[Web] ScrollController throws unexpected null exception on web, when getting maxScrollExtent

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Steps to reproduce

Create an app with two screens - home one with a ListView , another with any widget. Add check that position.maxScrollExtent > 0 in ScrollController 's onAttach method. Launch an app and go to the second page. Refresh page and you will see Unexpected null value exception. There's no app crash, etc. but the exception is thrown every time.
Expected results

No exception is thrown.
Actual results

Unexpected null value exception is thrown.
Code sample

void main() {
  runApp(
    const MyApp(),
class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      routerConfig: _router,
final _router = GoRouter(
  routes: [
    GoRoute(path: '/', builder: (context, state) => const PageA(), routes: [
      GoRoute(
        path: 'b',
        builder: (context, state) => const PageB(),
class PageA extends StatefulWidget {
  const PageA({super.key});
  @override
  State<PageA> createState() => _PageAState();
class _PageAState extends State<PageA> {
  late final ScrollController _scrollController;
  bool isScrollable = false;
  void onScrollControllerAttach(final ScrollPosition position) {
    // ignore: prefer_final_parameters
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (_scrollController.hasClients && position.maxScrollExtent > 0) {
        setState(() {
          isScrollable = true;
  @override
  void initState() {
    super.initState();
    _scrollController = ScrollController(onAttach: onScrollControllerAttach);
  @override
  void dispose() {
    _scrollController.dispose();
    super.dispose();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: isScrollable ? Colors.blue : Colors.white,
      body: ListView.builder(
        controller: _scrollController,
        itemCount: 50,
        itemBuilder: (context, index) => ListTile(onTap: () => context.go('/b'), title: Text('$index')),
class PageB extends StatelessWidget {
  const PageB({super.key});
  @override
  Widget build(BuildContext context) {
    return const Scaffold(
      body: Center(
        child: Text('PageB'),
Screenshots or Video
No response
══╡ EXCEPTION CAUGHT BY SCHEDULER LIBRARY ╞═════════════════════════════════════════════════════════
The following TypeErrorImpl was thrown during a scheduler callback:
Unexpected null value.
When the exception was thrown, this was the stack:
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 296:3       throw_
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 586:18  nullCheck
packages/flutter/src/widgets/scroll_position.dart 228:49                          get maxScrollExtent
packages/untitled1/main.dart 48:51                                                <fn>
packages/flutter/src/scheduler/binding.dart 1392:7                                [_invokeFrameCallback]
packages/flutter/src/scheduler/binding.dart 1326:11                               handleDrawFrame
packages/flutter/src/scheduler/binding.dart 1035:9                                <fn>
dart-sdk/lib/_internal/js_dev_runtime/private/isolate_helper.dart 48:11           internalCallback
════════════════════════════════════════════════════════════════════════════════════════════════════




    

Flutter Doctor output
Doctor output
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 3.22.0, on macOS 14.5 23F79 darwin-arm64, locale ru-RU)
[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 15.4)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2023.3)
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[✓] IntelliJ IDEA Community Edition (version 2022.2)
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    ! Error: Browsing on the local area network for iPhoneK. Ensure the device is unlocked and attached with a cable or associated with the same local area network as this Mac.
      The device must be opted into Developer Mode to connect wirelessly. (code -27)
[✓] Network resources
• No issues found!
          Thanks for the report. I was able to replicate this only on web, as on, mobile and desktop, hot restarting doesn't throw the said exception.
 stable, master flutter doctor -v 
[!] Flutter (Channel stable, 3.22.2, on macOS 12.2.1 21D62 darwin-x64, locale
    en-GB)
    • Flutter version 3.22.2 on channel stable at
      /Users/dhs/documents/fluttersdk/flutter
    ! Warning: `flutter` on your path resolves to
      /Users/dhs/Documents/Fluttersdk/flutter/bin/flutter, which is not inside
      your current Flutter SDK checkout at
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      /Users/dhs/documents/fluttersdk/flutter/bin to the front of your path.
    ! Warning: `dart` on your path resolves to
      /Users/dhs/Documents/Fluttersdk/flutter/bin/dart, which is not inside your
      current Flutter SDK checkout at /Users/dhs/documents/fluttersdk/flutter.
      Consider adding /Users/dhs/documents/fluttersdk/flutter/bin to the front
      of your path.
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 761747bfc5 (33 hours ago), 2024-06-05 22:15:13 +0200
    • Engine revision edd8546116
    • Dart version 3.4.3
    • DevTools version 2.34.3
    • If those were intentional, you can disregard the above warnings; however
      it is recommended to use "git" directly to perform update checks and
      upgrades.
[!] Xcode - develop for iOS and macOS (Xcode 12.3)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    ! Flutter recommends a minimum Xcode version of 13.
      Download the latest version or update via the Mac App Store.
    • CocoaPods version 1.11.2
[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] VS Code (version 1.62.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.21.0
[✓] Connected device (5 available)
    • SM G975F (mobile)       • RZ8M802WY0X • android-arm64   • Android 11 (API 30)
    • Darshan's iphone (mobile)  • 21150b119064aecc249dfcfe05e259197461ce23 •
      ios            • iOS 14.4.1 18D61
    • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729     •
      ios            • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator)
    • macOS (desktop)            • macos                                    •
      darwin-x64     • Mac OS X 10.15.4 19E2269 darwin-x64
    • Chrome (web)               • chrome                                   •
      web-javascript • Google Chrome 98.0.4758.80
[✓] HTTP Host Availability
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! Doctor found issues in 1 category.
[!] Flutter (Channel master, 3.23.0-13.0.pre.149, on macOS 12.2.1 21D62
    darwin-x64, locale en-GB)
    • Flutter version 3.23.0-13.0.pre.149 on channel master at
      /Users/dhs/documents/fluttersdk/flutter
    ! Warning: `flutter` on your path resolves to
      /Users/dhs/Documents/Fluttersdk/flutter/bin/flutter, which is not inside
      your current Flutter SDK checkout at
      /Users/dhs/documents/fluttersdk/flutter. Consider adding
      /Users/dhs/documents/fluttersdk/flutter/bin to the front of your path.
    ! Warning: `dart` on your path resolves to
      /Users/dhs/Documents/Fluttersdk/flutter/bin/dart, which is not inside your
      current Flutter SDK checkout at /Users/dhs/documents/fluttersdk/flutter.
      Consider adding /Users/dhs/documents/fluttersdk/flutter/bin to the front
      of your path.
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision ae47edab7a (68 minutes ago), 2024-06-07 01:34:14 -0400
    • Engine revision 087feab992
    • Dart version 3.5.0 (build 3.5.0-234.0.dev)
    • DevTools version 2.36.0
    • If those were intentional, you can disregard the above warnings; however
      it is recommended to use "git" directly to perform update checks and
      upgrades.
[!] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at /Users/dhs/Library/Android/sdk
    ✗ cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/macos#android-setup for
      more details.
[✓] Xcode - develop for iOS and macOS (Xcode 13.2.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 13C100
    • CocoaPods version 1.11.2
[✓] Chrome - develop for the web
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[✓] IntelliJ IDEA Ultimate Edition (version 2021.3.2)
    • IntelliJ at /Applications/IntelliJ IDEA.app
    • Flutter plugin version 65.1.4
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[✓] VS Code (version 1.62.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.29.0
[✓] Connected device (3 available)
    • Darshan's iphone (mobile) • 21150b119064aecc249dfcfe05e259197461ce23 • ios
      • iOS 15.3.1 19D52
    • macOS (desktop)           • macos                                    •
      darwin-x64     • macOS 12.2.1 21D62 darwin-x64
    • Chrome (web)              • chrome                                   •
      web-javascript • Google Chrome 109.0.5414.119
[✓] Network resources
    • All expected network resources are available.
! Doctor found issues in 1 category.
[!] Xcode - develop for iOS and macOS (Xcode 12.3)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    ! Flutter recommends a minimum Xcode version of 13.
      Download the latest version or update via the Mac App Store.
    • CocoaPods version 1.11.2
[✓] Chrome - develop for the web
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[✓] VS Code (version 1.62.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.21.0
[✓] Connected device (5 available)
    • SM G975F (mobile)       • RZ8M802WY0X • android-arm64   • Android 11 (API 30)
    • Darshan's iphone (mobile)  • 21150b119064aecc249dfcfe05e259197461ce23 •
      ios            • iOS 14.4.1 18D61
    • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729     •
      ios            • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator)
    • macOS (desktop)            • macos                                    •
      darwin-x64     • Mac OS X 10.15.4 19E2269 darwin-x64
    • Chrome (web)               • chrome                                   •
      web-javascript • Google Chrome 98.0.4758.80
[✓] HTTP Host Availability
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! Doctor found issues in 1 category.