fix: ✏️ Append LastMessage Field in ChatRoomDetail Response (#196)

* feat: add chat_room_res info dto for service return data mapping

* fix: chat_room_mapper use chat_room_res.info dto within parameter

* fix: when search my chatroom, add flow for read last message

* fix: usecase is fixed by dto spec

* test: fix unit test

pennyway-app-external-api/src/main/java/kr/co/pennyway/api/apis/chat/dto/ChatRoomRes.java

@@ -5,6 +5,7 @@
 import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
 import io.swagger.v3.oas.annotations.media.Schema;
 import kr.co.pennyway.domain.domains.chatroom.domain.ChatRoom;
+import kr.co.pennyway.domain.domains.chatroom.dto.ChatRoomDetail;
 import lombok.Builder;
 
 import java.time.LocalDateTime;
@@ -13,6 +14,23 @@
 import java.util.Set;
 
 public final class ChatRoomRes {
+    /**
+     * 채팅방 정보를 담기 위한 DTO
+     *
+     * @param chatRoom           {@link ChatRoomDetail} : 채팅방 정보
+     * @param unreadMessageCount long : 읽지 않은 메시지 수
+     * @param lastMessage        {@link ChatRes.ChatDetail} : 가장 최근 메시지. 없을 경우 null
+     */
+    public record Info(
+            ChatRoomDetail chatRoom,
+            long unreadMessageCount,
+            ChatRes.ChatDetail lastMessage
+    ) {
+        public static Info of(ChatRoomDetail chatRoom, long unreadMessageCount, ChatRes.ChatDetail recentMessage) {
+            return new Info(chatRoom, unreadMessageCount, recentMessage);
+        }
+    }
+
     @Schema(description = "채팅방 상세 정보")
     public record Detail(
             @Schema(description = "채팅방 ID", type = "long")
@@ -33,10 +51,12 @@ public record Detail(
             @JsonSerialize(using = LocalDateTimeSerializer.class)
             @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
             LocalDateTime createdAt,
+            @Schema(description = "마지막 메시지 정보. 없을 경우 null이 반환된다.")
+            ChatRes.ChatDetail lastMessage,
             @Schema(description = "읽지 않은 메시지 수. 100 이상의 값을 가지면, 100으로 표시된다.")
             long unreadMessageCount
     ) {
-        public Detail(Long id, String title, String description, String backgroundImageUrl, boolean isPrivate, boolean isAdmin, int participantCount, LocalDateTime createdAt, long unreadMessageCount) {
+        public Detail(Long id, String title, String description, String backgroundImageUrl, boolean isPrivate, boolean isAdmin, int participantCount, LocalDateTime createdAt, ChatRes.ChatDetail lastMessage, long unreadMessageCount) {
             this.id = id;
             this.title = title;
             this.description = Objects.toString(description, "");
@@ -45,10 +65,11 @@ public Detail(Long id, String title, String description, String backgroundImageU
             this.isAdmin = isAdmin;
             this.participantCount = participantCount;
             this.createdAt = createdAt;
+            this.lastMessage = lastMessage;
             this.unreadMessageCount = (unreadMessageCount > 100) ? 100 : unreadMessageCount;
         }
 
-        public static Detail of(ChatRoom chatRoom, boolean isAdmin, int participantCount, long unreadMessageCount) {
+        public static Detail of(ChatRoom chatRoom, ChatRes.ChatDetail lastMessage, boolean isAdmin, int participantCount, long unreadMessageCount) {
             return new Detail(
                     chatRoom.getId(),
                     chatRoom.getTitle(),
@@ -58,9 +79,25 @@ public static Detail of(ChatRoom chatRoom, boolean isAdmin, int participantCount
                     isAdmin,
                     participantCount,
                     chatRoom.getCreatedAt(),
+                    lastMessage,
                     unreadMessageCount
             );
         }
+
+        public static Detail from(ChatRoomRes.Info info) {
+            return new Detail(
+                    info.chatRoom().id(),
+                    info.chatRoom().title(),
+                    info.chatRoom().description(),
+                    info.chatRoom().backgroundImageUrl(),
+                    info.chatRoom().password() != null,
+                    info.chatRoom().isAdmin(),
+                    info.chatRoom().participantCount(),
+                    info.chatRoom().createdAt(),
+                    info.lastMessage(),
+                    info.unreadMessageCount()
+            );
+        }
     }
 
     @Schema(description = "채팅방 요약 정보")

pennyway-app-external-api/src/main/java/kr/co/pennyway/api/apis/chat/mapper/ChatRoomMapper.java

@@ -14,10 +14,17 @@
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 
 @Mapper
 public final class ChatRoomMapper {
+    /**
+     * 채팅방 상세 정보를 SliceResponseTemplate 형태로 변환한다.
+     * 해당 메서드는 언제나 채팅방 검색 응답으로 사용되며, 마지막 메시지 정보는 null로 설정된다.
+     *
+     * @param details
+     * @param pageable
+     * @return
+     */
     public static SliceResponseTemplate<ChatRoomRes.Detail> toChatRoomResDetails(Slice<ChatRoomDetail> details, Pageable pageable) {
         List<ChatRoomRes.Detail> contents = new ArrayList<>();
         for (ChatRoomDetail detail : details.getContent()) {
@@ -31,6 +38,7 @@ public static SliceResponseTemplate<ChatRoomRes.Detail> toChatRoomResDetails(Sli
                             detail.isAdmin(),
                             detail.participantCount(),
                             detail.createdAt(),
+                            null,
                             0
                     )
             );
@@ -39,31 +47,31 @@ public static SliceResponseTemplate<ChatRoomRes.Detail> toChatRoomResDetails(Sli
         return SliceResponseTemplate.of(contents, pageable, contents.size(), details.hasNext());
     }
 
-    public static List<ChatRoomRes.Detail> toChatRoomResDetails(Map<ChatRoomDetail, Long> details) {
+    public static List<ChatRoomRes.Detail> toChatRoomResDetails(List<ChatRoomRes.Info> details) {
         List<ChatRoomRes.Detail> responses = new ArrayList<>();
 
-        for (Map.Entry<ChatRoomDetail, Long> entry : details.entrySet()) {
-            ChatRoomDetail detail = entry.getKey();
+        for (ChatRoomRes.Info info : details) {
             responses.add(
                     new ChatRoomRes.Detail(
-                            detail.id(),
-                            detail.title(),
-                            detail.description(),
-                            detail.backgroundImageUrl(),
-                            detail.password() != null,
-                            detail.isAdmin(),
-                            detail.participantCount(),
-                            detail.createdAt(),
-                            entry.getValue()
+                            info.chatRoom().id(),
+                            info.chatRoom().title(),
+                            info.chatRoom().description(),
+                            info.chatRoom().backgroundImageUrl(),
+                            info.chatRoom().password() != null,
+                            info.chatRoom().isAdmin(),
+                            info.chatRoom().participantCount(),
+                            info.chatRoom().createdAt(),
+                            info.lastMessage(),
+                            info.unreadMessageCount()
                     )
             );
         }
 
         return responses;
     }
 
-    public static ChatRoomRes.Detail toChatRoomResDetail(ChatRoom chatRoom, boolean isAdmin, int participantCount, long unreadMessageCount) {
-        return ChatRoomRes.Detail.of(chatRoom, isAdmin, participantCount, unreadMessageCount);
+    public static ChatRoomRes.Detail toChatRoomResDetail(ChatRoom chatRoom, ChatRes.ChatDetail lastMessage, boolean isAdmin, int participantCount, long unreadMessageCount) {
+        return ChatRoomRes.Detail.of(chatRoom, lastMessage, isAdmin, participantCount, unreadMessageCount);
     }
 
     public static ChatRoomRes.RoomWithParticipants toChatRoomResRoomWithParticipants(ChatMemberResult.Detail myInfo, List<ChatMemberResult.Detail> recentParticipants, List<ChatMemberResult.Summary> otherParticipants, List<ChatMessage> chatMessages) {

pennyway-app-external-api/src/main/java/kr/co/pennyway/api/apis/chat/service/ChatRoomSearchService.java

@@ -1,5 +1,8 @@
 package kr.co.pennyway.api.apis.chat.service;
 
+import kr.co.pennyway.api.apis.chat.dto.ChatRes;
+import kr.co.pennyway.api.apis.chat.dto.ChatRoomRes;
+import kr.co.pennyway.domain.common.redis.message.domain.ChatMessage;
 import kr.co.pennyway.domain.common.redis.message.service.ChatMessageService;
 import kr.co.pennyway.domain.domains.chatroom.dto.ChatRoomDetail;
 import kr.co.pennyway.domain.domains.chatroom.service.ChatRoomService;
@@ -11,9 +14,8 @@
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
-import java.util.HashMap;
+import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 
 @Slf4j
 @Service
@@ -26,17 +28,19 @@ public class ChatRoomSearchService {
     /**
      * 사용자 ID가 속한 채팅방 목록을 조회한다.
      *
-     * @return 채팅방 목록 (채팅방 정보, 읽지 않은 메시지 수)
+     * @return 채팅방 목록. {@link ChatRoomRes.Info} 리스트 형태로 반환
      */
     @Transactional(readOnly = true)
-    public Map<ChatRoomDetail, Long> readChatRooms(Long userId) {
+    public List<ChatRoomRes.Info> readChatRooms(Long userId) {
         List<ChatRoomDetail> chatRooms = chatRoomService.readChatRoomsByUserId(userId);
-        Map<ChatRoomDetail, Long> result = new HashMap<>();
+        List<ChatRoomRes.Info> result = new ArrayList<>();
 
         for (ChatRoomDetail chatRoom : chatRooms) {
             Long lastReadMessageId = chatMessageStatusService.readLastReadMessageId(userId, chatRoom.id());
+            ChatMessage lastMessage = chatMessageService.readRecentMessages(chatRoom.id(), 1).stream().findFirst().orElse(null);
             Long unreadCount = chatMessageService.countUnreadMessages(chatRoom.id(), lastReadMessageId);
-            result.put(chatRoom, unreadCount);
+
+            result.add(ChatRoomRes.Info.of(chatRoom, unreadCount, lastMessage == null ? null : ChatRes.ChatDetail.from(lastMessage)));
         }
 
         return result;

pennyway-app-external-api/src/main/java/kr/co/pennyway/api/apis/chat/usecase/ChatMemberUseCase.java

@@ -26,7 +26,7 @@ public class ChatMemberUseCase {
     public ChatRoomRes.Detail joinChatRoom(Long userId, Long chatRoomId, Integer password) {
         Triple<ChatRoom, Integer, Long> chatRoom = chatMemberJoinService.execute(userId, chatRoomId, password);
 
-        return ChatRoomMapper.toChatRoomResDetail(chatRoom.getLeft(), false, chatRoom.getMiddle(), chatRoom.getRight());
+        return ChatRoomMapper.toChatRoomResDetail(chatRoom.getLeft(), null, false, chatRoom.getMiddle(), chatRoom.getRight());
     }
 
     public List<ChatMemberRes.MemberDetail> readChatMembers(Long chatRoomId, Set<Long> chatMemberIds) {

pennyway-app-external-api/src/main/java/kr/co/pennyway/api/apis/chat/usecase/ChatRoomUseCase.java

@@ -16,7 +16,6 @@
 import org.springframework.data.domain.Slice;
 
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 
 @UseCase
@@ -31,11 +30,11 @@ public class ChatRoomUseCase {
     public ChatRoomRes.Detail createChatRoom(ChatRoomReq.Create request, Long userId) {
         ChatRoom chatRoom = chatRoomSaveService.createChatRoom(request, userId);
 
-        return ChatRoomMapper.toChatRoomResDetail(chatRoom, true, 1, 0);
+        return ChatRoomMapper.toChatRoomResDetail(chatRoom, null, true, 1, 0);
     }
 
     public List<ChatRoomRes.Detail> getChatRooms(Long userId) {
-        Map<ChatRoomDetail, Long> chatRooms = chatRoomSearchService.readChatRooms(userId);
+        List<ChatRoomRes.Info> chatRooms = chatRoomSearchService.readChatRooms(userId);
 
         return ChatRoomMapper.toChatRoomResDetails(chatRooms);
     }

pennyway-app-external-api/src/test/java/kr/co/pennyway/api/apis/chat/controller/ChatRoomSaveControllerUnitTest.java

@@ -52,7 +52,7 @@ void createChatRoomSuccess() throws Exception {
         // given
         ChatRoom fixture = ChatRoomFixture.PRIVATE_CHAT_ROOM.toEntity(1L);
         ChatRoomReq.Create request = ChatRoomFixture.PRIVATE_CHAT_ROOM.toCreateRequest();
-        given(chatRoomUseCase.createChatRoom(request, 1L)).willReturn(ChatRoomRes.Detail.of(fixture, true, 1, 10));
+        given(chatRoomUseCase.createChatRoom(request, 1L)).willReturn(ChatRoomRes.Detail.of(fixture, null, true, 1, 10));
 
         // when
         ResultActions result = performPostChatRoom(request);
@@ -70,7 +70,7 @@ void createChatRoomSuccessWithNullBackgroundImageUrl() throws Exception {
         ChatRoom fixture = ChatRoomFixture.PUBLIC_CHAT_ROOM.toEntity(1L);
         ChatRoomReq.Create request = ChatRoomFixture.PUBLIC_CHAT_ROOM.toCreateRequest();
 
-        given(chatRoomUseCase.createChatRoom(request, 1L)).willReturn(ChatRoomRes.Detail.of(fixture, true, 1, 10));
+        given(chatRoomUseCase.createChatRoom(request, 1L)).willReturn(ChatRoomRes.Detail.of(fixture, null, true, 1, 10));
 
         // when
         ResultActions result = performPostChatRoom(request);

pennyway-app-external-api/src/test/java/kr/co/pennyway/api/apis/chat/service/ChatRoomSearchServiceTest.java

@@ -1,6 +1,11 @@
 package kr.co.pennyway.api.apis.chat.service;
 
+import kr.co.pennyway.api.apis.chat.dto.ChatRoomRes;
+import kr.co.pennyway.domain.common.redis.message.domain.ChatMessage;
+import kr.co.pennyway.domain.common.redis.message.domain.ChatMessageBuilder;
 import kr.co.pennyway.domain.common.redis.message.service.ChatMessageService;
+import kr.co.pennyway.domain.common.redis.message.type.MessageCategoryType;
+import kr.co.pennyway.domain.common.redis.message.type.MessageContentType;
 import kr.co.pennyway.domain.domains.chatroom.dto.ChatRoomDetail;
 import kr.co.pennyway.domain.domains.chatroom.service.ChatRoomService;
 import kr.co.pennyway.domain.domains.chatstatus.service.ChatMessageStatusService;
@@ -15,11 +20,12 @@
 import java.time.LocalDateTime;
 import java.util.Collections;
 import java.util.List;
-import java.util.Map;
 
 import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.BDDMockito.given;
-import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.*;
 
 @ExtendWith(MockitoExtension.class)
 class ChatRoomSearchServiceTest {
@@ -34,7 +40,7 @@ class ChatRoomSearchServiceTest {
     private ChatMessageService chatMessageService;
 
     @Test
-    @DisplayName("사용자의 채팅방 목록과 각 방의 읽지 않은 메시지 수를 정상적으로 조회한다")
+    @DisplayName("사용자의 채팅방 목록과 각 방의 읽지 않은 메시지 수, 마지막 메시지를 정상적으로 조회한다")
     void successReadChatRooms() {
         // given
         Long userId = 1L;
@@ -46,21 +52,29 @@ void successReadChatRooms() {
         given(chatRoomService.readChatRoomsByUserId(userId)).willReturn(chatRooms);
 
         // room1: 마지막으로 읽은 메시지 ID 10, 읽지 않은 메시지 5개
+        ChatMessage firstRoomLastMessage = ChatMessageBuilder.builder().chatRoomId(2L).chatId(1L).content("Hello").contentType(MessageContentType.TEXT).categoryType(MessageCategoryType.NORMAL).sender(userId).build();
+
         given(chatMessageStatusService.readLastReadMessageId(userId, 1L)).willReturn(10L);
         given(chatMessageService.countUnreadMessages(1L, 10L)).willReturn(5L);
+        given(chatMessageService.readRecentMessages(1L, 1)).willReturn(List.of(firstRoomLastMessage));
 
         // room2: 마지막으로 읽은 메시지 ID 20, 읽지 않은 메시지 3개
+        ChatMessage secondRoomLastMessage = ChatMessageBuilder.builder().chatRoomId(2L).chatId(100L).content("jayang님이 입장하셨습니다.").contentType(MessageContentType.TEXT).categoryType(MessageCategoryType.SYSTEM).sender(userId).build();
+
         given(chatMessageStatusService.readLastReadMessageId(userId, 2L)).willReturn(20L);
         given(chatMessageService.countUnreadMessages(2L, 20L)).willReturn(3L);
+        given(chatMessageService.readRecentMessages(2L, 1)).willReturn(List.of(secondRoomLastMessage));
 
         // when
-        Map<ChatRoomDetail, Long> result = chatRoomSearchService.readChatRooms(userId);
+        List<ChatRoomRes.Info> result = chatRoomSearchService.readChatRooms(userId);
 
         // then
         assertAll(
-                () -> assertEquals(2, result.size()),
-                () -> assertEquals(5L, result.get(chatRooms.get(0))),
-                () -> assertEquals(3L, result.get(chatRooms.get(1)))
+                () -> assertEquals(2, result.size(), "조회된 채팅방 목록은 2개여야 한다."),
+                () -> assertEquals(5L, result.get(0).unreadMessageCount(), "Room1의 읽지 않은 메시지 수는 5개여야 한다."),
+                () -> assertEquals(firstRoomLastMessage.getChatId(), result.get(0).lastMessage().chatId(), "Room1의 마지막 메시지는 ID가 일치해야 한다."),
+                () -> assertEquals(3L, result.get(1).unreadMessageCount(), "Room2의 읽지 않은 메시지 수는 3개여야 한다."),
+                () -> assertEquals(secondRoomLastMessage.getChatId(), result.get(1).lastMessage().chatId(), "Room2의 마지막 메시지는 ID가 일치해야 한다.")
         );
     }
 
@@ -72,10 +86,13 @@ void returnEmptyMapWhenNoRooms() {
         given(chatRoomService.readChatRoomsByUserId(userId)).willReturn(Collections.emptyList());
 
         // when
-        Map<ChatRoomDetail, Long> result = chatRoomSearchService.readChatRooms(userId);
+        List<ChatRoomRes.Info> result = chatRoomSearchService.readChatRooms(userId);
 
         // then
         assertTrue(result.isEmpty());
+        verify(chatMessageStatusService, never()).readLastReadMessageId(eq(userId), anyLong());
+        verify(chatMessageService, never()).countUnreadMessages(anyLong(), anyLong());
+        verify(chatMessageService, never()).countUnreadMessages(anyLong(), anyLong());
     }
 
     @Test
@@ -110,10 +127,11 @@ void verifyServiceCallOrder() {
                 new ChatRoomDetail(1L, "Room1", "", "", 123456, LocalDateTime.now(), true, 2)
         );
 
-        InOrder inOrder = inOrder(chatRoomService, chatMessageStatusService, chatMessageService);
+        InOrder inOrder = inOrder(chatRoomService, chatMessageStatusService, chatMessageService, chatMessageService);
 
         given(chatRoomService.readChatRoomsByUserId(userId)).willReturn(chatRooms);
         given(chatMessageStatusService.readLastReadMessageId(userId, 1L)).willReturn(10L);
+        given(chatMessageService.readRecentMessages(1L, 1)).willReturn(Collections.emptyList());
         given(chatMessageService.countUnreadMessages(userId, 10L)).willReturn(5L);
 
         // when