Widgets app refactor (#22269)

* Refactor of cupertino/material/widgets app

* update docs 

* Update tests for const

dev/integration_tests/ui/lib/commands.dart

@@ -15,7 +15,7 @@ void main() {
     await WidgetsBinding.instance.reassembleApplication();
     return log;
   });
-  runApp(MaterialApp(home: const Test()));
+  runApp(const MaterialApp(home: Test()));
 }
 
 class Test extends SingleChildRenderObjectWidget {

dev/manual_tests/lib/animated_icons.dart

@@ -7,9 +7,9 @@ import 'package:flutter/material.dart';
 class AnimatedIconsTestApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
+    return const MaterialApp(
       title: 'Animated Icons Test',
-      home: const Scaffold(
+      home: Scaffold(
         body: IconsList(),
       ),
     );

dev/manual_tests/lib/material_arc.dart

@@ -474,7 +474,7 @@ class _AnimationDemoState extends State<AnimationDemo> with TickerProviderStateM
 }
 
 void main() {
-  runApp(MaterialApp(
-    home: const AnimationDemo(),
+  runApp(const MaterialApp(
+    home: AnimationDemo(),
   ));
 }

examples/flutter_gallery/test/accessibility_test.dart

@@ -91,7 +91,7 @@ void main() {
 
     testWidgets('grid_list_demo', (WidgetTester tester) async {
       final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const GridListDemo()));
+      await tester.pumpWidget(const MaterialApp(home: GridListDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
@@ -105,21 +105,21 @@ void main() {
 
     testWidgets('leave_behind_demo', (WidgetTester tester) async {
      final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const LeaveBehindDemo()));
+      await tester.pumpWidget(const MaterialApp(home: LeaveBehindDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
 
     testWidgets('list_demo', (WidgetTester tester) async {
      final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const ListDemo()));
+      await tester.pumpWidget(const MaterialApp(home: ListDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
 
     testWidgets('menu_demo', (WidgetTester tester) async {
      final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const MenuDemo()));
+      await tester.pumpWidget(const MaterialApp(home: MenuDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
@@ -133,7 +133,7 @@ void main() {
 
     testWidgets('overscroll_demo', (WidgetTester tester) async {
      final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const OverscrollDemo()));
+      await tester.pumpWidget(const MaterialApp(home: OverscrollDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
@@ -161,7 +161,7 @@ void main() {
 
     testWidgets('reorderable_list_demo', (WidgetTester tester) async {
      final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const ReorderableListDemo()));
+      await tester.pumpWidget(const MaterialApp(home: ReorderableListDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
@@ -196,7 +196,7 @@ void main() {
 
     testWidgets('snack_bar_demo', (WidgetTester tester) async {
       final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const SnackBarDemo()));
+      await tester.pumpWidget(const MaterialApp(home: SnackBarDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
@@ -217,7 +217,7 @@ void main() {
 
     testWidgets('text_form_field_demo', (WidgetTester tester) async {
       final SemanticsHandle handle = tester.ensureSemantics();
-      await tester.pumpWidget(MaterialApp(home: const TextFormFieldDemo()));
+      await tester.pumpWidget(const MaterialApp(home: TextFormFieldDemo()));
       expect(tester, meetsGuideline(androidTapTargetGuideline));
       handle.dispose();
     });
@@ -380,12 +380,12 @@ void main() {
         handle.dispose();
       });
 
-      testWidgets('overscroll_demo $themeName', (WidgetTester tester) async {
-        final SemanticsHandle handle = tester.ensureSemantics();
-        await tester.pumpWidget(MaterialApp(theme: theme, home: const OverscrollDemo()));
-        await expectLater(tester, meetsGuideline(textContrastGuideline));
-        handle.dispose();
-      });
+    testWidgets('overscroll_demo', (WidgetTester tester) async {
+      final SemanticsHandle handle = tester.ensureSemantics();
+      await tester.pumpWidget(const MaterialApp(home: OverscrollDemo()));
+      await expectLater(tester, meetsGuideline(textContrastGuideline));
+      handle.dispose();
+    });
 
       testWidgets('page_selector_demo $themeName', (WidgetTester tester) async {
         final SemanticsHandle handle = tester.ensureSemantics();

examples/flutter_gallery/test/calculator/smoke_test.dart

@@ -14,7 +14,7 @@ void main() {
   // We press the "1" and the "2" buttons and check that the display
   // reads "12".
   testWidgets('Flutter calculator app smoke test', (WidgetTester tester) async {
-    await tester.pumpWidget(MaterialApp(home: const CalculatorDemo()));
+    await tester.pumpWidget(const MaterialApp(home: CalculatorDemo()));
 
     final Finder oneButton = find.widgetWithText(InkResponse, '1');
     expect(oneButton, findsOneWidget);

examples/flutter_gallery/test/demo/material/text_form_field_demo_test.dart

@@ -8,7 +8,7 @@ import 'package:flutter_test/flutter_test.dart';
 
 void main() {
   testWidgets('validates name field correctly', (WidgetTester tester) async {
-    await tester.pumpWidget(MaterialApp(home: const TextFormFieldDemo()));
+    await tester.pumpWidget(const MaterialApp(home: TextFormFieldDemo()));
 
     final Finder submitButton = find.widgetWithText(RaisedButton, 'SUBMIT');
     expect(submitButton, findsOneWidget);

packages/flutter/lib/src/cupertino/tab_view.dart

@@ -4,6 +4,7 @@
 
 import 'package:flutter/widgets.dart';
 
+import 'app.dart' show CupertinoApp;
 import 'route.dart';
 
 /// A single tab view with its own [Navigator] state and history.
@@ -114,7 +115,7 @@ class _CupertinoTabViewState extends State<CupertinoTabView> {
   @override
   void initState() {
     super.initState();
-    _heroController = HeroController(); // Linear tweening.
+    _heroController = CupertinoApp.createCupertinoHeroController();
     _updateObservers();
   }
 

packages/flutter/test/cupertino/dialog_test.dart

@@ -66,7 +66,7 @@ void main() {
 
   testWidgets('Has semantic annotations', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
-    await tester.pumpWidget(MaterialApp(home: const Material(
+    await tester.pumpWidget(const MaterialApp(home: Material(
       child: CupertinoAlertDialog(
         title: Text('The Title'),
         content: Text('Content'),

packages/flutter/test/cupertino/nav_bar_test.dart

@@ -16,8 +16,8 @@ int count = 0;
 void main() {
   testWidgets('Middle still in center with asymmetrical actions', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           leading: CupertinoButton(child: Text('Something'), onPressed: null,),
           middle: Text('Title'),
         ),
@@ -30,8 +30,8 @@ void main() {
 
   testWidgets('Middle still in center with back button', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           middle: Text('Title'),
         ),
       ),
@@ -54,8 +54,8 @@ void main() {
 
   testWidgets('Opaque background does not add blur effects', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           middle: Text('Title'),
           backgroundColor: Color(0xFFE5E5E5),
         ),
@@ -66,8 +66,8 @@ void main() {
 
   testWidgets('Non-opaque background adds blur effects', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           middle: Text('Title'),
         ),
       ),
@@ -120,8 +120,8 @@ void main() {
 
   testWidgets('Padding works in RTL', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Directionality(
+      const CupertinoApp(
+        home: Directionality(
           textDirection: TextDirection.rtl,
           child: Align(
             alignment: Alignment.topCenter,
@@ -151,8 +151,8 @@ void main() {
   testWidgets('Verify styles of each slot', (WidgetTester tester) async {
     count = 0x000000;
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           leading: _ExpectStyles(color: Color(0xFF001122), index: 0x000001),
           middle: _ExpectStyles(color: Color(0xFF000000), letterSpacing: -0.08, index: 0x000100),
           trailing: _ExpectStyles(color: Color(0xFF001122), index: 0x010000),
@@ -165,8 +165,8 @@ void main() {
 
   testWidgets('No slivers with no large titles', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoPageScaffold(
+      const CupertinoApp(
+        home: CupertinoPageScaffold(
           navigationBar: CupertinoNavigationBar(
             middle: Text('Title'),
           ),
@@ -431,8 +431,8 @@ void main() {
 
   testWidgets('Auto back/close button', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           middle: Text('Home page'),
         ),
       ),
@@ -486,8 +486,8 @@ void main() {
 
   testWidgets('Long back label turns into "back"', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Placeholder(),
+      const CupertinoApp(
+        home: Placeholder(),
       ),
     );
 
@@ -529,8 +529,8 @@ void main() {
 
   testWidgets('Border should be displayed by default', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           middle: Text('Title'),
         ),
       ),
@@ -551,8 +551,8 @@ void main() {
 
   testWidgets('Overrides border color', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           middle: Text('Title'),
           border: Border(
             bottom: BorderSide(
@@ -580,8 +580,8 @@ void main() {
 
   testWidgets('Border should not be displayed when null', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoNavigationBar(
+      const CupertinoApp(
+        home: CupertinoNavigationBar(
           middle: Text('Title'),
           border: null,
         ),
@@ -746,8 +746,8 @@ void main() {
     'Standard title golden',
     (WidgetTester tester) async {
       await tester.pumpWidget(
-        CupertinoApp(
-          home: const RepaintBoundary(
+        const CupertinoApp(
+          home: RepaintBoundary(
             child: CupertinoPageScaffold(
               navigationBar: CupertinoNavigationBar(
                 middle: Text('Bling bling'),

packages/flutter/test/cupertino/nav_bar_transition_test.dart

@@ -14,8 +14,8 @@ Future<void> startTransitionBetween(
   String toTitle,
 }) async {
   await tester.pumpWidget(
-    CupertinoApp(
-      home: const Placeholder(),
+    const CupertinoApp(
+      home: Placeholder(),
     ),
   );
 
@@ -195,8 +195,8 @@ void main() {
   testWidgets('Fullscreen dialogs do not create heroes',
       (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Placeholder(),
+      const CupertinoApp(
+        home: Placeholder(),
       ),
     );
 

packages/flutter/test/cupertino/page_test.dart

@@ -146,8 +146,8 @@ void main() {
 
   testWidgets('test iOS fullscreen dialog transition', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Center(child: Text('Page 1')),
+      const CupertinoApp(
+        home: Center(child: Text('Page 1')),
       ),
     );
 

packages/flutter/test/cupertino/route_test.dart

@@ -9,8 +9,8 @@ import 'package:flutter_test/flutter_test.dart';
 void main() {
   testWidgets('Middle auto-populates with title', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Placeholder(),
+      const CupertinoApp(
+        home: Placeholder(),
       ),
     );
 
@@ -39,8 +39,8 @@ void main() {
 
   testWidgets('Large title auto-populates with title', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Placeholder(),
+      const CupertinoApp(
+        home: Placeholder(),
       ),
     );
 
@@ -104,8 +104,8 @@ void main() {
 
   testWidgets('Leading auto-populates with back button with previous title', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Placeholder(),
+      const CupertinoApp(
+        home: Placeholder(),
       ),
     );
 
@@ -150,8 +150,8 @@ void main() {
 
   testWidgets('Previous title is correct on first transition frame', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Placeholder(),
+      const CupertinoApp(
+        home: Placeholder(),
       ),
     );
 
@@ -193,8 +193,8 @@ void main() {
 
   testWidgets('Previous title stays up to date with changing routes', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const Placeholder(),
+      const CupertinoApp(
+        home: Placeholder(),
       ),
     );
 

packages/flutter/test/cupertino/scaffold_test.dart

@@ -11,8 +11,8 @@ import '../painting/mocks_for_image_cache.dart';
 void main() {
   testWidgets('Contents are behind translucent bar', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoPageScaffold(
+      const CupertinoApp(
+        home: CupertinoPageScaffold(
           // Default nav bar is translucent.
           navigationBar: CupertinoNavigationBar(
             middle: Text('Title'),
@@ -276,8 +276,8 @@ void main() {
 
   testWidgets('Decorated with white background by default', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoPageScaffold(
+      const CupertinoApp(
+        home: CupertinoPageScaffold(
           child: Center(),
         ),
       ),
@@ -292,8 +292,8 @@ void main() {
 
   testWidgets('Overrides background color', (WidgetTester tester) async {
     await tester.pumpWidget(
-      CupertinoApp(
-        home: const CupertinoPageScaffold(
+      const CupertinoApp(
+        home: CupertinoPageScaffold(
           child: Center(),
           backgroundColor: Color(0xFF010203),
         ),

packages/flutter/test/material/about_test.dart

@@ -67,9 +67,9 @@ void main() {
 
   testWidgets('About box logic defaults to executable name for app name', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
+      const MaterialApp(
         title: 'flutter_tester',
-        home: const Material(child: AboutListTile()),
+        home: Material(child: AboutListTile()),
       ),
     );
     expect(find.text('About flutter_tester'), findsOneWidget);
@@ -89,8 +89,8 @@ void main() {
     });
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Center(
+      const MaterialApp(
+        home: Center(
           child: LicensePage(),
         ),
       ),

packages/flutter/test/material/app_test.dart

@@ -28,9 +28,9 @@ class StateMarkerState extends State<StateMarker> {
 void main() {
   testWidgets('Can nest apps', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
+      const MaterialApp(
         home: MaterialApp(
-          home: const Text('Home sweet home'),
+          home: Text('Home sweet home'),
         ),
       ),
     );
@@ -57,8 +57,8 @@ void main() {
     await tester.pumpWidget(FocusScope(
       autofocus: true,
       node: focusScopeNode,
-      child: MaterialApp(
-        home: const Text('Home'),
+      child: const MaterialApp(
+        home: Text('Home'),
       ),
     ));
 
@@ -67,8 +67,8 @@ void main() {
 
   testWidgets('Can show grid without losing sync', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const StateMarker(),
+      const MaterialApp(
+        home: StateMarker(),
       ),
     );
 
@@ -76,9 +76,9 @@ void main() {
     state1.marker = 'original';
 
     await tester.pumpWidget(
-      MaterialApp(
+      const MaterialApp(
         debugShowMaterialGrid: true,
-        home: const StateMarker(),
+        home: StateMarker(),
       ),
     );
 
@@ -205,7 +205,7 @@ void main() {
   });
 
   testWidgets('Cannot pop the initial route', (WidgetTester tester) async {
-    await tester.pumpWidget(MaterialApp(home: const Text('Home')));
+    await tester.pumpWidget(const MaterialApp(home: Text('Home')));
 
     expect(find.text('Home'), findsOneWidget);
 
@@ -400,9 +400,9 @@ void main() {
       home: const Placeholder(),
     ));
     expect(key.currentState, isInstanceOf<NavigatorState>());
-    await tester.pumpWidget(MaterialApp(
-      color: const Color(0xFF112233),
-      home: const Placeholder(),
+    await tester.pumpWidget(const MaterialApp(
+      color: Color(0xFF112233),
+      home: Placeholder(),
     ));
     expect(key.currentState, isNull);
     await tester.pumpWidget(MaterialApp(

packages/flutter/test/material/bottom_app_bar_test.dart

@@ -9,8 +9,8 @@ import 'package:flutter/rendering.dart';
 void main() {
   testWidgets('no overlap with floating action button', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           floatingActionButton: FloatingActionButton(
             onPressed: null,
           ),
@@ -95,8 +95,8 @@ void main() {
   // _BottomAppBarClipper will try an illegal downcast.
   testWidgets('toggle shape to null', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar: BottomAppBar(
             shape: RectangularNotch(),
           ),
@@ -105,8 +105,8 @@ void main() {
     );
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar: BottomAppBar(
             shape: null,
           ),
@@ -115,8 +115,8 @@ void main() {
     );
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar: BottomAppBar(
             shape: RectangularNotch(),
           ),
@@ -127,8 +127,8 @@ void main() {
 
   testWidgets('no notch when notch param is null', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar: ShapeListener(BottomAppBar(
             shape: null,
           )),
@@ -159,8 +159,8 @@ void main() {
 
   testWidgets('notch no margin', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar: ShapeListener(
             BottomAppBar(
               child: SizedBox(height: 100.0),
@@ -211,8 +211,8 @@ void main() {
 
   testWidgets('notch with margin', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar: ShapeListener(
             BottomAppBar(
               child: SizedBox(height: 100.0),
@@ -263,8 +263,8 @@ void main() {
 
   testWidgets('observes safe area', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const MediaQuery(
+      const MaterialApp(
+        home: MediaQuery(
           data: MediaQueryData(
             padding: EdgeInsets.all(50.0),
           ),
@@ -287,8 +287,8 @@ void main() {
 
   testWidgets('clipBehavior is propagated', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar:
               BottomAppBar(
                 child: SizedBox(height: 100.0),
@@ -303,8 +303,8 @@ void main() {
     expect(physicalShape.clipBehavior, Clip.none);
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomNavigationBar:
           BottomAppBar(
             child: SizedBox(height: 100.0),

packages/flutter/test/material/chip_test.dart

@@ -1181,8 +1181,8 @@ void main() {
     testWidgets('label only', (WidgetTester tester) async {
       final SemanticsTester semanticsTester = SemanticsTester(tester);
 
-      await tester.pumpWidget(MaterialApp(
-        home: const Material(
+      await tester.pumpWidget(const MaterialApp(
+        home: Material(
           child: RawChip(
             label: Text('test'),
           ),

packages/flutter/test/material/dialog_test.dart

@@ -106,8 +106,8 @@ void main() {
 
   testWidgets('Simple dialog control test', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: Center(
             child: RaisedButton(
               onPressed: null,
@@ -149,8 +149,8 @@ void main() {
 
   testWidgets('Barrier dismissible', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: Center(
             child: RaisedButton(
               onPressed: null,
@@ -212,8 +212,8 @@ void main() {
     final SemanticsTester semantics = SemanticsTester(tester);
     const String buttonText = 'A button covered by dialog overlay';
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: Center(
             child: RaisedButton(
               onPressed: null,

packages/flutter/test/material/drawer_test.dart

@@ -61,8 +61,8 @@ void main() {
     final SemanticsTester semantics = SemanticsTester(tester);
     debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           drawer: Drawer()
         ),
       ),
@@ -86,8 +86,8 @@ void main() {
   testWidgets('Drawer dismiss barrier has no label on Android', (WidgetTester tester) async {
     final SemanticsTester semantics = SemanticsTester(tester);
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
             drawer: Drawer()
         ),
       ),

packages/flutter/test/material/floating_action_button_test.dart

@@ -36,8 +36,8 @@ void main() {
 
   testWidgets('Floating Action Button tooltip', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           floatingActionButton: FloatingActionButton(
             onPressed: null,
             tooltip: 'Add',
@@ -54,8 +54,8 @@ void main() {
   // Regression test for: https://github.com/flutter/flutter/pull/21084
   testWidgets('Floating Action Button tooltip (long press button edge)', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           floatingActionButton: FloatingActionButton(
             onPressed: null,
             tooltip: 'Add',
@@ -75,8 +75,8 @@ void main() {
   // Regression test for: https://github.com/flutter/flutter/pull/21084
   testWidgets('Floating Action Button tooltip (long press button edge - no child)', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           floatingActionButton: FloatingActionButton(
             onPressed: null,
             tooltip: 'Add',
@@ -94,8 +94,8 @@ void main() {
 
   testWidgets('Floating Action Button tooltip (no child)', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           floatingActionButton: FloatingActionButton(
             onPressed: null,
             tooltip: 'Add',
@@ -150,8 +150,8 @@ void main() {
 
   testWidgets('FloatingActionButton.isExtended', (WidgetTester tester) async {
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           floatingActionButton: FloatingActionButton(onPressed: null),
         ),
       ),

packages/flutter/test/material/persistent_bottom_sheet_test.dart

@@ -180,8 +180,8 @@ void main() {
 
     // Remove the persistent bottomSheet
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Scaffold(
+      const MaterialApp(
+        home: Scaffold(
           bottomSheet: null,
           body: Placeholder(),
         ),

packages/flutter/test/material/scaffold_test.dart

@@ -124,7 +124,7 @@ void main() {
   });
 
   testWidgets('Floating action entrance/exit animation', (WidgetTester tester) async {
-    await tester.pumpWidget(MaterialApp(home: const Scaffold(
+    await tester.pumpWidget(const MaterialApp(home: Scaffold(
       floatingActionButton: FloatingActionButton(
         key: Key('one'),
         onPressed: null,
@@ -134,7 +134,7 @@ void main() {
 
     expect(tester.binding.transientCallbackCount, 0);
 
-    await tester.pumpWidget(MaterialApp(home: const Scaffold(
+    await tester.pumpWidget(const MaterialApp(home: Scaffold(
       floatingActionButton: FloatingActionButton(
         key: Key('two'),
         onPressed: null,
@@ -146,11 +146,11 @@ void main() {
     await tester.pumpWidget(Container());
     expect(tester.binding.transientCallbackCount, 0);
 
-    await tester.pumpWidget(MaterialApp(home: const Scaffold()));
+    await tester.pumpWidget(const MaterialApp(home: Scaffold()));
 
     expect(tester.binding.transientCallbackCount, 0);
 
-    await tester.pumpWidget(MaterialApp(home: const Scaffold(
+    await tester.pumpWidget(const MaterialApp(home: Scaffold(
       floatingActionButton: FloatingActionButton(
         key: Key('one'),
         onPressed: null,
@@ -569,7 +569,7 @@ void main() {
     const String drawerLabel = 'I am the reason for this test';
 
     final SemanticsTester semantics = SemanticsTester(tester);
-    await tester.pumpWidget(MaterialApp(home: const Scaffold(
+    await tester.pumpWidget(const MaterialApp(home: Scaffold(
       body: Text(bodyLabel),
       persistentFooterButtons: <Widget>[Text(persistentFooterButtonLabel)],
       bottomNavigationBar: Text(bottomNavigationBarLabel),
@@ -970,7 +970,7 @@ void main() {
       const String endDrawerLabel = 'I am the label on end side';
 
       final SemanticsTester semantics = SemanticsTester(tester);
-      await tester.pumpWidget(MaterialApp(home: const Scaffold(
+      await tester.pumpWidget(const MaterialApp(home: Scaffold(
         body: Text(bodyLabel),
         drawer: Drawer(child: Text(drawerLabel)),
         endDrawer: Drawer(child: Text(endDrawerLabel)),

packages/flutter/test/material/text_field_focus_test.dart

@@ -37,8 +37,8 @@ void main() {
     expect(tester.testTextInput.isVisible, isFalse);
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: Center(
             child: TextField(
               autofocus: true,
@@ -59,8 +59,8 @@ void main() {
     expect(tester.testTextInput.isVisible, isFalse);
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: Center(
             child: TextField(),
           ),
@@ -93,8 +93,8 @@ void main() {
     expect(tester.testTextInput.isVisible, isFalse);
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: Center(
             child: TextField(
               autofocus: true,
@@ -211,8 +211,8 @@ void main() {
     // Regression test for https://github.com/flutter/flutter/issues/16880
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: Center(
             child: TextField(
               decoration: null

packages/flutter/test/material/text_field_helper_text_test.dart

@@ -7,11 +7,11 @@ import 'package:flutter_test/flutter_test.dart';
 
 void main() {
   testWidgets('TextField works correctly when changing helperText', (WidgetTester tester) async {
-    await tester.pumpWidget(MaterialApp(home: const Material(child: TextField(decoration: InputDecoration(helperText: 'Awesome')))));
+    await tester.pumpWidget(const MaterialApp(home: Material(child: TextField(decoration: InputDecoration(helperText: 'Awesome')))));
     expect(find.text('Awesome'), findsNWidgets(1));
     await tester.pump(const Duration(milliseconds: 100));
     expect(find.text('Awesome'), findsNWidgets(1));
-    await tester.pumpWidget(MaterialApp(home: const Material(child: TextField(decoration: InputDecoration(errorText: 'Awesome')))));
+    await tester.pumpWidget(const MaterialApp(home: Material(child: TextField(decoration: InputDecoration(errorText: 'Awesome')))));
     expect(find.text('Awesome'), findsNWidgets(2));
   });
 }

packages/flutter/test/material/text_field_test.dart

@@ -1721,8 +1721,8 @@ void main() {
   });
 
   testWidgets('setting maxLength shows counter', (WidgetTester tester) async {
-    await tester.pumpWidget(MaterialApp(
-      home: const Material(
+    await tester.pumpWidget(const MaterialApp(
+      home: Material(
         child: DefaultTextStyle(
           style: TextStyle(fontFamily: 'Ahem', fontSize: 10.0),
           child: Center(
@@ -1746,8 +1746,8 @@ void main() {
     final SemanticsTester semantics = SemanticsTester(tester);
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Material(
+      const MaterialApp(
+        home: Material(
           child: DefaultTextStyle(
             style: TextStyle(fontFamily: 'Ahem', fontSize: 10.0),
             child: Center(

packages/flutter/test/material/tooltip_test.dart

@@ -610,8 +610,8 @@ void main() {
     final SemanticsTester semantics = SemanticsTester(tester);
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Center(
+      const MaterialApp(
+        home: Center(
           child: Tooltip(
             message: 'Foo',
             child: Text('Bar'),
@@ -645,8 +645,8 @@ void main() {
     final SemanticsTester semantics = SemanticsTester(tester);
 
     await tester.pumpWidget(
-      MaterialApp(
-        home: const Center(
+      const MaterialApp(
+        home: Center(
           child: Tooltip(
             message: 'Foo',
             child: Text('Bar'),

packages/flutter/test/widgets/banner_test.dart

@@ -269,7 +269,7 @@ void main() {
 
   testWidgets('Banner widget in MaterialApp', (WidgetTester tester) async {
     debugDisableShadows = false;
-    await tester.pumpWidget(MaterialApp(home: const Placeholder()));
+    await tester.pumpWidget(const MaterialApp(home: Placeholder()));
     expect(find.byType(CheckedModeBanner), paints
       ..save()
       ..translate(x: 800.0, y: 0.0)

packages/flutter/test/widgets/reassemble_test.dart

@@ -7,8 +7,8 @@ import 'package:flutter_test/flutter_test.dart';
 
 void main() {
   testWidgets('reassemble does not crash', (WidgetTester tester) async {
-    await tester.pumpWidget(MaterialApp(
-      home: const Text('Hello World')
+    await tester.pumpWidget(const MaterialApp(
+      home: Text('Hello World')
     ));
     await tester.pump();
     tester.binding.reassembleApplication();

packages/flutter_test/test/test_text_input_test.dart

@@ -10,8 +10,8 @@ void main() {
   testWidgets('receiveAction() forwards exception when exception occurs during action processing',
           (WidgetTester tester) async {
     // Setup a widget that can receive focus so that we can open the keyboard.
-    final Widget widget = MaterialApp(
-      home: const Material(
+    const Widget widget = MaterialApp(
+      home: Material(
         child: TextField(),
       ),
     );

packages/flutter_test/test/widget_tester_test.dart

@@ -533,8 +533,8 @@ void main() {
   group('getSemanticsData', () {
     testWidgets('throws when there are no semantics', (WidgetTester tester) async {
       await tester.pumpWidget(
-        MaterialApp(
-          home: const Scaffold(
+        const MaterialApp(
+          home: Scaffold(
             body: Text('hello'),
           ),
         ),