use_ref_read_synchronously

v0.4.0 Warning Async Safety

This rule catches ref.read() calls that happen after an await inside async callbacks within a ConsumerWidget or ConsumerState build method, without a mounted check first. If the widget is unmounted while the async operation runs, ref.read may return stale or invalid data.

Why use this rule

Async callbacks like onPressed: () async { ... } can easily outlive the widget that created them. After an await, the widget might already be disposed. Calling ref.read at that point reads from a potentially dead reference. In ConsumerWidget callbacks, use context.mounted as the guard (for Notifier methods, the sibling rule use_ref_and_state_synchronously checks for ref.mounted instead).

See also: Riverpod documentation

Don’t

class MyWidget extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return ElevatedButton(
      onPressed: () async {
        await Future<void>.delayed(const Duration(seconds: 1));
        // Widget may be unmounted — ref.read is unsafe
        ref.read(someProvider);
      },
      child: const Text('Tap'),
    );
  }
}

Do

class MyWidget extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return ElevatedButton(
      onPressed: () async {
        await Future<void>.delayed(const Duration(seconds: 1));
        if (!context.mounted) return;
        ref.read(someProvider);
      },
      child: const Text('Tap'),
    );
  }
}

Configuration

To disable this rule:

plugins:
  many_lints:
    diagnostics:
      use_ref_read_synchronously: false