답변 좋아요 기능을 구현한다.

maeil-wiki/src/main/java/maeilwiki/comment/CommentApi.java

@@ -19,4 +19,11 @@ public ResponseEntity<Void> createComment(@RequestBody CommentRequest request, @
 
         return ResponseEntity.noContent().build();
     }
+
+    @PostMapping("/wiki/{wikiId}/comment/{id}/like")
+    public ResponseEntity<Void> createCommentLike(@PathVariable Long wikiId, @PathVariable Long id) {
+        commentService.toggleLike(id);
+
+        return ResponseEntity.noContent().build();
+    }
 }

maeil-wiki/src/main/java/maeilwiki/comment/CommentLike.java

@@ -1,11 +1,9 @@
 package maeilwiki.comment;
 
 import java.time.LocalDateTime;
-
-import org.springframework.data.annotation.CreatedDate;
-
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
+import jakarta.persistence.EntityListeners;
 import jakarta.persistence.FetchType;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
@@ -16,10 +14,13 @@
 import lombok.Getter;
 import lombok.NoArgsConstructor;
 import maeilwiki.member.Member;
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.jpa.domain.support.AuditingEntityListener;
 
 @Entity
 @Getter
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
+@EntityListeners(AuditingEntityListener.class)
 public class CommentLike {
 
     @Id

maeil-wiki/src/main/java/maeilwiki/comment/CommentLikeRepository.java

@@ -0,0 +1,9 @@
+package maeilwiki.comment;
+
+import java.util.Optional;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+interface CommentLikeRepository extends JpaRepository<CommentLike, Long> {
+
+    Optional<CommentLike> findByCommentIdAndMemberId(Long commentId, Long memberId);
+}

maeil-wiki/src/main/java/maeilwiki/comment/CommentService.java

@@ -1,14 +1,17 @@
 package maeilwiki.comment;
 
+import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import lombok.RequiredArgsConstructor;
 import maeilwiki.member.Member;
 import maeilwiki.member.MemberRepository;
 import maeilwiki.wiki.Wiki;
 import maeilwiki.wiki.WikiRepository;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
 
 @Service
 @RequiredArgsConstructor
@@ -17,6 +20,9 @@ class CommentService {
     private final WikiRepository wikiRepository;
     private final CommentRepository commentRepository;
     private final MemberRepository memberRepository;
+    private final CommentLikeRepository commentLikeRepository;
+
+    private final Map<String, Member> transactionTmpMemberMap = new ConcurrentHashMap<>();
 
     @Transactional
     public void comment(CommentRequest request, Long wikiId) {
@@ -29,4 +35,38 @@ public void comment(CommentRequest request, Long wikiId) {
 
         commentRepository.save(comment);
     }
+
+    @Transactional
+    public void toggleLike(Long id) {
+        Member member = memberSetting();
+        Comment comment = commentRepository.findById(id)
+                .orElseThrow(NoSuchElementException::new);
+
+        commentLikeRepository.findByCommentIdAndMemberId(comment.getId(), member.getId())
+                .ifPresentOrElse(this::unlike, () -> like(member, comment));
+    }
+
+    // TODO: 인가 적용 시 제거
+    private Member memberSetting() {
+        String key = TransactionSynchronizationManager.getCurrentTransactionName();
+        Member member = transactionTmpMemberMap.get(key);
+        if (member == null) {
+            String uuid = UUID.randomUUID().toString();
+            Member newMember = new Member(uuid, uuid, "GITHUB");
+            memberRepository.save(newMember);
+            transactionTmpMemberMap.put(key, newMember);
+            return newMember;
+        }
+
+        return member;
+    }
+
+    private void unlike(CommentLike commentLike) {
+        commentLikeRepository.delete(commentLike);
+    }
+
+    private void like(Member member, Comment comment) {
+        CommentLike commentLike = new CommentLike(member, comment);
+        commentLikeRepository.save(commentLike);
+    }
 }

maeil-wiki/src/test/java/maeilwiki/comment/CommentServiceTest.java

@@ -1,9 +1,15 @@
 package maeilwiki.comment;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
+import java.util.List;
 import java.util.NoSuchElementException;
+import maeilwiki.member.Member;
+import maeilwiki.member.MemberRepository;
 import maeilwiki.support.IntegrationTestSupport;
+import maeilwiki.wiki.Wiki;
+import maeilwiki.wiki.WikiRepository;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -13,6 +19,18 @@ class CommentServiceTest extends IntegrationTestSupport {
     @Autowired
     private CommentService commentService;
 
+    @Autowired
+    private CommentRepository commentRepository;
+
+    @Autowired
+    private CommentLikeRepository commentLikeRepository;
+
+    @Autowired
+    private MemberRepository memberRepository;
+
+    @Autowired
+    private WikiRepository wikiRepository;
+
     @Test
     @DisplayName("존재하지 않는 위키에 답변을 작성할 수 없다.")
     void notfound() {
@@ -22,4 +40,47 @@ void notfound() {
         assertThatThrownBy(() -> commentService.comment(request, unknownWikiId))
                 .isInstanceOf(NoSuchElementException.class);
     }
+
+    @Test
+    @DisplayName("존재하지 않는 답변에 좋아요를 생성할 수 없다.")
+    void notFoundComment() {
+        Long unknownCommentId = -1L;
+
+        assertThatThrownBy(() -> commentService.toggleLike(unknownCommentId))
+                .isInstanceOf(NoSuchElementException.class);
+    }
+
+    @Test
+    @DisplayName("답변에 좋아요를 생성할 수 있다.")
+    void like() {
+        Comment comment = createComment();
+
+        commentService.toggleLike(comment.getId());
+
+        List<CommentLike> likes = commentLikeRepository.findAll();
+        assertThat(likes).hasSize(1);
+    }
+
+    @Test
+    @DisplayName("이미 해당 사용자가 좋아요를 생성한 상황에서 재요청하는 경우, 좋아요를 취소한다.")
+    void unlike() {
+        Comment comment = createComment();
+        commentService.toggleLike(comment.getId());
+
+        commentService.toggleLike(comment.getId());
+
+        List<CommentLike> likes = commentLikeRepository.findAll();
+        assertThat(likes).hasSize(0);
+    }
+
+    private Comment createComment() {
+        Member member = new Member("name", "providerId", "GITHUB");
+        memberRepository.save(member);
+
+        Wiki wiki = new Wiki("question", "backend", false, member);
+        wikiRepository.save(wiki);
+
+        Comment comment = new Comment("answer", false, member, wiki);
+        return commentRepository.save(comment);
+    }
 }

maeil-wiki/src/test/java/maeilwiki/support/IntegrationTestSupport.java

@@ -2,9 +2,18 @@
 
 import maeilwiki.WikiConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.Import;
+import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
 import org.springframework.transaction.annotation.Transactional;
 
 @Transactional
 @SpringBootTest(classes = WikiConfiguration.class)
+@Import(IntegrationTestSupport.TestConfig.class)
 public abstract class IntegrationTestSupport {
+
+    @EnableJpaAuditing
+    @TestConfiguration
+    public static class TestConfig {
+    }
 }