Function onIdTokenChanged

onIdTokenChanged(
    auth: Auth,
    nextOrObserver: NextOrObserver<User>,
    _error?: ErrorFn,
    _completed?: CompleteFn,
): Unsubscribe
Subscribes to ID token changes for the given Auth instance.
Parameters
- auth: Auth
- nextOrObserver: NextOrObserver<User>
- Optional_error: ErrorFn
- Optional_completed: CompleteFn
Returns Unsubscribe
An unsubscribe function.

Remarks
The legacy error and completed callback overload exists for firebase-js-sdk API parity. Native auth listeners never invoke separate error or completed callbacks.
- Defined in auth/lib/modular.ts:505