unreads: Handle updates when there are moved messages

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

lib/model/unreads.dart

@@ -296,13 +296,38 @@ class Unreads extends ChangeNotifier {
         madeAnyUpdate |= mentions.add(messageId);
     }
 
-    // TODO(#901) handle moved messages
+    madeAnyUpdate |= _handleMessageMove(event);
 
     if (madeAnyUpdate) {
       notifyListeners();
     }
   }
 
+  bool _handleMessageMove(UpdateMessageEvent event) {
+    final messageMove = event.moveData;
+    if (messageMove == null) {
+      // No moved messages or malformed event.
+      return false;
+    }
+
+    final topics = streams[messageMove.origStreamId];
+    if (topics == null || topics[messageMove.origTopic] == null) {
+      // No known unreads affected by move; nothing to do.
+      return false;
+    }
+
+    final messageToMoveIds = _removeAllInStreamTopic(
+      event.messageIds.toSet(),
+      messageMove.origStreamId, messageMove.origTopic);
+    if (messageToMoveIds.isEmpty) {
+      return false;
+    }
+    _addAllInStreamTopic(
+      messageToMoveIds..sort(),
+      messageMove.newStreamId, messageMove.newTopic);
+    return true;
+  }
+
   void handleDeleteMessageEvent(DeleteMessageEvent event) {
     mentions.removeAll(event.messageIds);
     final messageIdsSet = Set.of(event.messageIds);

test/model/unreads_test.dart

@@ -469,6 +469,107 @@ void main() {
         }
       }
     });
+
+    group('moves', () {
+      final origChannel = eg.stream();
+      const origTopic = 'origTopic';
+      const newTopic = 'newTopic';
+
+      test('move read messages to new topic', () {
+        final message = eg.streamMessage(
+          stream: origChannel, topic: origTopic, flags: [MessageFlag.read]);
+        prepare();
+        fillWithMessages([message]);
+
+        model.handleUpdateMessageEvent(eg.updateMessageEventMoveFrom(
+          origMessages: [message],
+          newTopicStr: newTopic));
+        checkNotNotified();
+        checkMatchesMessages([]);
+      });
+
+      test('move read messages from topic with unreads', () {
+        final message1 = eg.streamMessage(
+          stream: origChannel, topic: origTopic, flags: [MessageFlag.read]);
+        final message2 = eg.streamMessage(
+          stream: origChannel, topic: origTopic);
+        prepare();
+        fillWithMessages([message1, message2]);
+
+        model.handleUpdateMessageEvent(eg.updateMessageEventMoveFrom(
+          origMessages: [message1],
+          newTopicStr: newTopic));
+        checkNotNotified();
+        checkMatchesMessages([message2]);
+      });
+
+      test('move read messages to topic with unreads', () {
+        final message1 = eg.streamMessage(
+          stream: origChannel, topic: origTopic, flags: [MessageFlag.read]);
+        final message2 = eg.streamMessage(
+          stream: origChannel, topic: newTopic);
+        prepare();
+        fillWithMessages([message1, message2]);
+
+        model.handleUpdateMessageEvent(eg.updateMessageEventMoveFrom(
+          origMessages: [message1],
+          newTopicStr: newTopic,
+        ));
+        checkNotNotified();
+        checkMatchesMessages([message2]);
+      });
+
+      test('move unread messages to topic with unreads', () {
+        final message1 = eg.streamMessage(
+          id: 1, stream: origChannel, topic: origTopic);
+        final message2 = eg.streamMessage(
+          id: 2, stream: origChannel, topic: newTopic);
+        prepare();
+        fillWithMessages([message1, message2]);
+
+        model.handleUpdateMessageEvent(eg.updateMessageEventMoveFrom(
+          origMessages: [message1],
+          newTopicStr: newTopic));
+        checkNotifiedOnce();
+        checkMatchesMessages([
+          Message.fromJson(message1.toJson()..['subject'] = newTopic),
+          message2,
+        ]);
+      });
+
+      test('move unread messages to new topic', () {
+        final message = eg.streamMessage(id: 1, stream: origChannel);
+        prepare();
+        fillWithMessages([message]);
+
+        model.handleUpdateMessageEvent(eg.updateMessageEventMoveFrom(
+          origMessages: [message],
+          newTopicStr: newTopic));
+        checkNotifiedOnce();
+        checkMatchesMessages([
+          Message.fromJson(message.toJson()..['subject'] = newTopic),
+        ]);
+      });
+
+      test('move unread messages to new channel', () {
+        final message = eg.streamMessage(
+          id: 1, stream: origChannel, topic: origTopic);
+        final newChannel = eg.stream();
+        prepare();
+        fillWithMessages([message]);
+
+        model.handleUpdateMessageEvent(eg.updateMessageEventMoveFrom(
+          origMessages: [message],
+          newStreamId: newChannel.streamId,
+          newTopicStr: newTopic));
+        checkNotifiedOnce();
+        checkMatchesMessages([
+          Message.fromJson(message.toJson()
+            ..['stream_id'] = newChannel.streamId
+            ..['subject'] = newTopic),
+        ]);
+      });
+    });
   });