msglist: Unconditionally add ApiNarrowIsUnread to markNarrowAsRead

Fixes: zulip#377

Author: sirpengi

lib/widgets/message_list.dart

@@ -734,13 +734,17 @@ Future<void> markNarrowAsRead(BuildContext context, Narrow narrow) async {
   int responseCount = 0;
   int updatedCount = 0;
 
-  final apiNarrow = switch (narrow) {
-    // Since there's a database index on is:unread, it's a fast
-    // search query and thus worth using as an optimization
-    // when processing all messages.
-    AllMessagesNarrow() => [ApiNarrowIsUnread()],
-    _                   => narrow.apiEncode(),
-  };
+  // This process can take a long time in narrows with a lot
+  // of history given the server ends up processing a large
+  // number of already read messages. Unconditionally add
+  // [ApiNarrowIsUnread] here to take advantage of a database
+  // index on `is:unread`.
+  // This optimization is also used server side for the
+  // (deprecated) specialized endpoints for marking messages
+  // as read. See `do_mark_stream_messages_as_read` in
+  // `zulip:zerver/actions/message_flags.py`.
+  final apiNarrow = narrow.apiEncode()..add(ApiNarrowIsUnread());
+
   while (true) {
     final result = await updateMessageFlagsForNarrow(connection,
       anchor: anchor,

test/widgets/message_list_test.dart

@@ -9,6 +9,7 @@ import 'package:http/http.dart' as http;
 import 'package:zulip/api/model/events.dart';
 import 'package:zulip/api/model/initial_snapshot.dart';
 import 'package:zulip/api/model/model.dart';
+import 'package:zulip/api/model/narrow.dart';
 import 'package:zulip/api/route/messages.dart';
 import 'package:zulip/model/localizations.dart';
 import 'package:zulip/model/narrow.dart';
@@ -479,6 +480,7 @@ void main() {
           firstProcessedId: null, lastProcessedId: null,
           foundOldest: true, foundNewest: true).toJson());
         await tester.tap(find.byType(MarkAsReadWidget));
+        final apiNarrow = narrow.apiEncode()..add(ApiNarrowIsUnread());
         check(connection.lastRequest).isA<http.Request>()
           ..method.equals('POST')
           ..url.path.equals('/api/v1/messages/flags/narrow')
@@ -487,7 +489,7 @@ void main() {
               'include_anchor': 'false',
               'num_before': '0',
               'num_after': '1000',
-              'narrow': jsonEncode(narrow.apiEncode()),
+              'narrow': jsonEncode(apiNarrow),
               'op': 'add',
               'flag': 'read',
             });
@@ -537,6 +539,7 @@ void main() {
           firstProcessedId: 1, lastProcessedId: 1989,
           foundOldest: true, foundNewest: false).toJson());
         await tester.tap(find.byType(MarkAsReadWidget));
+        final apiNarrow = narrow.apiEncode()..add(ApiNarrowIsUnread());
         check(connection.lastRequest).isA<http.Request>()
           ..method.equals('POST')
           ..url.path.equals('/api/v1/messages/flags/narrow')
@@ -545,7 +548,7 @@ void main() {
               'include_anchor': 'false',
               'num_before': '0',
               'num_after': '1000',
-              'narrow': jsonEncode(narrow.apiEncode()),
+              'narrow': jsonEncode(apiNarrow),
               'op': 'add',
               'flag': 'read',
             });
@@ -564,7 +567,7 @@ void main() {
               'include_anchor': 'false',
               'num_before': '0',
               'num_after': '1000',
-              'narrow': jsonEncode(narrow.apiEncode()),
+              'narrow': jsonEncode(apiNarrow),
               'op': 'add',
               'flag': 'read',
             });
@@ -583,6 +586,7 @@ void main() {
           firstProcessedId: null, lastProcessedId: null,
           foundOldest: true, foundNewest: false).toJson());
         await tester.tap(find.byType(MarkAsReadWidget));
+        final apiNarrow = narrow.apiEncode()..add(ApiNarrowIsUnread());
         check(connection.lastRequest).isA<http.Request>()
           ..method.equals('POST')
           ..url.path.equals('/api/v1/messages/flags/narrow')
@@ -591,7 +595,7 @@ void main() {
               'include_anchor': 'false',
               'num_before': '0',
               'num_after': '1000',
-              'narrow': jsonEncode(narrow.apiEncode()),
+              'narrow': jsonEncode(apiNarrow),
               'op': 'add',
               'flag': 'read',
             });