Handle user canceled "error" in demo app

Demo/AuthenticatorDemo/ViewController+WordPressAuthenticator.swift

@@ -1,3 +1,4 @@
+import AuthenticationServices
 import WebKit
 import WordPressAuthenticator
 import WordPressKit
@@ -96,6 +97,11 @@ extension ViewController {
                 )
             } catch let error as OAuthError {
                 presentAlert(title: "❌", message: error.errorDescription, onDismiss: {})
+            } catch let error as ASWebAuthenticationSessionError
+                where error.code == ASWebAuthenticationSessionError.canceledLogin {
+                // In a production app, the UX would be better if we didn't present an alert.
+                // But here, it's useful to show it to make the error handling visible for reference.
+                presentAlert(title: "", message: "User cancelled", onDismiss: {})
             } catch {
                 fatalError("Caught an error that was not of the expected `OAuthError` type: \(error)")
             }

WordPressAuthenticator/Unified Auth/View Related/Google/GoogleAuthViewController.swift

@@ -1,3 +1,5 @@
+import SVProgressHUD
+
 /// View controller that handles the google authentication flow
 ///
 class GoogleAuthViewController: LoginViewController {
@@ -142,6 +144,7 @@ extension GoogleAuthViewController: GoogleAuthenticatorDelegate {
     }
 
     func googleAuthCancelled() {
+        SVProgressHUD.dismiss()
         navigationController?.popViewController(animated: true)
     }