feat: (#66) 이미 선호 카테고리 목록에 있는 카테고리를 추가하는 경우를 검증하는 로직 추가

backend/src/main/java/com/votogether/domain/category/service/CategoryService.java

@@ -32,6 +32,9 @@ public void addFavoriteCategory(final Member member, final Long categoryId) {
  Category category = categoryRepository.findById(categoryId)
  .orElseThrow(() -> new IllegalArgumentException("해당 카테고리가 존재하지 않습니다."));
 
+ memberCategoryRepository.findByMemberAndCategory(member, category)
+ .ifPresent(ignore -> new IllegalStateException("이미 선호 카테고리에 등록되어 있습니다."));
+
  MemberCategory memberCategory = MemberCategory.builder()
  .member(member)
  .category(category)

backend/src/main/java/com/votogether/domain/member/repository/MemberCategoryRepository.java

@@ -1,7 +1,12 @@
 package com.votogether.domain.member.repository;
 
+import com.votogether.domain.category.entity.Category;
+import com.votogether.domain.member.entity.Member;
 import com.votogether.domain.member.entity.MemberCategory;
+import java.util.Optional;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 public interface MemberCategoryRepository extends JpaRepository<MemberCategory, Long> {
+ Optional<MemberCategory> findByMemberAndCategory(final Member member, final Category category);
+
 }

backend/src/test/java/com/votogether/domain/member/repository/MemberCategoryRepositoryTest.java

@@ -59,4 +59,38 @@ void save() {
  assertThat(memberCategory.getId()).isNotNull();
  }
 
+ @Test
+ @DisplayName("멤버와 카테고리를 통해 멤버 카테고리를 조회한다.")
+ void findByMemberAndCategory() {
+ // given
+ Category category = Category.builder()
+ .name("개발")
+ .build();
+
+ Member member = Member.builder()
+ .gender(Gender.MALE)
+ .point(0)
+ .socialType(SocialType.GOOGLE)
+ .nickname("user1")
+ .socialId("kakao@gmail.com")
+ .birthDate(
+ LocalDateTime.of(1995, 07, 12, 00, 00))
+ .build();
+
+ MemberCategory memberCategory = MemberCategory.builder()
+ .member(member)
+ .category(category)
+ .build();
+
+ categoryRepository.save(category);
+ memberRepository.save(member);
+ memberCategoryRepository.save(memberCategory);
+
+ // when
+ MemberCategory findMemberCategory = memberCategoryRepository.findByMemberAndCategory(member, category).get();
+
+ // then
+ assertThat(findMemberCategory).isSameAs(memberCategory);
+ }
+
 }