Merge pull request #564 from woowacourse-teams/fix/find-all-tags

태그 중복 제거 문제 해결

backend/src/main/java/codezap/tag/repository/TemplateTagJpaRepository.java

@@ -13,7 +13,12 @@ public interface TemplateTagJpaRepository extends TemplateTagRepository, JpaRepo
 
     List<TemplateTag> findAllByTemplate(Template template);
 
-    List<TemplateTag> findDistinctByTemplateIn(List<Template> templates);
+    @Query("""
+            SELECT DISTINCT tt.id.tagId
+            FROM TemplateTag tt
+            WHERE tt.id.templateId IN :templateIds
+            """)
+    List<Long> findDistinctByTemplateIn(List<Long> templateIds);
 
     @Query("""
             SELECT DISTINCT tt.id.templateId

backend/src/main/java/codezap/tag/repository/TemplateTagRepository.java

@@ -9,7 +9,7 @@ public interface TemplateTagRepository {
 
     List<TemplateTag> findAllByTemplate(Template template);
 
-    List<TemplateTag> findDistinctByTemplateIn(List<Template> templates);
+    List<Long> findDistinctByTemplateIn(List<Long> templateIds);
 
     List<TemplateTag> findAll();
 

backend/src/main/java/codezap/tag/service/TemplateTagService.java

@@ -66,10 +66,11 @@ private void validateTagId(Long tagId) {
     }
 
     public FindAllTagsResponse findAllByTemplates(List<Template> templates) {
-        List<TemplateTag> templateTags = templateTagRepository.findDistinctByTemplateIn(templates);
+        List<Long> templateIds = templates.stream().map(Template::getId).toList();
+        List<Long> templateTagIds = templateTagRepository.findDistinctByTemplateIn(templateIds);
         return new FindAllTagsResponse(
-                templateTags.stream()
-                        .map(templateTag -> FindTagResponse.from(templateTag.getTag()))
+                templateTagIds.stream()
+                        .map(id -> FindTagResponse.from(tagRepository.fetchById(id)))
                         .toList()
         );
     }

backend/src/test/java/codezap/tag/repository/TemplateTagJpaRepositoryTest.java

@@ -0,0 +1,83 @@
+package codezap.tag.repository;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.List;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import codezap.category.domain.Category;
+import codezap.category.repository.CategoryRepository;
+import codezap.global.repository.JpaRepositoryTest;
+import codezap.member.domain.Member;
+import codezap.member.repository.MemberRepository;
+import codezap.tag.domain.Tag;
+import codezap.template.domain.Template;
+import codezap.template.domain.TemplateTag;
+import codezap.template.repository.TemplateRepository;
+
+@JpaRepositoryTest
+class TemplateTagJpaRepositoryTest {
+
+    @Autowired
+    private TemplateRepository templateRepository;
+    @Autowired
+    private MemberRepository memberRepository;
+    @Autowired
+    private CategoryRepository categoryRepository;
+    @Autowired
+    private TagRepository tagRepository;
+    @Autowired
+    private TemplateTagRepository templateTagRepository;
+
+    private Member member1, member2;
+    private Category category1, category2;
+    private Tag tag1, tag2;
+
+    @BeforeEach
+    void setUp() {
+        member1 = memberRepository.save(new Member("[email protected]", "pp"));
+        member2 = memberRepository.save(new Member("[email protected]", "pp"));
+
+        category1 = categoryRepository.save(new Category("Category 1", member1));
+        category2 = categoryRepository.save(new Category("Category 2", member1));
+
+        tag1 = tagRepository.save(new Tag("Tag 1"));
+        tag2 = tagRepository.save(new Tag("Tag 2"));
+
+        Template template1 = new Template(member1, "Template 1", "Description 1", category1);
+        TemplateTag templateTag11 = new TemplateTag(template1, tag1);
+        TemplateTag templateTag12 = new TemplateTag(template1, tag2);
+        templateRepository.save(template1);
+        templateTagRepository.save(templateTag11);
+        templateTagRepository.save(templateTag12);
+
+        Template template2 = new Template(member1, "Template 2", "Description 2", category2);
+        TemplateTag templateTag21 = new TemplateTag(template2, tag1);
+        TemplateTag templateTag22 = new TemplateTag(template2, tag2);
+        templateRepository.save(template2);
+        templateTagRepository.save(templateTag21);
+        templateTagRepository.save(templateTag22);
+
+        Template template3 = new Template(member2, "Another Template", "Another Description", category1);
+        TemplateTag templateTag31 = new TemplateTag(template3, tag2);
+        templateRepository.save(template3);
+        templateTagRepository.save(templateTag31);
+    }
+
+    @Test
+    void testFindDistinctByTemplateIn() {
+        // given
+        List<Long> templateIds = List.of(1L, 2L, 3L);
+
+        // when
+        List<Long> result = templateTagRepository.findDistinctByTemplateIn(templateIds);
+
+        // then
+        assertThat(result).isNotEmpty();
+        assertThat(result.stream().distinct().count())
+                .isEqualTo(result.size());
+    }
+}

backend/src/test/java/codezap/template/repository/FakeTemplateTagRepository.java

@@ -51,10 +51,11 @@ public List<TemplateTag> findAll() {
     }
 
     @Override
-    public List<TemplateTag> findDistinctByTemplateIn(List<Template> templates) {
+    public List<Long> findDistinctByTemplateIn(List<Long> templateIds) {
         return templateTags.stream()
-                .filter(templateTag -> templates.contains(templateTag.getTemplate()))
+                .filter(templateTag -> templateIds.contains(templateTag.getTemplate().getId()))
                 .distinct()
+                .map(templateTag -> templateTag.getTag().getId())
                 .toList();
     }