如何从ChangeNotifier提供者状态对值进行单元测试？

import 'package:flutter_test/flutter_test.dart';
import 'package:your_app/change_notifier_provider.dart'; // 替换为你的ChangeNotifier提供者文件路径

class ExampleTest extends StatefulWidget {
  @override
  _ExampleTestState createState() => _ExampleTestState();
}

class _ExampleTestState extends State<ExampleTest> with TestWidgetsFlutterBindingMixin {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Container(), // 替换为你的ChangeNotifier提供者的根部件
      ),
    );
  }
}

void testExample() {
  testWidgets('Test ChangeNotifier Provider', (WidgetTester tester) async {
    await tester.pumpWidget(ExampleTest()); // 创建测试环境

    // 获取ChangeNotifier提供者实例
    final provider = Provider.of<YourChangeNotifierProvider>(tester.element(find.byType(Container)));

    // 断言初始状态
    expect(provider.value, equals(initialValue));

    // 修改状态
    provider.updateValue(newValue);

    // 断言修改后的状态
    expect(provider.value, equals(newValue));
  });
}

void main() {
  testExample();
}

flutter test test/example_test.dart