feat(chat-ui): 메시지 그룹화, 시간 포맷팅, Repository 테스트 추가

app/build.gradle

@@ -209,4 +209,11 @@ dependencies {
     implementation "com.kakao.sdk:v2-user:2.21.0"
 
     implementation 'io.github.glailton.expandabletextview:expandabletextview:1.0.4'
+
+    // ----- Test dependencies -----
+    testImplementation 'junit:junit:4.13.2'
+    testImplementation 'org.mockito:mockito-core:5.12.0'
+    testImplementation 'org.mockito:mockito-inline:5.2.0'
+    testImplementation 'org.mockito.kotlin:mockito-kotlin:5.3.1'
+    testImplementation 'io.mockk:mockk:1.13.10'
 }

app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatMessageAdapter.kt

@@ -14,6 +14,7 @@ import android.view.animation.Animation
 import android.view.animation.AnimationUtils
 import android.widget.TextView
 import androidx.annotation.LayoutRes
+import androidx.annotation.VisibleForTesting
 import androidx.core.view.isVisible
 import androidx.recyclerview.widget.RecyclerView
 import kr.co.vividnext.sodalive.R
@@ -48,6 +49,34 @@ class ChatMessageAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
         const val VIEW_TYPE_AI_MESSAGE = 2
         const val VIEW_TYPE_NOTICE = 3
         const val VIEW_TYPE_TYPING_INDICATOR = 4
+
+        /**
+         * [list]와 [position]을 기준으로 그룹화 여부와 해당 아이템이 그룹의 마지막인지 계산한다.
+         * 테스트를 위해 노출된 유틸 함수이며, onBindViewHolder의 로직과 동일한 판정을 수행한다.
+         */
+        @VisibleForTesting
+        internal fun computeGroupingFlags(list: List<ChatListItem>, position: Int): Pair<Boolean, Boolean> {
+            fun isSameSender(prev: ChatListItem?, curr: ChatListItem?): Boolean {
+                if (prev == null || curr == null) return false
+                val p = when (prev) {
+                    is ChatListItem.UserMessage -> prev.data.mine
+                    is ChatListItem.AiMessage -> prev.data.mine
+                    else -> return false
+                }
+                val c = when (curr) {
+                    is ChatListItem.UserMessage -> curr.data.mine
+                    is ChatListItem.AiMessage -> curr.data.mine
+                    else -> return false
+                }
+                return p == c
+            }
+            val curr = list.getOrNull(position)
+            val prev = if (position > 0) list.getOrNull(position - 1) else null
+            val next = if (position < list.lastIndex) list.getOrNull(position + 1) else null
+            val grouped = isSameSender(prev, curr)
+            val isLast = !isSameSender(curr, next)
+            return grouped to isLast
+        }
     }
 
     private val items: MutableList<ChatListItem> = mutableListOf()
@@ -93,6 +122,15 @@ class ChatMessageAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
         notifyDataSetChanged()
     }
 
+    /**
+     * 테스트 전용: RecyclerView 프레임워크 없이 내부 리스트만 채우고 알림을 보내지 않는다.
+     */
+    @VisibleForTesting
+    internal fun setItemsForTest(newItems: List<ChatListItem>) {
+        items.clear()
+        items.addAll(newItems)
+    }
+
     fun addItem(item: ChatListItem) {
         items.add(item)
         notifyItemInserted(items.lastIndex)

app/src/test/java/kr/co/vividnext/sodalive/chat/talk/room/ChatMessageAdapterTest.kt

@@ -0,0 +1,77 @@
+package kr.co.vividnext.sodalive.chat.talk.room
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ChatMessageAdapterTest {
+
+    @Test
+    fun `getItemViewType returns correct types`() {
+        val adapter = ChatMessageAdapter()
+        val list = listOf(
+            ChatListItem.UserMessage(ChatMessage(1, "hi", "", mine = true, createdAt = 1L)),
+            ChatListItem.AiMessage(ChatMessage(2, "hello", "", mine = false, createdAt = 2L)),
+            ChatListItem.Notice("notice"),
+            ChatListItem.TypingIndicator
+        )
+        adapter.setItemsForTest(list)
+        assertEquals(ChatMessageAdapter.VIEW_TYPE_USER_MESSAGE, adapter.getItemViewType(0))
+        assertEquals(ChatMessageAdapter.VIEW_TYPE_AI_MESSAGE, adapter.getItemViewType(1))
+        assertEquals(ChatMessageAdapter.VIEW_TYPE_NOTICE, adapter.getItemViewType(2))
+        assertEquals(ChatMessageAdapter.VIEW_TYPE_TYPING_INDICATOR, adapter.getItemViewType(3))
+    }
+
+    @Test
+    fun `computeGroupingFlags determines group and last correctly`() {
+        val items = listOf(
+            ChatListItem.AiMessage(ChatMessage(1, "a1", "", mine = false, createdAt = 1L)),
+            ChatListItem.AiMessage(ChatMessage(2, "a2", "", mine = false, createdAt = 2L)),
+            ChatListItem.AiMessage(ChatMessage(3, "a3", "", mine = false, createdAt = 3L)),
+            ChatListItem.UserMessage(ChatMessage(4, "u1", "", mine = true, createdAt = 4L)),
+            ChatListItem.UserMessage(ChatMessage(5, "u2", "", mine = true, createdAt = 5L)),
+            ChatListItem.Notice("guide"),
+            ChatListItem.UserMessage(ChatMessage(6, "u3", "", mine = true, createdAt = 6L)),
+            ChatListItem.AiMessage(ChatMessage(7, "a4", "", mine = false, createdAt = 7L))
+        )
+        // index 0: 첫 메시지, 그룹 아님, 다음과 같으므로 마지막 아님
+        ChatMessageAdapter.computeGroupingFlags(items, 0).let { (grouped, last) ->
+            assertEquals(false, grouped)
+            assertEquals(false, last)
+        }
+        // index 1: 이전과 동일 발신자 -> 그룹, 다음과 동일 -> 마지막 아님
+        ChatMessageAdapter.computeGroupingFlags(items, 1).let { (grouped, last) ->
+            assertEquals(true, grouped)
+            assertEquals(false, last)
+        }
+        // index 2: 이전과 동일 발신자 -> 그룹, 다음은 다른 발신자 -> 마지막
+        ChatMessageAdapter.computeGroupingFlags(items, 2).let { (grouped, last) ->
+            assertEquals(true, grouped)
+            assertEquals(true, last)
+        }
+        // index 3: 사용자 메시지 시작 -> 그룹 아님, 다음 동일 -> 마지막 아님
+        ChatMessageAdapter.computeGroupingFlags(items, 3).let { (grouped, last) ->
+            assertEquals(false, grouped)
+            assertEquals(false, last)
+        }
+        // index 4: 사용자 그룹의 마지막 (다음 아이템은 Notice라 발신자 비교 실패) -> grouped true, last true
+        ChatMessageAdapter.computeGroupingFlags(items, 4).let { (grouped, last) ->
+            assertEquals(true, grouped)
+            assertEquals(true, last)
+        }
+        // index 5: Notice -> 그룹 로직 비대상, grouped false, last true(다음과 비교 불가로 true)
+        ChatMessageAdapter.computeGroupingFlags(items, 5).let { (grouped, last) ->
+            assertEquals(false, grouped)
+            assertEquals(true, last)
+        }
+        // index 6: Notice 다음의 사용자 단독 -> grouped false, 다음은 ai라 last true
+        ChatMessageAdapter.computeGroupingFlags(items, 6).let { (grouped, last) ->
+            assertEquals(false, grouped)
+            assertEquals(true, last)
+        }
+        // index 7: 마지막 ai -> grouped false, last true
+        ChatMessageAdapter.computeGroupingFlags(items, 7).let { (grouped, last) ->
+            assertEquals(false, grouped)
+            assertEquals(true, last)
+        }
+    }
+}

app/src/test/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRepositoryTest.kt

@@ -0,0 +1,67 @@
+package kr.co.vividnext.sodalive.chat.talk.room
+
+import io.mockk.coEvery
+import io.mockk.coVerify
+import io.mockk.every
+import io.mockk.mockk
+import io.reactivex.rxjava3.core.Single
+import kr.co.vividnext.sodalive.chat.talk.TalkApi
+import kr.co.vividnext.sodalive.chat.talk.room.db.ChatMessageDao
+import kr.co.vividnext.sodalive.common.ApiResponse
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ChatRepositoryTest {
+
+    @Test
+    fun `enterChatRoom inserts messages and returns response`() {
+        val dao = mockk<ChatMessageDao>(relaxed = true)
+        val api = mockk<TalkApi>()
+        val repo = ChatRepository(dao, api)
+
+        val serverMessages = listOf(
+            ServerChatMessage(1, "a1", "", mine = false, createdAt = 1000L),
+            ServerChatMessage(2, "u1", "", mine = true, createdAt = 2000L)
+        )
+        val character = CharacterInfo(10, "name", "", kr.co.vividnext.sodalive.chat.character.detail.CharacterType.CLONE)
+        val resp = ChatRoomEnterResponse(99, character, serverMessages, hasMoreMessages = false)
+
+        every { api.enterChatRoom(any(), any()) } returns Single.just(ApiResponse(true, resp, null))
+        coEvery { dao.getNthLatestCreatedAt(any(), any()) } returns null
+
+        val result = repo.enterChatRoom("token", 99).blockingGet()
+
+        // 반환 검증
+        assertEquals(99, result.roomId)
+        assertEquals(2, result.messages.size)
+
+        // 로컬 저장 검증
+        coVerify { dao.insertMessages(match { it.size == 2 }) }
+    }
+
+    @Test
+    fun `getRecentMessagesFromLocal maps to domain`() {
+        val dao = mockk<ChatMessageDao>()
+        val api = mockk<TalkApi>()
+        val repo = ChatRepository(dao, api)
+
+        val entities = listOf(
+            kr.co.vividnext.sodalive.chat.talk.room.db.ChatMessageEntity(
+                messageId = 1L,
+                roomId = 1L,
+                message = "hello",
+                profileImageUrl = "",
+                mine = true,
+                createdAt = 10L,
+                status = MessageStatus.SENT,
+                localId = null
+            )
+        )
+        coEvery { dao.getRecentMessages(1L) } returns entities
+
+        val list = repo.getRecentMessagesFromLocal(1L).blockingGet()
+        assertEquals(1, list.size)
+        assertEquals("hello", list[0].message)
+        assertEquals(true, list[0].mine)
+    }
+}

app/src/test/java/kr/co/vividnext/sodalive/chat/talk/room/TimeUtilsTest.kt

@@ -0,0 +1,18 @@
+package kr.co.vividnext.sodalive.chat.talk.room
+
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.util.Locale
+
+class TimeUtilsTest {
+    @Test
+    fun `formatMessageTime returns localized pattern for ko_KR`() {
+        val ts = 1734190980000L // 임의 epoch millis
+        val result = formatMessageTime(ts, Locale.KOREA)
+        // 한국어 로케일일 때 "오전/오후 h:mm" 패턴 일부라도 충족하는지 확인
+        assertTrue(result.isNotBlank())
+        assertTrue(result.contains(":"))
+        // 오전 또는 오후 텍스트 포함
+        assertTrue(result.contains("오전") || result.contains("오후"))
+    }
+}