How to handle errors in flutter providers?

[codemewell]

ChangeNotifiers' unhandled exceptions don't seems to be catched by SentryFlutter appRunner wrapper.

Is there any recommended way to catch these exceptions in providers and report to Sentry?

[ueman]

Do you have some example code to reproduce this?
Also which Sentry and Flutter versions are you using?

[codemewell]

📦 provider: 4.3.3
📦 sentry_flutter: 4.0.4

🏴 Flutter: 1.22.6

🐛 Minimal reproduction code:

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

import 'package:provider/provider.dart';
import 'package:sentry_flutter/sentry_flutter.dart';

void main() async {
  //! error mishandling when these are called before SentryFlutter.init():
  WidgetsFlutterBinding.ensureInitialized();
  await SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown,
  ]);
  await SentryFlutter.init(
    (options) {
      options.dsn =
          '{DNS address}';
    },
    appRunner: () => runApp(
      MultiProvider(
        providers: [
          ChangeNotifierProvider(create: (_) => Counter(), lazy: false),
        ],
        child: const MyApp(),
      ),
    ),
  );
}

class Counter with ChangeNotifier {
  int _count = 0;

  int get count => _count;

  //! error mishandling on asynchronous methods:
  Future<void> increment() async {
    _count++;
    throw Exception('Counter unhandled error');
    notifyListeners();
  }
}

class MyApp extends StatelessWidget {
  const MyApp({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  const MyHomePage({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Example'),
      ),
      body: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          mainAxisAlignment: MainAxisAlignment.center,
          children: const <Widget>[
            Text('You have pushed the button this many times:'),
            Count(),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        key: const Key('increment_floatingActionButton'),
        onPressed: () => context.read<Counter>().increment(),
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}

class Count extends StatelessWidget {
  const Count({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Text('${context.watch<Counter>().count}',
        key: const Key('counterState'),
        style: Theme.of(context).textTheme.headline4);
  }
}

🔥 Bug appears in asynchronous provider's methods. (Synch methods work fine)

🏆 Solution I came up with is following:

• move this code block inside async appRunner method before runApp call:

WidgetsFlutterBinding.ensureInitialized();
  await SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown,
  ]);

[ueman]

You don't need to call WidgetsFlutterBinding.ensureInitialized() yourself because it is already done by Sentry.
Other than that your solution is the recommended approach to use it. All code should ideally be inside the appRunner callback, so that Sentry can catch all exceptions.