msglist: Exclude muted users from typing-status text

Following web:
  zulip#1429 (review)

Author: chrisbobbe

lib/widgets/message_list.dart

@@ -1327,13 +1327,14 @@ class _TypingStatusWidgetState extends State<TypingStatusWidget> with PerAccount
     final store = PerAccountStoreWidget.of(context);
     final zulipLocalizations = ZulipLocalizations.of(context);
     final typistIds = model!.typistIdsInNarrow(narrow);
-    if (typistIds.isEmpty) return const SizedBox();
-    final text = switch (typistIds.length) {
+    final filteredTypistIds = typistIds.whereNot(store.isUserMuted);
+    if (filteredTypistIds.isEmpty) return const SizedBox();
+    final text = switch (filteredTypistIds.length) {
       1 => zulipLocalizations.onePersonTyping(
-             store.userDisplayName(typistIds.first)),
+             store.userDisplayName(filteredTypistIds.first)),
       2 => zulipLocalizations.twoPeopleTyping(
-             store.userDisplayName(typistIds.first),
-             store.userDisplayName(typistIds.last)),
+             store.userDisplayName(filteredTypistIds.first),
+             store.userDisplayName(filteredTypistIds.last)),
       _ => zulipLocalizations.manyPeopleTyping,
     };
 

test/widgets/message_list_test.dart

@@ -893,6 +893,22 @@ void main() {
       // Wait for the pending timers to end.
       await tester.pump(const Duration(seconds: 15));
     });
+
+    testWidgets('muted user typing', (tester) async {
+      await setupMessageListPage(tester,
+        narrow: topicNarrow, users: users, messages: [streamMessage]);
+
+      await store.setMutedUsers([eg.otherUser.userId]);
+      await tester.pump();
+
+      await checkTyping(tester,
+        eg.typingEvent(topicNarrow, TypingOp.start, eg.thirdUser.userId),
+        expected: 'Third User is typing…', // no "Other User"
+      );
+
+      // Wait for the pending timers to end.
+      await tester.pump(const Duration(seconds: 15));
+    });
   });
 
   group('MarkAsReadWidget', () {