React-Native + Apple sign-in + Firestore: permission-denied - firebase

Question

I'm trying to add Apple Sign-In to my project which is based on react native and firestore. Authentication flow itself works fine but firestore security rules reject my request when I try to create a user profile afterwards.
Firebase security rules:
rules_version = '2';
service cloud.firestore {
match /users/{userId} {
allow create:
if request.auth != null;
...
}
...
}
Simplified React Native code:
import { firebase } from './config';
import { firebase as RNFBAuth } from '#react-native-firebase/auth';
// Step 1
const credential = RNFBAuth.auth.AppleAuthProvider.credential(token, nonce);
// Step 2
RNFBAuth.auth().signInWithCredential(credential).then((response) => {
if (response.additionalUserInfo.isNewUser) {
// Step 3
firebase.firestore()
.collection('users')
.doc(uid)
.set({
// profile details
})
.then(() => {
// update local state
})
.catch((_error) => {
console.log(_error + ": " + _error.code);
});
}
});
Step 3 is failing with error code FirebaseError: The caller does not have permission: permission-denied.
Error is gone when Firestore security rules are downgraded to "allow create: if true". Unfortunately it does not fly for me for obvious reasons.
My guess is firebase/firestore does not know that user completed authentication via firebase/auth package thus request in "Step 3" is being send as unauthenticated one. Any ideas how to sync them?
Other Auth Providers like Google and Facebook are located at the main firebase package instead of firebase/auth thus same problem does not apply for them:
const credential = firebase.auth.FacebookAuthProvider.credential(token);
const credential = firebase.auth.GoogleAuthProvider.credential(token);
const credential = RNFBAuth.auth.AppleAuthProvider.credential(token, nonce);
Any ideas how to solve it?

Answer 1

Eventually the problem has been found - incompatible package versions. I've upgraded all firebase packages and #invertase/react-native-apple-authentication to the latest versions and everything seems to work fine now.

Answer 2

As sugested in the comment you should use the onAuthStateChanged listener:
firebase.auth().onAuthStateChanged((user) => {
if (user) {
// User is signed in, see docs for a list of available properties
// https://firebase.google.com/docs/reference/js/firebase.User
var uid = user.uid;
// ...
} else {
// User is signed out
// ...
}
});
That way you have a general solution for all auth providers. It would not matter wich one you use. The trigger will be fired asap a user is signed in. I also use that method in all of my apps to sync user data.
You can read more about it here.