fix: route user-tag taps to the group member screen for members (#686)

lib/screens/chat_screen.dart

@@ -547,6 +547,7 @@ class ChatScreen extends HookConsumerWidget {
                   : null,
               onHorizontalDragEnd: isSearchMode ? null : () => input.setReplyingTo(message),
               mentionDisplayName: resolveMentionDisplayName,
+              groupId: isGroupChat ? groupId : null,
               onRetry:
                   !isSearchMode && isOwnMessage && message.deliveryStatus is DeliveryStatus_Failed
                   ? () async {

lib/screens/group_member_screen.dart

@@ -12,6 +12,7 @@ import 'package:whitenoise/hooks/use_user_metadata.dart';
 import 'package:whitenoise/l10n/l10n.dart';
 import 'package:whitenoise/providers/account_pubkey_provider.dart';
 import 'package:whitenoise/routes.dart';
+import 'package:whitenoise/screens/start_chat_screen.dart';
 import 'package:whitenoise/theme.dart';
 import 'package:whitenoise/utils/avatar_color.dart';
 import 'package:whitenoise/utils/metadata.dart' show presentName;
@@ -87,6 +88,21 @@ class GroupMemberScreen extends HookConsumerWidget {
       return null;
     }, [membersState.error]);
 
+    final didRedirect = useRef(false);
+    useEffect(() {
+      if (didRedirect.value) return null;
+      if (membersState.isLoading || membersState.error != null) return null;
+      if (membersState.members.contains(memberPubkey)) return null;
+      didRedirect.value = true;
+      WidgetsBinding.instance.addPostFrameCallback((_) {
+        if (!context.mounted) return;
+        Routes.goBack(context);
+        if (!context.mounted) return;
+        StartChatScreen.show(context, userPubkey: memberPubkey);
+      });
+      return null;
+    }, [membersState.isLoading, membersState.members]);
+
     final isCurrentUserAdmin = membersState.admins.contains(accountPubkey);
     final isMemberAdmin = membersState.admins.contains(memberPubkey);
     final displayName = presentName(metadata) ?? memberPubkey.substring(0, 8);

lib/screens/start_chat_screen.dart

@@ -191,8 +191,8 @@ class StartChatScreen extends HookConsumerWidget {
         child: SafeArea(
           child: Column(
             children: [
-              const Spacer(),
               WnSlate(
+                shrinkWrapContent: true,
                 header: WnSlateNavigationHeader(
                   title: context.l10n.startNewChat,
                   onNavigate: () => Routes.goBack(context),

lib/widgets/chat_message_bubble.dart

@@ -3,6 +3,7 @@ import 'package:go_router/go_router.dart';
 import 'package:url_launcher/url_launcher.dart';
 import 'package:whitenoise/hooks/use_chat_messages.dart' show ChatMessageQuoteData;
 import 'package:whitenoise/l10n/l10n.dart';
+import 'package:whitenoise/routes.dart';
 import 'package:whitenoise/screens/start_chat_screen.dart';
 import 'package:whitenoise/src/rust/api/markdown.dart';
 import 'package:whitenoise/src/rust/api/messages.dart';
@@ -38,6 +39,7 @@ class ChatMessageBubble extends StatelessWidget {
   final VoidCallback? onHorizontalDragEnd;
   final VoidCallback? onRetry;
   final String? Function(String hexPubkey)? mentionDisplayName;
+  final String? groupId;
 
   const ChatMessageBubble({
     super.key,
@@ -60,6 +62,7 @@ class ChatMessageBubble extends StatelessWidget {
     this.onHorizontalDragEnd,
     this.onRetry,
     this.mentionDisplayName,
+    this.groupId,
   });
 
   ChatStatusType? get _deliveryStatusType {
@@ -162,7 +165,11 @@ class ChatMessageBubble extends StatelessWidget {
       onNostrTap: (hrp, bech32) async {
         if (hrp == MarkdownNostrHrp.npub) {
           final hex = hexFromNpub(bech32);
-          if (hex != null && context.mounted) {
+          if (hex == null || !context.mounted) return;
+          final gid = groupId;
+          if (gid != null) {
+            Routes.pushToGroupMember(context, gid, hex);
+          } else {
             await StartChatScreen.show(context, userPubkey: hex);
           }
           return;

test/screens/group_member_screen_test.dart

@@ -5,6 +5,8 @@ import 'package:flutter_riverpod/flutter_riverpod.dart' show AsyncData;
 import 'package:flutter_test/flutter_test.dart';
 import 'package:whitenoise/providers/auth_provider.dart';
 import 'package:whitenoise/routes.dart';
+import 'package:whitenoise/screens/group_member_screen.dart';
+import 'package:whitenoise/screens/start_chat_screen.dart';
 import 'package:whitenoise/src/rust/api/groups.dart';
 import 'package:whitenoise/src/rust/api/metadata.dart';
 import 'package:whitenoise/src/rust/frb_generated.dart';
@@ -726,5 +728,27 @@ void main() {
         expect(find.text('Add to group'), findsWidgets);
       });
     });
+
+    group('non-member redirect', () {
+      testWidgets('redirects to StartChatScreen when the user is not in the group', (
+        tester,
+      ) async {
+        _api.adminsList = [_testPubkey];
+        await pumpGroupMemberScreen(tester, memberPubkey: testPubkeyD);
+        await tester.pumpAndSettle();
+
+        expect(find.byType(GroupMemberScreen), findsNothing);
+        expect(find.byType(StartChatScreen), findsOneWidget);
+      });
+
+      testWidgets('does not redirect when the user is a member', (tester) async {
+        _api.adminsList = [_testPubkey];
+        await pumpGroupMemberScreen(tester, memberPubkey: _memberPubkey);
+        await tester.pumpAndSettle();
+
+        expect(find.byType(GroupMemberScreen), findsOneWidget);
+        expect(find.byType(StartChatScreen), findsNothing);
+      });
+    });
   });
 }

test/widgets/chat_message_bubble_test.dart

@@ -919,6 +919,42 @@ void main() {
         );
       });
 
+      testWidgets('npub mention in a group navigates to the group member screen', (tester) async {
+        await _mountBubbleWithRouter(
+          tester,
+          ChatMessageBubble(
+            message: withDoc(
+              const MarkdownDocument(
+                blocks: [
+                  MarkdownBlock.paragraph(
+                    inlines: [
+                      MarkdownInline.nostrMention(
+                        entity: MarkdownNostrEntity(
+                          hrp: MarkdownNostrHrp.npub,
+                          bech32: testNpubA,
+                        ),
+                      ),
+                    ],
+                  ),
+                ],
+              ),
+            ),
+            isOwnMessage: false,
+            groupId: testGroupId,
+          ),
+        );
+        final span = tester.widget<RichText>(find.byType(RichText).first).text as TextSpan;
+        final entity = _firstTextSpanWithRecognizer(span);
+        (entity.recognizer as TapGestureRecognizer).onTap!();
+        await tester.pumpAndSettle();
+        expect(launcher.calls, isEmpty);
+        expect(find.byType(StartChatScreen), findsNothing);
+        expect(
+          find.byKey(const ValueKey('group_member_route_${testGroupId}_$testPubkeyA')),
+          findsOneWidget,
+        );
+      });
+
       testWidgets('whitenoise://chat/<id> tap navigates via GoRouter', (tester) async {
         await _mountBubbleWithRouter(
           tester,
@@ -1075,6 +1111,16 @@ Future<void> _mountBubbleWithRouter(WidgetTester tester, Widget bubble) async {
           body: const SizedBox(),
         ),
       ),
+      GoRoute(
+        name: 'groupMember',
+        path: '/group-member/:groupId/:memberPubkey',
+        builder: (_, state) => Scaffold(
+          key: ValueKey(
+            'group_member_route_${state.pathParameters['groupId']}_${state.pathParameters['memberPubkey']}',
+          ),
+          body: const SizedBox(),
+        ),
+      ),
     ],
   );
   await tester.pumpWidget(