feat(auth, windows): verifyBeforeUpdateEmail() API support (#12825)

Author: russellwheatley

packages/firebase_auth/firebase_auth/windows/firebase_auth_plugin.cpp

@@ -1244,10 +1244,26 @@ void FirebaseAuthPlugin::VerifyBeforeUpdateEmail(
     const AuthPigeonFirebaseApp& app, const std::string& new_email,
     const PigeonActionCodeSettings* action_code_settings,
     std::function<void(std::optional<FlutterError> reply)> result) {
-  result(FlutterError(
-      "unimplemented",
-      "VerifyBeforeUpdateEmail is not available on this platform yet.",
-      nullptr));
+  firebase::auth::Auth* firebaseAuth = GetAuthFromPigeon(app);
+  firebase::auth::User user = firebaseAuth->current_user();
+
+  if (action_code_settings != nullptr) {
+    printf(
+        "Firebase C++ SDK does not support using `ActionCodeSettings` for "
+        "`verifyBeforeUpdateEmail()` API currently");
+  }
+
+  firebase::Future<void> future =
+      user.SendEmailVerificationBeforeUpdatingEmail(new_email.c_str());
+
+  future.OnCompletion(
+      [result, firebaseAuth](const firebase::Future<void>& completed_future) {
+        if (completed_future.error() == 0) {
+          result(std::nullopt);
+        } else {
+          result(FirebaseAuthPlugin::ParseError(completed_future));
+        }
+      });
 }
 
 void FirebaseAuthPlugin::RevokeTokenWithAuthorizationCode(

packages/firebase_auth/firebase_auth/windows/messages.g.cpp

@@ -4025,10 +4025,16 @@ void FirebaseAuthUserHostApi::SetUp(flutter::BinaryMessenger* binary_messenger,
               const auto& new_email_arg =
                   std::get<std::string>(encodable_new_email_arg);
               const auto& encodable_action_code_settings_arg = args.at(2);
-              const auto* action_code_settings_arg =
-                  &(std::any_cast<const PigeonActionCodeSettings&>(
-                      std::get<CustomEncodableValue>(
-                          encodable_action_code_settings_arg)));
+              // IF CODE REGENERATED, PLEASE REINSERT THIS. IF ARG IS NULL, APP
+              // CRASHES
+              const PigeonActionCodeSettings* action_code_settings_arg =
+                  nullptr;
+              if (!encodable_action_code_settings_arg.IsNull()) {
+                action_code_settings_arg =
+                    &(std::any_cast<const PigeonActionCodeSettings&>(
+                        std::get<CustomEncodableValue>(
+                            encodable_action_code_settings_arg)));
+              }
               api->VerifyBeforeUpdateEmail(
                   app_arg, new_email_arg, action_code_settings_arg,
                   [reply](std::optional<FlutterError>&& output) {