fix/#220 : 참여 화면 state immutable 로 변경

- core:model의 모델을 state로 사용 -> 화면 전용 immutable 모델 선언 및 state 사용
- uiState 선언시 등호 대신 by 사용하여 State 내부 타입 바로 접근

feature/mygroup/src/main/java/com/boostcamp/mapisode/mygroup/screen/GroupJoinScreen.kt

@@ -17,7 +17,6 @@ import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
-import androidx.compose.runtime.State
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.saveable.rememberSaveable
@@ -59,7 +58,7 @@ fun GroupJoinScreen(
 	viewModel: GroupJoinViewModel = hiltViewModel(),
 ) {
 	val context = LocalContext.current
-	val uiState = viewModel.uiState.collectAsStateWithLifecycle()
+	val uiState by viewModel.uiState.collectAsStateWithLifecycle()
 	val effect = rememberFlowWithLifecycle(
 		flow = viewModel.sideEffect,
 		initialValue = GroupJoinSideEffect.Idle,
@@ -95,7 +94,7 @@ fun GroupJoinScreen(
 
 @Composable
 fun GroupJoinContent(
-	uiState: State<GroupJoinState>,
+	uiState: GroupJoinState,
 	onBackClick: () -> Unit,
 	onGetGroup: (String) -> Unit,
 	onJoinGroup: () -> Unit,
@@ -193,13 +192,13 @@ fun GroupJoinContent(
 					MapisodeDivider(direction = Direction.Horizontal, thickness = Thickness.Thin)
 					Spacer(modifier = Modifier.padding(10.dp))
 				}
-				if (uiState.value.isGroupExist && uiState.value.group != null) {
+				if (uiState.isGroupExist && uiState.group != null) {
 					item {
-						ConfirmJoinGroup(uiState.value.group!!)
+						ConfirmJoinGroup(uiState.group.toGroupModel())
 						Spacer(modifier = Modifier.padding(bottom = 70.dp))
 					}
 				}
-				if (uiState.value.isGroupExist.not() || uiState.value.group == null) {
+				if (uiState.isGroupExist.not() || uiState.group == null) {
 					item {
 						MapisodeText(
 							text = "존재하지 않는 그룹입니다.",
@@ -208,7 +207,7 @@ fun GroupJoinContent(
 					}
 				}
 			}
-			if (uiState.value.isGroupExist && uiState.value.group != null) {
+			if (uiState.isGroupExist && uiState.group != null) {
 				Column(
 					modifier = Modifier
 						.fillMaxWidth()

feature/mygroup/src/main/java/com/boostcamp/mapisode/mygroup/state/GroupJoinState.kt

@@ -1,13 +1,13 @@
 package com.boostcamp.mapisode.mygroup.state
 
 import androidx.compose.runtime.Immutable
-import com.boostcamp.mapisode.model.GroupModel
+import com.boostcamp.mapisode.mygroup.model.GroupCreationModel
 import com.boostcamp.mapisode.ui.base.UiState
 
 @Immutable
 data class GroupJoinState(
 	val isGroupExist: Boolean = false,
 	val isGroupLoading: Boolean = false,
 	val isJoinedSuccess: Boolean = false,
-	val group: GroupModel? = null,
+	val group: GroupCreationModel? = null,
 ) : UiState

feature/mygroup/src/main/java/com/boostcamp/mapisode/mygroup/viewmodel/GroupJoinViewModel.kt

@@ -5,6 +5,7 @@ import com.boostcamp.mapisode.datastore.UserPreferenceDataStore
 import com.boostcamp.mapisode.mygroup.GroupRepository
 import com.boostcamp.mapisode.mygroup.R
 import com.boostcamp.mapisode.mygroup.intent.GroupJoinIntent
+import com.boostcamp.mapisode.mygroup.model.toGroupCreationModel
 import com.boostcamp.mapisode.mygroup.sideeffect.GroupJoinSideEffect
 import com.boostcamp.mapisode.mygroup.state.GroupJoinState
 import com.boostcamp.mapisode.ui.base.BaseViewModel
@@ -54,7 +55,7 @@ class GroupJoinViewModel @Inject constructor(
 			intent { copy(isGroupLoading = true) }
 			try {
 				val group = groupRepository.getGroupByInviteCodes(inviteCodes)
-				intent { copy(isGroupExist = true, group = group) }
+				intent { copy(isGroupExist = true, group = group.toGroupCreationModel()) }
 			} catch (e: Exception) {
 				intent { copy(isGroupExist = false) }
 				postSideEffect(GroupJoinSideEffect.ShowToast(R.string.group_join_not_exist))