[WEAV-350] 채팅방 멤버 도메인 설계 (#258)

domain/src/main/kotlin/com/studentcenter/weave/domain/chat/entity/ChatMember.kt

@@ -0,0 +1,21 @@
+package com.studentcenter.weave.domain.chat.entity
+
+import com.studentcenter.weave.domain.common.DomainEntity
+import com.studentcenter.weave.support.common.uuid.UuidCreator
+import java.util.*
+
+data class ChatMember(
+    override val id: UUID = UuidCreator.create(),
+    val userId: UUID,
+    val lastReadMessageId: UUID? = null,
+) : DomainEntity {
+
+    companion object {
+
+        fun create(userId: UUID): ChatMember {
+            return ChatMember(userId = userId)
+        }
+
+    }
+
+}

domain/src/main/kotlin/com/studentcenter/weave/domain/chat/entity/ChatRoom.kt

@@ -12,8 +12,18 @@ data class ChatRoom(
     val receivingTeamId: UUID,
     val requestingTeamId: UUID,
     val createdAt: LocalDateTime = LocalDateTime.now(),
+    val members: Set<ChatMember> = emptySet(),
 ) : AggregateRoot {
 
+    fun addMember(userId: UUID): ChatRoom {
+        require(members.none { it.userId == userId }) {
+            "이미 채팅방에 참여하고 있는 사용자입니다."
+        }
+
+        val newMember: ChatMember = ChatMember.create(userId)
+        return copy(members = members + newMember)
+    }
+
     companion object {
 
         fun create(meeting: Meeting): ChatRoom {

domain/src/test/kotlin/com/studentcenter/weave/domain/chat/entity/ChatRoomTest.kt

@@ -2,16 +2,18 @@ package com.studentcenter.weave.domain.chat.entity
 
 import com.studentcenter.weave.domain.meeting.entity.MeetingFixtureFactory
 import com.studentcenter.weave.domain.meeting.enums.MeetingStatus
+import com.studentcenter.weave.support.common.uuid.UuidCreator
 import io.kotest.assertions.throwables.shouldThrow
 import io.kotest.core.annotation.DisplayName
 import io.kotest.core.spec.style.DescribeSpec
 import io.kotest.matchers.shouldBe
+import java.util.*
 
 
 @DisplayName("ChatRoomTest")
 class ChatRoomTest : DescribeSpec({
 
-    describe("채팅방 생성 테스트") {
+    describe("채팅방 생성") {
         context("미팅이 매칭된 상태일 경우") {
             it("미팅 팀을 통해 채팅방을 생성한다") {
                 // arrange
@@ -49,4 +51,37 @@ class ChatRoomTest : DescribeSpec({
             }
     }
 
+    describe("채팅 멤버 추가") {
+        context("멤버가 존재하지 않는 경우") {
+            it("멤버를 추가한다") {
+                // arrange
+                val chatRoom: ChatRoom = ChatRoomFixtureFactory.create()
+                val userId: UUID = UuidCreator.create()
+
+                // act
+                val newMember: ChatRoom = chatRoom.addMember(userId)
+
+                // assert
+                newMember.members.size shouldBe 1
+            }
+        }
+
+        context("멤버가 이미 존재하는 경우") {
+            it("예외를 발생시킨다.") {
+                // arrange
+                val userId: UUID = UuidCreator.create()
+
+                val chatMember: ChatMember = ChatMemberFixtureFactory.create(userId = userId)
+                val chatRoom: ChatRoom = ChatRoomFixtureFactory.create(
+                    members = setOf(chatMember)
+                )
+
+                // act, assert
+                shouldThrow<IllegalArgumentException> {
+                    chatRoom.addMember(userId)
+                }
+            }
+        }
+    }
+
 })

domain/src/testFixtures/kotlin/com/studentcenter/weave/domain/chat/entity/ChatMemberFixtureFactory.kt

@@ -0,0 +1,20 @@
+package com.studentcenter.weave.domain.chat.entity
+
+import com.studentcenter.weave.support.common.uuid.UuidCreator
+import java.util.*
+
+object ChatMemberFixtureFactory {
+
+    fun create(
+        id: UUID = UuidCreator.create(),
+        userId: UUID = UuidCreator.create(),
+        lastReadMessageId: UUID? = null,
+    ): ChatMember {
+        return ChatMember(
+            id = id,
+            userId = userId,
+            lastReadMessageId = lastReadMessageId,
+        )
+    }
+
+}

domain/src/testFixtures/kotlin/com/studentcenter/weave/domain/chat/entity/ChatRoomFixtureFactory.kt

@@ -12,14 +12,16 @@ object ChatRoomFixtureFactory {
         requestingTeamId: UUID = UuidCreator.create(),
         receivingTeamId: UUID = UuidCreator.create(),
         createdAt: LocalDateTime = LocalDateTime.now(),
+        members: Set<ChatMember> = emptySet(),
     ): ChatRoom {
         return ChatRoom(
             id = id,
             meetingId = meetingId,
             requestingTeamId = requestingTeamId,
             receivingTeamId = receivingTeamId,
             createdAt = createdAt,
+            members = members
         )
-
     }
+
 }