Respect realm setting for mandatory topics

lib/api/model/initial_snapshot.dart

@@ -64,6 +64,8 @@ class InitialSnapshot {
 
   final List<UserTopicItem>? userTopics; // TODO(server-6)
 
+  final bool realmMandatoryTopics;
+
   /// The number of days until a user's account is treated as a full member.
   ///
   /// Search for "realm_waiting_period_threshold" in https://zulip.com/api/register-queue.
@@ -125,6 +127,7 @@ class InitialSnapshot {
     required this.streams,
     required this.userSettings,
     required this.userTopics,
+    required this.realmMandatoryTopics,
     required this.realmWaitingPeriodThreshold,
     required this.realmDefaultExternalAccounts,
     required this.maxFileUploadSizeMib,

lib/model/store.dart

@@ -268,6 +268,7 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
       globalStore: globalStore,
       connection: connection,
       realmUrl: realmUrl,
+      realmMandatoryTopics: initialSnapshot.realmMandatoryTopics,
       realmWaitingPeriodThreshold: initialSnapshot.realmWaitingPeriodThreshold,
       maxFileUploadSizeMib: initialSnapshot.maxFileUploadSizeMib,
       realmDefaultExternalAccounts: initialSnapshot.realmDefaultExternalAccounts,
@@ -311,6 +312,7 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
     required GlobalStore globalStore,
     required this.connection,
     required this.realmUrl,
+    required this.realmMandatoryTopics,
     required this.realmWaitingPeriodThreshold,
     required this.maxFileUploadSizeMib,
     required this.realmDefaultExternalAccounts,
@@ -375,6 +377,7 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
   Uri? tryResolveUrl(String reference) => _tryResolveUrl(realmUrl, reference);
 
   String get zulipVersion => account.zulipVersion;
+  final bool realmMandatoryTopics;  // TODO(#668): update this realm setting
   /// For docs, please see [InitialSnapshot.realmWaitingPeriodThreshold].
   final int realmWaitingPeriodThreshold;  // TODO(#668): update this realm setting
   final int maxFileUploadSizeMib; // No event for this.

lib/widgets/compose_box.dart

@@ -89,13 +89,14 @@ enum TopicValidationError {
 }
 
 class ComposeTopicController extends ComposeController<TopicValidationError> {
-  ComposeTopicController() {
+  ComposeTopicController({required this.store}) {
     _update();
   }
 
-  // TODO: subscribe to this value:
-  //   https://zulip.com/help/require-topics
-  final mandatory = true;
+  PerAccountStore store;
+
+  // TODO(#668): listen to [PerAccountStore] once we subscribe to this value
+  bool get mandatory => store.realmMandatoryTopics;
 
   // TODO(#307) use `max_topic_length` instead of hardcoded limit
   @override final maxLengthUnicodeCodePoints = kMaxTopicLengthCodePoints;
@@ -1227,7 +1228,10 @@ 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
@@ -1308,16 +1312,20 @@ 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);
+        if (_controller == null) {
+          _controller = StreamComposeBoxController(store: store);
+        } else {
+          (controller as StreamComposeBoxController).topic.store = store;
+        }
       case TopicNarrow():
       case DmNarrow():
         _controller = FixedDestinationComposeBoxController();
@@ -1330,7 +1338,7 @@ class _ComposeBoxState extends State<ComposeBox> implements ComposeBoxState {
 
   @override
   void dispose() {
-    _controller.dispose();
+    controller.dispose();
     super.dispose();
   }
 
@@ -1370,15 +1378,16 @@ class _ComposeBoxState extends State<ComposeBox> implements ComposeBoxState {
       return _ComposeBoxContainer(body: null, errorBanner: errorBanner);
     }
 
+    final controller = this.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/example_data.dart

@@ -856,6 +856,7 @@ InitialSnapshot initialSnapshot({
   List<ZulipStream>? streams,
   UserSettings? userSettings,
   List<UserTopicItem>? userTopics,
+  bool? realmMandatoryTopics,
   int? realmWaitingPeriodThreshold,
   Map<String, RealmDefaultExternalAccount>? realmDefaultExternalAccounts,
   int? maxFileUploadSizeMib,
@@ -890,6 +891,7 @@ InitialSnapshot initialSnapshot({
       emojiset: Emojiset.google,
     ),
     userTopics: userTopics,
+    realmMandatoryTopics: realmMandatoryTopics ?? true,
     realmWaitingPeriodThreshold: realmWaitingPeriodThreshold ?? 0,
     realmDefaultExternalAccounts: realmDefaultExternalAccounts ?? {},
     maxFileUploadSizeMib: maxFileUploadSizeMib ?? 25,

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/model/store_checks.dart

@@ -31,6 +31,7 @@ extension PerAccountStoreChecks on Subject<PerAccountStore> {
   Subject<bool> get isLoading => has((x) => x.isLoading, 'isLoading');
   Subject<Uri> get realmUrl => has((x) => x.realmUrl, 'realmUrl');
   Subject<String> get zulipVersion => has((x) => x.zulipVersion, 'zulipVersion');
+  Subject<bool> get realmMandatoryTopics => has((x) => x.realmMandatoryTopics, 'realmMandatoryTopics');
   Subject<int> get maxFileUploadSizeMib => has((x) => x.maxFileUploadSizeMib, 'maxFileUploadSizeMib');
   Subject<Map<String, RealmDefaultExternalAccount>> get realmDefaultExternalAccounts => has((x) => x.realmDefaultExternalAccounts, 'realmDefaultExternalAccounts');
   Subject<List<CustomProfileField>> get customProfileFields => has((x) => x.customProfileFields, 'customProfileFields');

test/model/test_store.dart

@@ -85,6 +85,9 @@ class TestGlobalStore extends GlobalStore {
   /// [PerAccountStore] when [perAccount] is subsequently called for this
   /// account, in particular when a [PerAccountStoreWidget] is mounted.
   Future<void> add(Account account, InitialSnapshot initialSnapshot) async {
+    assert(initialSnapshot.zulipVersion == account.zulipVersion);
+    assert(initialSnapshot.zulipMergeBase == account.zulipMergeBase);
+    assert(initialSnapshot.zulipFeatureLevel == account.zulipFeatureLevel);
     await insertAccount(account.toCompanion(false));
     assert(!_initialSnapshots.containsKey(account.id));
     _initialSnapshots[account.id] = initialSnapshot;

test/widgets/compose_box_test.dart

@@ -44,9 +44,9 @@ void main() {
   Future<void> prepareComposeBox(WidgetTester tester, {
     required Narrow narrow,
     User? selfUser,
-    int? realmWaitingPeriodThreshold,
-    List<User> users = const [],
+    List<User> otherUsers = const [],
     List<ZulipStream> streams = const [],
+    bool? mandatoryTopics,
   }) async {
     if (narrow case ChannelNarrow(:var streamId) || TopicNarrow(: var streamId)) {
       assert(streams.any((stream) => stream.streamId == streamId),
@@ -56,11 +56,12 @@ void main() {
     selfUser ??= eg.selfUser;
     final selfAccount = eg.account(user: selfUser);
     await testBinding.globalStore.add(selfAccount, eg.initialSnapshot(
-      realmWaitingPeriodThreshold: realmWaitingPeriodThreshold));
+      realmMandatoryTopics: mandatoryTopics,
+    ));
 
     store = await testBinding.globalStore.perAccount(selfAccount.id);
 
-    await store.addUsers([selfUser, ...users]);
+    await store.addUsers([selfUser, ...otherUsers]);
     await store.addStreams(streams);
     connection = store.connection as FakeApiConnection;
 
@@ -560,6 +561,60 @@ void main() {
     });
   });
 
+  group('sending to empty topic', () {
+    late ZulipStream channel;
+
+    Future<void> setupAndTapSend(WidgetTester tester, {
+      required String topicInputText,
+      required bool mandatoryTopics,
+    }) async {
+      TypingNotifier.debugEnable = false;
+      addTearDown(TypingNotifier.debugReset);
+
+      channel = eg.stream();
+      final narrow = ChannelNarrow(channel.streamId);
+      await prepareComposeBox(tester,
+        narrow: narrow, streams: [channel],
+        mandatoryTopics: mandatoryTopics);
+
+      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: '',
+        mandatoryTopics: false);
+      check(connection.lastRequest).isA<http.Request>()
+        ..method.equals('POST')
+        ..url.path.equals('/api/v1/messages')
+        ..bodyFields['topic'].equals('(no topic)');
+    });
+
+    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(
@@ -748,15 +803,15 @@ void main() {
         testWidgets('compose box replaced with a banner', (tester) async {
           final deactivatedUser = eg.user(isActive: false);
           await prepareComposeBox(tester, narrow: dmNarrowWith(deactivatedUser),
-            users: [deactivatedUser]);
+            otherUsers: [deactivatedUser]);
           checkComposeBox(isShown: false);
         });
 
         testWidgets('active user becomes deactivated -> '
             'compose box is replaced with a banner', (tester) async {
           final activeUser = eg.user(isActive: true);
           await prepareComposeBox(tester, narrow: dmNarrowWith(activeUser),
-            users: [activeUser]);
+            otherUsers: [activeUser]);
           checkComposeBox(isShown: true);
 
           await changeUserStatus(tester, user: activeUser, isActive: false);
@@ -767,7 +822,7 @@ void main() {
             'banner is replaced with the compose box', (tester) async {
           final deactivatedUser = eg.user(isActive: false);
           await prepareComposeBox(tester, narrow: dmNarrowWith(deactivatedUser),
-            users: [deactivatedUser]);
+            otherUsers: [deactivatedUser]);
           checkComposeBox(isShown: false);
 
           await changeUserStatus(tester, user: deactivatedUser, isActive: true);
@@ -779,15 +834,15 @@ void main() {
         testWidgets('compose box replaced with a banner', (tester) async {
           final deactivatedUsers = [eg.user(isActive: false), eg.user(isActive: false)];
           await prepareComposeBox(tester, narrow: groupDmNarrowWith(deactivatedUsers),
-            users: deactivatedUsers);
+            otherUsers: deactivatedUsers);
           checkComposeBox(isShown: false);
         });
 
         testWidgets('at least one user becomes deactivated -> '
             'compose box is replaced with a banner', (tester) async {
           final activeUsers = [eg.user(isActive: true), eg.user(isActive: true)];
           await prepareComposeBox(tester, narrow: groupDmNarrowWith(activeUsers),
-            users: activeUsers);
+            otherUsers: activeUsers);
           checkComposeBox(isShown: true);
 
           await changeUserStatus(tester, user: activeUsers[0], isActive: false);
@@ -798,7 +853,7 @@ void main() {
             'banner is replaced with the compose box', (tester) async {
           final deactivatedUsers = [eg.user(isActive: false), eg.user(isActive: false)];
           await prepareComposeBox(tester, narrow: groupDmNarrowWith(deactivatedUsers),
-            users: deactivatedUsers);
+            otherUsers: deactivatedUsers);
           checkComposeBox(isShown: false);
 
           await changeUserStatus(tester, user: deactivatedUsers[0], isActive: true);