntityManager em;

    public void save(Order order) {
        em.persist(order);

    }

    public Order findOne(Long id) {
        return em.find(Order.class, id);
    }

//    public List<Order> findAll(OrderSearch orderSearch) {
//
//    }

}

Order 코드

package jpabook.jpashop.domain;

import lombok.AccessLevel;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;

import javax.persistence.*;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;

@Entity
@Table(name = "orders")
@Getter @Setter
@NoArgsConstructor(access = AccessLevel.PROTECTED)
public class Order {
    @Id @GeneratedValue
    @Column(name="order_id")
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name="member_id")
    private Member member;


    @OneToMany(mappedBy = "order", cascade = CascadeType.ALL)
    private List<OrderItem> orderItems = new ArrayList<>();

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name="delivery_id")
    private Delivery delivery;

    private LocalDateTime orderDate;


    @Enumerated(EnumType.STRING)
    private OrderStatus status; //주문상태 [ORDER, CANCEL]

    //연관관계 먀서드//
    public void setMember(Member member){
        this.member = member;
        member.getOrders().add(this);
    }

    public void addOrderItem(OrderItem orderItem){
        orderItems.add(orderItem);
        orderItem.setOrder(this);

    }

    public void setDelivery(Delivery delivery) {
        this.delivery = delivery;
        delivery.setOrder(this);
    }

    //생성 매서드//
    public static Order createOrder(Member member, Delivery delivery, OrderItem... orderItems){
        Order order = new Order();
        order.setMember(member);
        order.setDelivery(delivery);
        for (OrderItem orderItem : orderItems) {
            order.addOrderItem(orderItem);

        }
        order.setStatus(OrderStatus.ORDER);
        order.setOrderDate(LocalDateTime.now());
        return order;
    }

    //비지니스 로직
    /*
    주문 취소
     */

    public void cancel() {
        if (delivery.getStatus() == DeliveryStatus.COMP) {
            throw new IllegalStateException("이미 배송완료된 상품은 취소가 불가능합니다");
        }
        this.setStatus(OrderStatus.CANCEL);
        for (OrderItem orderItem : orderItems) {
            orderItem.cancel();
        }
    }

    //조회 로직

    /**
     *
     * 전체 주문가격 조회
     */
    public int getTotalPrice() {
        int totalPrice = orderItems.stream().mapToInt(OrderItem::getTotalPrice).sum();
        return totalPrice;
    }

}

OrderServiceTest 코드

package jpabook.jpashop.service;

import jpabook.jpashop.domain.*;
import jpabook.jpashop.domain.item.Book;
import jpabook.jpashop.repository.OrderRepository;
import org.junit.Assert;
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;



@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("member1");
        member.setAddress(new Address("seoul", "river", "934=134"));

        Book book = new Book();
        book.setName("pricnciple");
        book.setPrice(1000);
        book.setStockQuantity(10);

        int orderCount = 2;


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

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

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

에러 메시지

java.lang.NullPointerException: Cannot invoke "jpabook.jpashop.service.OrderService.order(java.lang.Long, java.lang.Long, int)" because "this.orderService" is null

	at jpabook.jpashop.service.OrderServiceTest.상품주문(OrderServiceTest.java:50)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:366)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:331)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:79)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:329)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:66)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:293)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:306)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:413)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)

import org.junit.jupiter.api.Test;