api: Indicate support for handling empty topics

Look for `allow_empty_topic_name` and `empty_topic_name` under "Feature
level 334" in the API Changelog to verify the affected routes:
  https://zulip.com/api/changelog

To keep the API bindings thin, instead of setting
`allow_empty_topic_name` for the callers, we require the callers to pass
the appropriate values instead.

Fixes: #1250

Author: PIG208

lib/api/route/channels.dart

@@ -7,8 +7,12 @@ part 'channels.g.dart';
 /// https://zulip.com/api/get-stream-topics
 Future<GetStreamTopicsResult> getStreamTopics(ApiConnection connection, {
   required int streamId,
+  required bool allowEmptyTopicName,
 }) {
-  return connection.get('getStreamTopics', GetStreamTopicsResult.fromJson, 'users/me/$streamId/topics', {});
+  assert(allowEmptyTopicName, '`allowEmptyTopicName` should only be true');
+  return connection.get('getStreamTopics', GetStreamTopicsResult.fromJson, 'users/me/$streamId/topics', {
+    'allow_empty_topic_name': allowEmptyTopicName,
+  });
 }
 
 @JsonSerializable(fieldRename: FieldRename.snake)

lib/api/route/events.dart

@@ -18,6 +18,7 @@ Future<InitialSnapshot> registerQueue(ApiConnection connection) {
       'user_avatar_url_field_optional': false, // TODO(#254): turn on
       'stream_typing_notifications': true,
       'user_settings_object': true,
+      'empty_topic_name': true,
     },
   });
 }

lib/api/route/messages.dart

@@ -16,6 +16,7 @@ part 'messages.g.dart';
 Future<Message?> getMessageCompat(ApiConnection connection, {
   required int messageId,
   bool? applyMarkdown,
+  required bool allowEmptyTopicName,
 }) async {
   final useLegacyApi = connection.zulipFeatureLevel! < 120;
   if (useLegacyApi) {
@@ -25,6 +26,7 @@ Future<Message?> getMessageCompat(ApiConnection connection, {
       numBefore: 0,
       numAfter: 0,
       applyMarkdown: applyMarkdown,
+      allowEmptyTopicName: allowEmptyTopicName,
 
       // Hard-code this param to `true`, as the new single-message API
       // effectively does:
@@ -37,6 +39,7 @@ Future<Message?> getMessageCompat(ApiConnection connection, {
       final response = await getMessage(connection,
         messageId: messageId,
         applyMarkdown: applyMarkdown,
+        allowEmptyTopicName: allowEmptyTopicName,
       );
       return response.message;
     } on ZulipApiException catch (e) {
@@ -57,10 +60,13 @@ Future<Message?> getMessageCompat(ApiConnection connection, {
 Future<GetMessageResult> getMessage(ApiConnection connection, {
   required int messageId,
   bool? applyMarkdown,
+  required bool allowEmptyTopicName,
 }) {
+  assert(allowEmptyTopicName, '`allowEmptyTopicName` should only be true');
   assert(connection.zulipFeatureLevel! >= 120);
   return connection.get('getMessage', GetMessageResult.fromJson, 'messages/$messageId', {
     if (applyMarkdown != null) 'apply_markdown': applyMarkdown,
+    'allow_empty_topic_name': allowEmptyTopicName,
   });
 }
 
@@ -89,8 +95,10 @@ Future<GetMessagesResult> getMessages(ApiConnection connection, {
   required int numAfter,
   bool? clientGravatar,
   bool? applyMarkdown,
+  required bool allowEmptyTopicName,
   // bool? useFirstUnreadAnchor // omitted because deprecated
 }) {
+  assert(allowEmptyTopicName, '`allowEmptyTopicName` should only be true');
   return connection.get('getMessages', GetMessagesResult.fromJson, 'messages', {
     'narrow': resolveApiNarrowForServer(narrow, connection.zulipFeatureLevel!),
     'anchor': RawParameter(anchor.toJson()),
@@ -99,6 +107,7 @@ Future<GetMessagesResult> getMessages(ApiConnection connection, {
     'num_after': numAfter,
     if (clientGravatar != null) 'client_gravatar': clientGravatar,
     if (applyMarkdown != null) 'apply_markdown': applyMarkdown,
+    'allow_empty_topic_name': allowEmptyTopicName,
   });
 }
 

lib/model/autocomplete.dart

@@ -904,7 +904,9 @@ class TopicAutocompleteView extends AutocompleteView<TopicAutocompleteQuery, Top
   Future<void> _fetch() async {
      assert(!_isFetching);
     _isFetching = true;
-    final result = await getStreamTopics(store.connection, streamId: streamId);
+    final result = await getStreamTopics(store.connection, streamId: streamId,
+      allowEmptyTopicName: true,
+    );
     _topics = result.topics.map((e) => e.name);
     _isFetching = false;
     return _startSearch();

lib/model/message_list.dart

@@ -495,6 +495,7 @@ class MessageListView with ChangeNotifier, _MessageSequence {
       anchor: AnchorCode.newest,
       numBefore: kMessageListFetchBatchSize,
       numAfter: 0,
+      allowEmptyTopicName: true,
     );
     if (this.generation > generation) return;
     _adjustNarrowForTopicPermalink(result.messages.firstOrNull);
@@ -567,6 +568,7 @@ class MessageListView with ChangeNotifier, _MessageSequence {
           includeAnchor: false,
           numBefore: kMessageListFetchBatchSize,
           numAfter: 0,
+          allowEmptyTopicName: true,
         );
       } catch (e) {
         hasFetchError = true;

lib/widgets/actions.dart

@@ -260,6 +260,7 @@ abstract final class ZulipAction {
       fetchedMessage = await getMessageCompat(PerAccountStoreWidget.of(context).connection,
         messageId: messageId,
         applyMarkdown: false,
+        allowEmptyTopicName: true,
       );
       if (fetchedMessage == null) {
         errorMessage = zulipLocalizations.errorMessageDoesNotSeemToExist;

test/api/route/messages_test.dart

@@ -20,10 +20,12 @@ void main() {
       required bool expectLegacy,
       required int messageId,
       bool? applyMarkdown,
+      required bool allowEmptyTopicName,
     }) async {
       final result = await getMessageCompat(connection,
         messageId: messageId,
         applyMarkdown: applyMarkdown,
+        allowEmptyTopicName: allowEmptyTopicName,
       );
       if (expectLegacy) {
         check(connection.lastRequest).isA<http.Request>()
@@ -35,6 +37,7 @@ void main() {
             'num_before': '0',
             'num_after': '0',
             if (applyMarkdown != null) 'apply_markdown': applyMarkdown.toString(),
+            'allow_empty_topic_name': allowEmptyTopicName.toString(),
             'client_gravatar': 'true',
           });
       } else {
@@ -43,6 +46,7 @@ void main() {
           ..url.path.equals('/api/v1/messages/$messageId')
           ..url.queryParameters.deepEquals({
             if (applyMarkdown != null) 'apply_markdown': applyMarkdown.toString(),
+            'allow_empty_topic_name': allowEmptyTopicName.toString(),
           });
       }
       return result;
@@ -57,6 +61,7 @@ void main() {
           expectLegacy: false,
           messageId: message.id,
           applyMarkdown: true,
+          allowEmptyTopicName: true,
         );
         check(result).isNotNull().jsonEquals(message);
       });
@@ -71,6 +76,7 @@ void main() {
           expectLegacy: false,
           messageId: message.id,
           applyMarkdown: true,
+          allowEmptyTopicName: true,
         );
         check(result).isNull();
       });
@@ -92,6 +98,7 @@ void main() {
           expectLegacy: true,
           messageId: message.id,
           applyMarkdown: true,
+          allowEmptyTopicName: true,
         );
         check(result).isNotNull().jsonEquals(message);
       });
@@ -113,6 +120,7 @@ void main() {
           expectLegacy: true,
           messageId: message.id,
           applyMarkdown: true,
+          allowEmptyTopicName: true,
         );
         check(result).isNull();
       });
@@ -124,11 +132,13 @@ void main() {
       FakeApiConnection connection, {
       required int messageId,
       bool? applyMarkdown,
+      required bool allowEmptyTopicName,
       required Map<String, String> expected,
     }) async {
       final result = await getMessage(connection,
         messageId: messageId,
         applyMarkdown: applyMarkdown,
+        allowEmptyTopicName: allowEmptyTopicName,
       );
       check(connection.lastRequest).isA<http.Request>()
         ..method.equals('GET')
@@ -145,7 +155,11 @@ void main() {
         await checkGetMessage(connection,
           messageId: 1,
           applyMarkdown: true,
-          expected: {'apply_markdown': 'true'});
+          allowEmptyTopicName: true,
+          expected: {
+            'apply_markdown': 'true',
+            'allow_empty_topic_name': 'true',
+          });
       });
     });
 
@@ -155,7 +169,21 @@ void main() {
         await checkGetMessage(connection,
           messageId: 1,
           applyMarkdown: false,
-          expected: {'apply_markdown': 'false'});
+          allowEmptyTopicName: true,
+          expected: {
+            'apply_markdown': 'false',
+            'allow_empty_topic_name': 'true',
+          });
+      });
+    });
+
+    test('allow empty topic name', () {
+      return FakeApiConnection.with_((connection) async {
+        connection.prepare(json: fakeResult.toJson());
+        await checkGetMessage(connection,
+          messageId: 1,
+          allowEmptyTopicName: true,
+          expected: {'allow_empty_topic_name': 'true'});
       });
     });
 
@@ -164,6 +192,7 @@ void main() {
         connection.prepare(json: fakeResult.toJson());
         check(() => getMessage(connection,
           messageId: 1,
+          allowEmptyTopicName: true,
         )).throws<AssertionError>();
       });
     });
@@ -255,12 +284,14 @@ void main() {
       required int numAfter,
       bool? clientGravatar,
       bool? applyMarkdown,
+      required bool allowEmptyTopicName,
       required Map<String, String> expected,
     }) async {
       final result = await getMessages(connection,
         narrow: narrow, anchor: anchor, includeAnchor: includeAnchor,
         numBefore: numBefore, numAfter: numAfter,
         clientGravatar: clientGravatar, applyMarkdown: applyMarkdown,
+        allowEmptyTopicName: allowEmptyTopicName,
       );
       check(connection.lastRequest).isA<http.Request>()
         ..method.equals('GET')
@@ -279,11 +310,13 @@ void main() {
         await checkGetMessages(connection,
           narrow: const CombinedFeedNarrow().apiEncode(),
           anchor: AnchorCode.newest, numBefore: 10, numAfter: 20,
+          allowEmptyTopicName: true,
           expected: {
             'narrow': jsonEncode([]),
             'anchor': 'newest',
             'num_before': '10',
             'num_after': '20',
+            'allow_empty_topic_name': 'true',
           });
       });
     });
@@ -294,13 +327,15 @@ void main() {
         await checkGetMessages(connection,
           narrow: [ApiNarrowDm([123, 234])],
           anchor: AnchorCode.newest, numBefore: 10, numAfter: 20,
+          allowEmptyTopicName: true,
           expected: {
             'narrow': jsonEncode([
               {'operator': 'pm-with', 'operand': [123, 234]},
             ]),
             'anchor': 'newest',
             'num_before': '10',
             'num_after': '20',
+            'allow_empty_topic_name': 'true',
           });
       });
     });
@@ -312,11 +347,13 @@ void main() {
           narrow: const CombinedFeedNarrow().apiEncode(),
           anchor: const NumericAnchor(42),
           numBefore: 10, numAfter: 20,
+          allowEmptyTopicName: true,
           expected: {
             'narrow': jsonEncode([]),
             'anchor': '42',
             'num_before': '10',
             'num_after': '20',
+            'allow_empty_topic_name': 'true',
           });
       });
     });

test/model/autocomplete_test.dart

@@ -3,6 +3,7 @@ import 'dart:convert';
 
 import 'package:checks/checks.dart';
 import 'package:flutter/widgets.dart';
+import 'package:http/http.dart' as http;
 import 'package:test/scaffolding.dart';
 import 'package:zulip/api/model/initial_snapshot.dart';
 import 'package:zulip/api/model/model.dart';
@@ -19,6 +20,7 @@ import 'package:zulip/widgets/compose_box.dart';
 import '../api/fake_api.dart';
 import '../example_data.dart' as eg;
 import '../fake_async.dart';
+import '../stdlib_checks.dart';
 import 'test_store.dart';
 import 'autocomplete_checks.dart';
 
@@ -1026,6 +1028,21 @@ void main() {
     check(done).isTrue();
   });
 
+  test('TopicAutocompleteView getStreamTopics request', () async {
+    final store = eg.store();
+    final connection = store.connection as FakeApiConnection;
+
+    connection.prepare(json: GetStreamTopicsResult(
+      topics: [eg.getStreamTopicsEntry(name: '')],
+    ).toJson());
+    TopicAutocompleteView.init(store: store, streamId: 1000,
+      query: TopicAutocompleteQuery('foo'));
+    check(connection.lastRequest).isA<http.Request>()
+      ..method.equals('GET')
+      ..url.path.equals('/api/v1/users/me/1000/topics')
+      ..url.queryParameters['allow_empty_topic_name'].equals('true');
+  });
+
   group('TopicAutocompleteQuery.testTopic', () {
     final store = eg.store();
     void doCheck(String rawQuery, String topic, bool expected) {

test/model/message_list_test.dart

@@ -82,6 +82,7 @@ void main() {
     bool? includeAnchor,
     required int numBefore,
     required int numAfter,
+    required bool allowEmptyTopicName,
   }) {
     check(connection.lastRequest).isA<http.Request>()
       ..method.equals('GET')
@@ -92,6 +93,7 @@ void main() {
         if (includeAnchor != null) 'include_anchor': includeAnchor.toString(),
         'num_before': numBefore.toString(),
         'num_after': numAfter.toString(),
+        'allow_empty_topic_name': allowEmptyTopicName.toString(),
       });
   }
 
@@ -126,6 +128,7 @@ void main() {
           anchor: 'newest',
           numBefore: kMessageListFetchBatchSize,
           numAfter: 0,
+          allowEmptyTopicName: true,
         );
       }
 
@@ -238,6 +241,7 @@ void main() {
         includeAnchor: false,
         numBefore: kMessageListFetchBatchSize,
         numAfter: 0,
+        allowEmptyTopicName: true,
       );
     });
 

test/widgets/action_sheet_test.dart

@@ -1155,6 +1155,18 @@ void main() {
         await setupToMessageActionSheet(tester, message: message, narrow: const StarredMessagesNarrow());
         check(findQuoteAndReplyButton(tester)).isNull();
       });
+
+      testWidgets('handle empty topic', (tester) async {
+        final message = eg.streamMessage();
+        await setupToMessageActionSheet(tester,
+          message: message, narrow: TopicNarrow.ofMessage(message));
+
+        prepareRawContentResponseSuccess(message: message, rawContent: 'Hello world');
+        await tapQuoteAndReplyButton(tester);
+        check(connection.lastRequest).isA<http.Request>()
+          .url.queryParameters['allow_empty_topic_name'].equals('true');
+        await tester.pump(Duration.zero);
+      });
     });
 
     group('MarkAsUnread', () {

test/widgets/message_list_test.dart

@@ -331,6 +331,7 @@ void main() {
             'anchor': AnchorCode.newest.toJson(),
             'num_before': kMessageListFetchBatchSize.toString(),
             'num_after': '0',
+            'allow_empty_topic_name': 'true',
           });
       });
 
@@ -363,6 +364,7 @@ void main() {
             'anchor': AnchorCode.newest.toJson(),
             'num_before': kMessageListFetchBatchSize.toString(),
             'num_after': '0',
+            'allow_empty_topic_name': 'true',
           });
       });
     });