Prevent NativeEventObserver crash during monitor events

[joe2708]

I hit an intermittent iOS crash during DeviceActivity monitor event flows (save/sync/start-stop), with stack traces pointing to NativeEventObserver.registerListener and crash signatures like EXC_BAD_ACCESS / KERN_PROTECTION_FAILURE.

This PR hardens the native observer callback lifecycle:

• Routes callback handling through NativeEventObserver and guards module access before calling sendEvent
• Uses safer observer pointer ownership for callback lifetime
• Makes unregister() nil-safe and clears observer pointer after removal
• Adds deinit cleanup by calling unregister()

No JS API or feature behavior changes in this PR; this is an iOS native stability fix only to prevent unwanted crashes during saving schedules.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/kingstinct/react-native-device-activity@83

commit: 709d837

[robertherber]

Thanks for your contribution @joe2708! Have gotten this as well at times

[joe2708]

Thanks for your contribution @joe2708! Have gotten this as well at times

Glad this resonates. After applying the patch, this reduced crashes during save/sync monitor churn by hardening the observer callback lifecycle. It significantly lowers this intermittent EXC_BAD_ACCESS path, but it can’t guarantee 100% crash-free behaviour for every edge case.