如何对访问 Provider.of(context) 的小部件进行 Flutter 测试

Posted 2023-02-23

【中文标题】如何对访问 Provider.of(context) 的小部件进行 Flutter 测试

【英文标题】：How to do a Flutter Test for a widget that accesses Provider.of(context)

【发布时间】：2021-04-29 19:18:35

【问题描述】：

我想知道是否有人可以帮助我，我无法为我的 Flutter 项目的主页编写测试，因为它依赖于 Provider。

home_page.dart

Future<NewsModel> newsData = Provider.of<Future<NewsModel>>(context);

return FutureProvider(
  create: (context) => newsData,
  child: (newsData != null)
      ? Scaffold(
          body: SmartRefresher(
            controller: _refreshController,
            onRefresh: _refreshNews,
            onLoading: _onLoading,
            child: Consumer<NewsModel>(
              builder: (_, news, __) ...

main.dart

return MultiProvider(
  providers: [
    FutureProvider(create: (context) => geolocatorService.getlocation()),
    ProxyProvider<Position, Future<NewsModel>>(
      update: (context, position, news) 
        return (position != null) ? newsService.getNews() : null;
      ,
    ),

home_page_test.dart

testWidgets('Test the home screen', (WidgetTester tester) async 
HomePage homePage = new HomePage();

await tester.pumpWidget(
  makeWidgetTestable(
    child: homePage,
  ),
);

);

当我运行这个测试时，我收到以下错误，我真的很困惑，需要一些指导。我对 Flutter 相当有经验，但我是为需要外部依赖项的小部件编写小部件测试的新手。如果有人可以提供帮助，那就太好了。

错误：

The following ProviderNotFoundException was thrown building HomePage(dirty, dependencies [MediaQuery], state: _HomePageState#ce244): Error: Could not find the correct Provider<Future<NewsModel>> above this HomePage Widget

【参考方案1】：

如果您使用主文件中的提供程序包装以下代码：

await tester.pumpWidget(
  makeWidgetTestable(
    child: homePage,
  ),
);

并把它变成：

testWidgets('Test the home screen', (WidgetTester tester) async 
//No longer need the following line
//HomePage homePage = new HomePage();

await tester.pumpWidget(
MultiProvider(
  providers: [
    FutureProvider(create: (context) => geolocatorService.getlocation()),
    ProxyProvider<Position, Future<NewsModel>>(
      update: (context, position, news) 
        return (position != null) ? newsService.getNews() : null;
      ,
    ),
    child: homePage,
  ),
);