[iOS] Native editor doesn't dismiss when the contact is deleted from it (iOS 26+)

[liliana-tagonsoft]

Description

On iOS, FlutterContacts.native.showEditor(contactId) presents a CNContactViewController with
allowsEditing = true. On iOS 26+ that editor offers a Delete Contact row at the bottom
(earlier iOS versions don't show it in a third-party editor, which is probably why this hasn't come
up before).

Deleting the contact from that row leaves the app stuck:

1. contactViewController(_:didCompleteWith:) is never called, so the sheet stays on screen
   still rendering the contact that was just deleted.

2. The showEditor Future doesn't complete until the user closes the sheet by hand. Because the
   controller is presented in editing mode it shows its own ✕ / ✓ items rather than the injected
   Done button, so ✕ is what the user ends up tapping — and the Future then resolves to null, the
   same value as "cancelled", so the caller has no way to know the contact is gone.

3. Calling showEditor again for that id then throws:

   PlatformException(flutter_contacts_error, Updated Record Does Not Exist, null, null)
   

   because store.unifiedContact(withIdentifier:) in ShowEditorImpl.handle fails on the deleted
   identifier.

Steps to reproduce

1. On iOS 26+, await FlutterContacts.native.showEditor(contactId: someExistingId).
2. Scroll to the bottom of the editor, tap Delete Contact, confirm.
3. Observe the sheet stays open on the deleted contact; close it by hand (✕).
4. Call showEditor again with the same id.

Expected

The editor dismisses itself when the contact is deleted from it, and showEditor completes.

Actual

The sheet stays up until the user dismisses it by hand, showEditor resolves to null, and a
second call throws Updated Record Does Not Exist.

Environment

• flutter_contacts 2.3.1
• Flutter 3.44.1 (stable)
• iOS 26.3 simulator (iPhone 17 Pro); also seen on a physical device

Fix

PR #249 observes .CNContactStoreDidChange while the editor is presented and dismisses it once the
edited contact no longer resolves. Verified on the iOS 26.3 simulator: delete now closes the sheet,
and normal save / cancel are unchanged.

[joachim-quis]

Hi @liliana-tagonsoft, thanks for the report and the fix 🙏 Merged #249 and just released v2.4.0. Confirmed the Delete Contact row is iOS 26 only. I added some hardening on top: the observer is removed before dismissing, the existence check fetches only the identifier, and it registers after presentation. Your note about null led to a bigger find: showEditor was replying as soon as the editor appeared, so it always returned null, even on save. Fixed too; it now returns the identifier on save. Did this solve your problem?

[liliana-tagonsoft]

Yes, it’s fixed now. Thank you for the fix and the additional hardening! 🙏