feat(llc, persistence): add messageCount to channel model and event (#2403)

Author: xsahil03x

packages/stream_chat/CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Upcoming
 
+✅ Added
+
+- Added support for `Channel.messageCount` field.
+
 🐞 Fixed
 
 - Fixed thread messages increasing the unread count in the main channel.

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

@@ -416,6 +416,24 @@ class Channel {
     return state!.channelStateStream.map((cs) => cs.channel?.memberCount);
   }
 
+  /// Channel message count.
+  ///
+  /// Note: This field is only populated if the `count_messages` option is
+  /// enabled for your app.
+  int? get messageCount {
+    _checkInitialized();
+    return state!._channelState.channel?.messageCount;
+  }
+
+  /// Channel message count as a stream.
+  ///
+  /// Note: This field is only populated if the `count_messages` option is
+  /// enabled for your app.
+  Stream<int?> get messageCountStream {
+    _checkInitialized();
+    return state!.channelStateStream.map((cs) => cs.channel?.messageCount);
+  }
+
   /// Channel id.
   String? get id => state?._channelState.channel?.id ?? _id;
 
@@ -2165,6 +2183,8 @@ class ChannelClientState {
 
     _listenChannelUpdated();
 
+    _listenChannelMessageCount();
+
     _listenMemberAdded();
 
     _listenMemberRemoved();
@@ -2334,6 +2354,23 @@ class ChannelClientState {
     }));
   }
 
+  void _listenChannelMessageCount() {
+    _subscriptions.add(_channel.on().listen(
+      (Event e) {
+        final messageCount = e.channelMessageCount;
+        if (messageCount == null) return;
+
+        updateChannelState(
+          channelState.copyWith(
+            channel: channelState.channel?.copyWith(
+              messageCount: messageCount,
+            ),
+          ),
+        );
+      },
+    ));
+  }
+
   void _listenChannelTruncated() {
     _subscriptions.add(_channel
         .on(EventType.channelTruncated, EventType.notificationChannelTruncated)

packages/stream_chat/lib/src/core/models/channel_model.dart

@@ -31,6 +31,7 @@ class ChannelModel {
     bool? disabled,
     bool? hidden,
     DateTime? truncatedAt,
+    this.messageCount,
   })  : assert(
           (cid != null && cid.contains(':')) || (id != null && type != null),
           'provide either a cid or an id and type',
@@ -151,6 +152,13 @@ class ChannelModel {
     return null;
   }
 
+  /// The total number of messages in the channel.
+  ///
+  /// Note: This field is only populated if the `count_messages` option is
+  /// enabled for your app.
+  @JsonKey(includeToJson: false)
+  final int? messageCount;
+
   /// Known top level fields.
   /// Useful for [Serializer] methods.
   static const topLevelFields = [
@@ -169,6 +177,7 @@ class ChannelModel {
     'members',
     'team',
     'cooldown',
+    'message_count',
   ];
 
   /// Serialize to json
@@ -197,6 +206,7 @@ class ChannelModel {
     bool? disabled,
     bool? hidden,
     DateTime? truncatedAt,
+    int? messageCount,
   }) =>
       ChannelModel(
         id: id ?? this.id,
@@ -223,6 +233,7 @@ class ChannelModel {
                 // ignore: cast_nullable_to_non_nullable
                 : DateTime.parse(extraData?['truncated_at'] as String)) ??
             this.truncatedAt,
+        messageCount: messageCount ?? this.messageCount,
       );
 
   /// Returns a new [ChannelModel] that is a combination of this channelModel
@@ -249,6 +260,7 @@ class ChannelModel {
       disabled: other.disabled,
       hidden: other.hidden,
       truncatedAt: other.truncatedAt,
+      messageCount: other.messageCount,
     );
   }
 }

packages/stream_chat/lib/src/core/models/channel_model.g.dart

@@ -43,6 +43,7 @@ class Event {
     this.reminder,
     this.pushPreference,
     this.channelPushPreference,
+    this.channelMessageCount,
     this.extraData = const {},
     this.isLocal = true,
   }) : createdAt = createdAt?.toUtc() ?? DateTime.now().toUtc();
@@ -162,6 +163,9 @@ class Event {
   /// Push notification preferences for the current user for this channel.
   final ChannelPushPreference? channelPushPreference;
 
+  /// The total number of messages in the channel.
+  final int? channelMessageCount;
+
   /// Map of custom channel extraData
   final Map<String, Object?> extraData;
 
@@ -203,6 +207,7 @@ class Event {
     'reminder',
     'push_preference',
     'channel_push_preference',
+    'channel_message_count',
   ];
 
   /// Serialize to json
@@ -246,6 +251,7 @@ class Event {
     MessageReminder? reminder,
     PushPreference? pushPreference,
     ChannelPushPreference? channelPushPreference,
+    int? channelMessageCount,
     Map<String, Object?>? extraData,
   }) =>
       Event(
@@ -284,6 +290,7 @@ class Event {
         pushPreference: pushPreference ?? this.pushPreference,
         channelPushPreference:
             channelPushPreference ?? this.channelPushPreference,
+        channelMessageCount: channelMessageCount ?? this.channelMessageCount,
         isLocal: isLocal,
         extraData: extraData ?? this.extraData,
       );

packages/stream_chat/lib/src/core/models/event.dart

@@ -5637,5 +5637,165 @@ void main() {
         },
       );
     });
+
+    group('Channel message count events', () {
+      const channelId = 'test-channel-id';
+      const channelType = 'test-channel-type';
+      late Channel channel;
+
+      setUp(() {
+        final channelState = _generateChannelState(channelId, channelType);
+        channel = Channel.fromState(client, channelState);
+      });
+
+      tearDown(() {
+        channel.dispose();
+      });
+
+      test(
+        'should update channel messageCount when event contains channelMessageCount',
+        () async {
+          // Verify initial state - no messageCount
+          expect(channel.messageCount, isNull);
+
+          // Create event with channelMessageCount
+          final messageCountEvent = Event(
+            cid: channel.cid,
+            type: EventType.messageNew,
+            channelMessageCount: 42,
+          );
+
+          // Dispatch event
+          client.addEvent(messageCountEvent);
+
+          // Wait for the event to be processed
+          await Future.delayed(Duration.zero);
+
+          // Verify channel messageCount was updated
+          expect(channel.messageCount, equals(42));
+        },
+      );
+
+      test(
+        'should update channel messageCount from message.new and message.deleted events',
+        () async {
+          // Test with message.new event - count increases
+          final messageNewEvent = Event(
+            cid: channel.cid,
+            type: EventType.messageNew,
+            message: Message(
+              id: 'new-message-1',
+              text: 'Hello world!',
+              user: User(id: 'user-1'),
+            ),
+            channelMessageCount: 1,
+          );
+
+          client.addEvent(messageNewEvent);
+          await Future.delayed(Duration.zero);
+          expect(channel.messageCount, equals(1));
+
+          // Test with another message.new event - count increases
+          final messageNewEvent2 = Event(
+            cid: channel.cid,
+            type: EventType.messageNew,
+            message: Message(
+              id: 'new-message-2',
+              text: 'Second message',
+              user: User(id: 'user-2'),
+            ),
+            channelMessageCount: 2,
+          );
+
+          client.addEvent(messageNewEvent2);
+          await Future.delayed(Duration.zero);
+          expect(channel.messageCount, equals(2));
+
+          // Test with message.deleted event - count decreases
+          final messageDeletedEvent = Event(
+            cid: channel.cid,
+            type: EventType.messageDeleted,
+            message: Message(
+              id: 'new-message-1',
+              text: 'Hello world!',
+              user: User(id: 'user-1'),
+            ),
+            channelMessageCount: 1,
+          );
+
+          client.addEvent(messageDeletedEvent);
+          await Future.delayed(Duration.zero);
+          expect(channel.messageCount, equals(1));
+        },
+      );
+
+      test(
+        'should preserve other channel properties when updating messageCount',
+        () async {
+          // Set initial channel state with some properties
+          final initialChannel = channel.state?.channelState.channel?.copyWith(
+            extraData: {'name': 'Test Channel'},
+            memberCount: 5,
+            frozen: true,
+          );
+
+          if (initialChannel != null) {
+            channel.state?.updateChannelState(
+              channel.state!.channelState.copyWith(channel: initialChannel),
+            );
+          }
+
+          // Verify initial state
+          expect(channel.name, 'Test Channel');
+          expect(channel.memberCount, equals(5));
+          expect(channel.frozen, equals(true));
+          expect(channel.messageCount, isNull);
+
+          // Update messageCount via event
+          final messageCountEvent = Event(
+            cid: channel.cid,
+            type: EventType.messageNew,
+            channelMessageCount: 100,
+          );
+
+          client.addEvent(messageCountEvent);
+          await Future.delayed(Duration.zero);
+
+          // Verify messageCount was updated while preserving other properties
+          expect(channel.messageCount, equals(100));
+          expect(channel.name, 'Test Channel');
+          expect(channel.memberCount, equals(5));
+          expect(channel.frozen, equals(true));
+        },
+      );
+
+      test(
+        'should provide messageCountStream for reactive updates',
+        () async {
+          expectLater(
+            channel.messageCountStream.distinct(),
+            emitsInOrder([null, 1, 5, 10]),
+          );
+
+          // Update messageCount multiple times
+          final counts = [1, 5, 10];
+          for (final count in counts) {
+            final event = Event(
+              cid: channel.cid,
+              type: EventType.messageNew,
+              message: Message(
+                id: 'msg-$count',
+                text: 'Message $count',
+                user: User(id: 'user-1'),
+              ),
+              channelMessageCount: count,
+            );
+
+            client.addEvent(event);
+            await Future.delayed(Duration.zero);
+          }
+        },
+      );
+    });
   });
 }

packages/stream_chat/lib/src/core/models/event.g.dart

@@ -1,3 +1,7 @@
+## Upcoming
+
+- Added support for `Channel.messageCount` field.
+
 ## 9.17.0
 
 - Updated `stream_chat` dependency to [`9.17.0`](https://pub.dev/packages/stream_chat/changelog).

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

@@ -55,7 +55,7 @@ class DriftChatDatabase extends _$DriftChatDatabase {
 
   // you should bump this number whenever you change or add a table definition.
   @override
-  int get schemaVersion => 23;
+  int get schemaVersion => 24;
 
   @override
   MigrationStrategy get migration => MigrationStrategy(