| // 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/foundation.dart'; |
| import 'package:flutter/material.dart'; |
| import 'package:flutter_test/flutter_test.dart'; |
| |
| // This test is very fragile and bypasses some zone-related checks. |
| // It is written this way to verify some invariants that would otherwise |
| // be difficult to check. |
| // Do not use this test as a guide for writing good Flutter code. |
| |
| class TestBinding extends WidgetsFlutterBinding { |
| @override |
| void initInstances() { |
| super.initInstances(); |
| _instance = this; |
| } |
| |
| @override |
| bool debugCheckZone(String entryPoint) { return true; } |
| |
| static TestBinding get instance => BindingBase.checkInstance(_instance); |
| static TestBinding? _instance; |
| |
| static TestBinding ensureInitialized() { |
| if (TestBinding._instance == null) { |
| TestBinding(); |
| } |
| return TestBinding.instance; |
| } |
| } |
| |
| void main() { |
| setUp(() { |
| TestBinding.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.rootElement, isNull); |
| fakeAsync.flushTimers(); |
| expect(WidgetsBinding.instance.rootElement, isNotNull); |
| }); |
| }); |
| } |