gistfile1.txt

import AuthenticationServices

func signInWithGoogle() async throws -> String {
    try await withCheckedThrowingContinuation { continuation in
        let session = ASWebAuthenticationSession(
            url: URL(string: "https://oauth.example.com/auth")!,
            callbackURLScheme: "myapp"
        ) { callbackURL, error in
            if let error = error {
                continuation.resume(throwing: error)
            } else if let token = callbackURL?.lastPathComponent {
                continuation.resume(returning: token)
            }
        }
        session.start()
    }
}