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

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(),
-          FavoritesPage.routeName: (context) => FavoritesPage(),
+          HomePage.routeName: (context) => const HomePage(),
+          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(
-    this.itemNo,
-  );
+  const FavoriteItemTile(this.itemNo, {Key? key}) : super(key: key);
 
   @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(
-    this.itemNo,
-  );
+  const ItemTile(this.itemNo, {Key? key}) : super(key: key);
 
   @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(),
       ),
     );