Enforce `use_key_in_widget_constructors` and `file_names` lints (#913)

* Start enforcing use_key_in_widget_constructors and file_names lints

* dart format

* analysis fixes

* analysis fixes, pt2

* analysis fixes, part 3

* Revert platform_design (test failure)

* More reverts

* Notate why we aren't enforcing a lint

add_to_app/android_view/flutter_module_using_plugin/test/widget_test.dart

@@ -6,9 +6,8 @@
 // tree, read text, and verify that the values of widget properties are correct.
 
 import 'package:flutter/material.dart';
-import 'package:flutter_test/flutter_test.dart';
-
 import 'package:flutter_module_using_plugin/main.dart';
+import 'package:flutter_test/flutter_test.dart';
 import 'package:provider/provider.dart';
 
 class MockCounterModel extends ChangeNotifier implements CounterModel {

add_to_app/books/flutter_module_books/lib/api.dart

@@ -94,6 +94,7 @@ abstract class FlutterBookApi {
       if (api == null) {
         channel.setMessageHandler(null);
       } else {
+        // ignore: avoid_types_on_closure_parameters
         channel.setMessageHandler((Object? message) async {
           assert(message != null,
               'Argument for dev.flutter.pigeon.FlutterBookApi.displayBookDetails was null.');

experimental/federated_plugin/federated_plugin_platform_interface/pubspec.yaml

@@ -1,7 +1,6 @@
 name: federated_plugin_platform_interface
 description: A platform interface for federated_plugin.
 version: 0.0.1
-author:
 homepage:
 publish_to: none
 

experimental/federated_plugin/federated_plugin_windows/pubspec.yaml

@@ -1,7 +1,6 @@
 name: federated_plugin_windows
 description: Windows implementation of federated_plugin to retrieve current battery level.
 version: 0.0.1
-author:
 homepage:
 publish_to: none
 

experimental/linting_tool/analysis_options.yaml

@@ -15,10 +15,8 @@ linter:
     cancel_subscriptions: true
     close_sinks: true
     directives_ordering: true
-    file_names: false
     package_api_docs: true
     package_prefixed_library_names: true
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

experimental/web_dashboard/analysis_options.yaml

@@ -17,4 +17,3 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

experimental/web_dashboard/lib/src/app.dart

@@ -39,14 +39,16 @@ class DashboardApp extends StatefulWidget {
   final ApiBuilder apiBuilder;
 
   /// Runs the app using Firebase
-  DashboardApp.firebase()
+  DashboardApp.firebase({Key key})
       : auth = FirebaseAuthService(),
-        apiBuilder = _apiBuilder;
+        apiBuilder = _apiBuilder,
+        super(key: key);
 
   /// Runs the app using mock data
-  DashboardApp.mock()
+  DashboardApp.mock({Key key})
       : auth = MockAuthService(),
-        apiBuilder = _mockApiBuilder;
+        apiBuilder = _mockApiBuilder,
+        super(key: key);
 
   @override
   _DashboardAppState createState() => _DashboardAppState();
@@ -84,7 +86,8 @@ class SignInSwitcher extends StatefulWidget {
   const SignInSwitcher({
     this.appState,
     this.apiBuilder,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   _SignInSwitcherState createState() => _SignInSwitcherState();

experimental/web_dashboard/lib/src/pages/dashboard.dart

@@ -10,6 +10,8 @@ import '../app.dart';
 import '../widgets/category_chart.dart';
 
 class DashboardPage extends StatelessWidget {
+  const DashboardPage({Key key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     var appState = Provider.of<AppState>(context);
@@ -41,7 +43,7 @@ class DashboardPage extends StatelessWidget {
 class Dashboard extends StatelessWidget {
   final List<Category> categories;
 
-  const Dashboard(this.categories);
+  const Dashboard(this.categories, {Key key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

experimental/web_dashboard/lib/src/pages/entries.dart

@@ -12,6 +12,8 @@ import '../widgets/categories_dropdown.dart';
 import '../widgets/dialogs.dart';
 
 class EntriesPage extends StatefulWidget {
+  const EntriesPage({Key key}) : super(key: key);
+
   @override
   _EntriesPageState createState() => _EntriesPageState();
 }
@@ -100,7 +102,8 @@ class EntryTile extends StatelessWidget {
   const EntryTile({
     this.category,
     this.entry,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

experimental/web_dashboard/lib/src/pages/home.dart

@@ -14,7 +14,8 @@ class HomePage extends StatefulWidget {
 
   const HomePage({
     @required this.onSignOut,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   _HomePageState createState() => _HomePageState();
@@ -70,7 +71,7 @@ class _HomePageState extends State<HomePage> {
     if (_pageIndex == 0) {
       showDialog<NewCategoryDialog>(
         context: context,
-        builder: (context) => NewCategoryDialog(),
+        builder: (context) => const NewCategoryDialog(),
       );
       return;
     }
@@ -78,7 +79,7 @@ class _HomePageState extends State<HomePage> {
     if (_pageIndex == 1) {
       showDialog<NewEntryDialog>(
         context: context,
-        builder: (context) => NewEntryDialog(),
+        builder: (context) => const NewEntryDialog(),
       );
       return;
     }
@@ -115,11 +116,11 @@ class _HomePageState extends State<HomePage> {
 
   static Widget _pageAtIndex(int index) {
     if (index == 0) {
-      return DashboardPage();
+      return const DashboardPage();
     }
 
     if (index == 1) {
-      return EntriesPage();
+      return const EntriesPage();
     }
 
     return const Center(child: Text('Settings page'));

experimental/web_dashboard/lib/src/pages/sign_in.dart

@@ -13,7 +13,8 @@ class SignInPage extends StatelessWidget {
   const SignInPage({
     @required this.auth,
     @required this.onSuccess,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -32,7 +33,8 @@ class SignInButton extends StatefulWidget {
   const SignInButton({
     @required this.auth,
     @required this.onSuccess,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   _SignInButtonState createState() => _SignInButtonState();

experimental/web_dashboard/lib/src/widgets/categories_dropdown.dart

@@ -16,7 +16,8 @@ class CategoryDropdown extends StatefulWidget {
   const CategoryDropdown({
     @required this.api,
     @required this.onSelected,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   _CategoryDropdownState createState() => _CategoryDropdownState();

experimental/web_dashboard/lib/src/widgets/category_chart.dart

@@ -20,7 +20,8 @@ class CategoryChart extends StatelessWidget {
   const CategoryChart({
     @required this.category,
     @required this.api,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

experimental/web_dashboard/lib/src/widgets/category_forms.dart

@@ -8,6 +8,8 @@ import 'package:web_dashboard/src/api/api.dart';
 import 'package:web_dashboard/src/app.dart';
 
 class NewCategoryForm extends StatefulWidget {
+  const NewCategoryForm({Key key}) : super(key: key);
+
   @override
   _NewCategoryFormState createState() => _NewCategoryFormState();
 }
@@ -37,7 +39,8 @@ class EditCategoryForm extends StatefulWidget {
   const EditCategoryForm({
     @required this.category,
     @required this.onDone,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   _EditCategoryFormState createState() => _EditCategoryFormState();

experimental/web_dashboard/lib/src/widgets/dialogs.dart

@@ -11,10 +11,12 @@ import '../app.dart';
 import 'edit_entry.dart';
 
 class NewCategoryDialog extends StatelessWidget {
+  const NewCategoryDialog({Key key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
-    return SimpleDialog(
+    return const SimpleDialog(
-      title: const Text('New Category'),
+      title: Text('New Category'),
       children: <Widget>[
         NewCategoryForm(),
       ],
@@ -27,7 +29,8 @@ class EditCategoryDialog extends StatelessWidget {
 
   const EditCategoryDialog({
     @required this.category,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -51,6 +54,8 @@ class EditCategoryDialog extends StatelessWidget {
 }
 
 class NewEntryDialog extends StatefulWidget {
+  const NewEntryDialog({Key key}) : super(key: key);
+
   @override
   _NewEntryDialogState createState() => _NewEntryDialogState();
 }
@@ -58,8 +63,8 @@ class NewEntryDialog extends StatefulWidget {
 class _NewEntryDialogState extends State<NewEntryDialog> {
   @override
   Widget build(BuildContext context) {
-    return SimpleDialog(
+    return const SimpleDialog(
-      title: const Text('New Entry'),
+      title: Text('New Entry'),
       children: [
         NewEntryForm(),
       ],
@@ -74,7 +79,8 @@ class EditEntryDialog extends StatelessWidget {
   const EditEntryDialog({
     this.category,
     this.entry,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

experimental/web_dashboard/lib/src/widgets/edit_entry.dart

@@ -11,6 +11,8 @@ import '../app.dart';
 import 'categories_dropdown.dart';
 
 class NewEntryForm extends StatefulWidget {
+  const NewEntryForm({Key key}) : super(key: key);
+
   @override
   _NewEntryFormState createState() => _NewEntryFormState();
 }
@@ -58,7 +60,8 @@ class EditEntryForm extends StatefulWidget {
   const EditEntryForm({
     @required this.entry,
     @required this.onDone,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   _EditEntryFormState createState() => _EditEntryFormState();

experimental/web_dashboard/lib/src/widgets/third_party/adaptive_scaffold.dart

@@ -43,7 +43,8 @@ class AdaptiveScaffold extends StatefulWidget {
     @required this.destinations,
     this.onNavigationIndexChange,
     this.floatingActionButton,
-  });
+    Key key,
+  }) : super(key: key);
 
   @override
   _AdaptiveScaffoldState createState() => _AdaptiveScaffoldState();

platform_channels/analysis_options.yaml

@@ -12,10 +12,8 @@ linter:
     cancel_subscriptions: true
     close_sinks: true
     directives_ordering: true
-    file_names: false
     package_api_docs: true
     package_prefixed_library_names: true
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

platform_channels/lib/main.dart

@@ -10,19 +10,21 @@ import 'package:platform_channels/src/pet_list_screen.dart';
 import 'package:platform_channels/src/platform_image_demo.dart';
 
 void main() {
-  runApp(PlatformChannelSample());
+  runApp(const PlatformChannelSample());
 }
 
 class PlatformChannelSample extends StatelessWidget {
+  const PlatformChannelSample({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
       routes: {
-        '/methodChannelDemo': (context) => MethodChannelDemo(),
+        '/methodChannelDemo': (context) => const MethodChannelDemo(),
-        '/eventChannelDemo': (context) => EventChannelDemo(),
+        '/eventChannelDemo': (context) => const EventChannelDemo(),
-        '/platformImageDemo': (context) => PlatformImageDemo(),
+        '/platformImageDemo': (context) => const PlatformImageDemo(),
-        '/petListScreen': (context) => PetListScreen(),
+        '/petListScreen': (context) => const PetListScreen(),
-        '/addPetDetails': (context) => AddPetDetails(),
+        '/addPetDetails': (context) => const AddPetDetails(),
       },
       title: 'Platform Channel Sample',
       theme: ThemeData(
@@ -30,7 +32,7 @@ class PlatformChannelSample extends StatelessWidget {
           backgroundColor: Colors.blue[500],
         ),
       ),
-      home: HomePage(),
+      home: const HomePage(),
     );
   }
 }
@@ -62,6 +64,8 @@ List<DemoInfo> demoList = [
 ];
 
 class HomePage extends StatelessWidget {
+  const HomePage({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -79,7 +83,7 @@ class HomePage extends StatelessWidget {
 class DemoTile extends StatelessWidget {
   final DemoInfo demoInfo;
 
-  const DemoTile(this.demoInfo);
+  const DemoTile(this.demoInfo, {Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

platform_channels/lib/src/add_pet_details.dart

@@ -10,6 +10,8 @@ import 'package:platform_channels/src/pet_list_message_channel.dart';
 /// The widget uses [TextField] and [RadioListTile] to take the [PetDetails.breed] and
 /// [PetDetails.petType] from the user respectively.
 class AddPetDetails extends StatefulWidget {
+  const AddPetDetails({Key? key}) : super(key: key);
+
   @override
   _AddPetDetailsState createState() => _AddPetDetailsState();
 }

platform_channels/lib/src/event_channel_demo.dart

@@ -14,6 +14,8 @@ import 'package:platform_channels/src/accelerometer_event_channel.dart';
 /// [Text] widgets to display the value of [AccelerometerReadings.x],
 /// [AccelerometerReadings.y], and [AccelerometerReadings.z] respectively.
 class EventChannelDemo extends StatelessWidget {
+  const EventChannelDemo({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     final textStyle = Theme.of(context).textTheme.headline5;

platform_channels/lib/src/method_channel_demo.dart

@@ -10,6 +10,8 @@ import 'package:platform_channels/src/counter_method_channel.dart';
 /// It has two [ElevatedButton]s to increment and decrement the value of
 /// [count], and a [Text] widget to display its value.
 class MethodChannelDemo extends StatefulWidget {
+  const MethodChannelDemo({Key? key}) : super(key: key);
+
   @override
   _MethodChannelDemoState createState() => _MethodChannelDemoState();
 }

platform_channels/lib/src/pet_list_screen.dart

@@ -9,6 +9,8 @@ import 'package:platform_channels/src/pet_list_message_channel.dart';
 /// Demonstrates how to use [BasicMessageChannel] to send & receive the platform
 /// Message.
 class PetListScreen extends StatefulWidget {
+  const PetListScreen({Key? key}) : super(key: key);
+
   @override
   _PetListScreenState createState() => _PetListScreenState();
 }
@@ -59,7 +61,7 @@ class _PetListScreenState extends State<PetListScreen> {
 class BuildPetList extends StatelessWidget {
   final List<PetDetails> petList;
 
-  const BuildPetList(this.petList);
+  const BuildPetList(this.petList, {Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

platform_channels/lib/src/platform_image_demo.dart

@@ -13,6 +13,8 @@ import 'package:platform_channels/src/image_basic_message_channel.dart';
 /// The widget uses [Image.memory] to display the image obtained from the
 /// platform.
 class PlatformImageDemo extends StatefulWidget {
+  const PlatformImageDemo({Key? key}) : super(key: key);
+
   @override
   _PlatformImageDemoState createState() => _PlatformImageDemoState();
 }

platform_channels/test/home_page_test.dart

@@ -9,7 +9,7 @@ import 'package:platform_channels/main.dart';
 void main() {
   group('HomePage tests', () {
     testWidgets('HomePage has multiple Text widgets', (tester) async {
-      await tester.pumpWidget(MaterialApp(
+      await tester.pumpWidget(const MaterialApp(
         home: HomePage(),
       ));
 

platform_channels/test/src/add_pet_details_test.dart

@@ -20,7 +20,7 @@ void main() {
     });
 
     testWidgets('Enter pet details', (tester) async {
-      await tester.pumpWidget(MaterialApp(home: AddPetDetails()));
+      await tester.pumpWidget(const MaterialApp(home: AddPetDetails()));
 
       // Enter the breed of cat.
       await tester.enterText(find.byType(TextField), 'Persian');

platform_channels/test/src/event_channel_demo_test.dart

@@ -49,7 +49,7 @@ void main() {
 
     testWidgets('EventChannel AccelerometerReadings Stream test',
         (tester) async {
-      await tester.pumpWidget(MaterialApp(
+      await tester.pumpWidget(const MaterialApp(
         home: EventChannelDemo(),
       ));
 

platform_channels/test/src/method_channel_demo_test.dart

@@ -26,7 +26,7 @@ void main() {
     });
 
     testWidgets('MethodChannelDemo count test', (tester) async {
-      await tester.pumpWidget(MaterialApp(
+      await tester.pumpWidget(const MaterialApp(
         home: MethodChannelDemo(),
       ));
 

platform_channels/test/src/platform_image_demo_test.dart

@@ -20,7 +20,7 @@ void main() {
     });
 
     testWidgets('Platform Image test', (tester) async {
-      await tester.pumpWidget(MaterialApp(
+      await tester.pumpWidget(const MaterialApp(
         home: PlatformImageDemo(),
       ));
 

platform_design/analysis_options.yaml

@@ -17,4 +17,5 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
+    # Tests fail if we enforce `use_key_in_widget_constructors`
     use_key_in_widget_constructors: false

platform_view_swift/analysis_options.yaml

@@ -17,4 +17,3 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

platform_view_swift/lib/main.dart

@@ -8,10 +8,12 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
 void main() {
-  runApp(PlatformView());
+  runApp(const PlatformView());
 }
 
 class PlatformView extends StatelessWidget {
+  const PlatformView({Key key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(

provider_counter/analysis_options.yaml

@@ -17,4 +17,3 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

provider_counter/lib/main.dart

@@ -18,7 +18,7 @@ void main() {
       // can own Counter's lifecycle, making sure to call `dispose`
       // when not needed anymore.
       create: (context) => Counter(),
-      child: MyApp(),
+      child: const MyApp(),
     ),
   );
 }
@@ -37,6 +37,8 @@ class Counter with ChangeNotifier {
 }
 
 class MyApp extends StatelessWidget {
+  const MyApp({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -44,12 +46,14 @@ class MyApp extends StatelessWidget {
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
-      home: MyHomePage(),
+      home: const MyHomePage(),
     );
   }
 }
 
 class MyHomePage extends StatelessWidget {
+  const MyHomePage({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

provider_counter/test/widget_test.dart

@@ -13,7 +13,7 @@ void main() {
     await tester.pumpWidget(
       ChangeNotifierProvider(
         create: (context) => Counter(),
-        child: MyApp(),
+        child: const MyApp(),
       ),
     );
 

provider_shopper/analysis_options.yaml

@@ -17,4 +17,3 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

provider_shopper/lib/main.dart

@@ -12,10 +12,12 @@ import 'package:provider_shopper/screens/catalog.dart';
 import 'package:provider_shopper/screens/login.dart';
 
 void main() {
-  runApp(MyApp());
+  runApp(const MyApp());
 }
 
 class MyApp extends StatelessWidget {
+  const MyApp({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     // Using MultiProvider is convenient when providing multiple objects.
@@ -41,9 +43,9 @@ class MyApp extends StatelessWidget {
         theme: appTheme,
         initialRoute: '/',
         routes: {
-          '/': (context) => MyLogin(),
+          '/': (context) => const MyLogin(),
-          '/catalog': (context) => MyCatalog(),
+          '/catalog': (context) => const MyCatalog(),
-          '/cart': (context) => MyCart(),
+          '/cart': (context) => const MyCart(),
         },
       ),
     );

provider_shopper/lib/screens/cart.dart

@@ -7,6 +7,8 @@ import 'package:provider/provider.dart';
 import 'package:provider_shopper/models/cart.dart';
 
 class MyCart extends StatelessWidget {
+  const MyCart({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

provider_shopper/lib/screens/catalog.dart

@@ -8,6 +8,8 @@ import 'package:provider_shopper/models/cart.dart';
 import 'package:provider_shopper/models/catalog.dart';
 
 class MyCatalog extends StatelessWidget {
+  const MyCatalog({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

provider_shopper/lib/screens/login.dart

@@ -5,6 +5,8 @@
 import 'package:flutter/material.dart';
 
 class MyLogin extends StatelessWidget {
+  const MyLogin({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(

provider_shopper/test/cart_widget_test.dart

@@ -24,7 +24,7 @@ Widget createCartScreen() => MultiProvider(
           },
         ),
       ],
-      child: MaterialApp(
+      child: const MaterialApp(
         home: MyCart(),
       ),
     );

provider_shopper/test/catalog_widget_test.dart

@@ -21,7 +21,7 @@ Widget createCatalogScreen() => MultiProvider(
           },
         ),
       ],
-      child: MaterialApp(
+      child: const MaterialApp(
         home: MyCatalog(),
       ),
     );

provider_shopper/test/login_widget_test.dart

@@ -26,8 +26,8 @@ void main() {
       child: MaterialApp(
         initialRoute: '/',
         routes: {
-          '/': (context) => MyLogin(),
+          '/': (context) => const MyLogin(),
-          '/catalog': (context) => MyCatalog(),
+          '/catalog': (context) => const MyCatalog(),
         },
       ),
     ));

provider_shopper/test/widget_test.dart

@@ -9,7 +9,7 @@ import 'package:provider_shopper/main.dart';
 void main() {
   testWidgets('smoke test', (tester) async {
     // Build our app and trigger a frame.
-    await tester.pumpWidget(MyApp());
+    await tester.pumpWidget(const MyApp());
 
     // Navigating through login page.
     await tester.tap(find.text('ENTER'));

testing_app/analysis_options.yaml

@@ -12,10 +12,8 @@ linter:
     cancel_subscriptions: true
     close_sinks: true
     directives_ordering: true
-    file_names: false
     package_api_docs: true
     package_prefixed_library_names: true
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

testing_app/integration_test/app_test.dart

@@ -12,7 +12,7 @@ void main() {
     IntegrationTestWidgetsFlutterBinding.ensureInitialized();
 
     testWidgets('Finding an item in the list', (tester) async {
-      await tester.pumpWidget(TestingApp());
+      await tester.pumpWidget(const TestingApp());
 
       // Create variables for finders that are used multiple times.
       final itemFinder = find.byKey(const ValueKey('text_25'));
@@ -28,7 +28,7 @@ void main() {
     });
 
     testWidgets('Testing IconButtons', (tester) async {
-      await tester.pumpWidget(TestingApp());
+      await tester.pumpWidget(const TestingApp());
 
       // Create a finder for the icon.
       final iconFinder = find.byKey(const ValueKey('icon_0'));
@@ -51,7 +51,7 @@ void main() {
 
     testWidgets('Verifying whether item gets added to favorites',
         (tester) async {
-      await tester.pumpWidget(TestingApp());
+      await tester.pumpWidget(const TestingApp());
 
       // Add item to favorites.
       await tester.tap(find.byKey(const ValueKey('icon_5')));
@@ -71,7 +71,7 @@ void main() {
     });
 
     testWidgets('Testing remove button', (tester) async {
-      await tester.pumpWidget(TestingApp());
+      await tester.pumpWidget(const TestingApp());
 
       // Add item to favorites.
       await tester.tap(find.byKey(const ValueKey('icon_5')));

testing_app/integration_test/perf_test.dart

@@ -17,7 +17,7 @@ void main() {
     binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
 
     testWidgets('Scrolling test', (tester) async {
-      await tester.pumpWidget(TestingApp());
+      await tester.pumpWidget(const TestingApp());
 
       // Create variables for finders that are used multiple times.
       final listFinder = find.byType(ListView);
@@ -49,7 +49,7 @@ void main() {
     });
 
     testWidgets('Favorites operations test', (tester) async {
-      await tester.pumpWidget(TestingApp());
+      await tester.pumpWidget(const TestingApp());
 
       // Record the performance summary as operations are performed
       // on the favorites list.

testing_app/integration_test/state_mgmt_test.dart

@@ -16,7 +16,7 @@ Widget createFavoritesScreen() => ChangeNotifierProvider<Favorites>(
         favoritesList = Favorites();
         return favoritesList;
       },
-      child: MaterialApp(
+      child: const MaterialApp(
         home: FavoritesPage(),
       ),
     );

testing_app/lib/main.dart

@@ -9,10 +9,12 @@ import 'package:testing_app/screens/favorites.dart';
 import 'package:testing_app/screens/home.dart';
 
 void main() {
-  runApp(TestingApp());
+  runApp(const TestingApp());
 }
 
 class TestingApp extends StatelessWidget {
+  const TestingApp({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return ChangeNotifierProvider<Favorites>(
@@ -24,8 +26,8 @@ class TestingApp extends StatelessWidget {
           visualDensity: VisualDensity.adaptivePlatformDensity,
         ),
         routes: {
-          HomePage.routeName: (context) => HomePage(),
+          HomePage.routeName: (context) => const HomePage(),
-          FavoritesPage.routeName: (context) => FavoritesPage(),
+          FavoritesPage.routeName: (context) => const FavoritesPage(),
         },
         initialRoute: HomePage.routeName,
       ),

testing_app/lib/screens/favorites.dart

@@ -9,6 +9,8 @@ import 'package:testing_app/models/favorites.dart';
 class FavoritesPage extends StatelessWidget {
   static String routeName = '/favorites_page';
 
+  const FavoritesPage({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -34,9 +36,7 @@ class FavoritesPage extends StatelessWidget {
 class FavoriteItemTile extends StatelessWidget {
   final int itemNo;
 
-  const FavoriteItemTile(
+  const FavoriteItemTile(this.itemNo, {Key? key}) : super(key: key);
-    this.itemNo,
-  );
 
   @override
   Widget build(BuildContext context) {

testing_app/lib/screens/home.dart

@@ -10,6 +10,8 @@ import 'package:testing_app/screens/favorites.dart';
 class HomePage extends StatelessWidget {
   static String routeName = '/';
 
+  const HomePage({Key? key}) : super(key: key);
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -40,9 +42,7 @@ class HomePage extends StatelessWidget {
 class ItemTile extends StatelessWidget {
   final int itemNo;
 
-  const ItemTile(
+  const ItemTile(this.itemNo, {Key? key}) : super(key: key);
-    this.itemNo,
-  );
 
   @override
   Widget build(BuildContext context) {

testing_app/test/favorites_test.dart

@@ -15,7 +15,7 @@ Widget createFavoritesScreen() => ChangeNotifierProvider<Favorites>(
         favoritesList = Favorites();
         return favoritesList;
       },
-      child: MaterialApp(
+      child: const MaterialApp(
         home: FavoritesPage(),
       ),
     );

testing_app/test/home_test.dart

@@ -10,7 +10,7 @@ import 'package:testing_app/screens/home.dart';
 
 Widget createHomeScreen() => ChangeNotifierProvider<Favorites>(
       create: (context) => Favorites(),
-      child: MaterialApp(
+      child: const MaterialApp(
         home: HomePage(),
       ),
     );

veggieseasons/analysis_options.yaml

@@ -17,4 +17,3 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

veggieseasons/lib/main.dart

@@ -18,7 +18,7 @@ void main() {
   ]);
 
   runApp(
-    RootRestorationScope(
+    const RootRestorationScope(
       restorationId: 'root',
       child: VeggieApp(),
     ),
@@ -26,6 +26,8 @@ void main() {
 }
 
 class VeggieApp extends StatefulWidget {
+  const VeggieApp({Key key}) : super(key: key);
+
   @override
   State<StatefulWidget> createState() => _VeggieAppState();
 }

veggieseasons/lib/screens/details.dart

@@ -13,7 +13,7 @@ import 'package:veggieseasons/widgets/close_button.dart';
 import 'package:veggieseasons/widgets/trivia.dart';
 
 class ServingInfoChart extends StatelessWidget {
-  const ServingInfoChart(this.veggie, this.prefs);
+  const ServingInfoChart(this.veggie, this.prefs, {Key key}) : super(key: key);
 
   final Veggie veggie;
 
@@ -158,7 +158,7 @@ class ServingInfoChart extends StatelessWidget {
 class InfoView extends StatelessWidget {
   final int id;
 
-  const InfoView(this.id);
+  const InfoView(this.id, {Key key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -239,7 +239,7 @@ class DetailsScreen extends StatefulWidget {
   final int id;
   final String restorationId;
 
-  const DetailsScreen({this.id, this.restorationId});
+  const DetailsScreen({this.id, this.restorationId, Key key}) : super(key: key);
 
   static String show(NavigatorState navigator, int veggieId) {
     return navigator.restorablePush<void>(_routeBuilder, arguments: veggieId);

veggieseasons/lib/widgets/close_button.dart

@@ -80,7 +80,7 @@ class _ColorChangingIconState
 
 /// A simple "close this modal" button that invokes a callback when pressed.
 class CloseButton extends StatefulWidget {
-  const CloseButton(this.onPressed);
+  const CloseButton(this.onPressed, {Key key}) : super(key: key);
 
   final VoidCallback onPressed;
 

veggieseasons/lib/widgets/settings_group.dart

@@ -14,7 +14,7 @@ import 'settings_item.dart';
 // See https://github.com/flutter/flutter/projects/29 for more info.
 
 class SettingsGroupHeader extends StatelessWidget {
-  const SettingsGroupHeader(this.title);
+  const SettingsGroupHeader(this.title, {Key key}) : super(key: key);
 
   final String title;
 
@@ -35,7 +35,7 @@ class SettingsGroupHeader extends StatelessWidget {
 }
 
 class SettingsGroupFooter extends StatelessWidget {
-  const SettingsGroupFooter(this.title);
+  const SettingsGroupFooter(this.title, {Key key}) : super(key: key);
 
   final String title;
 
@@ -58,8 +58,10 @@ class SettingsGroup extends StatelessWidget {
     @required this.items,
     this.header,
     this.footer,
+    Key key,
   })  : assert(items != null),
-        assert(items.isNotEmpty);
+        assert(items.isNotEmpty),
+        super(key: key);
 
   final List<SettingsItem> items;
   final Widget header;

veggieseasons/lib/widgets/trivia.dart

@@ -11,7 +11,7 @@ class TriviaView extends StatefulWidget {
   final int id;
   final String restorationId;
 
-  const TriviaView({this.id, this.restorationId});
+  const TriviaView({this.id, this.restorationId, Key key}) : super(key: key);
 
   @override
   _TriviaViewState createState() => _TriviaViewState();

veggieseasons/lib/widgets/veggie_card.dart

@@ -14,7 +14,8 @@ class FrostyBackground extends StatelessWidget {
     this.color,
     this.intensity = 25,
     this.child,
-  });
+    Key key,
+  }) : super(key: key);
 
   final Color color;
   final double intensity;
@@ -105,7 +106,9 @@ class _PressableCardState extends State<PressableCard> {
 }
 
 class VeggieCard extends StatelessWidget {
-  const VeggieCard(this.veggie, this.isInSeason, this.isPreferredCategory);
+  const VeggieCard(this.veggie, this.isInSeason, this.isPreferredCategory,
+      {Key key})
+      : super(key: key);
 
   /// Veggie to be displayed by the card.
   final Veggie veggie;

veggieseasons/lib/widgets/veggie_headline.dart

@@ -12,7 +12,9 @@ class ZoomClipAssetImage extends StatelessWidget {
       {@required this.zoom,
       this.height,
       this.width,
-      @required this.imageAsset});
+      @required this.imageAsset,
+      Key key})
+      : super(key: key);
 
   final double zoom;
   final double height;
@@ -43,7 +45,7 @@ class ZoomClipAssetImage extends StatelessWidget {
 class VeggieHeadline extends StatelessWidget {
   final Veggie veggie;
 
-  const VeggieHeadline(this.veggie);
+  const VeggieHeadline(this.veggie, {Key key}) : super(key: key);
 
   List<Widget> _buildSeasonDots(List<Season> seasons) {
     var widgets = <Widget>[];

veggieseasons/test/restoration_test.dart

@@ -16,7 +16,7 @@ void main() {
     AppState.debugCurrentSeason = Season.autumn;
 
     await tester.pumpWidget(
-      RootRestorationScope(
+      const RootRestorationScope(
         restorationId: 'root',
         child: VeggieApp(),
       ),

web/filipino_cuisine/analysis_options.yaml

@@ -17,4 +17,3 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false

web/filipino_cuisine/lib/cook.dart

@@ -5,7 +5,8 @@ class Cook extends StatefulWidget {
   final String? img;
   final String? nme;
 
-  const Cook(this.dr, this.img, this.nme);
+  const Cook(this.dr, this.img, this.nme, {Key? key}) : super(key: key);
+
   @override
   CState createState() => CState();
 }

web/filipino_cuisine/lib/flutter_swiper.dart

@@ -1423,7 +1423,8 @@ class SwiperPluginView extends StatelessWidget {
   final SwiperPlugin plugin;
   final SwiperPluginConfig config;
 
-  const SwiperPluginView(this.plugin, this.config);
+  const SwiperPluginView(this.plugin, this.config, {Key? key})
+      : super(key: key);
 
   @override
   Widget build(BuildContext context) {

web/filipino_cuisine/lib/main.dart

@@ -5,16 +5,17 @@ import 'package:http/http.dart' as http;
 import 'cook.dart';
 import 'flutter_swiper.dart';
 
-void main() => runApp(MyApp());
+void main() => runApp(const MyApp());
 
 class MyApp extends StatelessWidget {
+  const MyApp({Key? key}) : super(key: key);
+
+  @override
+  Widget build(context) {
     final _themeData = ThemeData(
       brightness: Brightness.light,
       iconTheme: const IconThemeData(color: Colors.red),
     );
-
-  @override
-  Widget build(context) {
     return MaterialApp(
         theme: _themeData.copyWith(
           colorScheme: _themeData.colorScheme.copyWith(
@@ -22,11 +23,13 @@ class MyApp extends StatelessWidget {
           ),
         ),
         title: "Filipino Cuisine",
-        home: Home());
+        home: const Home());
   }
 }
 
 class Home extends StatefulWidget {
+  const Home({Key? key}) : super(key: key);
+
   @override
   HState createState() => HState();
 }

web/filipino_cuisine/lib/transformer_page_view.dart

@@ -141,7 +141,8 @@ class ParallaxColor extends StatefulWidget {
     required this.colors,
     required this.info,
     required this.child,
-  });
+    Key? key,
+  }) : super(key: key);
 
   @override
   State<StatefulWidget> createState() {
@@ -159,7 +160,9 @@ class ParallaxContainer extends StatelessWidget {
       {required this.child,
       required this.position,
       this.translationFactor = 100.0,
-      this.opacityFactor = 1.0});
+      this.opacityFactor = 1.0,
+      Key? key})
+      : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -178,13 +181,14 @@ class ParallaxImage extends StatelessWidget {
   final double imageFactor;
 
   ParallaxImage.asset(String name,
-      {required double position, this.imageFactor = 0.3})
+      {required double position, this.imageFactor = 0.3, Key? key})
       : image = Image.asset(name,
             fit: BoxFit.cover,
             alignment: FractionalOffset(
               0.5 + position * imageFactor,
               0.5,
-            ));
+            )),
+        super(key: key);
 
   @override
   Widget build(BuildContext context) {

web/filipino_cuisine/pubspec.lock

@@ -14,7 +14,7 @@ packages:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   charcode:
     dependency: transitive
     description:

web/samples_index/analysis_options.yaml

@@ -19,4 +19,3 @@ linter:
     test_types_in_equals: true
     throw_in_finally: true
     unnecessary_statements: true
-    use_key_in_widget_constructors: false