compose: Send to general chat if empty topic

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

Author: PIG208

lib/widgets/compose_box.dart

@@ -104,13 +104,20 @@ class ComposeTopicController extends ComposeController<TopicValidationError> {
   @override
   String _computeTextNormalized() {
     String trimmed = text.trim();
-    return trimmed.isEmpty ? kNoTopicTopic : trimmed;
+    // TODO(server-10): simplify
+    if (store.connection.zulipFeatureLevel! < 334) {
+      return trimmed.isEmpty ? kNoTopicTopic : trimmed;
+    }
+
+    return trimmed;
   }
 
   @override
   List<TopicValidationError> _computeValidationErrors() {
     return [
-      if (mandatory && textNormalized == kNoTopicTopic)
+      if (mandatory && (textNormalized.isEmpty
+                        || textNormalized == kNoTopicTopic
+                        || textNormalized == store.realmEmptyTopicDisplayName))
         TopicValidationError.mandatoryButEmpty,
 
       if (

test/widgets/compose_box_test.dart

@@ -681,6 +681,7 @@ void main() {
     Future<void> setupAndTapSend(WidgetTester tester, {
       required String topicInputText,
       required bool mandatoryTopics,
+      int? zulipFeatureLevel,
     }) async {
       TypingNotifier.debugEnable = false;
       addTearDown(TypingNotifier.debugReset);
@@ -689,7 +690,8 @@ void main() {
       final narrow = ChannelNarrow(channel.streamId);
       await prepareComposeBox(tester,
         narrow: narrow, streams: [channel],
-        mandatoryTopics: mandatoryTopics);
+        mandatoryTopics: mandatoryTopics,
+        zulipFeatureLevel: zulipFeatureLevel);
 
       await enterTopic(tester, narrow: narrow, topic: topicInputText);
       await tester.enterText(contentInputFinder, 'test content');
@@ -704,10 +706,21 @@ void main() {
         expectedMessage: 'Topics are required in this organization.');
     }
 
-    testWidgets('empty topic -> "(no topic)"', (tester) async {
+    testWidgets('empty topic -> empty topic', (tester) async {
       await setupAndTapSend(tester,
         topicInputText: '',
         mandatoryTopics: false);
+      check(connection.lastRequest).isA<http.Request>()
+        ..method.equals('POST')
+        ..url.path.equals('/api/v1/messages')
+        ..bodyFields['topic'].equals('');
+    }, skip: true); // null topic names soon to be enabled
+
+    testWidgets('legacy: empty topic -> "(no topic)"', (tester) async {
+      await setupAndTapSend(tester,
+        topicInputText: '',
+        mandatoryTopics: false,
+        zulipFeatureLevel: 333);
       check(connection.lastRequest).isA<http.Request>()
         ..method.equals('POST')
         ..url.path.equals('/api/v1/messages')
@@ -721,12 +734,27 @@ void main() {
       checkMessageNotSent(tester);
     });
 
+    testWidgets('if topics are mandatory, reject `realmEmptyTopicDisplayName`', (tester) async {
+      await setupAndTapSend(tester,
+        topicInputText: eg.defaultRealmEmptyTopicDisplayName,
+        mandatoryTopics: true);
+      checkMessageNotSent(tester);
+    }, skip: true); // null topic names soon to be enabled
+
     testWidgets('if topics are mandatory, reject "(no topic)"', (tester) async {
       await setupAndTapSend(tester,
         topicInputText: '(no topic)',
         mandatoryTopics: true);
       checkMessageNotSent(tester);
     });
+
+    testWidgets('legacy: if topics are mandatory, reject "(no topic)"', (tester) async {
+      await setupAndTapSend(tester,
+        topicInputText: '(no topic)',
+        mandatoryTopics: true,
+        zulipFeatureLevel: 333);
+      checkMessageNotSent(tester);
+    });
   });
 
   group('uploads', () {