From 93fd2a4c2849083a3de63f60f7e7deb3ebb8a398 Mon Sep 17 00:00:00 2001
From: nYeonG4001 <2371324@hansung.ac.kr>
Date: Sun, 12 Apr 2026 20:20:50 +0900
Subject: [PATCH] =?UTF-8?q?DP-309:=20=EC=82=AC=EC=9A=A9=EC=9E=90=20?=
 =?UTF-8?q?=ED=94=84=EB=A1=9C=ED=95=84=20recentAnswers=20=EB=8F=99?=
 =?UTF-8?q?=EC=9D=BC=20=EA=B2=8C=EC=8B=9C=EA=B8=80=20=EC=A4=91=EB=B3=B5=20?=
 =?UTF-8?q?=EC=A0=9C=EA=B1=B0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

한 게시글에 답변을 여러 개 달았을 때 recentAnswers에 동일 postId가
답변 수만큼 중복 포함되던 버그 수정. Collectors.toMap으로 postId 기준
중복 제거 (가장 최신 답변 유지). 중복 제거 검증 테스트 추가.
---
 .../user/dto/PublicUserProfileResponse.java   | 17 ++++++---
 .../domain/user/service/UserServiceTest.java  | 35 +++++++++++++++++++
 2 files changed, 47 insertions(+), 5 deletions(-)

diff --git a/src/main/java/com/devpick/domain/user/dto/PublicUserProfileResponse.java b/src/main/java/com/devpick/domain/user/dto/PublicUserProfileResponse.java
index 193752c1..69ce6bd6 100644
--- a/src/main/java/com/devpick/domain/user/dto/PublicUserProfileResponse.java
+++ b/src/main/java/com/devpick/domain/user/dto/PublicUserProfileResponse.java
@@ -9,8 +9,10 @@
 
 import java.time.Instant;
 import java.time.ZoneOffset;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.UUID;
+import java.util.stream.Collectors;
 
 public record PublicUserProfileResponse(
         UUID userId,
@@ -50,11 +52,16 @@ public static PublicUserProfileResponse of(
                                 p.getCreatedAt() != null ? p.getCreatedAt().toInstant(ZoneOffset.UTC) : null))
                         .toList(),
                 answers.stream()
-                        .map(a -> new RecentAnswer(
-                                a.getId(),
-                                a.getPost().getId(),
-                                a.getPost().getTitle(),
-                                a.getCreatedAt() != null ? a.getCreatedAt().toInstant(ZoneOffset.UTC) : null))
+                        .collect(Collectors.toMap(
+                                a -> a.getPost().getId(),
+                                a -> new RecentAnswer(
+                                        a.getId(),
+                                        a.getPost().getId(),
+                                        a.getPost().getTitle(),
+                                        a.getCreatedAt() != null ? a.getCreatedAt().toInstant(ZoneOffset.UTC) : null),
+                                (existing, replacement) -> existing,  // 가장 최신 답변 유지 (쿼리가 createdAt DESC 순)
+                                LinkedHashMap::new))
+                        .values().stream()
                         .toList()
         );
     }
diff --git a/src/test/java/com/devpick/domain/user/service/UserServiceTest.java b/src/test/java/com/devpick/domain/user/service/UserServiceTest.java
index 7e21f3d3..6817bfc5 100644
--- a/src/test/java/com/devpick/domain/user/service/UserServiceTest.java
+++ b/src/test/java/com/devpick/domain/user/service/UserServiceTest.java
@@ -145,6 +145,41 @@ void getPublicProfile_withCreatedAt_convertsToInstant() {
         assertThat(response.recentAnswers().get(0).createdAt()).isNotNull();
     }
 
+    @Test
+    @DisplayName("getPublicProfile — 동일 게시글에 답변 여러 개일 때 recentAnswers에 게시글 1개만 포함")
+    void getPublicProfile_multipleAnswersOnSamePost_deduplicatesRecentAnswers() {
+        Post post = Post.builder().user(user).title("Spring 질문").content("내용").level(Level.JUNIOR).build();
+
+        Answer answer1 = Mockito.mock(Answer.class);
+        Answer answer2 = Mockito.mock(Answer.class);
+        UUID postId = UUID.randomUUID();
+        UUID answer1Id = UUID.randomUUID();
+        UUID answer2Id = UUID.randomUUID();
+
+        Post mockPost = Mockito.mock(Post.class);
+        Mockito.when(mockPost.getId()).thenReturn(postId);
+        Mockito.when(mockPost.getTitle()).thenReturn("Spring 질문");
+
+        Mockito.when(answer1.getId()).thenReturn(answer1Id);
+        Mockito.when(answer1.getPost()).thenReturn(mockPost);
+        Mockito.when(answer1.getCreatedAt()).thenReturn(null);
+
+        Mockito.when(answer2.getId()).thenReturn(answer2Id);
+        Mockito.when(answer2.getPost()).thenReturn(mockPost);
+        Mockito.when(answer2.getCreatedAt()).thenReturn(null);
+
+        given(userRepository.findByIdAndIsActiveTrue(userId)).willReturn(Optional.of(user));
+        given(userBadgeRepository.findByUser_IdOrderByAcquiredAtDesc(userId)).willReturn(List.of());
+        given(postRepository.findByUser_IdOrderByCreatedAtDesc(userId)).willReturn(List.of(post));
+        given(answerRepository.findByUserIdWithPost(userId)).willReturn(List.of(answer1, answer2));
+
+        PublicUserProfileResponse response = userService.getPublicProfile(userId);
+
+        assertThat(response.recentAnswers()).hasSize(1);
+        assertThat(response.recentAnswers().get(0).postId()).isEqualTo(postId);
+        assertThat(response.recentAnswers().get(0).answerId()).isEqualTo(answer1Id); // 첫 번째(최신) 답변 유지
+    }
+
     @Test
     @DisplayName("getPublicProfile — 비활성 사용자 USER_NOT_FOUND 예외")
     void getPublicProfile_inactiveUser_throwsUserNotFound() {