model: Update narrow when propageMode is changeAll or changeLater.

This prepares for the later UI change that make MessageListPage follow
to the narrow of moved messages.

Signed-off-by: Zixuan James Li <zixuan@zulip.com>

Author: PIG208

lib/model/message.dart

@@ -210,6 +210,7 @@ class MessageStoreImpl with MessageStore {
         origTopic: origTopic,
         newTopic: newTopic,
         messageIds: event.messageIds,
+        propagateMode: event.propagateMode,
       );
     }
   }

lib/model/message_list.dart

@@ -358,8 +358,8 @@ class MessageListView with ChangeNotifier, _MessageSequence {
     super.dispose();
   }
 
+  Narrow narrow;
   final PerAccountStore store;
-  final Narrow narrow;
 
   /// Whether [message] should actually appear in this message list,
   /// given that it does belong to the narrow.
@@ -525,8 +525,17 @@ class MessageListView with ChangeNotifier, _MessageSequence {
     fetchInitial();
   }
 
-  void _messagesMovedFromNarrow(List<int> messageIds) {
+  void _messagesMovedFromNarrow(
+    List<int> messageIds,
+    {TopicNarrow? newNarrow, PropagateMode? propagateMode}
+  ) {
     if (_removeMessagesById(messageIds)) {
+      if (propagateMode == PropagateMode.changeAll
+          || propagateMode == PropagateMode.changeLater) {
+        narrow = newNarrow!;
+        _reset();
+        fetchInitial();
+      }
       notifyListeners();
     }
   }
@@ -537,6 +546,7 @@ class MessageListView with ChangeNotifier, _MessageSequence {
     required String origTopic,
     required String newTopic,
     required List<int> messageIds,
+    required PropagateMode? propagateMode,
   }) {
     switch (narrow) {
       case DmNarrow():
@@ -566,7 +576,9 @@ class MessageListView with ChangeNotifier, _MessageSequence {
           case (false, false): return;
           case (true,  true ): _messagesMovedInternally(messageIds);
           case (false, true ): _messagesMovedIntoNarrow();
-          case (true,  false): _messagesMovedFromNarrow(messageIds); // TODO handle propagateMode
+          case (true,  false): _messagesMovedFromNarrow(messageIds,
+            newNarrow: TopicNarrow(newStreamId, newTopic),
+            propagateMode: propagateMode!);
         }
     }
   }

test/example_data.dart

@@ -445,6 +445,7 @@ UpdateMessageEvent updateMessageMoveEvent(
   String? newTopic,
   String? origContent,
   String? newContent,
+  PropagateMode propagateMode = PropagateMode.changeOne,
 }) {
   assert(messages.isNotEmpty);
   assert(origTopic != null, 'origTopic required for a message move');
@@ -462,7 +463,7 @@ UpdateMessageEvent updateMessageMoveEvent(
     editTimestamp: 1234567890, // TODO generate timestamp
     origStreamId: origStreamId ?? (origMessage is StreamMessage ? origMessage.streamId : null),
     newStreamId: newStreamId,
-    propagateMode: null,
+    propagateMode: propagateMode,
     origTopic: origTopic,
     newTopic: newTopic,
     origContent: origContent,

test/model/message_list_test.dart

@@ -491,6 +491,33 @@ void main() {
         checkHasMessages(initialMessages);
         checkNotifiedOnce();
       });
+
+     void testMessageMove(PropagateMode propagateMode) =>
+      awaitFakeAsync((async) async {
+        await prepareNarrow(narrow, initialMessages + movedMessages);
+        connection.prepare(delay: const Duration(seconds: 1), json: newestResult(
+          foundOldest: false,
+          messages: movedMessages,
+        ).toJson());
+        await store.handleEvent(eg.updateMessageMoveEvent(movedMessages,
+          newTopic: 'new',
+          origTopic: movedMessages[0].topic,
+          newStreamId: otherStream.streamId,
+          origStreamId: stream.streamId,
+          propagateMode: propagateMode,
+        ));
+        checkNotifiedOnce();
+        async.elapse(const Duration(seconds: 1));
+        checkHasMessages(movedMessages);
+        check(model).narrow.equals(TopicNarrow(otherStream.streamId, 'new'));
+        checkNotifiedOnce();
+      });
+
+      test('follow to the new narrow when propagateMode = changeLater', () =>
+        testMessageMove(PropagateMode.changeLater));
+
+      test('follow to the new narrow when propagateMode = changeAll', () =>
+        testMessageMove(PropagateMode.changeAll));
     });
 
     group('in stream narrow', () {
@@ -542,6 +569,33 @@ void main() {
         checkHasMessages(initialMessages);
         checkNotifiedOnce();
       });
+
+     void testMessageMove(PropagateMode propagateMode) =>
+      awaitFakeAsync((async) async {
+        await prepareNarrow(narrow, initialMessages + movedMessages);
+        connection.prepare(delay: const Duration(seconds: 1), json: newestResult(
+          foundOldest: false,
+          messages: movedMessages,
+        ).toJson());
+        await store.handleEvent(eg.updateMessageMoveEvent(movedMessages,
+          newTopic: 'new',
+          origTopic: movedMessages[0].topic,
+          newStreamId: otherStream.streamId,
+          origStreamId: stream.streamId,
+          propagateMode: propagateMode,
+        ));
+        checkNotifiedOnce();
+        async.elapse(const Duration(seconds: 1));
+        checkHasMessages(initialMessages);
+        check(model).narrow.equals(StreamNarrow(stream.streamId));
+        checkNotNotified();
+      });
+
+      test('do not follow when propagateMode = changeLater', () =>
+        testMessageMove(PropagateMode.changeLater));
+
+      test('do not follow when propagateMode = changeAll', () =>
+        testMessageMove(PropagateMode.changeAll));
     });
 
     group('in combined narrow', () {