SwiftUI return Bool from authorizationController async - firebase

Question

How could I return a Bool from this sign in with apple function that uses the authorizationController? I have been looking at withCheckedThrowingContinuation but with no luck. I have also seen some examples of using completion handlers but I would like to use async.
func signInWithApple(withState state: SignInState) async -> Bool {
let request = signInWithAppleRequest(withState: state)
let authorizationController = ASAuthorizationController(authorizationRequests: [request])
authorizationController.delegate = self
authorizationController.performRequests()
}
func authorizationController(controller: ASAuthorizationController, didCompleteWithAuthorization authorization: ASAuthorization) {
//...
let credential = OAuthProvider.credential(withProviderID: "apple.com", idToken: idTokenString, rawNonce: nonce)
switch state {
case .signIn:
Task {
authenticationState = .authenticating
do {
let result = try await Auth.auth().signIn(with: credential)
if result.additionalUserInfo?.isNewUser == true {
self.isNewUser = true
}
return true
} catch {
self.authenticationState = .unauthenticated
print(error.localizedDescription)
return false
}
}
case .reauth:
Task {
if let user = Auth.auth().currentUser {
do {
try await user.reauthenticate(with: credential)
return true
} catch {
print(error.localizedDescription)
return false
}
}
}
}
}
}

Answer 1

I don't have all your types, so here is a simple example of a continuation which at least compiles.
The class must inherit from NSObject and adopt ASAuthorizationControllerDelegate.
The continuation is set in the same scope where the request is executed.
The most important rule is: The continuation must be resumed exactly once
import AuthenticationServices
class Authorization: NSObject, ASAuthorizationControllerDelegate {
private var continuation : CheckedContinuation<ASAuthorization,Error>?
func signInWithApple() async throws -> ASAuthorization {
return try await withCheckedThrowingContinuation { continuation in
self.continuation = continuation
let appleIDProvider = ASAuthorizationAppleIDProvider()
let request = appleIDProvider.createRequest()
request.requestedScopes = [.fullName, .email]
let authorizationController = ASAuthorizationController(authorizationRequests: [request])
authorizationController.delegate = self
authorizationController.performRequests()
}
}
func authorizationController(controller: ASAuthorizationController, didCompleteWithAuthorization authorization: ASAuthorization) {
continuation?.resume(returning: authorization)
}
func authorizationController(controller: ASAuthorizationController, didCompleteWithError error: Error) {
continuation?.resume(throwing: error)
}
}