Be more lenient with the power levels as they can still be missing at the time the various screens are created e.g. after accepting an invite.

The correct solution is to subscribe to update and update the UI accordingly when receiving them.

ElementX/Sources/Screens/KnockRequestsListScreen/KnockRequestsListScreenViewModel.swift

@@ -26,7 +26,7 @@ class KnockRequestsListScreenViewModel: KnockRequestsListScreenViewModelType, Kn
         self.userIndicatorController = userIndicatorController
         super.init(initialViewState: KnockRequestsListScreenViewState(), mediaProvider: mediaProvider)
         
-        updateRoomInfo(roomInfo: roomProxy.infoPublisher.value)
+        updateRoomInfo(roomProxy.infoPublisher.value)
         
         setupSubscriptions()
     }
@@ -185,7 +185,7 @@ class KnockRequestsListScreenViewModel: KnockRequestsListScreenViewModelType, Kn
         roomProxy.infoPublisher
             .receive(on: DispatchQueue.main)
             .sink { [weak self] roomInfo in
-                self?.updateRoomInfo(roomInfo: roomInfo)
+                self?.updateRoomInfo(roomInfo)
             }
             .store(in: &cancellables)
         
@@ -210,7 +210,7 @@ class KnockRequestsListScreenViewModel: KnockRequestsListScreenViewModelType, Kn
             .store(in: &cancellables)
     }
     
-    private func updateRoomInfo(roomInfo: RoomInfoProxyProtocol) {
+    private func updateRoomInfo(_ roomInfo: RoomInfoProxyProtocol) {
         switch roomInfo.joinRule {
         case .knock, .knockRestricted:
             state.isKnockableRoom = true
@@ -218,10 +218,11 @@ class KnockRequestsListScreenViewModel: KnockRequestsListScreenViewModelType, Kn
             state.isKnockableRoom = false
         }
         
-        guard let powerLevels = roomProxy.infoPublisher.value.powerLevels else { fatalError("Missing room power levels") }
+        if let powerLevels = roomProxy.infoPublisher.value.powerLevels {
-        state.canAccept = powerLevels.canOwnUserInvite()
+            state.canAccept = powerLevels.canOwnUserInvite()
-        state.canDecline = powerLevels.canOwnUserKick()
+            state.canDecline = powerLevels.canOwnUserKick()
-        state.canBan = powerLevels.canOwnUserBan()
+            state.canBan = powerLevels.canOwnUserBan()
+        }
     }
     
     private static let loadingIndicatorIdentifier = "\(KnockRequestsListScreenViewModel.self)-Loading"

ElementX/Sources/Screens/RoomDetailsEditScreen/RoomDetailsEditScreenViewModel.swift

@@ -39,6 +39,13 @@ class RoomDetailsEditScreenViewModel: RoomDetailsEditScreenViewModelType, RoomDe
                                                                     avatarURL: roomAvatar,
                                                                     bindings: .init(name: roomName ?? "", topic: roomTopic ?? "")), mediaProvider: mediaProvider)
         
+        roomProxy.infoPublisher
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] roomInfo in
+                self?.updateRoomInfo(roomInfo: roomInfo)
+            }
+            .store(in: &cancellables)
+        
         updateRoomInfo(roomInfo: roomProxy.infoPublisher.value)
     }
     
@@ -87,10 +94,11 @@ class RoomDetailsEditScreenViewModel: RoomDetailsEditScreenViewModelType, RoomDe
     // MARK: - Private
     
     private func updateRoomInfo(roomInfo: RoomInfoProxyProtocol) {
-        guard let powerLevels = roomInfo.powerLevels else { fatalError("Missing room power levels") }
+        if let powerLevels = roomInfo.powerLevels {
-        state.canEditAvatar = powerLevels.canOwnUser(sendStateEvent: .roomAvatar)
+            state.canEditAvatar = powerLevels.canOwnUser(sendStateEvent: .roomAvatar)
-        state.canEditName = powerLevels.canOwnUser(sendStateEvent: .roomName)
+            state.canEditName = powerLevels.canOwnUser(sendStateEvent: .roomName)
-        state.canEditTopic = powerLevels.canOwnUser(sendStateEvent: .roomTopic)
+            state.canEditTopic = powerLevels.canOwnUser(sendStateEvent: .roomTopic)
+        }
     }
     
     private func saveRoomDetails() {

ElementX/Sources/Screens/RoomDetailsScreen/RoomDetailsScreenViewModel.swift

@@ -179,7 +179,7 @@ class RoomDetailsScreenViewModel: RoomDetailsScreenViewModelType, RoomDetailsScr
     
     private func setupRoomSubscription() {
         roomProxy.infoPublisher
-            .throttle(for: .milliseconds(200), scheduler: DispatchQueue.main, latest: true)
+            .receive(on: DispatchQueue.main)
             .sink { [weak self] roomInfo in
                 self?.updateRoomInfo(roomInfo)
             }
@@ -233,8 +233,6 @@ class RoomDetailsScreenViewModel: RoomDetailsScreenViewModelType, RoomDetailsScr
             state.canBanUsers = powerLevels.canOwnUserBan()
             state.canJoinCall = powerLevels.canOwnUserJoinCall()
             state.canEditRolesOrPermissions = powerLevels.suggestedRole(forUser: roomProxy.ownUserID) == .administrator
-        } else {
-            fatalError("Missing room power levels")
         }
     }
     

ElementX/Sources/Screens/RoomMemberListScreen/RoomMembersListScreenViewModel.swift

@@ -103,10 +103,11 @@ class RoomMembersListScreenViewModel: RoomMembersListScreenViewModelType, RoomMe
                                bannedMembers: roomMembersDetails.bannedMembers,
                                bindings: state.bindings)
             
-            guard let powerLevels = roomProxy.infoPublisher.value.powerLevels else { fatalError("Missing room power levels") }
+            if let powerLevels = roomProxy.infoPublisher.value.powerLevels {
-            self.state.canInviteUsers = powerLevels.canOwnUserInvite()
+                self.state.canInviteUsers = powerLevels.canOwnUserInvite()
-            self.state.canKickUsers = powerLevels.canOwnUserKick()
+                self.state.canKickUsers = powerLevels.canOwnUserKick()
-            self.state.canBanUsers = powerLevels.canOwnUserBan()
+                self.state.canBanUsers = powerLevels.canOwnUserBan()
+            }
         }
     }
     

ElementX/Sources/Screens/RoomRolesAndPermissionsScreen/RoomRolesAndPermissionsScreenViewModel.swift

@@ -114,8 +114,9 @@ class RoomRolesAndPermissionsScreenViewModel: RoomRolesAndPermissionsScreenViewM
     // MARK: - Permissions
     
     private func updateRoomInfo(roomInfo: RoomInfoProxyProtocol) {
-        guard let powerLevels = roomInfo.powerLevels else { fatalError("Missing room power levels") }
+        if let powerLevels = roomInfo.powerLevels {
-        state.permissions = .init(powerLevels: powerLevels.values)
+            state.permissions = .init(powerLevels: powerLevels.values)
+        }
     }
     
     private func editPermissions(group: RoomRolesAndPermissionsScreenPermissionsGroup) {

ElementX/Sources/Screens/RoomScreen/ComposerToolbar/CompletionSuggestionService.swift

@@ -19,10 +19,13 @@ private enum SuggestionTriggerRegex {
 final class CompletionSuggestionService: CompletionSuggestionServiceProtocol {
     private let roomProxy: JoinedRoomProxyProtocol
     private var canMentionAllUsers = false
+    
     private(set) var suggestionsPublisher: AnyPublisher<[SuggestionItem], Never> = Empty().eraseToAnyPublisher()
     
     private let suggestionTriggerSubject = CurrentValueSubject<SuggestionTrigger?, Never>(nil)
     
+    private var cancellables = Set<AnyCancellable>()
+    
     init(roomProxy: JoinedRoomProxyProtocol,
          roomListPublisher: AnyPublisher<[RoomSummary], Never>) {
         self.roomProxy = roomProxy
@@ -47,8 +50,14 @@ final class CompletionSuggestionService: CompletionSuggestionServiceProtocol {
                 self?.suggestionTriggerSubject.value != nil ? .milliseconds(500) : .milliseconds(0)
             }
         
-        guard let powerLevels = roomProxy.infoPublisher.value.powerLevels else { fatalError("Missing room power levels") }
+        roomProxy.infoPublisher
-        canMentionAllUsers = powerLevels.canOwnUserTriggerRoomNotification()
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] roomInfo in
+                self?.updateRoomInfo(roomInfo)
+            }
+            .store(in: &cancellables)
+        
+        updateRoomInfo(roomProxy.infoPublisher.value)
     }
     
     func processTextMessage(_ textMessage: String, selectedRange: NSRange) {
@@ -61,6 +70,12 @@ final class CompletionSuggestionService: CompletionSuggestionServiceProtocol {
     
     // MARK: - Private
     
+    private func updateRoomInfo(_ roomInfo: RoomInfoProxyProtocol) {
+        if let powerLevels = roomProxy.infoPublisher.value.powerLevels {
+            canMentionAllUsers = powerLevels.canOwnUserTriggerRoomNotification()
+        }
+    }
+    
     private func membersSuggestions(suggestionTrigger: SuggestionTrigger,
                                     members: [RoomMemberProxyProtocol],
                                     ownUserID: String) -> [SuggestionItem] {

ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift

@@ -77,12 +77,12 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
         super.init(initialViewState: appHooks.roomScreenHook.update(viewState),
                    mediaProvider: mediaProvider)
         
+        updateRoomInfo(roomProxy.infoPublisher.value)
+        setupSubscriptions(ongoingCallRoomIDPublisher: ongoingCallRoomIDPublisher)
+        
         Task {
-            await handleRoomInfoUpdate(roomProxy.infoPublisher.value)
             await updateVerificationBadge()
         }
-        
-        setupSubscriptions(ongoingCallRoomIDPublisher: ongoingCallRoomIDPublisher)
     }
 
     override func process(viewAction: RoomScreenViewAction) {
@@ -157,31 +157,14 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
         appSettings.$knockingEnabled
             .weakAssign(to: \.state.isKnockingEnabled, on: self)
             .store(in: &cancellables)
-        
+                
-        let roomInfoSubscription = roomProxy
+        roomProxy.infoPublisher
-            .infoPublisher
+            .receive(on: DispatchQueue.main)
-        
-        roomInfoSubscription
-            .throttle(for: .seconds(1), scheduler: DispatchQueue.main, latest: true)
             .sink { [weak self] roomInfo in
-                guard let self else { return }
+                self?.updateRoomInfo(roomInfo)
-                state.roomTitle = roomInfo.displayName ?? roomProxy.id
-                state.roomAvatar = roomInfo.avatar
-                state.hasOngoingCall = roomInfo.hasRoomCall
             }
             .store(in: &cancellables)
         
-        Task { [weak self] in
-            for await roomInfo in roomInfoSubscription.receive(on: DispatchQueue.main).values {
-                guard !Task.isCancelled else {
-                    return
-                }
-                
-                await self?.handleRoomInfoUpdate(roomInfo)
-            }
-        }
-        .store(in: &cancellables)
-        
         let identityStatusChangesPublisher = roomProxy.identityStatusChangesPublisher.receive(on: DispatchQueue.main)
         
         Task { [weak self] in
@@ -332,7 +315,10 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
         }
     }
     
-    private func handleRoomInfoUpdate(_ roomInfo: RoomInfoProxyProtocol) async {
+    private func updateRoomInfo(_ roomInfo: RoomInfoProxyProtocol) {
+        state.roomTitle = roomInfo.displayName ?? roomProxy.id
+        state.roomAvatar = roomInfo.avatar
+        state.hasOngoingCall = roomInfo.hasRoomCall
         state.hasSuccessor = roomInfo.successor != nil
         
         let pinnedEventIDs = roomInfo.pinnedEventIDs
@@ -348,12 +334,13 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
             state.isKnockableRoom = false
         }
 
-        guard let powerLevels = roomInfo.powerLevels else { fatalError("Missing room power levels") }
+        if let powerLevels = roomInfo.powerLevels {
-        state.canSendMessage = powerLevels.canOwnUser(sendMessage: .roomMessage)
+            state.canSendMessage = powerLevels.canOwnUser(sendMessage: .roomMessage)
-        state.canJoinCall = powerLevels.canOwnUserJoinCall()
+            state.canJoinCall = powerLevels.canOwnUserJoinCall()
-        state.canAcceptKnocks = powerLevels.canOwnUserInvite()
+            state.canAcceptKnocks = powerLevels.canOwnUserInvite()
-        state.canDeclineKnocks = powerLevels.canOwnUserKick()
+            state.canDeclineKnocks = powerLevels.canOwnUserKick()
-        state.canBan = powerLevels.canOwnUserBan()
+            state.canBan = powerLevels.canOwnUserBan()
+        }
     }
     
     private func setupPinnedEventsTimelineItemProviderIfNeeded() {

ElementX/Sources/Screens/ThreadTimelineScreen/ThreadTimelineScreenViewModel.swift

@@ -23,18 +23,14 @@ class ThreadTimelineScreenViewModel: ThreadTimelineScreenViewModelType, ThreadTi
         
         super.init(initialViewState: ThreadTimelineScreenViewState())
         
-        Task { [weak self] in
+        roomProxy.infoPublisher
-            for await roomInfo in roomProxy.infoPublisher.receive(on: DispatchQueue.main).values {
+            .receive(on: DispatchQueue.main)
-                guard !Task.isCancelled else {
+            .sink { [weak self] roomInfo in
-                    return
+                self?.updateRoomInfo(roomInfo)
-                }
-                
-                self?.handleRoomInfoUpdate(roomInfo)
             }
-        }
+            .store(in: &cancellables)
-        .store(in: &cancellables)
         
-        handleRoomInfoUpdate(roomProxy.infoPublisher.value)
+        updateRoomInfo(roomProxy.infoPublisher.value)
     }
     
     // MARK: - Public
@@ -62,8 +58,9 @@ class ThreadTimelineScreenViewModel: ThreadTimelineScreenViewModelType, ThreadTi
     
     // MARK: - Private
     
-    private func handleRoomInfoUpdate(_ roomInfo: RoomInfoProxyProtocol) {
+    private func updateRoomInfo(_ roomInfo: RoomInfoProxyProtocol) {
-        guard let powerLevels = roomInfo.powerLevels else { fatalError("Missing room power levels") }
+        if let powerLevels = roomInfo.powerLevels {
-        state.canSendMessage = powerLevels.canOwnUser(sendMessage: .roomMessage)
+            state.canSendMessage = powerLevels.canOwnUser(sendMessage: .roomMessage)
+        }
     }
 }

ElementX/Sources/Screens/Timeline/TimelineViewModel.swift

@@ -119,8 +119,6 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
         setupSubscriptions()
         setupDirectRoomSubscriptionsIfNeeded()
         
-        updateRoomInfo(roomInfo: roomProxy.infoPublisher.value)
-        
         state.audioPlayerStateProvider = { [weak self] itemID -> AudioPlayerState? in
             guard let self else {
                 return nil
@@ -144,6 +142,7 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
         state.timelineState.paginationState = timelineController.paginationState
         buildTimelineViews(timelineItems: timelineController.timelineItems)
         
+        updateRoomInfo(roomProxy.infoPublisher.value)
         updateMembers(roomProxy.membersPublisher.value)
 
         // Note: beware if we get to e.g. restore a reply / edit,
@@ -402,16 +401,17 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
         }
     }
     
-    private func updateRoomInfo(roomInfo: RoomInfoProxyProtocol) {
+    private func updateRoomInfo(_ roomInfo: RoomInfoProxyProtocol) {
         state.pinnedEventIDs = roomInfo.pinnedEventIDs
         
-        guard let powerLevels = roomInfo.powerLevels else { fatalError("Missing room power levels") }
+        if let powerLevels = roomInfo.powerLevels {
-        state.canCurrentUserSendMessage = powerLevels.canOwnUser(sendMessage: .roomMessage)
+            state.canCurrentUserSendMessage = powerLevels.canOwnUser(sendMessage: .roomMessage)
-        state.canCurrentUserRedactOthers = powerLevels.canOwnUserRedactOther()
+            state.canCurrentUserRedactOthers = powerLevels.canOwnUserRedactOther()
-        state.canCurrentUserRedactSelf = powerLevels.canOwnUserRedactOwn()
+            state.canCurrentUserRedactSelf = powerLevels.canOwnUserRedactOwn()
-        state.canCurrentUserPin = powerLevels.canOwnUserPinOrUnpin()
+            state.canCurrentUserPin = powerLevels.canOwnUserPinOrUnpin()
-        state.canCurrentUserKick = powerLevels.canOwnUserKick()
+            state.canCurrentUserKick = powerLevels.canOwnUserKick()
-        state.canCurrentUserBan = powerLevels.canOwnUserBan()
+            state.canCurrentUserBan = powerLevels.canOwnUserBan()
+        }
     }
     
     private func setupSubscriptions() {
@@ -440,17 +440,12 @@ class TimelineViewModel: TimelineViewModelType, TimelineViewModelProtocol {
             }
             .store(in: &cancellables)
 
-        let roomInfoSubscription = roomProxy.infoPublisher
+        roomProxy.infoPublisher
-        Task { [weak self] in
+            .receive(on: DispatchQueue.main)
-            for await roomInfo in roomInfoSubscription.receive(on: DispatchQueue.main).values {
+            .sink { [weak self] roomInfo in
-                guard !Task.isCancelled else {
+                self?.updateRoomInfo(roomInfo)
-                    return
-                }
-                
-                self?.updateRoomInfo(roomInfo: roomInfo)
             }
-        }
+            .store(in: &cancellables)
-        .store(in: &cancellables)
         
         setupAppSettingsSubscriptions()
         

UnitTests/Sources/RoomScreenViewModelTests.swift

@@ -165,15 +165,19 @@ class RoomScreenViewModelTests: XCTestCase {
     
     func testRoomInfoUpdate() async throws {
         var configuration = JoinedRoomProxyMockConfiguration(id: "TestID", name: "StartingName", avatarURL: nil, hasOngoingCall: false)
-        let infoSubject = CurrentValueSubject<RoomInfoProxyProtocol, Never>(RoomInfoProxyMock(configuration))
         let roomProxyMock = JoinedRoomProxyMock(configuration)
         
         let powerLevelsMock = RoomPowerLevelsProxyMock(configuration: .init())
+        powerLevelsMock.canUserJoinCallUserIDReturnValue = .success(false)
+        powerLevelsMock.canOwnUserJoinCallReturnValue = false
         roomProxyMock.powerLevelsReturnValue = .success(powerLevelsMock)
         
-        // setup the room proxy actions publisher
+        let roomInfoProxyMock = RoomInfoProxyMock(configuration)
-        powerLevelsMock.canUserJoinCallUserIDReturnValue = .success(false)
+        roomInfoProxyMock.powerLevels = powerLevelsMock
+        
+        let infoSubject = CurrentValueSubject<RoomInfoProxyProtocol, Never>(roomInfoProxyMock)
         roomProxyMock.underlyingInfoPublisher = infoSubject.asCurrentValuePublisher()
+        
         let viewModel = RoomScreenViewModel(clientProxy: ClientProxyMock(),
                                             roomProxy: roomProxyMock,
                                             initialSelectedPinnedEventID: nil,
@@ -186,27 +190,25 @@ class RoomScreenViewModelTests: XCTestCase {
                                             userIndicatorController: ServiceLocator.shared.userIndicatorController)
         self.viewModel = viewModel
         
-        var deferred = deferFulfillment(viewModel.context.$viewState) { viewState in
+        XCTAssertEqual(viewModel.state.roomTitle, "StartingName")
-            viewState.roomTitle == "StartingName" &&
+        XCTAssertEqual(viewModel.state.roomAvatar, .room(id: "TestID", name: "StartingName", avatarURL: nil))
-                viewState.roomAvatar == .room(id: "TestID", name: "StartingName", avatarURL: nil) &&
+        XCTAssertFalse(viewModel.state.canJoinCall)
-                !viewState.canJoinCall &&
+        XCTAssertFalse(viewModel.state.hasOngoingCall)
-                !viewState.hasOngoingCall
+                
-        }
+        let deferred = deferFulfillment(viewModel.context.$viewState) { viewState in
-        try await deferred.fulfill()
-        
-        configuration.name = "NewName"
-        configuration.avatarURL = .mockMXCAvatar
-        configuration.hasOngoingCall = true
-        powerLevelsMock.canUserJoinCallUserIDReturnValue = .success(true)
-        
-        deferred = deferFulfillment(viewModel.context.$viewState) { viewState in
             viewState.roomTitle == "NewName" &&
                 viewState.roomAvatar == .room(id: "TestID", name: "NewName", avatarURL: .mockMXCAvatar) &&
                 viewState.canJoinCall &&
                 viewState.hasOngoingCall
         }
         
+        configuration.name = "NewName"
+        configuration.avatarURL = .mockMXCAvatar
+        configuration.hasOngoingCall = true
+        powerLevelsMock.canUserJoinCallUserIDReturnValue = .success(true)
+        
         infoSubject.send(RoomInfoProxyMock(configuration))
+        
         try await deferred.fulfill()
     }