fix: 관련 아티클 tagtype null filter 수정

Author: juny0955

src/main/java/com/davcatch/devcatch/repository/article/ArticleRepositoryCustomImpl.java

@@ -159,17 +159,14 @@ public Optional<ArticleResponse> findArticleDetail(Long articleId) {
 
 	@Override
 	public List<ArticleResponse> findRelatedArticles(Long articleId, List<TagType> tagTypes) {
-		if (tagTypes == null || tagTypes.isEmpty())
-			return Collections.emptyList();
-
 		Map<Long, ArticleResponse> transform = queryFactory
 			.from(article)
 			.join(article.source, source)
 			.join(article.articleTags, articleTag)
 			.join(articleTag.tag, tag)
 			.where(
 				article.id.ne(articleId),
-				tag.tagType.in(tagTypes)
+				tag.tagType.in(tagTypes).isNull()
 			)
 			.orderBy(article.publishedAt.desc())
 			.limit(RELATED_ARTICLE_SIZE)

src/main/java/com/davcatch/devcatch/web/service/article/ArticleCommendService.java

@@ -1,6 +1,8 @@
 package com.davcatch.devcatch.web.service.article;
 
+import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
@@ -65,7 +67,16 @@ public ArticleResponse getArticleDetail(Long articleId) throws CustomException {
 	 * @return 아티클 리스트
 	 */
 	public List<ArticleResponse> getRelatedArticles(Long articleId, List<TagType> tagTypes) {
-		return articleRepository.findRelatedArticles(articleId, tagTypes);
+		List<TagType> filteredNullTagTypes = tagTypes == null ?
+			Collections.emptyList() :
+			tagTypes.stream()
+				.filter(Objects::nonNull)
+				.toList();
+
+		if (filteredNullTagTypes.isEmpty())
+			return Collections.emptyList();
+
+		return articleRepository.findRelatedArticles(articleId, filteredNullTagTypes);
 	}
 
 }