fix(llc, core): retain cached channel messages on offline access with unread messages

packages/stream_chat/CHANGELOG.md

@@ -1,5 +1,10 @@
 ## Upcoming
 
+🐞 Fixed
+
+- Fixed cached messages are cleared from channels with unread messages when accessed
+  offline. [[#2083]](https://github.com/GetStream/stream-chat-flutter/issues/2083)
+
 🔄 Changed
 
 - Deprecated `SortOption.new` constructor in favor of `SortOption.desc` and `SortOption.asc`.

packages/stream_chat/lib/src/client/channel.dart

@@ -1776,7 +1776,18 @@ class Channel {
       if (this.state == null) {
         _initState(channelState);
       } else {
-        // Otherwise, update the channel state.
+        // Otherwise, we update the existing state with the new channel state.
+        //
+        // But, before updating the state, we check if we are querying around a
+        // message, If we are, we have to truncate the state to avoid potential
+        // gaps in the message sequence.
+        final isQueryingAround = switch (messagesPagination) {
+          PaginationParams(idAround: _?) => true,
+          PaginationParams(createdAtAround: _?) => true,
+          _ => false,
+        };
+
+        if (isQueryingAround) this.state?.truncate();
         this.state?.updateChannelState(channelState);
       }
 

packages/stream_chat/lib/src/core/api/requests.dart

@@ -137,6 +137,11 @@ class PaginationParams extends Equatable {
         greaterThanOrEqual,
         lessThan,
         lessThanOrEqual,
+        createdAtAfterOrEqual,
+        createdAtAfter,
+        createdAtBeforeOrEqual,
+        createdAtBefore,
+        createdAtAround,
       ];
 }
 

packages/stream_chat/test/src/client/channel_test.dart

@@ -2749,6 +2749,121 @@ void main() {
           ),
         ).called(1);
       });
+
+      test('should truncate state when querying around message id', () async {
+        final initialMessages = [
+          Message(id: 'msg1', text: 'Hello 1'),
+          Message(id: 'msg2', text: 'Hello 2'),
+          Message(id: 'msg3', text: 'Hello 3'),
+        ];
+
+        final stateWithMessages = _generateChannelState(
+          channelId,
+          channelType,
+        ).copyWith(messages: initialMessages);
+
+        channel.state!.updateChannelState(stateWithMessages);
+        expect(channel.state!.messages, hasLength(3));
+
+        final newState = _generateChannelState(
+          channelId,
+          channelType,
+        ).copyWith(messages: [
+          Message(id: 'msg-before-1', text: 'Message before 1'),
+          Message(id: 'msg-before-2', text: 'Message before 2'),
+          Message(id: 'target-message-id', text: 'Target message'),
+          Message(id: 'msg-after-1', text: 'Message after 1'),
+          Message(id: 'msg-after-2', text: 'Message after 2'),
+        ]);
+
+        when(
+          () => client.queryChannel(
+            channelType,
+            channelId: channelId,
+            channelData: any(named: 'channelData'),
+            messagesPagination: any(named: 'messagesPagination'),
+            membersPagination: any(named: 'membersPagination'),
+            watchersPagination: any(named: 'watchersPagination'),
+          ),
+        ).thenAnswer((_) async => newState);
+
+        const pagination = PaginationParams(idAround: 'target-message-id');
+
+        final res = await channel.query(messagesPagination: pagination);
+
+        expect(res, isNotNull);
+        expect(channel.state!.messages, hasLength(5));
+        expect(channel.state!.messages[2].id, 'target-message-id');
+
+        verify(
+          () => client.queryChannel(
+            channelType,
+            channelId: channelId,
+            channelData: any(named: 'channelData'),
+            messagesPagination: pagination,
+            membersPagination: any(named: 'membersPagination'),
+            watchersPagination: any(named: 'watchersPagination'),
+          ),
+        ).called(1);
+      });
+
+      test('should truncate state when querying around created date', () async {
+        final initialMessages = [
+          Message(id: 'msg1', text: 'Hello 1'),
+          Message(id: 'msg2', text: 'Hello 2'),
+          Message(id: 'msg3', text: 'Hello 3'),
+        ];
+
+        final stateWithMessages = _generateChannelState(
+          channelId,
+          channelType,
+        ).copyWith(messages: initialMessages);
+
+        channel.state!.updateChannelState(stateWithMessages);
+        expect(channel.state!.messages, hasLength(3));
+
+        final targetDate = DateTime.now();
+        final newState = _generateChannelState(
+          channelId,
+          channelType,
+        ).copyWith(messages: [
+          Message(id: 'msg-before-1', text: 'Message before 1'),
+          Message(id: 'msg-before-2', text: 'Message before 2'),
+          Message(id: 'target-message', text: 'Target message'),
+          Message(id: 'msg-after-1', text: 'Message after 1'),
+          Message(id: 'msg-after-2', text: 'Message after 2'),
+        ]);
+
+        when(
+          () => client.queryChannel(
+            channelType,
+            channelId: channelId,
+            channelData: any(named: 'channelData'),
+            messagesPagination: any(named: 'messagesPagination'),
+            membersPagination: any(named: 'membersPagination'),
+            watchersPagination: any(named: 'watchersPagination'),
+          ),
+        ).thenAnswer((_) async => newState);
+
+        final pagination = PaginationParams(createdAtAround: targetDate);
+
+        final res = await channel.query(messagesPagination: pagination);
+
+        expect(res, isNotNull);
+        expect(channel.state!.messages, hasLength(5));
+        expect(channel.state!.messages[2].id, 'target-message');
+
+        verify(
+          () => client.queryChannel(
+            channelType,
+            channelId: channelId,
+            channelData: any(named: 'channelData'),
+            messagesPagination: pagination,
+            membersPagination: any(named: 'membersPagination'),
+            watchersPagination: any(named: 'watchersPagination'),
+          ),
+        ).called(1);
+      });
     });
 
     test('`.queryMembers`', () async {

packages/stream_chat_flutter_core/CHANGELOG.md

@@ -1,3 +1,10 @@
+## Upcoming
+
+🐞 Fixed
+
+- Fixed cached messages are cleared from channels with unread messages when accessed
+  offline. [[#2083]](https://github.com/GetStream/stream-chat-flutter/issues/2083)
+
 ## 9.13.0
 
 🐞 Fixed

packages/stream_chat_flutter_core/lib/src/stream_channel.dart

@@ -358,7 +358,6 @@ class StreamChannelState extends State<StreamChannel> {
   }) async {
     if (channel.state == null) return null;
     channel.state?.isUpToDate = false;
-    channel.state?.truncate();
 
     final pagination = PaginationParams(
       limit: limit,
@@ -461,7 +460,6 @@ class StreamChannelState extends State<StreamChannel> {
   }) async {
     if (channel.state == null) return null;
     channel.state?.isUpToDate = false;
-    channel.state?.truncate();
 
     final pagination = PaginationParams(
       limit: limit,