Fix crash when identityToken is null

Author: morganchen12

OAuth/FirebaseOAuthUI/FUIOAuth.m

@@ -191,7 +191,8 @@ + (FUIOAuth *)yahooAuthProvider {
 }
 
 + (FUIOAuth *)appleAuthProvider {
- return [self appleAuthProviderWithUserInterfaceStyle:UITraitCollection.currentTraitCollection.userInterfaceStyle];
+ UIUserInterfaceStyle style = UITraitCollection.currentTraitCollection.userInterfaceStyle;
+ return [self appleAuthProviderWithUserInterfaceStyle:style];
 }
 
 + (FUIOAuth *)appleAuthProviderWithUserInterfaceStyle:(UIUserInterfaceStyle)userInterfaceStyle {
@@ -203,6 +204,12 @@ + (FUIOAuth *)appleAuthProviderWithUserInterfaceStyle:(UIUserInterfaceStyle)user
  iconImage = [iconImage imageWithTintColor:[UIColor blackColor]];
  buttonColor = [UIColor whiteColor];
  buttonTextColor = [UIColor blackColor];
+ } else if (userInterfaceStyle == UIUserInterfaceStyleLight) {
+ iconImage = [iconImage imageWithTintColor:[UIColor whiteColor]];
+ buttonColor = [UIColor blackColor];
+ buttonTextColor = [UIColor whiteColor];
+ } else {
+ iconImage = [iconImage imageWithTintColor:[UIColor whiteColor]];
  }
  FUIOAuth *provider = [[FUIOAuth alloc] initWithAuthUI:[FUIAuth defaultAuthUI]
  providerID:@"apple.com"
@@ -213,7 +220,7 @@ + (FUIOAuth *)appleAuthProviderWithUserInterfaceStyle:(UIUserInterfaceStyle)user
  scopes:@[@"name", @"email"]
  customParameters:nil
  loginHintKey:nil];
- provider.buttonAlignment = FUIButtonAlignmentCenter;
+ provider.buttonAlignment = FUIButtonAlignmentLeading;
  provider.buttonTextColor = buttonTextColor;
  return provider;
 }
@@ -312,6 +319,14 @@ - (BOOL)handleOpenURL:(NSURL *)URL sourceApplication:(nullable NSString *)source
 
 - (void)authorizationController:(ASAuthorizationController *)controller didCompleteWithAuthorization:(ASAuthorization *)authorization API_AVAILABLE(ios(13.0)) {
  ASAuthorizationAppleIDCredential* appleIDCredential = authorization.credential;
+ NSData *rawIdentityToken = appleIDCredential.identityToken;
+ if (rawIdentityToken == nil) {
+ // It's pretty awful to not have an error when login is unsuccessful, but Apple's docs
+ // don't provide any useful information here.
+ // https://developer.apple.com/documentation/authenticationservices/asauthorizationappleidcredential
+ NSLog(@"Sign in with Apple completed with authorization, but no jwt: %@", authorization);
+ _providerSignInCompletion(nil, nil, nil, nil);
+ }
  NSString *idToken = [[NSString alloc] initWithData:appleIDCredential.identityToken encoding:NSUTF8StringEncoding];
  FIROAuthCredential *credential = [FIROAuthProvider credentialWithProviderID:@"apple.com"
  IDToken:idToken