Landing beta changes in master for the new stable release (#747)

provider_shopper/lib/main.dart

@@ -30,6 +30,7 @@ class MyApp extends StatelessWidget {
         ChangeNotifierProxyProvider<CatalogModel, CartModel>(
           create: (context) => CartModel(),
           update: (context, catalog, cart) {
+            if (cart == null) throw ArgumentError.notNull('cart');
             cart.catalog = catalog;
             return cart;
           },

provider_shopper/lib/models/cart.dart

@@ -7,7 +7,7 @@ import 'package:provider_shopper/models/catalog.dart';
 
 class CartModel extends ChangeNotifier {
   /// The private field backing [catalog].
-  CatalogModel _catalog;
+  late CatalogModel _catalog;
 
   /// Internal, private state of the cart. Stores the ids of each item.
   final List<int> _itemIds = [];
@@ -16,9 +16,6 @@ class CartModel extends ChangeNotifier {
   CatalogModel get catalog => _catalog;
 
   set catalog(CatalogModel newCatalog) {
-    assert(newCatalog != null);
-    assert(_itemIds.every((id) => newCatalog.getById(id) != null),
-        'The catalog $newCatalog does not have one of $_itemIds in it.');
     _catalog = newCatalog;
     // Notify listeners, in case the new catalog provides information
     // different from the previous one. For example, availability of an item

provider_shopper/lib/screens/cart.dart

@@ -65,7 +65,7 @@ class _CartTotal extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     var hugeStyle =
-        Theme.of(context).textTheme.headline1.copyWith(fontSize: 48);
+        Theme.of(context).textTheme.headline1!.copyWith(fontSize: 48);
 
     return SizedBox(
       height: 200,
@@ -85,7 +85,7 @@ class _CartTotal extends StatelessWidget {
             SizedBox(width: 24),
             TextButton(
               onPressed: () {
-                Scaffold.of(context).showSnackBar(
+                ScaffoldMessenger.of(context).showSnackBar(
                     SnackBar(content: Text('Buying not supported yet.')));
               },
               style: TextButton.styleFrom(primary: Colors.white),

provider_shopper/lib/screens/catalog.dart

@@ -28,7 +28,7 @@ class MyCatalog extends StatelessWidget {
 class _AddButton extends StatelessWidget {
   final Item item;
 
-  const _AddButton({Key key, @required this.item}) : super(key: key);
+  const _AddButton({required this.item, Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -55,7 +55,7 @@ class _AddButton extends StatelessWidget {
               cart.add(item);
             },
       style: ButtonStyle(
-        overlayColor: MaterialStateProperty.resolveWith<Color>((states) {
+        overlayColor: MaterialStateProperty.resolveWith<Color?>((states) {
           if (states.contains(MaterialState.pressed)) {
             return Theme.of(context).primaryColor;
           }
@@ -86,7 +86,7 @@ class _MyAppBar extends StatelessWidget {
 class _MyListItem extends StatelessWidget {
   final int index;
 
-  _MyListItem(this.index, {Key key}) : super(key: key);
+  _MyListItem(this.index, {Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

provider_shopper/pubspec.lock

@@ -7,49 +7,49 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.3"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.5"
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.3"
+    version: "1.2.0"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.5"
+    version: "1.15.0"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.3"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -66,42 +66,42 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.3"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.6"
+    version: "1.3.0"
   nested:
     dependency: transitive
     description:
       name: nested
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.4"
+    version: "1.0.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.3"
+    version: "1.8.0"
   pedantic:
     dependency: "direct dev"
     description:
       name: pedantic
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.2"
+    version: "1.10.0"
   provider:
     dependency: "direct main"
     description:
       name: provider
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.3.3"
+    version: "5.0.0-nullsafety.5"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -113,56 +113,56 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.4"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.6"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.3"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.6"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.5"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.5"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.12.0-0.0 <3.0.0"
+  dart: ">=2.12.0-259.16.beta <3.0.0"
   flutter: ">=1.16.0"

provider_shopper/pubspec.yaml

@@ -4,19 +4,19 @@ description: A shopping app sample that uses Provider for state management.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.5.0 <3.0.0"
+  sdk: '>=2.12.0-259.16.beta <3.0.0'
 
 dependencies:
   flutter:
     sdk: flutter
 
   # Import the provider package.
-  provider: ^4.3.2
+  provider: '>=5.0.0-nullsafety.5 <6.0.0'
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  pedantic: ^1.9.0
+  pedantic: ^1.10.0
 
 flutter:
   uses-material-design: true

provider_shopper/test/cart_widget_test.dart

@@ -9,8 +9,8 @@ import 'package:provider_shopper/models/cart.dart';
 import 'package:provider_shopper/models/catalog.dart';
 import 'package:provider_shopper/screens/cart.dart';
 
-CartModel cartModel;
-CatalogModel catalogModel;
+CartModel? cartModel;
+CatalogModel? catalogModel;
 Widget createCartScreen() => MultiProvider(
       providers: [
         Provider(create: (context) => CatalogModel()),
@@ -19,7 +19,7 @@ Widget createCartScreen() => MultiProvider(
           update: (context, catalog, cart) {
             catalogModel = catalog;
             cartModel = cart;
-            cart.catalog = catalogModel;
+            cart!.catalog = catalogModel!;
             return cart;
           },
         ),
@@ -48,8 +48,8 @@ void main() {
 
       // Adding five items in the cart and testing.
       for (var i = 0; i < 5; i++) {
-        var item = catalogModel.getByPosition(i);
-        cartModel.add(item);
+        var item = catalogModel!.getByPosition(i);
+        cartModel!.add(item);
         await tester.pumpAndSettle();
         expect(find.text(item.name), findsOneWidget);
       }

provider_shopper/test/catalog_widget_test.dart

@@ -16,7 +16,7 @@ Widget createCatalogScreen() => MultiProvider(
         ChangeNotifierProxyProvider<CatalogModel, CartModel>(
           create: (context) => CartModel(),
           update: (context, catalog, cart) {
-            cart.catalog = catalog;
+            cart!.catalog = catalog;
             return cart;
           },
         ),

provider_shopper/test/login_widget_test.dart

@@ -18,7 +18,7 @@ void main() {
         ChangeNotifierProxyProvider<CatalogModel, CartModel>(
           create: (context) => CartModel(),
           update: (context, catalog, cart) {
-            cart.catalog = catalog;
+            cart!.catalog = catalog;
             return cart;
           },
         ),