[go_router] Fixes issue that path parameters are not set when using t… (flutter#6698)

�he goBranch.

fixes flutter#129878

Author: chunhtai

packages/go_router/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 14.1.2
+
+- Fixes issue that path parameters are not set when using the `goBranch`.
+
 ## 14.1.1
 
 - Fixes correctness of the state provided in the `onExit`.

packages/go_router/lib/src/route.dart

@@ -1134,7 +1134,12 @@ class StatefulNavigationShell extends StatefulWidget {
       /// Recursively traverses the routes of the provided StackedShellBranch to
       /// find the first GoRoute, from which a full path will be derived.
       final GoRoute route = branch.defaultRoute!;
-      return _router.configuration.locationForRoute(route)!;
+      final List<String> parameters = <String>[];
+      patternToRegExp(route.path, parameters);
+      assert(parameters.isEmpty);
+      final String fullPath = _router.configuration.locationForRoute(route)!;
+      return patternToPath(
+          fullPath, shellRouteContext.routerState.pathParameters);
     }
   }
 

packages/go_router/pubspec.yaml

@@ -1,7 +1,7 @@
 name: go_router
 description: A declarative router for Flutter based on Navigation 2 supporting
   deep linking, data-driven routes and more
-version: 14.1.1
+version: 14.1.2
 repository: https://github.com/flutter/packages/tree/main/packages/go_router
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router%22
 

packages/go_router/test/go_router_test.dart

@@ -3956,6 +3956,50 @@ void main() {
       expect(statefulWidgetKey.currentState?.counter, equals(0));
     });
 
+    testWidgets(
+        'Navigates to correct nested navigation tree in StatefulShellRoute '
+        'and maintains path parameters', (WidgetTester tester) async {
+      StatefulNavigationShell? routeState;
+
+      final List<RouteBase> routes = <RouteBase>[
+        GoRoute(
+            path: '/:id',
+            builder: (_, __) => const Placeholder(),
+            routes: <RouteBase>[
+              StatefulShellRoute.indexedStack(
+                builder: (BuildContext context, GoRouterState state,
+                    StatefulNavigationShell navigationShell) {
+                  routeState = navigationShell;
+                  return navigationShell;
+                },
+                branches: <StatefulShellBranch>[
+                  StatefulShellBranch(routes: <GoRoute>[
+                    GoRoute(
+                      path: 'a',
+                      builder: (BuildContext context, GoRouterState state) =>
+                          Text('a id is ${state.pathParameters['id']}'),
+                    ),
+                  ]),
+                  StatefulShellBranch(routes: <GoRoute>[
+                    GoRoute(
+                      path: 'b',
+                      builder: (BuildContext context, GoRouterState state) =>
+                          Text('b id is ${state.pathParameters['id']}'),
+                    ),
+                  ]),
+                ],
+              ),
+            ])
+      ];
+
+      await createRouter(routes, tester, initialLocation: '/123/a');
+      expect(find.text('a id is 123'), findsOneWidget);
+
+      routeState!.goBranch(1);
+      await tester.pumpAndSettle();
+      expect(find.text('b id is 123'), findsOneWidget);
+    });
+
     testWidgets('Maintains state for nested StatefulShellRoute',
         (WidgetTester tester) async {
       final GlobalKey<NavigatorState> rootNavigatorKey =