Test fails due to pending timer when using ShadApp.material in Flutter counter app example #294
Description
Steps to reproduce
- Create a new Flutter project using
flutter create counter_app. - Replace the
MaterialAppinlib/main.dartwithShadApp.material. - Run the default test (
test/widget_test.dart) usingflutter test.
Code Example:
Here is the modified lib/main.dart:
import 'package:flutter/material.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return ShadApp.material(
title: 'Flutter Demo',
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// TRY THIS: Try changing the color here to a specific color (to
// Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
// change color while the other colors stay the same.
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
//
// TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
// action in the IDE, or press "p" in the console), to see the
// wireframe for each widget.
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headlineMedium,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
Expected results
The test should pass without any errors, just as it does when using MaterialApp.
Actual results
The test fails with the following error:
A Timer is still pending even after the widget tree was disposed.
'package:flutter_test/src/binding.dart':
Failed assertion: line 1537 pos 12: '!timersPending'
shadcn_ui version
0.19.3
Platform
MacOS
Code sample
Code sample
Here is the modified lib/main.dart:
import 'package:flutter/material.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return ShadApp.material(
title: 'Flutter Demo',
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter++;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// TRY THIS: Try changing the color here to a specific color (to
// Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
// change color while the other colors stay the same.
backgroundColor: Theme.of(context).colorScheme.inversePrimary,
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
//
// TRY THIS: Invoke "debug painting" (choose the "Toggle Debug Paint"
// action in the IDE, or press "p" in the console), to see the
// wireframe for each widget.
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headlineMedium,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
Screenshots or Video
Screenshots / Video demonstration
[Upload media here]
Logs
Logs
[Pending timers:
Timer (duration: 0:00:00.000000, periodic: false), created:
#0 new FakeTimer._ (package:fake_async/fake_async.dart:308:62)
#1 FakeAsync._createTimer (package:fake_async/fake_async.dart:252:27)
#2 FakeAsync.run.<anonymous closure> (package:fake_async/fake_async.dart:185:19)
#6 _AnimateState._restart (package:flutter_animate/src/animate.dart:318:23)
#7 _AnimateState.initState (package:flutter_animate/src/animate.dart:290:5)
#8 StatefulElement._firstBuild (package:flutter/src/widgets/framework.dart:5762:55)
#9 ComponentElement.mount (package:flutter/src/widgets/framework.dart:5607:5)
... Normal element mounting (17 frames)
#26 Element.inflateWidget (package:flutter/src/widgets/framework.dart:4480:16)
#27 MultiChildRenderObjectElement.inflateWidget (package:flutter/src/widgets/framework.dart:7049:36)
#28 MultiChildRenderObjectElement.mount (package:flutter/src/widgets/framework.dart:7061:32)
... Normal element mounting (464 frames)
#492 Element.inflateWidget (package:flutter/src/widgets/framework.dart:4480:16)
#493 Element.updateChild (package:flutter/src/widgets/framework.dart:3957:20)
#494 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#495 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#496 ProxyElement.update (package:flutter/src/widgets/framework.dart:5960:5)
#497 _InheritedNotifierElement.update (package:flutter/src/widgets/inherited_notifier.dart:112:11)
#498 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#499 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#500 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5794:11)
#501 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#502 StatefulElement.update (package:flutter/src/widgets/framework.dart:5817:5)
#503 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#504 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#505 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#506 ProxyElement.update (package:flutter/src/widgets/framework.dart:5960:5)
#507 _InheritedNotifierElement.update (package:flutter/src/widgets/inherited_notifier.dart:112:11)
#508 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#509 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#510 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5794:11)
#511 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#512 StatefulElement.update (package:flutter/src/widgets/framework.dart:5817:5)
#513 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#514 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#515 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5794:11)
#516 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#517 StatefulElement.update (package:flutter/src/widgets/framework.dart:5817:5)
#518 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#519 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#520 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#521 ProxyElement.update (package:flutter/src/widgets/framework.dart:5960:5)
#522 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#523 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#524 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5794:11)
#525 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#526 StatefulElement.update (package:flutter/src/widgets/framework.dart:5817:5)
#527 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#528 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#529 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#530 ProxyElement.update (package:flutter/src/widgets/framework.dart:5960:5)
#531 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#532 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#533 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#534 ProxyElement.update (package:flutter/src/widgets/framework.dart:5960:5)
#535 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#536 _RawViewElement._updateChild (package:flutter/src/widgets/view.dart:465:16)
#537 _RawViewElement.update (package:flutter/src/widgets/view.dart:552:5)
#538 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#539 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#540 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#541 StatelessElement.update (package:flutter/src/widgets/framework.dart:5707:5)
#542 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#543 ComponentElement.performRebuild (package:flutter/src/widgets/framework.dart:5656:16)
#544 StatefulElement.performRebuild (package:flutter/src/widgets/framework.dart:5794:11)
#545 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#546 StatefulElement.update (package:flutter/src/widgets/framework.dart:5817:5)
#547 Element.updateChild (package:flutter/src/widgets/framework.dart:3941:15)
#548 RootElement._rebuild (package:flutter/src/widgets/binding.dart:1636:16)
#549 RootElement.update (package:flutter/src/widgets/binding.dart:1614:5)
#550 RootElement.performRebuild (package:flutter/src/widgets/binding.dart:1628:7)
#551 Element.rebuild (package:flutter/src/widgets/framework.dart:5347:7)
#552 BuildScope._tryRebuild (package:flutter/src/widgets/framework.dart:2694:15)
#553 BuildScope._flushDirtyElements (package:flutter/src/widgets/framework.dart:2753:11)
#554 BuildOwner.buildScope (package:flutter/src/widgets/framework.dart:3048:18)
#555 AutomatedTestWidgetsFlutterBinding.drawFrame (package:flutter_test/src/binding.dart:1428:19)
#556 RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:475:5)
#557 SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:1397:15)
#558 SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:1318:9)
#559 AutomatedTestWidgetsFlutterBinding.pump.<anonymous closure> (package:flutter_test/src/binding.dart:1283:9)
#562 TestAsyncUtils.guard (package:flutter_test/src/test_async_utils.dart:74:41)
#563 AutomatedTestWidgetsFlutterBinding.pump (package:flutter_test/src/binding.dart:1270:27)
#564 WidgetTester.pumpWidget.<anonymous closure> (package:flutter_test/src/widget_tester.dart:608:22)
#567 TestAsyncUtils.guard (package:flutter_test/src/test_async_utils.dart:74:41)
#568 WidgetTester.pumpWidget (package:flutter_test/src/widget_tester.dart:605:27)
#569 main.<anonymous closure> (file:///Users/malte/code/counter_app/test/widget_test.dart:16:18)
#570 testWidgets.<anonymous closure>.<anonymous closure> (package:flutter_test/src/widget_tester.dart:189:29)
<asynchronous suspension>
#571 TestWidgetsFlutterBinding._runTestBody (package:flutter_test/src/binding.dart:1027:5)
<asynchronous suspension>
<asynchronous suspension>
(elided 8 frames from dart:async and package:stack_trace)
══╡ EXCEPTION CAUGHT BY FLUTTER TEST FRAMEWORK ╞════════════════════════════════════════════════════
The following assertion was thrown running a test:
A Timer is still pending even after the widget tree was disposed.
'package:flutter_test/src/binding.dart':
Failed assertion: line 1537 pos 12: '!timersPending'
When the exception was thrown, this was the stack:
#2 AutomatedTestWidgetsFlutterBinding._verifyInvariants (package:flutter_test/src/binding.dart:1537:12)
#3 TestWidgetsFlutterBinding._runTestBody (package:flutter_test/src/binding.dart:1044:7)
<asynchronous suspension>
<asynchronous suspension>
(elided 3 frames from class _AssertionError and package:stack_trace)
The test description was:
Counter increments smoke test
════════════════════════════════════════════════════════════════════════════════════════════════════
Temporary Workaround
As a temporary workaround, I used this:
// This is a basic Flutter widget test.
//
// To perform an interaction with a widget in your test, use the WidgetTester
// utility in the flutter_test package. For example, you can send tap and scroll
// gestures. You can also use WidgetTester to find child widgets in the widget
// tree, read text, and verify that the values of widget properties are correct.
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:counter_app/main.dart';
void main() {
testWidgets('Counter increments smoke test', (WidgetTester tester) async {
// Build our app and trigger a frame.
- await tester.pumpWidget(const MyApp());
+ await tester.runAsync(() => tester.pumpWidget(const MyApp()));
// Verify that our counter starts at 0.
expect(find.text('0'), findsOneWidget);
expect(find.text('1'), findsNothing);
// Tap the '+' icon and trigger a frame.
await tester.tap(find.byIcon(Icons.add));
await tester.pump();
// Verify that our counter has incremented.
expect(find.text('0'), findsNothing);
expect(find.text('1'), findsOneWidget);
});
}
Flutter Doctor output
Doctor output
[✓] Flutter (Channel stable, 3.27.3, on macOS 14.5 23F79 darwin-x64, locale en-CH)
• Flutter version 3.27.3 on channel stable at /Users/private/.puro/envs/stable/flutter
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision c519ee916e (3 weeks ago), 2025-01-21 10:32:23 -0800
• Engine revision e672b006cb
• Dart version 3.6.1
• DevTools version 2.40.2
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.1)
• Android SDK at /Users/private/Library/Android/sdk
• Platform android-35, build-tools 35.0.1
• Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 21.0.4+-12422083-b607.1)
• All Android licenses accepted.
[✗] Xcode - develop for iOS and macOS
✗ Xcode installation is incomplete; a full installation is necessary for iOS and macOS development.
Download at: https://developer.apple.com/xcode/
Or install Xcode via the App Store.
Once installed, run:
sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
sudo xcodebuild -runFirstLaunch
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Without CocoaPods, plugins will not work on iOS or macOS.
For more info, see https://flutter.dev/to/platform-plugins
For installation instructions, see https://guides.cocoapods.org/using/getting-started.html#installation
[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 2024.2)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 21.0.4+-12422083-b607.1)
[✓] VS Code (version 1.95.2)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.102.0
[✓] Connected device (3 available)
• sdk gphone64 x86 64 (mobile) • emulator-5554 • android-x64 • Android 15 (API 35) (emulator)
• macOS (desktop) • macos • darwin-x64 • macOS 14.5 23F79 darwin-x64
• Chrome (web) • chrome • web-javascript • Google Chrome 133.0.6943.54
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• All expected network resources are available.
! Doctor found issues in 1 category.