_RouterState should dispose created _RestorableRouteInformation. (#136556)

### Description
- Fixes https://github.com/flutter/flutter/issues/134205.

### Tests
- Removes ignoring the `_RestorableRouteInformation` leak from `cupertino/app_test.dart`;
- Removes ignoring the `_RestorableRouteInformation` leak from `material/app_test.dart`;
- Removes ignoring the `_RestorableRouteInformation` leak from `widgets/app_test.dart`;
- Removes ignoring the `_RestorableRouteInformation` leak from `widgets/route_notification_messages_test.dart`;
- Removes ignoring the `_RestorableRouteInformation` leak from `widgets/router_restoration_test.dart`;
- Updates `widgets/router_test.dart` to use `testWidgetsWithLeakTracking`.

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

@@ -632,6 +632,10 @@ class _RouterState<T> extends State<Router<T>> with RestorationMixin {
   }
 
   void _reportRouteInformation(Duration timestamp) {
+    if (!mounted) {
+      return;
+    }
+
     assert(_routeInformationReportingTaskScheduled);
     _routeInformationReportingTaskScheduled = false;
 
@@ -726,6 +730,7 @@ class _RouterState<T> extends State<Router<T>> with RestorationMixin {
 
   @override
   void dispose() {
+    _routeInformation.dispose();
     widget.routeInformationProvider?.removeListener(_handleRouteInformationProviderNotification);
     widget.backButtonDispatcher?.removeCallback(_handleBackButtonDispatcherNotification);
     widget.routerDelegate.removeListener(_handleRouterDelegateNotification);

packages/flutter/test/cupertino/app_test.dart

@@ -178,12 +178,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  // TODO(polina-c): remove after fixing
-  // https://github.com/flutter/flutter/issues/134205
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    allowAllNotDisposed: true,
-  ));
+  });
 
   testWidgetsWithLeakTracking('CupertinoApp.router route information parser is optional', (WidgetTester tester) async {
     final SimpleNavigatorRouterDelegate delegate = SimpleNavigatorRouterDelegate(
@@ -209,12 +204,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  // TODO(polina-c): remove after fixing
-  // https://github.com/flutter/flutter/issues/134205
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    allowAllNotDisposed: true,
-  ));
+  });
 
   testWidgetsWithLeakTracking('CupertinoApp.router throw if route information provider is provided but no route information parser', (WidgetTester tester) async {
     final SimpleNavigatorRouterDelegate delegate = SimpleNavigatorRouterDelegate(
@@ -300,12 +290,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  // TODO(polina-c): remove after fixing
-  // https://github.com/flutter/flutter/issues/134205
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    allowAllNotDisposed: true,
-  ));
+  });
 
   testWidgetsWithLeakTracking('CupertinoApp has correct default ScrollBehavior', (WidgetTester tester) async {
     late BuildContext capturedContext;

packages/flutter/test/material/app_test.dart

@@ -1114,12 +1114,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  // TODO(polina-c): remove after fixing
-  // https://github.com/flutter/flutter/issues/134205
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    allowAllNotDisposed: true,
-  ));
+  });
 
   testWidgetsWithLeakTracking('MaterialApp.router route information parser is optional', (WidgetTester tester) async {
     final SimpleNavigatorRouterDelegate delegate = SimpleNavigatorRouterDelegate(
@@ -1145,12 +1140,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  // TODO(polina-c): remove after fixing
-  // https://github.com/flutter/flutter/issues/134205
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    allowAllNotDisposed: true,
-  ));
+  });
 
   testWidgetsWithLeakTracking('MaterialApp.router throw if route information provider is provided but no route information parser', (WidgetTester tester) async {
     final SimpleNavigatorRouterDelegate delegate = SimpleNavigatorRouterDelegate(
@@ -1236,12 +1226,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  // TODO(polina-c): remove after fixing
-  // https://github.com/flutter/flutter/issues/134205
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    allowAllNotDisposed: true,
-  ));
+  });
 
   testWidgetsWithLeakTracking('MaterialApp.builder can build app without a Navigator', (WidgetTester tester) async {
     Widget? builderChild;

packages/flutter/test/widgets/app_test.dart

@@ -304,12 +304,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    // TODO(ksokolovskyi): remove after fixing
-    // https://github.com/flutter/flutter/issues/134205
-    notDisposedAllowList: <String, int?> {'_RestorableRouteInformation': 1},
-  ));
+  });
 
   testWidgetsWithLeakTracking('WidgetsApp.router route information parser is optional', (WidgetTester tester) async {
     final SimpleNavigatorRouterDelegate delegate = SimpleNavigatorRouterDelegate(
@@ -336,12 +331,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    // TODO(ksokolovskyi): remove after fixing
-    // https://github.com/flutter/flutter/issues/134205
-    notDisposedAllowList: <String, int?> {'_RestorableRouteInformation': 1},
-  ));
+  });
 
   testWidgetsWithLeakTracking('WidgetsApp.router throw if route information provider is provided but no route information parser', (WidgetTester tester) async {
     final SimpleNavigatorRouterDelegate delegate = SimpleNavigatorRouterDelegate(
@@ -432,12 +422,7 @@ void main() {
     await tester.binding.defaultBinaryMessenger.handlePlatformMessage('flutter/navigation', message, (_) { });
     await tester.pumpAndSettle();
     expect(find.text('popped'), findsOneWidget);
-  },
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    // TODO(ksokolovskyi): remove after fixing
-    // https://github.com/flutter/flutter/issues/134205
-    notDisposedAllowList: <String, int?> {'_RestorableRouteInformation': 1},
-  ));
+  });
 
   testWidgetsWithLeakTracking('WidgetsApp.router has correct default', (WidgetTester tester) async {
     final SimpleNavigatorRouterDelegate delegate = SimpleNavigatorRouterDelegate(
@@ -453,12 +438,7 @@ void main() {
       color: const Color(0xFF123456),
     ));
     expect(find.text('/'), findsOneWidget);
-  },
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    // TODO(ksokolovskyi): remove after fixing
-    // https://github.com/flutter/flutter/issues/134205
-    notDisposedAllowList: <String, int?> {'_RestorableRouteInformation': 1},
-  ));
+  });
 
   testWidgetsWithLeakTracking('WidgetsApp has correct default ScrollBehavior', (WidgetTester tester) async {
     late BuildContext capturedContext;

packages/flutter/test/widgets/route_notification_messages_test.dart

@@ -316,12 +316,7 @@ void main() {
         'replace': false,
       }),
     ]);
-  },
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    // TODO(ksokolovskyi): remove after fixing
-    // https://github.com/flutter/flutter/issues/134205
-    notDisposedAllowList: <String, int?> {'_RestorableRouteInformation': 1},
-  ));
+  });
 }
 
 typedef SimpleRouterDelegateBuilder = Widget Function(BuildContext, RouteInformation);

packages/flutter/test/widgets/router_restoration_test.dart

@@ -40,12 +40,7 @@ void main() {
     expect(find.text('Current config: /foo'), findsOneWidget);
     expect(delegate().newRoutePaths, isEmpty);
     expect(delegate().restoredRoutePaths, <String>['/foo', '/foo']);
-  },
-  leakTrackingTestConfig: const LeakTrackingTestConfig(
-    // TODO(ksokolovskyi): remove after fixing
-    // https://github.com/flutter/flutter/issues/134205
-    notDisposedAllowList: <String, int?> {'_RestorableRouteInformation': 2},
-  ));
+  });
 
   testWidgets('Router state restoration with RouteInformationProvider', (WidgetTester tester) async {
     final UniqueKey router = UniqueKey();

packages/flutter/test/widgets/router_test.dart

@@ -11,20 +11,24 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:leak_tracker_flutter_testing/leak_tracker_flutter_testing.dart';
 
 void main() {
-  testWidgets('Simple router basic functionality - synchronized', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Simple router basic functionality - synchronized', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
+      builder: (BuildContext context, RouteInformation? information) {
+        return Text(Uri.decodeComponent(information!.uri.toString()));
+      },
+    );
+    addTearDown(delegate.dispose);
+
     await tester.pumpWidget(buildBoilerPlate(
       Router<RouteInformation>(
         routeInformationProvider: provider,
         routeInformationParser: SimpleRouteInformationParser(),
-        routerDelegate: SimpleRouterDelegate(
-          builder: (BuildContext context, RouteInformation? information) {
-            return Text(Uri.decodeComponent(information!.uri.toString()));
-          },
-        ),
+        routerDelegate: delegate,
       ),
     ));
     expect(find.text('initial'), findsOneWidget);
@@ -37,8 +41,9 @@ void main() {
     expect(find.text('update'), findsOneWidget);
   });
 
-  testWidgets('Simple router basic functionality - asynchronized', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Simple router basic functionality - asynchronized', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
@@ -51,6 +56,8 @@ void main() {
         return Text(information.uri.toString());
       },
     );
+    addTearDown(delegate.dispose);
+
     await tester.runAsync(() async {
       await tester.pumpWidget(buildBoilerPlate(
         Router<RouteInformation>(
@@ -81,8 +88,9 @@ void main() {
     });
   });
 
-  testWidgets('Interrupts route parsing should not crash', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Interrupts route parsing should not crash', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
@@ -95,6 +103,8 @@ void main() {
         return Text(information.uri.toString());
       },
     );
+    addTearDown(delegate.dispose);
+
     await tester.runAsync(() async {
       await tester.pumpWidget(buildBoilerPlate(
         Router<RouteInformation>(
@@ -130,7 +140,7 @@ void main() {
     });
   });
 
-  testWidgets('Router.maybeOf can be null', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Router.maybeOf can be null', (WidgetTester tester) async {
     final GlobalKey key = GlobalKey();
     await tester.pumpWidget(buildBoilerPlate(
       Text('dummy', key: key),
@@ -147,18 +157,14 @@ void main() {
     );
   });
 
-  testWidgets('Simple router can handle pop route', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Simple router can handle pop route', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final BackButtonDispatcher dispatcher = RootBackButtonDispatcher();
-
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        routeInformationProvider: provider,
-        routeInformationParser: SimpleRouteInformationParser(),
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         return Text(Uri.decodeComponent(information!.uri.toString()));
       },
@@ -168,7 +174,14 @@ void main() {
         );
         return SynchronousFuture<bool>(true);
       },
-        ),
+    );
+    addTearDown(delegate.dispose);
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        routeInformationProvider: provider,
+        routeInformationParser: SimpleRouteInformationParser(),
+        routerDelegate: delegate,
         backButtonDispatcher: dispatcher,
       ),
     ));
@@ -186,20 +199,24 @@ void main() {
     expect(find.text('popped'), findsOneWidget);
   });
 
-  testWidgets('Router throw when passing routeInformationProvider without routeInformationParser', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Router throw when passing routeInformationProvider without routeInformationParser', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
+      builder: (BuildContext context, RouteInformation? information) {
+        return Text(Uri.decodeComponent(information!.uri.toString()));
+      },
+    );
+    addTearDown(delegate.dispose);
+
     expect(
       () {
         Router<RouteInformation>(
           routeInformationProvider: provider,
-          routerDelegate: SimpleRouterDelegate(
-            builder: (BuildContext context, RouteInformation? information) {
-              return Text(Uri.decodeComponent(information!.uri.toString()));
-            },
-          ),
+          routerDelegate: delegate,
         );
       },
       throwsA(isAssertionError.having(
@@ -210,8 +227,9 @@ void main() {
     );
   });
 
-  testWidgets('PopNavigatorRouterDelegateMixin works', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('PopNavigatorRouterDelegateMixin works', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
@@ -227,6 +245,8 @@ void main() {
         return route.didPop(result);
       },
     );
+    addTearDown(delegate.dispose);
+
     await tester.pumpWidget(buildBoilerPlate(
       Router<RouteInformation>(
         routeInformationProvider: provider,
@@ -263,25 +283,18 @@ void main() {
     expect(find.text('popped'), findsOneWidget);
   });
 
-  testWidgets('Nested routers back button dispatcher works', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Nested routers back button dispatcher works', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        backButtonDispatcher: outerDispatcher,
-        routeInformationProvider: provider,
-        routeInformationParser: SimpleRouteInformationParser(),
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate outerDelegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         final BackButtonDispatcher innerDispatcher = ChildBackButtonDispatcher(outerDispatcher);
         innerDispatcher.takePriority();
-            // Creates the sub-router.
-            return Router<RouteInformation>(
-              backButtonDispatcher: innerDispatcher,
-              routerDelegate: SimpleRouterDelegate(
+        final SimpleRouterDelegate innerDelegate = SimpleRouterDelegate(
           builder: (BuildContext context, RouteInformation? innerInformation) {
             return Text(Uri.decodeComponent(information!.uri.toString()));
           },
@@ -291,7 +304,12 @@ void main() {
             );
             return SynchronousFuture<bool>(true);
           },
-              ),
+        );
+        addTearDown(innerDelegate.dispose);
+        // Creates the sub-router.
+        return Router<RouteInformation>(
+          backButtonDispatcher: innerDispatcher,
+          routerDelegate: innerDelegate,
         );
       },
       onPopRoute: () {
@@ -300,7 +318,15 @@ void main() {
         );
         return SynchronousFuture<bool>(true);
       },
-        ),
+    );
+    addTearDown(outerDelegate.dispose);
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        backButtonDispatcher: outerDispatcher,
+        routeInformationProvider: provider,
+        routeInformationParser: SimpleRouteInformationParser(),
+        routerDelegate: outerDelegate,
       ),
     ));
     expect(find.text('initial'), findsOneWidget);
@@ -313,28 +339,29 @@ void main() {
     expect(find.text('popped inner'), findsOneWidget);
   });
 
-  testWidgets('Nested router back button dispatcher works for multiple children', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Nested router back button dispatcher works for multiple children', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
     final BackButtonDispatcher innerDispatcher1 = ChildBackButtonDispatcher(outerDispatcher);
     final BackButtonDispatcher innerDispatcher2 = ChildBackButtonDispatcher(outerDispatcher);
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        backButtonDispatcher: outerDispatcher,
-        routeInformationProvider: provider,
-        routeInformationParser: SimpleRouteInformationParser(),
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate outerDelegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
+        late final SimpleRouterDelegate innerDelegate1;
+        addTearDown(() => innerDelegate1.dispose());
+        late final SimpleRouterDelegate innerDelegate2;
+        addTearDown(() => innerDelegate2.dispose());
+
         // Creates the sub-router.
         return Column(
           children: <Widget>[
             Text(Uri.decodeComponent(information!.uri.toString())),
             Router<RouteInformation>(
               backButtonDispatcher: innerDispatcher1,
-                  routerDelegate: SimpleRouterDelegate(
+              routerDelegate: innerDelegate1 = SimpleRouterDelegate(
                 builder: (BuildContext context, RouteInformation? innerInformation) {
                   return Container();
                 },
@@ -348,7 +375,7 @@ void main() {
             ),
             Router<RouteInformation>(
               backButtonDispatcher: innerDispatcher2,
-                  routerDelegate: SimpleRouterDelegate(
+              routerDelegate: innerDelegate2 = SimpleRouterDelegate(
                 builder: (BuildContext context, RouteInformation? innerInformation) {
                   return Container();
                 },
@@ -369,7 +396,15 @@ void main() {
         );
         return SynchronousFuture<bool>(true);
       },
-        ),
+    );
+    addTearDown(outerDelegate.dispose);
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        backButtonDispatcher: outerDispatcher,
+        routeInformationProvider: provider,
+        routeInformationParser: SimpleRouteInformationParser(),
+        routerDelegate: outerDelegate,
       ),
     ));
     expect(find.text('initial'), findsOneWidget);
@@ -398,88 +433,107 @@ void main() {
     expect(find.text('popped inner2'), findsOneWidget);
   });
 
-  testWidgets('ChildBackButtonDispatcher can be replaced without calling the takePriority', (WidgetTester tester) async {
-
+  testWidgetsWithLeakTracking('ChildBackButtonDispatcher can be replaced without calling the takePriority', (WidgetTester tester) async {
     final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
     BackButtonDispatcher innerDispatcher = ChildBackButtonDispatcher(outerDispatcher);
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        backButtonDispatcher: outerDispatcher,
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate outerDelegate1 = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
+        final SimpleRouterDelegate innerDelegate1 = SimpleRouterDelegate(
+          builder: (BuildContext context, RouteInformation? innerInformation) {
+            return Container();
+          },
+        );
+        addTearDown(innerDelegate1.dispose);
+
         // Creates the sub-router.
         return Column(
           children: <Widget>[
             const Text('initial'),
             Router<RouteInformation>(
               backButtonDispatcher: innerDispatcher,
-                  routerDelegate: SimpleRouterDelegate(
-                    builder: (BuildContext context, RouteInformation? innerInformation) {
-                      return Container();
-                    },
-                  ),
+              routerDelegate: innerDelegate1,
             ),
           ],
         );
       },
-        ),
+    );
+    addTearDown(outerDelegate1.dispose);
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        backButtonDispatcher: outerDispatcher,
+        routerDelegate: outerDelegate1,
       ),
     ));
 
     // Creates a new child back button dispatcher and rebuild, this will cause
     // the old one to be replaced and discarded.
     innerDispatcher = ChildBackButtonDispatcher(outerDispatcher);
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        backButtonDispatcher: outerDispatcher,
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate outerDelegate2 = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
+        final SimpleRouterDelegate innerDelegate2 = SimpleRouterDelegate(
+          builder: (BuildContext context, RouteInformation? innerInformation) {
+            return Container();
+          },
+        );
+        addTearDown(innerDelegate2.dispose);
+
         // Creates the sub-router.
         return Column(
           children: <Widget>[
             const Text('initial'),
             Router<RouteInformation>(
               backButtonDispatcher: innerDispatcher,
-                  routerDelegate: SimpleRouterDelegate(
-                    builder: (BuildContext context, RouteInformation? innerInformation) {
-                      return Container();
-                    },
-                  ),
+              routerDelegate: innerDelegate2,
             ),
           ],
         );
       },
-        ),
+    );
+    addTearDown(outerDelegate2.dispose);
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        backButtonDispatcher: outerDispatcher,
+        routerDelegate: outerDelegate2,
       ),
     ));
 
     expect(tester.takeException(), isNull);
   });
 
-testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester tester) async {
-
+testWidgetsWithLeakTracking('ChildBackButtonDispatcher take priority recursively', (WidgetTester tester) async {
     final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
     final BackButtonDispatcher innerDispatcher1 = ChildBackButtonDispatcher(outerDispatcher);
     final BackButtonDispatcher innerDispatcher2 = ChildBackButtonDispatcher(innerDispatcher1);
     final BackButtonDispatcher innerDispatcher3 = ChildBackButtonDispatcher(innerDispatcher2);
+    late final SimpleRouterDelegate outerDelegate;
+    addTearDown(() => outerDelegate.dispose());
+    late final SimpleRouterDelegate innerDelegate1;
+    addTearDown(() => innerDelegate1.dispose());
+    late final SimpleRouterDelegate innerDelegate2;
+    addTearDown(() => innerDelegate2.dispose());
+    late final SimpleRouterDelegate innerDelegate3;
+    addTearDown(() => innerDelegate3.dispose());
     bool isPopped = false;
+
     await tester.pumpWidget(buildBoilerPlate(
       Router<RouteInformation>(
         backButtonDispatcher: outerDispatcher,
-        routerDelegate: SimpleRouterDelegate(
+        routerDelegate: outerDelegate = SimpleRouterDelegate(
           builder: (BuildContext context, RouteInformation? information) {
             // Creates the sub-router.
             return Router<RouteInformation>(
               backButtonDispatcher: innerDispatcher1,
-              routerDelegate: SimpleRouterDelegate(
+              routerDelegate: innerDelegate1 = SimpleRouterDelegate(
                 builder: (BuildContext context, RouteInformation? innerInformation) {
                   return Router<RouteInformation>(
                     backButtonDispatcher: innerDispatcher2,
-                    routerDelegate: SimpleRouterDelegate(
+                    routerDelegate: innerDelegate2 = SimpleRouterDelegate(
                       builder: (BuildContext context, RouteInformation? innerInformation) {
                         return Router<RouteInformation>(
                           backButtonDispatcher: innerDispatcher3,
-                          routerDelegate: SimpleRouterDelegate(
+                          routerDelegate: innerDelegate3 = SimpleRouterDelegate(
                             onPopRoute: () {
                               isPopped = true;
                               return SynchronousFuture<bool>(true);
@@ -508,7 +562,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(isPopped, isTrue);
   });
 
-  testWidgets('router does report URL change correctly', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('router does report URL change correctly', (WidgetTester tester) async {
     RouteInformation? reportedRouteInformation;
     RouteInformationReportingType? reportedType;
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider(
@@ -520,6 +574,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         reportedType = type;
       },
     );
+    addTearDown(provider.dispose);
     final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       reportConfiguration: true,
       builder: (BuildContext context, RouteInformation? information) {
@@ -532,6 +587,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
       );
       return SynchronousFuture<bool>(true);
     };
+    addTearDown(delegate.dispose);
     final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
 
     provider.value = RouteInformation(
@@ -584,7 +640,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(reportedType, RouteInformationReportingType.none);
   });
 
-  testWidgets('router can be forced to recognize or ignore navigating events', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('router can be forced to recognize or ignore navigating events', (WidgetTester tester) async {
     RouteInformation? reportedRouteInformation;
     RouteInformationReportingType? reportedType;
     bool isNavigating = false;
@@ -598,10 +654,12 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         reportedType = type;
       },
     );
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final SimpleRouterDelegate delegate = SimpleRouterDelegate(reportConfiguration: true);
+    addTearDown(delegate.dispose);
     delegate.builder = (BuildContext context, RouteInformation? information) {
       return ElevatedButton(
         child: Text(Uri.decodeComponent(information!.uri.toString())),
@@ -662,7 +720,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     reportedRouteInformation = null;
   });
 
-  testWidgets('router ignore navigating events updates RouteInformationProvider', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('router ignore navigating events updates RouteInformationProvider', (WidgetTester tester) async {
     RouteInformation? updatedRouteInformation;
     late RouteInformation nextRouteInformation;
     RouteInformationReportingType? reportingType;
@@ -674,10 +732,12 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         reportingType = type;
       },
     );
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final SimpleRouterDelegate delegate = SimpleRouterDelegate(reportConfiguration: true);
+    addTearDown(delegate.dispose);
     delegate.builder = (BuildContext context, RouteInformation? information) {
       return ElevatedButton(
         child: Text(Uri.decodeComponent(information!.uri.toString())),
@@ -717,7 +777,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(reportingType, RouteInformationReportingType.neglect);
   });
 
-  testWidgets('state change without location changes updates RouteInformationProvider', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('state change without location changes updates RouteInformationProvider', (WidgetTester tester) async {
     RouteInformation? updatedRouteInformation;
     late RouteInformation nextRouteInformation;
     RouteInformationReportingType? reportingType;
@@ -730,11 +790,13 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         reportingType = type;
       },
     );
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
       state: 'state1',
     );
     final SimpleRouterDelegate delegate = SimpleRouterDelegate(reportConfiguration: true);
+    addTearDown(delegate.dispose);
     delegate.builder = (BuildContext context, RouteInformation? information) {
       return ElevatedButton(
         child: Text(Uri.decodeComponent(information!.uri.toString())),
@@ -770,12 +832,13 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(reportingType, RouteInformationReportingType.none);
   });
 
-  testWidgets('PlatformRouteInformationProvider works', (WidgetTester tester) async {
-    final RouteInformationProvider provider = PlatformRouteInformationProvider(
+  testWidgetsWithLeakTracking('PlatformRouteInformationProvider works', (WidgetTester tester) async {
+    final PlatformRouteInformationProvider provider = PlatformRouteInformationProvider(
       initialRouteInformation: RouteInformation(
         uri: Uri.parse('initial'),
       ),
     );
+    addTearDown(provider.dispose);
     final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         final List<Widget> children = <Widget>[];
@@ -790,6 +853,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
       },
     );
+    addTearDown(delegate.dispose);
 
     await tester.pumpWidget(MaterialApp.router(
         routeInformationProvider: provider,
@@ -821,7 +885,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('newTestRouteName'), findsOneWidget);
   });
 
-  testWidgets('PlatformRouteInformationProvider updates route information', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('PlatformRouteInformationProvider updates route information', (WidgetTester tester) async {
     final List<MethodCall> log = <MethodCall>[];
     TestDefaultBinaryMessengerBinding
       .instance.defaultBinaryMessenger
@@ -832,11 +896,12 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
 	  return null;
         }
       );
-    final RouteInformationProvider provider = PlatformRouteInformationProvider(
+    final PlatformRouteInformationProvider provider = PlatformRouteInformationProvider(
       initialRouteInformation: RouteInformation(
         uri: Uri.parse('initial'),
       ),
     );
+    addTearDown(provider.dispose);
 
     log.clear();
     provider.routerReportsNewRouteInformation(RouteInformation(uri: Uri.parse('a'), state: true));
@@ -868,7 +933,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     ]);
   });
 
-  testWidgets('PlatformRouteInformationProvider does not push new entry if query parameters are semantically the same', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('PlatformRouteInformationProvider does not push new entry if query parameters are semantically the same', (WidgetTester tester) async {
     final List<MethodCall> log = <MethodCall>[];
     TestDefaultBinaryMessengerBinding
         .instance.defaultBinaryMessenger
@@ -882,9 +947,10 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     final RouteInformation initial = RouteInformation(
       uri: Uri.parse('initial?a=ws/abcd'),
     );
-    final RouteInformationProvider provider = PlatformRouteInformationProvider(
+    final PlatformRouteInformationProvider provider = PlatformRouteInformationProvider(
       initialRouteInformation: initial
     );
+    addTearDown(provider.dispose);
     // Make sure engine is updated with initial route
     provider.routerReportsNewRouteInformation(initial);
     log.clear();
@@ -938,19 +1004,21 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     log.clear();
   });
 
-  testWidgets('RootBackButtonDispatcher works', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('RootBackButtonDispatcher works', (WidgetTester tester) async {
     final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
-    final RouteInformationProvider provider = PlatformRouteInformationProvider(
+    final PlatformRouteInformationProvider provider = PlatformRouteInformationProvider(
       initialRouteInformation: RouteInformation(
         uri: Uri.parse('initial'),
       ),
     );
+    addTearDown(provider.dispose);
     final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       reportConfiguration: true,
       builder: (BuildContext context, RouteInformation? information) {
         return Text(Uri.decodeComponent(information!.uri.toString()));
       },
     );
+    addTearDown(delegate.dispose);
     delegate.onPopRoute = () {
       delegate.routeInformation = RouteInformation(
         uri: Uri.parse('popped'),
@@ -973,18 +1041,14 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('popped'), findsOneWidget);
   });
 
-  testWidgets('BackButtonListener takes priority over root back dispatcher', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('BackButtonListener takes priority over root back dispatcher', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        backButtonDispatcher: outerDispatcher,
-        routeInformationProvider: provider,
-        routeInformationParser: SimpleRouteInformationParser(),
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         // Creates the sub-router.
         return Column(
@@ -1008,7 +1072,15 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
         return SynchronousFuture<bool>(true);
       },
-        ),
+    );
+    addTearDown(delegate.dispose);
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        backButtonDispatcher: outerDispatcher,
+        routeInformationProvider: provider,
+        routeInformationParser: SimpleRouteInformationParser(),
+        routerDelegate: delegate,
       ),
     ));
     expect(find.text('initial'), findsOneWidget);
@@ -1020,8 +1092,9 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('popped inner1'), findsOneWidget);
   });
 
-  testWidgets('BackButtonListener updates callback if it has been changed', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('BackButtonListener updates callback if it has been changed', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
@@ -1050,6 +1123,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
             );
             return SynchronousFuture<bool>(true);
           };
+    addTearDown(routerDelegate.dispose);
 
     await tester.pumpWidget(buildBoilerPlate(
       Router<RouteInformation>(
@@ -1099,8 +1173,9 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('second callback'), findsOneWidget);
   });
 
-  testWidgets('BackButtonListener clears callback if it is disposed', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('BackButtonListener clears callback if it is disposed', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
@@ -1129,6 +1204,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
             );
             return SynchronousFuture<bool>(true);
           };
+    addTearDown(routerDelegate.dispose);
 
     await tester.pumpWidget(buildBoilerPlate(
       Router<RouteInformation>(
@@ -1169,18 +1245,13 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('popped outer'), findsOneWidget);
   });
 
-  testWidgets('Nested backButtonListener should take priority', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Nested backButtonListener should take priority', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
-    final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        backButtonDispatcher: outerDispatcher,
-        routeInformationProvider: provider,
-        routeInformationParser: SimpleRouteInformationParser(),
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         // Creates the sub-router.
         return Column(
@@ -1212,7 +1283,16 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
         return SynchronousFuture<bool>(true);
       },
-        ),
+    );
+    addTearDown(delegate.dispose);
+    final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        backButtonDispatcher: outerDispatcher,
+        routeInformationProvider: provider,
+        routeInformationParser: SimpleRouteInformationParser(),
+        routerDelegate: delegate,
       ),
     ));
     expect(find.text('initial'), findsOneWidget);
@@ -1224,18 +1304,13 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('popped inner2'), findsOneWidget);
   });
 
-  testWidgets('Nested backButtonListener that returns false should call next on the line', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Nested backButtonListener that returns false should call next on the line', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
-    final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
-    await tester.pumpWidget(buildBoilerPlate(
-      Router<RouteInformation>(
-        backButtonDispatcher: outerDispatcher,
-        routeInformationProvider: provider,
-        routeInformationParser: SimpleRouteInformationParser(),
-        routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         // Creates the sub-router.
         return Column(
@@ -1267,7 +1342,16 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
         return SynchronousFuture<bool>(true);
       },
-        ),
+    );
+    addTearDown(delegate.dispose);
+    final BackButtonDispatcher outerDispatcher = RootBackButtonDispatcher();
+
+    await tester.pumpWidget(buildBoilerPlate(
+      Router<RouteInformation>(
+        backButtonDispatcher: outerDispatcher,
+        routeInformationProvider: provider,
+        routeInformationParser: SimpleRouteInformationParser(),
+        routerDelegate: delegate,
       ),
     ));
     expect(find.text('initial'), findsOneWidget);
@@ -1279,8 +1363,9 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('popped inner1'), findsOneWidget);
   });
 
-  testWidgets('`didUpdateWidget` test', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('`didUpdateWidget` test', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
@@ -1316,6 +1401,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
         return SynchronousFuture<bool>(true);
       };
+    addTearDown(routerDelegate.dispose);
 
     await tester.pumpWidget(buildBoilerPlate(
       Router<RouteInformation>(
@@ -1337,11 +1423,17 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(find.text('second callback'), findsOneWidget);
   });
 
-  testWidgets('Router reports location if it is different from location given by OS', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Router reports location if it is different from location given by OS', (WidgetTester tester) async {
     final List<RouteInformation> reportedRouteInformation = <RouteInformation>[];
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider(
       onRouterReport: (RouteInformation info, RouteInformationReportingType type) => reportedRouteInformation.add(info),
     )..value = RouteInformation(uri: Uri.parse('/home'));
+    addTearDown(provider.dispose);
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
+      builder: (BuildContext _, RouteInformation? info) => Text('Current route: ${info?.uri}'),
+      reportConfiguration: true,
+    );
+    addTearDown(delegate.dispose);
 
     await tester.pumpWidget(buildBoilerPlate(
       Router<RouteInformation>(
@@ -1349,10 +1441,7 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         routeInformationParser: RedirectingInformationParser(<String, RouteInformation>{
           '/doesNotExist' : RouteInformation(uri: Uri.parse('/404')),
         }),
-        routerDelegate: SimpleRouterDelegate(
-          builder: (BuildContext _, RouteInformation? info) => Text('Current route: ${info?.uri}'),
-          reportConfiguration: true,
-        ),
+        routerDelegate: delegate,
       ),
     ));
 
@@ -1366,22 +1455,14 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(reportedRouteInformation[1].uri.toString(), '/404');
   });
 
-  testWidgets('RouterInformationParser can look up dependencies and reparse', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('RouterInformationParser can look up dependencies and reparse', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final BackButtonDispatcher dispatcher = RootBackButtonDispatcher();
-    int expectedMaxLines = 1;
-    bool parserCalled = false;
-    final Widget router = Router<RouteInformation>(
-      routeInformationProvider: provider,
-      routeInformationParser: CustomRouteInformationParser((RouteInformation information, BuildContext context) {
-        parserCalled = true;
-        final DefaultTextStyle style = DefaultTextStyle.of(context);
-        return RouteInformation(uri: Uri.parse('${style.maxLines}'));
-      }),
-      routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         return Text(Uri.decodeComponent(information!.uri.toString()));
       },
@@ -1391,7 +1472,18 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
         return SynchronousFuture<bool>(true);
       },
-      ),
+    );
+    addTearDown(delegate.dispose);
+    int expectedMaxLines = 1;
+    bool parserCalled = false;
+    final Widget router = Router<RouteInformation>(
+      routeInformationProvider: provider,
+      routeInformationParser: CustomRouteInformationParser((RouteInformation information, BuildContext context) {
+        parserCalled = true;
+        final DefaultTextStyle style = DefaultTextStyle.of(context);
+        return RouteInformation(uri: Uri.parse('${style.maxLines}'));
+      }),
+      routerDelegate: delegate,
       backButtonDispatcher: dispatcher,
     );
     await tester.pumpWidget(buildBoilerPlate(
@@ -1419,22 +1511,14 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(parserCalled, isTrue);
   });
 
-  testWidgets('RouterInformationParser can look up dependencies without reparsing', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('RouterInformationParser can look up dependencies without reparsing', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final BackButtonDispatcher dispatcher = RootBackButtonDispatcher();
-    const int expectedMaxLines = 1;
-    bool parserCalled = false;
-    final Widget router = Router<RouteInformation>(
-      routeInformationProvider: provider,
-      routeInformationParser: CustomRouteInformationParser((RouteInformation information, BuildContext context) {
-        parserCalled = true;
-        final DefaultTextStyle style = context.getInheritedWidgetOfExactType<DefaultTextStyle>()!;
-        return RouteInformation(uri: Uri.parse('${style.maxLines}'));
-      }),
-      routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         return Text(Uri.decodeComponent(information!.uri.toString()));
       },
@@ -1444,7 +1528,18 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
         return SynchronousFuture<bool>(true);
       },
-      ),
+    );
+    addTearDown(delegate.dispose);
+    const int expectedMaxLines = 1;
+    bool parserCalled = false;
+    final Widget router = Router<RouteInformation>(
+      routeInformationProvider: provider,
+      routeInformationParser: CustomRouteInformationParser((RouteInformation information, BuildContext context) {
+        parserCalled = true;
+        final DefaultTextStyle style = context.getInheritedWidgetOfExactType<DefaultTextStyle>()!;
+        return RouteInformation(uri: Uri.parse('${style.maxLines}'));
+      }),
+      routerDelegate: delegate,
       backButtonDispatcher: dispatcher,
     );
     await tester.pumpWidget(buildBoilerPlate(
@@ -1474,21 +1569,14 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(parserCalled, isFalse);
   });
 
-  testWidgets('Looks up dependencies in RouterDelegate does not trigger re-parsing', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Looks up dependencies in RouterDelegate does not trigger re-parsing', (WidgetTester tester) async {
     final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
     provider.value = RouteInformation(
       uri: Uri.parse('initial'),
     );
     final BackButtonDispatcher dispatcher = RootBackButtonDispatcher();
-    int expectedMaxLines = 1;
-    bool parserCalled = false;
-    final Widget router = Router<RouteInformation>(
-      routeInformationProvider: provider,
-      routeInformationParser: CustomRouteInformationParser((RouteInformation information, BuildContext context) {
-        parserCalled = true;
-        return information;
-      }),
-      routerDelegate: SimpleRouterDelegate(
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
       builder: (BuildContext context, RouteInformation? information) {
         final DefaultTextStyle style = DefaultTextStyle.of(context);
         return Text('${style.maxLines}');
@@ -1499,7 +1587,17 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
         );
         return SynchronousFuture<bool>(true);
       },
-      ),
+    );
+    addTearDown(delegate.dispose);
+    int expectedMaxLines = 1;
+    bool parserCalled = false;
+    final Widget router = Router<RouteInformation>(
+      routeInformationProvider: provider,
+      routeInformationParser: CustomRouteInformationParser((RouteInformation information, BuildContext context) {
+        parserCalled = true;
+        return information;
+      }),
+      routerDelegate: delegate,
       backButtonDispatcher: dispatcher,
     );
     await tester.pumpWidget(buildBoilerPlate(
@@ -1528,14 +1626,19 @@ testWidgets('ChildBackButtonDispatcher take priority recursively', (WidgetTester
     expect(parserCalled, isFalse);
   });
 
-  testWidgets('Router can initialize with RouterConfig', (WidgetTester tester) async {
+  testWidgetsWithLeakTracking('Router can initialize with RouterConfig', (WidgetTester tester) async {
     const String expected = 'text';
+    final SimpleRouteInformationProvider provider = SimpleRouteInformationProvider();
+    addTearDown(provider.dispose);
+    provider.value = RouteInformation(uri: Uri.parse('/'));
+    final SimpleRouterDelegate delegate = SimpleRouterDelegate(
+      builder: (_, __) => const Text(expected),
+    );
+    addTearDown(delegate.dispose);
     final RouterConfig<RouteInformation> config = RouterConfig<RouteInformation>(
-      routeInformationProvider: SimpleRouteInformationProvider()..value = RouteInformation(uri: Uri.parse('/')),
+      routeInformationProvider: provider,
       routeInformationParser: SimpleRouteInformationParser(),
-      routerDelegate: SimpleRouterDelegate(
-        builder: (_, __) => const Text(expected),
-      ),
+      routerDelegate: delegate,
       backButtonDispatcher: RootBackButtonDispatcher(),
     );
     final Router<RouteInformation> router = Router<RouteInformation>.withConfig(config: config);