Merge pull request #176 from brianegan/change-notifier-provider-fix

ChangeNotifierProviderSample updates

Author: brianegan

change_notifier_provider/lib/app.dart

@@ -23,7 +23,7 @@ class ProviderApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return ChangeNotifierProvider(
-      create: (_) => TodoListModel(repository: repository),
+      create: (_) => TodoListModel(repository: repository)..loadTodos(),
       child: MaterialApp(
         theme: ArchSampleTheme.theme,
         localizationsDelegates: [

change_notifier_provider/lib/todo_list_model.dart

@@ -39,13 +39,6 @@ class TodoListModel extends ChangeNotifier {
   })  : _todos = todos ?? [],
         _filter = filter ?? VisibilityFilter.all;
 
-  @override
-  void addListener(VoidCallback listener) {
-    super.addListener(listener);
-    // update data for every subscriber, especially for the first one
-    loadTodos();
-  }
-
   /// Loads remote data
   ///
   /// Call this initially and when the user manually refreshes

change_notifier_provider/pubspec.yaml

@@ -17,7 +17,7 @@ environment:
   sdk: ">=2.6.0 <3.0.0"
 
 dependencies:
-  provider: ^4.0.1
+  provider: ^4.0.4
   todos_repository_local_storage:
     path: ../todos_repository_local_storage
   todos_app_core:

change_notifier_provider/test/home_screen_test.dart

@@ -1,17 +1,17 @@
-import 'package:flutter/cupertino.dart';
-import 'package:flutter/material.dart';
-import 'package:flutter_test/flutter_test.dart';
-import 'package:provider/provider.dart';
 import 'package:change_notifier_provider_sample/home/home_screen.dart';
 import 'package:change_notifier_provider_sample/localization.dart';
 import 'package:change_notifier_provider_sample/models.dart';
 import 'package:change_notifier_provider_sample/todo_list_model.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:provider/provider.dart';
 import 'package:todos_app_core/todos_app_core.dart';
 import 'package:todos_repository_core/todos_repository_core.dart';
 
 import 'mock_repository.dart';
 
-/// Demonstrates how to test Widgets
+/// Demonstrates how to test Widgets in combination with a ChangeNotifier
 void main() {
   group('HomeScreen', () {
     final todoListFinder = find.byKey(ArchSampleKeys.todoList);
@@ -91,16 +91,16 @@ class _TestWidget extends StatelessWidget {
     Key key,
     this.child,
     this.repository,
-    this.todos = const [],
+    this.todos,
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return ChangeNotifierProvider<TodoListModel>(
-      create: (_) => TodoListModel(
-        repository: MockRepository([]),
-        todos: defaultTodos(),
-      ),
+      create: (_) {
+        final repo = MockRepository(todos ?? _defaultTodos);
+        return TodoListModel(repository: repo)..loadTodos();
+      },
       child: MaterialApp(
         localizationsDelegates: [
           ProviderLocalizationsDelegate(),
@@ -110,14 +110,14 @@ class _TestWidget extends StatelessWidget {
       ),
     );
   }
-}
 
-List<Todo> defaultTodos() {
-  return [
-    Todo('T1', id: '1', note: 'N1'),
-    Todo('T2', id: '2'),
-    Todo('T3', id: '3', complete: true),
-  ];
+  static List<Todo> get _defaultTodos {
+    return [
+      Todo('T1', id: '1', note: 'N1'),
+      Todo('T2', id: '2'),
+      Todo('T3', id: '3', complete: true),
+    ];
+  }
 }
 
 Matcher isChecked(bool isChecked) {

…tifier_provider/test/app_state_test.dart …_provider/test/todo_list_model_test.dartchange_notifier_provider/test/app_state_test.dart renamed to change_notifier_provider/test/todo_list_model_test.dart change_notifier_provider/test/app_state_test.dart renamed to change_notifier_provider/test/todo_list_model_test.dart

@@ -141,5 +141,23 @@ void main() {
       expect(model.todos, [todo1, update, todo3]);
       expect(repository.saveCount, 1);
     });
+
+    test('should load todos from the repository', () async {
+      final todos = [Todo('a'), Todo('b'), Todo('c', complete: true)];
+      final repository = MockRepository(todos);
+      final model = TodoListModel(repository: repository);
+
+      expect(model.isLoading, isFalse);
+      expect(model.todos, []);
+
+      final loading = model.loadTodos();
+
+      expect(model.isLoading, isTrue);
+
+      await loading;
+
+      expect(model.isLoading, isFalse);
+      expect(model.todos, todos);
+    });
   });
 }