feat: add updateWith to FeedData for smarter updates

Author: xsahil03x

packages/stream_feeds/lib/src/models/feed_data.dart

@@ -145,3 +145,28 @@ extension FeedResponseMapper on FeedResponse {
     );
   }
 }
+
+/// Extension functions for [FeedData] to handle common operations.
+extension FeedDataMutations on FeedData {
+  /// Updates this feed with new data while preserving own data.
+  ///
+  /// Merges [updated] feed data with this instance, preserving [ownCapabilities],
+  /// [ownMembership], and [ownFollows] from this instance when not provided. This
+  /// ensures that user-specific data is not lost when updating from WebSocket events.
+  ///
+  /// Returns a new [FeedData] instance with the merged data.
+  FeedData updateWith(
+    FeedData updated, {
+    List<FeedOwnCapability>? ownCapabilities,
+    FeedMemberData? ownMembership,
+    List<FollowData>? ownFollows,
+  }) {
+    return updated.copyWith(
+      // Preserve own data from the current instance if not provided
+      // as they may not be reliable from WS events.
+      ownCapabilities: ownCapabilities ?? this.ownCapabilities,
+      ownMembership: ownMembership ?? this.ownMembership,
+      ownFollows: ownFollows ?? this.ownFollows,
+    );
+  }
+}

packages/stream_feeds/lib/src/state/feed_list_state.dart

@@ -45,10 +45,12 @@ class FeedListStateNotifier extends StateNotifier<FeedListState> {
 
   /// Handles updates to a specific feed.
   void onFeedUpdated(FeedData feed) {
-    final updatedFeeds = state.feeds.map((it) {
-      if (it.fid.rawValue != feed.fid.rawValue) return it;
-      return feed;
-    }).toList();
+    final updatedFeeds = state.feeds.sortedUpsert(
+      feed,
+      key: (it) => it.fid.rawValue,
+      compare: feedsSort.compare,
+      update: (existing, updated) => existing.updateWith(updated),
+    );
 
     state = state.copyWith(feeds: updatedFeeds);
   }

packages/stream_feeds/lib/src/state/feed_state.dart

@@ -341,8 +341,11 @@ class FeedStateNotifier extends StateNotifier<FeedState> {
 
   /// Handles updates to the feed state when the feed is updated.
   void onFeedUpdated(FeedData feed) {
+    final currentFeed = state.feed;
+    final updatedFeed = currentFeed?.updateWith(feed) ?? feed;
+
     // Update the feed data in the state
-    state = state.copyWith(feed: feed);
+    state = state.copyWith(feed: updatedFeed);
   }
 
   /// Handles updates to the feed state when a follow is added.