[v3.0.3] provider disposed early in async ref.read() call

[mash-g]

Hi,

I may be misusing the API, looking to get some guidance.

Code Example

[user_screen.dart]

class _UserScreen extends ConsumerState<UserScreen> {
  ...
  Future<void> _onUserAction() async {
    // this works, even though according to https://github.com/rrousselGit/riverpod/issues/3745 it can get stuck?
    final isValid = await ref.read(validatorProvider.future);
    if (!isValid) return;
    ...
    // the issue is within the doSideEffect() call
    final result = await ref.read(sideEffectProvider.notifier).doSideEffect();
    ...
  }
}

[side_effect_provider.dart]

@riverpod
class SideEffect extends _$SideEffect {
  @override
  Future<bool> build() async {
    print('build: start');
    ref.onDispose(() => print('build: disposed'));
    
    final result = await ref.watch(myProvider1.future);
    print('build: done')
    return result;
  }
  
  Future<bool> doSideEffect() async {
    await future;
    print('doSideEffect: ready');
    
    final data = ref.read(myProvider2);
    await data.doSideEffect(chatId, enable: enable);
    print('doSideEffect: done data side effect');
    
    // error: 'Cannot use the Ref of sideEffectProvider(3447) after it has been disposed'
    return ref.read(myProvider3.notifier);
  }
}

Logs

build: start
build: done
doSideEffect: ready
build: disposed
doSideEffect: done data side effect
Cannot use the Ref of sideEffectProvider(3447) after it has been disposed.

Issue

I expected build: disposed to be after doSideEffect: done data side effect.
Ie sideEffectProvider should not be disposed until _onUserAction() is done with it.
Should I be doing this differently?

Edit: this logic used to work fine in Riverpod v2, and broke in v3, probably related to:
https://riverpod.dev/docs/whats_new#refs-and-notifiers-can-no-longer-be-interacted-with-after-they-have-been-disposed

Thanks,
Mash.

[mash-g]

Workaround

For now we add the following line to our Widget.build() override:

class _UserScreen extends ConsumerState<UserScreen> {
  @override
  Widget build(BuildContext context) {
    ref.listen(sideEffectProvider, (_, _) {});
  }
}

This resolves the issue, but it's still not clear why the original ref.read() call disposes early, ideally it wouldn't.

[bh-oussama]

The issue is caused by the pause mechanism of invisible widgets. I am facing the same issue but in providers rather than widgets. In my app, providers are using other providers. It's not just a provider being used in a widget.

I tried using Mutations and it worked. It's a better approach than ref.listen just to keep a provider active while future is not completed. However, it's not possible to use it in a provider's build method since a provider can't cause the change of another provider; which happens when doing Mutation<void>().run(ref, (tsx) => tsx.get(otherProvider)).

If anyone has a better idea of how to approach this, it would be much appreciated.

[taiju59]

I think this is the issue mentioned here: #3745

[mash-g]

You are right, closing this issue.