// 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:fake_async/fake_async.dart'; import 'package:flutter/material.dart'; import 'package:flutter_test/flutter_test.dart'; void main() { setUp(() { WidgetsFlutterBinding.ensureInitialized(); WidgetsBinding.instance!.resetEpoch(); }); test('WidgetBinding build rendering tree and warm up frame back to back', () { final FakeAsync fakeAsync = FakeAsync(); fakeAsync.run((FakeAsync async) { runApp( const MaterialApp( home: Material( child: Text('test'), ), ), ); // Rendering tree is not built synchronously. expect(WidgetsBinding.instance!.renderViewElement, isNull); fakeAsync.flushTimers(); expect(WidgetsBinding.instance!.renderViewElement, isNotNull); }); }); }