Refactor : 프론트앤드에서 발생하는 POST /api/rooms 발생 에러 제어 (#146)

src/main/java/com/back/domain/studyroom/entity/Room.java

@@ -188,6 +188,12 @@ public static Room create(String title, String description, boolean isPrivate,
         room.createdBy = creator;
         room.theme = theme;
 
+        // 컬렉션 필드 명시적 초기화 (null 방지)
+        room.roomMembers = new ArrayList<>();
+        room.roomChatMessages = new ArrayList<>();
+        room.roomParticipantHistories = new ArrayList<>();
+        room.studyRecords = new ArrayList<>();
+
         return room;
     }
 

src/test/java/com/back/domain/studyroom/integration/RoomCreateIntegrationTest.java

@@ -0,0 +1,156 @@
+package com.back.domain.studyroom.integration;
+
+import com.back.domain.studyroom.dto.CreateRoomRequest;
+import com.back.domain.studyroom.entity.Room;
+import com.back.domain.studyroom.repository.RoomMemberRepository;
+import com.back.domain.studyroom.repository.RoomRepository;
+import com.back.domain.studyroom.service.RoomService;
+import com.back.domain.user.entity.Role;
+import com.back.domain.user.entity.User;
+import com.back.domain.user.entity.UserProfile;
+import com.back.domain.user.entity.UserStatus;
+import com.back.domain.user.repository.UserRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+import org.springframework.transaction.annotation.Transactional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+@ActiveProfiles("test")
+@Transactional
+@DisplayName("방 생성 통합 테스트 - 실제 DB 저장")
+public class RoomCreateIntegrationTest {
+
+    @Autowired
+    private RoomService roomService;
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Autowired
+    private RoomRepository roomRepository;
+
+    @Autowired
+    private RoomMemberRepository roomMemberRepository;
+
+    private User testUser;
+
+    @BeforeEach
+    void setUp() {
+        // 실제 사용자 생성 및 저장
+        UserProfile userProfile = new UserProfile();
+        userProfile.setNickname("테스트유저");
+        userProfile.setProfileImageUrl("https://example.com/profile.jpg");
+
+        testUser = User.builder()
+                .username("testuser@test.com")
+                .email("testuser@test.com")
+                .password("password123")
+                .role(Role.USER)
+                .userStatus(UserStatus.ACTIVE)
+                .build();
+
+        testUser.setUserProfile(userProfile);
+        testUser = userRepository.save(testUser);
+
+        System.out.println("=== 테스트 사용자 생성 완료: ID = " + testUser.getId());
+    }
+
+    @Test
+    @DisplayName("방 생성 실제 저장 테스트 - 프론트엔드 요청과 동일한 조건")
+    void createRoom_RealSave() {
+        // given - 프론트엔드가 보낸 것과 동일한 요청
+        String title = "테스트1";
+        String description = "테스트 제발 제발 제";
+        boolean isPrivate = true;
+        String password = "123123123";
+        int maxParticipants = 9;
+        boolean useWebRTC = false;
+
+        System.out.println("=== 방 생성 시작 ===");
+        System.out.println("Title: " + title);
+        System.out.println("Description: " + description);
+        System.out.println("IsPrivate: " + isPrivate);
+        System.out.println("Password: " + password);
+        System.out.println("MaxParticipants: " + maxParticipants);
+        System.out.println("UseWebRTC: " + useWebRTC);
+        System.out.println("CreatorId: " + testUser.getId());
+
+        // when - 실제 서비스 호출
+        Room createdRoom = roomService.createRoom(
+                title,
+                description,
+                isPrivate,
+                password,
+                maxParticipants,
+                testUser.getId(),
+                useWebRTC
+        );
+
+        // then
+        assertThat(createdRoom).isNotNull();
+        assertThat(createdRoom.getId()).isNotNull();
+        assertThat(createdRoom.getTitle()).isEqualTo(title);
+        assertThat(createdRoom.getDescription()).isEqualTo(description);
+        assertThat(createdRoom.isPrivate()).isEqualTo(isPrivate);
+        assertThat(createdRoom.getPassword()).isEqualTo(password);
+        assertThat(createdRoom.getMaxParticipants()).isEqualTo(maxParticipants);
+        assertThat(createdRoom.isAllowCamera()).isEqualTo(useWebRTC);
+        assertThat(createdRoom.isAllowAudio()).isEqualTo(useWebRTC);
+        assertThat(createdRoom.isAllowScreenShare()).isEqualTo(useWebRTC);
+
+        System.out.println("=== 방 생성 성공! ===");
+        System.out.println("Room ID: " + createdRoom.getId());
+        System.out.println("Room Members: " + createdRoom.getRoomMembers());
+        System.out.println("Room Chat Messages: " + createdRoom.getRoomChatMessages());
+
+        // DB에 실제로 저장되었는지 확인
+        Room savedRoom = roomRepository.findById(createdRoom.getId()).orElse(null);
+        assertThat(savedRoom).isNotNull();
+        assertThat(savedRoom.getTitle()).isEqualTo(title);
+
+        // 방장 멤버도 저장되었는지 확인
+        boolean hostExists = roomMemberRepository.existsByRoomIdAndUserId(
+                createdRoom.getId(), 
+                testUser.getId()
+        );
+        assertThat(hostExists).isTrue();
+
+        System.out.println("=== 방 생성 통합 테스트 완료 ===");
+    }
+
+    @Test
+    @DisplayName("방 생성 - 컬렉션 필드 null 체크")
+    void createRoom_CheckCollections() {
+        // given
+        String title = "컬렉션 테스트";
+
+        // when
+        Room createdRoom = roomService.createRoom(
+                title,
+                "설명",
+                false,
+                null,
+                10,
+                testUser.getId(),
+                true
+        );
+
+        // then - 컬렉션 필드들이 null이 아니어야 함
+        assertThat(createdRoom.getRoomMembers()).isNotNull();
+        assertThat(createdRoom.getRoomChatMessages()).isNotNull();
+        assertThat(createdRoom.getRoomParticipantHistories()).isNotNull();
+        assertThat(createdRoom.getStudyRecords()).isNotNull();
+
+        System.out.println("=== 컬렉션 필드 확인 ===");
+        System.out.println("RoomMembers: " + createdRoom.getRoomMembers());
+        System.out.println("RoomChatMessages: " + createdRoom.getRoomChatMessages());
+        System.out.println("RoomParticipantHistories: " + createdRoom.getRoomParticipantHistories());
+        System.out.println("StudyRecords: " + createdRoom.getStudyRecords());
+    }
+}