pushnamed can handle Object as type (#113242)

packages/flutter/lib/src/widgets/navigator.dart

@@ -4073,7 +4073,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     return index < _history.length ? _history[index] : null;
   }
 
-  Route<T>? _routeNamed<T>(String name, { required Object? arguments, bool allowNull = false }) {
+  Route<T?>? _routeNamed<T>(String name, { required Object? arguments, bool allowNull = false }) {
     assert(!_debugLocked);
     assert(name != null);
     if (allowNull && widget.onGenerateRoute == null) {
@@ -4096,7 +4096,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
       name: name,
       arguments: arguments,
     );
-    Route<T>? route = widget.onGenerateRoute!(settings) as Route<T>?;
+    Route<T?>? route = widget.onGenerateRoute!(settings) as Route<T?>?;
     if (route == null && !allowNull) {
       assert(() {
         if (widget.onUnknownRoute == null) {
@@ -4111,7 +4111,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
         }
         return true;
       }());
-      route = widget.onUnknownRoute!(settings) as Route<T>?;
+      route = widget.onUnknownRoute!(settings) as Route<T?>?;
       assert(() {
         if (route == null) {
           throw FlutterError.fromParts(<DiagnosticsNode>[
@@ -4155,7 +4155,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     String routeName, {
     Object? arguments,
   }) {
-    return push<T>(_routeNamed<T>(routeName, arguments: arguments)!);
+    return push<T?>(_routeNamed<T>(routeName, arguments: arguments)!);
   }
 
   /// Push a named route onto the navigator.
@@ -4225,7 +4225,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     TO? result,
     Object? arguments,
   }) {
-    return pushReplacement<T, TO>(_routeNamed<T>(routeName, arguments: arguments)!, result: result);
+    return pushReplacement<T?, TO>(_routeNamed<T>(routeName, arguments: arguments)!, result: result);
   }
 
   /// Replace the current route of the navigator by pushing the route named
@@ -4362,7 +4362,7 @@ class NavigatorState extends State<Navigator> with TickerProviderStateMixin, Res
     RoutePredicate predicate, {
     Object? arguments,
   }) {
-    return pushAndRemoveUntil<T>(_routeNamed<T>(newRouteName, arguments: arguments)!, predicate);
+    return pushAndRemoveUntil<T?>(_routeNamed<T>(newRouteName, arguments: arguments)!, predicate);
   }
 
   /// Push the route with the given name onto the navigator, and then remove all

packages/flutter/test/widgets/navigator_test.dart

@@ -318,36 +318,56 @@ void main() {
     expect(log, equals(<String>['left']));
   });
 
-   testWidgets('Pending gestures are rejected', (WidgetTester tester) async {
-     final List<String> log = <String>[];
-     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
-       '/': (BuildContext context) {
-         return Row(
-           children: <Widget>[
-             GestureDetector(
-               onTap: () {
-                 log.add('left');
-                 Navigator.pushNamed(context, '/second');
-               },
-               child: const Text('left'),
-             ),
-             GestureDetector(
-               onTap: () { log.add('right'); },
-               child: const Text('right'),
-             ),
-           ],
-         );
-       },
-       '/second': (BuildContext context) => Container(),
-     };
-     await tester.pumpWidget(MaterialApp(routes: routes));
-     final TestGesture gesture = await tester.startGesture(tester.getCenter(find.text('right')), pointer: 23);
-     expect(log, isEmpty);
-     await tester.tap(find.text('left'), pointer: 1);
-     expect(log, equals(<String>['left']));
-     await gesture.up();
-     expect(log, equals(<String>['left']));
-   });
+  testWidgets('pushnamed can handle Object as type', (WidgetTester tester) async {
+    final GlobalKey<NavigatorState> nav = GlobalKey<NavigatorState>();
+    final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+      '/': (BuildContext context) => const Text('/'),
+      '/second': (BuildContext context) => const Text('/second'),
+    };
+    await tester.pumpWidget(MaterialApp(navigatorKey: nav, routes: routes));
+    expect(find.text('/'), findsOneWidget);
+    Error? error;
+    try {
+      nav.currentState!.pushNamed<Object>('/second');
+    } on Error catch(e) {
+      error = e;
+    }
+    expect(error, isNull);
+    await tester.pumpAndSettle();
+    expect(find.text('/'), findsNothing);
+    expect(find.text('/second'), findsOneWidget);
+  });
+
+  testWidgets('Pending gestures are rejected', (WidgetTester tester) async {
+    final List<String> log = <String>[];
+    final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+      '/': (BuildContext context) {
+        return Row(
+          children: <Widget>[
+            GestureDetector(
+              onTap: () {
+                log.add('left');
+                Navigator.pushNamed(context, '/second');
+              },
+              child: const Text('left'),
+            ),
+            GestureDetector(
+              onTap: () { log.add('right'); },
+              child: const Text('right'),
+            ),
+          ],
+        );
+      },
+      '/second': (BuildContext context) => Container(),
+    };
+    await tester.pumpWidget(MaterialApp(routes: routes));
+    final TestGesture gesture = await tester.startGesture(tester.getCenter(find.text('right')), pointer: 23);
+    expect(log, isEmpty);
+    await tester.tap(find.text('left'), pointer: 1);
+    expect(log, equals(<String>['left']));
+    await gesture.up();
+    expect(log, equals(<String>['left']));
+  });
 
   testWidgets('popAndPushNamed', (WidgetTester tester) async {
     final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{