Repository 계층 테스트 전략 - Spring Boot로 시작하는 TDD 7편

Repository Layer Testing Strategy - TDD with Spring Boot Part 7

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    compileOnly 'org.projectlombok:lombok'
    annotationProcessor 'org.projectlombok:lombok'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
 
    // [추가] JPA와 H2 데이터베이스
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    runtimeOnly 'com.h2database:h2'
}

package com.example.tdd_study.product;
 
import jakarta.persistence.*;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.NoArgsConstructor;
import org.springframework.util.Assert;
 
@Entity
@Table(name = "products")
@Getter
@NoArgsConstructor(access = AccessLevel.PROTECTED)
public class Product {
 
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private int price;
 
    public Product(String name, int price) {
        Assert.hasText(name, "상품명은 필수입니다.");
        Assert.isTrue(price > 0, "상품 가격은 0보다 커야 합니다.");
        Assert.isTrue(price % 1000 == 0, "상품 가격은 1000원 단위여야 합니다."); 
        this.name = name;
        this.price = price;
    }
    // (중요) 기존의 assignId 메서드는 삭제합니다. DB가 ID를 자동 생성해주기 때문입니다.
}

package com.example.tdd_study.product;
 
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
 
@Repository
public interface ProductRepository extends JpaRepository<Product, Long> {
    // 코드가 비어있어도 괜찮습니다. JpaRepository가 save, findById 등을 대신 해줍니다.
}

package com.example.tdd_study.product;
 
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import static org.mockito.Mockito.verify;
import static org.mockito.ArgumentMatchers.any;
 
@ExtendWith(MockitoExtension.class) // Mockito 기능을 쓰겠다고 선언
class ProductServiceTest {
 
    @Mock // 가짜 Repository 생성
    private ProductRepository productRepository;
 
    @InjectMocks // 가짜 Repository를 Service에 주입
    private ProductService productService;
 
    @Test
    void 상품_등록_성공() {
        // given
        String name = "아메리카노";
        int price = 4000;
 
        // when
        productService.register(name, price);
 
        // then
        // productRepository.save()가 호출되었는지 검증
        verify(productRepository).save(any(Product.class));
    }
}

package com.example.tdd_study.product;
 
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import static org.assertj.core.api.Assertions.assertThat;
 
@DataJpaTest
class ProductRepositoryTest {
 
    @Autowired
    private ProductRepository productRepository;
 
    @Test
    void 상품_저장() {
        // given
        Product product = new Product("아메리카노", 4000);
 
        // when
        Product savedProduct = productRepository.save(product);
 
        // then
        assertThat(savedProduct.getId()).isNotNull();
        assertThat(savedProduct.getName()).isEqualTo("아메리카노");
    }
}

Hibernate: insert into products (name, price, id) values (?, ?, default)