From 7627f38b583096dd7853973cc88c5c161994503e Mon Sep 17 00:00:00 2001
From: Peter Wilson <519727+peterwilsoncc@users.noreply.github.com>
Date: Thu, 14 Dec 2023 14:36:25 +1100
Subject: [PATCH] Send wc_ prefixed fields for express payments.

---
 .../use-express-checkout-product-handler.js       | 12 +++++++++++-
 client/payment-request/index.js                   | 15 +++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/client/checkout/woopay/express-button/use-express-checkout-product-handler.js b/client/checkout/woopay/express-button/use-express-checkout-product-handler.js
index 5567cb4a1ae..3df0c452888 100644
--- a/client/checkout/woopay/express-button/use-express-checkout-product-handler.js
+++ b/client/checkout/woopay/express-button/use-express-checkout-product-handler.js
@@ -2,6 +2,7 @@
  * External dependencies
  */
 import validator from 'validator';
+import { applyFilters } from '@wordpress/hooks';
 
 const useExpressCheckoutProductHandler = ( api ) => {
 	const getAttributes = () => {
@@ -104,6 +105,14 @@ const useExpressCheckoutProductHandler = ( api ) => {
 		}
 
 		const addOnForm = document.querySelector( 'form.cart' );
+		let allowedFieldNames = applyFilters(
+			'wcpayPaymentRequestAllowedFieldNames',
+			[]
+		);
+		// Ensure allowedFieldNames is an array.
+		if ( ! Array.isArray( allowedFieldNames ) ) {
+			allowedFieldNames = [ allowedFieldNames ];
+		}
 
 		if ( addOnForm ) {
 			const formData = new FormData( addOnForm );
@@ -111,7 +120,8 @@ const useExpressCheckoutProductHandler = ( api ) => {
 			formData.forEach( ( value, name ) => {
 				if (
 					/^addon-/.test( name ) ||
-					/^wc_gc_giftcard_/.test( name )
+					/^wc_/.test( name ) ||
+					allowedFieldNames.includes( name )
 				) {
 					if ( /\[\]$/.test( name ) ) {
 						const fieldName = name.substring( 0, name.length - 2 );
diff --git a/client/payment-request/index.js b/client/payment-request/index.js
index 9578b42517c..2933cac2088 100644
--- a/client/payment-request/index.js
+++ b/client/payment-request/index.js
@@ -3,7 +3,7 @@
  * External dependencies
  */
 import { __ } from '@wordpress/i18n';
-import { doAction } from '@wordpress/hooks';
+import { applyFilters, doAction } from '@wordpress/hooks';
 /**
  * Internal dependencies
  */
@@ -175,8 +175,19 @@ jQuery( ( $ ) => {
 
 			// Add addons data to the POST body
 			const formData = $( 'form.cart' ).serializeArray();
+			let allowedFieldNames = applyFilters(
+				'wcpayPaymentRequestAllowedFieldNames',
+				[]
+			);
+			// Ensure allowedFieldNames is an array.
+			if ( ! Array.isArray( allowedFieldNames ) ) {
+				allowedFieldNames = [ allowedFieldNames ];
+			}
 			$.each( formData, ( i, field ) => {
-				if ( /^addon-/.test( field.name ) ) {
+				if (
+					allowedFieldNames.includes( field.name ) ||
+					/^(addon-|wc_)/.test( field.name )
+				) {
 					if ( /\[\]$/.test( field.name ) ) {
 						const fieldName = field.name.substring(
 							0,