msglist: In single-conversation view, make recipient headers not tappable.

Fixes: #1171

Author: lakshya1goel

Diff for: lib/widgets/message_list.dart

@@ -1108,9 +1108,14 @@ class StreamMessageRecipientHeader extends StatelessWidget {
         ]));
 
     return GestureDetector(
-      onTap: () => Navigator.push(context,
-        MessageListPage.buildRoute(context: context,
-          narrow: TopicNarrow.ofMessage(message))),
+      // When already in a topic narrow, disable tap interaction that would just
+      // push a MessageListPage for the same topic narrow.
+      // TODO(#1039) simplify by removing topic-narrow condition if we remove
+      //   recipient headers in topic narrows
+      onTap: narrow is TopicNarrow ? null
+        : () => Navigator.push(context,
+            MessageListPage.buildRoute(context: context,
+              narrow: TopicNarrow.ofMessage(message))),
       onLongPress: () => showTopicActionSheet(context,
         channelId: message.streamId, topic: topic),
       child: ColoredBox(
@@ -1157,9 +1162,14 @@ class DmRecipientHeader extends StatelessWidget {
     final messageListTheme = MessageListTheme.of(context);
 
     return GestureDetector(
-      onTap: () => Navigator.push(context,
-        MessageListPage.buildRoute(context: context,
-          narrow: DmNarrow.ofMessage(message, selfUserId: store.selfUserId))),
+      // When already in a DM narrow, disable tap interaction that would just
+      // push a MessageListPage for the same DM narrow.
+      // TODO(#1244) simplify by removing DM-narrow condition if we remove
+      //   recipient headers in DM narrows
+      onTap: narrow is DmNarrow ? null
+        : () => Navigator.push(context,
+            MessageListPage.buildRoute(context: context,
+              narrow: DmNarrow.ofMessage(message, selfUserId: store.selfUserId))),
       child: ColoredBox(
         color: messageListTheme.dmRecipientHeaderBg,
         child: Padding(

Diff for: test/widgets/message_list_test.dart

@@ -927,6 +927,54 @@ void main() {
         await tester.pump();
         tester.widget(find.text('new stream name'));
       });
+
+      testWidgets('navigates to TopicNarrow on tapping topic in ChannelNarrow', (tester) async {
+        final pushedRoutes = <Route<void>>[];
+        final navObserver = TestNavigatorObserver()
+          ..onPushed = (route, prevRoute) => pushedRoutes.add(route);
+        final channel = eg.stream();
+        final message = eg.streamMessage(stream: channel, topic: 'topic name');
+        await setupMessageListPage(tester,
+          narrow: ChannelNarrow(channel.streamId),
+          streams: [channel],
+          messages: [message],
+          navObservers: [navObserver]);
+
+        assert(pushedRoutes.length == 1);
+        pushedRoutes.clear();
+
+        connection.prepare(json: eg.newestGetMessagesResult(
+          foundOldest: true, messages: [message]).toJson());
+        await tester.tap(find.descendant(
+          of: find.byType(StreamMessageRecipientHeader),
+          matching: find.text('topic name')));
+        await tester.pump();
+        check(pushedRoutes).single.isA<WidgetRoute>().page.isA<MessageListPage>()
+          .initNarrow.equals(TopicNarrow.ofMessage(message));
+        await tester.pumpAndSettle();
+      });
+
+      testWidgets('does not navigate on tapping topic in TopicNarrow', (tester) async {
+        final pushedRoutes = <Route<void>>[];
+        final navObserver = TestNavigatorObserver()
+          ..onPushed = (route, prevRoute) => pushedRoutes.add(route);
+        final channel = eg.stream();
+        final message = eg.streamMessage(stream: channel, topic: 'topic name');
+        await setupMessageListPage(tester,
+          narrow: TopicNarrow.ofMessage(message),
+          streams: [channel],
+          messages: [message],
+          navObservers: [navObserver]);
+
+        assert(pushedRoutes.length == 1);
+        pushedRoutes.clear();
+
+        await tester.tap(find.descendant(
+          of: find.byType(StreamMessageRecipientHeader),
+          matching: find.text('topic name')));
+        await tester.pump();
+        check(pushedRoutes).isEmpty();
+      });
     });
 
     group('DmRecipientHeader', () {
@@ -992,6 +1040,46 @@ void main() {
       tester.widget(find.textContaining(RegExp("Dec 1[89], 2022")));
       tester.widget(find.textContaining(RegExp("Aug 2[23], 2022")));
     });
+
+    testWidgets('navigates to DmNarrow on tapping recipient header in CombinedFeedNarrow', (tester) async {
+      final pushedRoutes = <Route<void>>[];
+      final navObserver = TestNavigatorObserver()
+        ..onPushed = (route, prevRoute) => pushedRoutes.add(route);
+      final dmMessage = eg.dmMessage(from: eg.selfUser, to: [eg.otherUser]);
+      await setupMessageListPage(tester,
+        narrow: const CombinedFeedNarrow(),
+        messages: [dmMessage],
+        navObservers: [navObserver]);
+
+      assert(pushedRoutes.length == 1);
+      pushedRoutes.clear();
+
+      connection.prepare(json: eg.newestGetMessagesResult(
+        foundOldest: true, messages: [dmMessage]).toJson());
+      await tester.tap(find.byType(DmRecipientHeader));
+      await tester.pump();
+      check(pushedRoutes).single.isA<WidgetRoute>().page.isA<MessageListPage>()
+        .initNarrow.equals(DmNarrow.withUser(eg.otherUser.userId, selfUserId: eg.selfUser.userId));
+      await tester.pumpAndSettle();
+    });
+    
+    testWidgets('does not navigate on tapping recipient header in DmNarrow', (tester) async {
+      final pushedRoutes = <Route<void>>[];
+      final navObserver = TestNavigatorObserver()
+        ..onPushed = (route, prevRoute) => pushedRoutes.add(route);
+      final dmMessage = eg.dmMessage(from: eg.selfUser, to: [eg.otherUser]);
+      await setupMessageListPage(tester,
+        narrow: DmNarrow.withUser(eg.otherUser.userId, selfUserId: eg.selfUser.userId),
+        messages: [dmMessage],
+        navObservers: [navObserver]);
+
+      assert(pushedRoutes.length == 1);
+      pushedRoutes.clear();
+
+      await tester.tap(find.byType(DmRecipientHeader));
+      await tester.pump();
+      check(pushedRoutes).isEmpty();
+    });
   });
 
   group('formatHeaderDate', () {