// Copyright 2014 The Flutter Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. import 'package:flutter/scheduler.dart'; import 'package:flutter/services.dart'; import 'package:flutter/widgets.dart'; import 'package:flutter_test/flutter_test.dart'; void main() { test('attachRootWidget will schedule a frame', () async { final WidgetsFlutterBinding binding = WidgetsFlutterBinding.ensureInitialized() as WidgetsFlutterBinding; expect(SchedulerBinding.instance.hasScheduledFrame, isFalse); // Framework starts with detached statue. Sends resumed signal to enable frame. final ByteData message = const StringCodec().encodeMessage('AppLifecycleState.resumed')!; await ServicesBinding.instance.defaultBinaryMessenger.handlePlatformMessage('flutter/lifecycle', message, (_) { }); binding.attachRootWidget(const Placeholder()); expect(SchedulerBinding.instance.hasScheduledFrame, isTrue); }); }