compose: Respect realm setting for mandatory topics

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

Author: PIG208

lib/widgets/compose_box.dart

@@ -89,13 +89,15 @@ enum TopicValidationError {
 }
 
 class ComposeTopicController extends ComposeController<TopicValidationError> {
-  ComposeTopicController() {
+  ComposeTopicController({required this.store}) {
     _update();
   }
 
+  PerAccountStore store;
+
   // TODO: subscribe to this value:
   //   https://zulip.com/help/require-topics
-  final mandatory = true;
+  bool get mandatory => store.realmMandatoryTopics;
 
   // TODO(#307) use `max_topic_length` instead of hardcoded limit
   @override final maxLengthUnicodeCodePoints = kMaxTopicLengthCodePoints;
@@ -1227,7 +1229,10 @@ sealed class ComposeBoxController {
 }
 
 class StreamComposeBoxController extends ComposeBoxController {
-  final topic = ComposeTopicController();
+  StreamComposeBoxController({required PerAccountStore store})
+    : topic = ComposeTopicController(store: store);
+
+  final ComposeTopicController topic;
   final topicFocusNode = FocusNode();
 
   @override
@@ -1304,16 +1309,17 @@ abstract class ComposeBoxState extends State<ComposeBox> {
   ComposeBoxController get controller;
 }
 
-class _ComposeBoxState extends State<ComposeBox> implements ComposeBoxState {
-  @override ComposeBoxController get controller => _controller;
-  late final ComposeBoxController _controller;
+class _ComposeBoxState extends State<ComposeBox> with PerAccountStoreAwareStateMixin<ComposeBox> implements ComposeBoxState {
+  @override ComposeBoxController get controller => _controller!;
+  ComposeBoxController? _controller;
 
   @override
-  void initState() {
-    super.initState();
+  void onNewStore() {
     switch (widget.narrow) {
       case ChannelNarrow():
-        _controller = StreamComposeBoxController();
+        final store = PerAccountStoreWidget.of(context);
+        _controller ??= StreamComposeBoxController(store: store);
+        (controller as StreamComposeBoxController).topic.store = store;
       case TopicNarrow():
       case DmNarrow():
         _controller = FixedDestinationComposeBoxController();
@@ -1326,7 +1332,7 @@ class _ComposeBoxState extends State<ComposeBox> implements ComposeBoxState {
 
   @override
   void dispose() {
-    _controller.dispose();
+    _controller!.dispose();
     super.dispose();
   }
 
@@ -1366,15 +1372,16 @@ class _ComposeBoxState extends State<ComposeBox> implements ComposeBoxState {
       return _ComposeBoxContainer(body: null, errorBanner: errorBanner);
     }
 
+    final controller = _controller!;
     final narrow = widget.narrow;
-    switch (_controller) {
+    switch (controller) {
       case StreamComposeBoxController(): {
         narrow as ChannelNarrow;
-        body = _StreamComposeBoxBody(controller: _controller, narrow: narrow);
+        body = _StreamComposeBoxBody(controller: controller, narrow: narrow);
       }
       case FixedDestinationComposeBoxController(): {
         narrow as SendableNarrow;
-        body = _FixedDestinationComposeBoxBody(controller: _controller, narrow: narrow);
+        body = _FixedDestinationComposeBoxBody(controller: controller, narrow: narrow);
       }
     }
 

test/model/autocomplete_test.dart

@@ -835,7 +835,8 @@ void main() {
 
       final description = 'topic-input with text: $markedText produces: ${expectedQuery?.raw ?? 'No Query!'}';
       test(description, () {
-        final controller = ComposeTopicController();
+        final store = eg.store();
+        final controller = ComposeTopicController(store: store);
         controller.value = parsed.value;
         if (expectedQuery == null) {
           check(controller).autocompleteIntent.isNull();

test/widgets/compose_box_test.dart

@@ -566,6 +566,71 @@ void main() {
     });
   });
 
+  group('sending to empty topic', () {
+    late ZulipStream channel;
+
+    Future<void> setupAndTapSend(WidgetTester tester, {
+      bool? mandatoryTopics,
+      required String topicInputText,
+    }) async {
+      TypingNotifier.debugEnable = false;
+      addTearDown(TypingNotifier.debugReset);
+      addTearDown(testBinding.reset);
+
+      channel = eg.stream();
+      final account = eg.account(user: eg.selfUser);
+      final initialSnapshot = eg.initialSnapshot(
+        realmMandatoryTopics: mandatoryTopics);
+      await testBinding.globalStore.add(account, initialSnapshot);
+
+      store = await testBinding.globalStore.perAccount(account.id);
+      await store.addStream(channel);
+      await store.addUser(eg.selfUser);
+      connection = store.connection as FakeApiConnection;
+
+      final narrow = ChannelNarrow(channel.streamId);
+      await prepareComposeBox(tester,
+        narrow: narrow, account: account);
+      await enterTopic(tester, narrow: narrow, topic: topicInputText);
+      await tester.enterText(contentInputFinder, 'test content');
+      await tester.tap(find.byIcon(ZulipIcons.send));
+      await tester.pump();
+    }
+
+    void checkMessageNotSent(WidgetTester tester) {
+      check(connection.takeRequests()).isEmpty();
+      checkErrorDialog(tester,
+        expectedTitle: 'Message not sent',
+        expectedMessage: 'Topics are required in this organization.');
+    }
+
+    testWidgets('empty topic -> (no topic)', (tester) async {
+      await setupAndTapSend(tester, topicInputText: '');
+      check(connection.lastRequest).isA<http.Request>()
+        ..method.equals('POST')
+        ..url.path.equals('/api/v1/messages')
+        ..bodyFields.deepEquals({
+          'type': 'stream',
+          'to': channel.streamId.toString(),
+          'topic': '(no topic)',
+          'content': 'test content',
+          'read_by_sender': 'true',
+        });
+    });
+
+    testWidgets('if topics are mandatory, reject empty topic', (tester) async {
+      await setupAndTapSend(tester, topicInputText: '',
+        mandatoryTopics: true);
+      checkMessageNotSent(tester);
+    });
+
+    testWidgets('if topics are mandatory, reject (no topic)', (tester) async {
+      await setupAndTapSend(tester, topicInputText: '(no topic)',
+        mandatoryTopics: true);
+      checkMessageNotSent(tester);
+    });
+  });
+
   group('uploads', () {
     void checkAppearsLoading(WidgetTester tester, bool expected) {
       final sendButtonElement = tester.element(find.ancestor(