Function onAuthStateChanged

onAuthStateChanged(
auth: FirebaseAuthTypes.Module,
nextOrObserver: CallbackOrObserver<AuthListenerCallback>,
): () => void
Adds an observer for changes to the user's sign-in state.
Parameters
- auth: FirebaseAuthTypes.Module
  The Auth instance.
- nextOrObserver: CallbackOrObserver<AuthListenerCallback>
  A callback function or observer for auth state changes.
Returns () => void
A function to unsubscribe from the auth state changes.
- Defined in auth/lib/modular/index.d.ts:183