Fix channel list skipping some updates on iPad (#1059)

Author: laevandus

CHANGELOG.md

@@ -8,6 +8,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Expose `QuotedMessageViewContainer` [#1056](https://github.com/GetStream/stream-chat-swiftui/pull/1056)
 - Add `QuotedMessageContentView` and `ViewFactory.makeQuotedMessageContentView()` [#1056](https://github.com/GetStream/stream-chat-swiftui/pull/1056)
 - Allow customizing the attachment size and avatar size of the quoted message view [#1056](https://github.com/GetStream/stream-chat-swiftui/pull/1056)
+### 🐞 Fixed
+- Fix channel list skipping some updates on iPad [#1059](https://github.com/GetStream/stream-chat-swiftui/pull/1059)
 
 # [4.93.0](https://github.com/GetStream/stream-chat-swiftui/releases/tag/4.93.0)
 _November 18, 2025_

Sources/StreamChatSwiftUI/ChatChannelList/ChatChannelListViewModel.swift

@@ -25,42 +25,40 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
 
     /// Used when screen is shown from a deeplink.
     private var selectedChannelId: String?
-
-    /// Temporarly holding changes while message list is shown.
-    private var queuedChannelsChanges = LazyCachedMapCollection<ChatChannel>()
-
+    
     private var timer: Timer?
 
     /// Controls loading the channels.
     public private(set) var loadingNextChannels: Bool = false
 
-    /// Checks if the queued changes are completely applied.
-    private var markDirty = false
-
+    /// True, if channel updates were skipped and are applied when selectedChannel is set to nil
+    private var skippedChannelUpdates = false
+    
+    /// True, if channel updates can be skipped for optimizing view refreshes while showing message list.
+    ///
+    /// - Important: Only meant for stacked navigation view style.
+    private var canSkipChannelUpdates: Bool {
+        guard isIphone || !utils.messageListConfig.iPadSplitViewEnabled else { return false }
+        guard selectedChannel != nil || !searchText.isEmpty else { return false }
+        return true
+    }
+    
     /// Index of the selected channel.
     private var selectedChannelIndex: Int?
 
     /// When set, scrolls to the specified channel id (if it exists).
     @Published public var scrolledChannelId: String?
 
     /// Published variables.
-    @Published public var channels = LazyCachedMapCollection<ChatChannel>() {
-        didSet {
-            if !markDirty {
-                queuedChannelsChanges = []
-            } else {
-                markDirty = false
-            }
-        }
-    }
+    @Published public var channels = LazyCachedMapCollection<ChatChannel>()
 
     @Published public var selectedChannel: ChannelSelectionInfo? {
         willSet {
             hideTabBar = newValue != nil
             if selectedChannel != nil && newValue == nil {
                 // pop happened, apply the queued changes.
-                if !queuedChannelsChanges.isEmpty {
-                    channels = queuedChannelsChanges
+                if skippedChannelUpdates {
+                    updateChannels()
                 }
             }
             if newValue == nil {
@@ -317,8 +315,8 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
     // MARK: - private
 
     private func handleChannelListChanges(_ controller: ChatChannelListController) {
-        if selectedChannel != nil || !searchText.isEmpty {
-            queuedChannelsChanges = controller.channels
+        if canSkipChannelUpdates {
+            skippedChannelUpdates = true
             updateChannelsIfNeeded()
         } else {
             channels = controller.channels
@@ -537,15 +535,16 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
     }
 
     private func updateChannels() {
+        skippedChannelUpdates = false
         channels = controller?.channels ?? LazyCachedMapCollection<ChatChannel>()
     }
 
     private func handleChannelAppearance() {
-        if !queuedChannelsChanges.isEmpty && selectedChannel == nil {
-            channels = queuedChannelsChanges
-        } else if !queuedChannelsChanges.isEmpty {
-            handleQueuedChanges()
-        } else if queuedChannelsChanges.isEmpty && selectedChannel != nil {
+        if skippedChannelUpdates && selectedChannel == nil {
+            updateChannels()
+        } else if skippedChannelUpdates {
+            updateSelectedChannelData()
+        } else if !skippedChannelUpdates && selectedChannel != nil {
             if selectedChannel?.injectedChannelInfo == nil {
                 selectedChannel?.injectedChannelInfo = InjectedChannelInfo(unreadCount: 0)
             }
@@ -562,10 +561,10 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
         }
     }
 
-    private func handleQueuedChanges() {
+    private func updateSelectedChannelData() {
         let selected = selectedChannel?.channel
         var index: Int?
-        var temp = Array(queuedChannelsChanges)
+        var temp = Array(controller?.channels ?? [])
         for i in 0..<temp.count {
             let current = temp[i]
             if current.cid == selected?.cid {
@@ -583,7 +582,6 @@ open class ChatChannelListViewModel: ObservableObject, ChatChannelListController
         if let index = index, let selected = selected {
             temp[index] = selected
         }
-        markDirty = true
         channels = LazyCachedMapCollection(source: temp, map: { $0 })
     }
 

StreamChatSwiftUITests/Tests/ChatChannelList/ChatChannelListViewModel_Tests.swift

@@ -532,6 +532,36 @@ class ChatChannelListViewModel_Tests: StreamChatTestCase {
         // Then
         XCTAssertNil(viewModel.selectedChannel, "selectedChannel should be cleared immediately when opening another channel")
     }
+    
+    // MARK: - Optimized Channel List Updates
+    
+    func test_channelListOptimizedUpdates_whenStackedViewAndSelection_thenUpdatesSkipped() {
+        // Given
+        let config = MessageListConfig(updateChannelsFromMessageList: false, iPadSplitViewEnabled: false)
+        streamChat = StreamChat(chatClient: chatClient, utils: Utils(messageListConfig: config))
+        let existingChannel = ChatChannel.mockDMChannel()
+        let channelListController = makeChannelListController(channels: [existingChannel])
+
+        // When
+        let viewModel = ChatChannelListViewModel(
+            channelListController: channelListController,
+            selectedChannelId: nil
+        )
+        viewModel.selectedChannel = .init(channel: existingChannel, message: nil)
+        let insertedChannel = ChatChannel.mockDMChannel()
+        channelListController.simulate(
+            channels: [insertedChannel, existingChannel],
+            changes: [.insert(insertedChannel, index: IndexPath(item: 0, section: 0))]
+        )
+
+        // Then
+        XCTAssertEqual(viewModel.channels.count, 1)
+        
+        // When selection is popped, changes are applied
+        viewModel.selectedChannel = nil
+        
+        XCTAssertEqual(viewModel.channels.count, 2)
+    }
 
     // MARK: - private