Fix get order signature method when order is invalid (#4075)

* Fix get order signature method when order is invalid

* Changelog and readme entries

* Update PHPDoc

---------

Co-authored-by: Diego Curbelo <[email protected]>

Author: wjrosa

changelog.txt

@@ -4,6 +4,7 @@
 * Fix - Temporarily disables the subscriptions detached notice feature due to long loading times on stores with many subscriptions.
 * Fix - Update ACH capability check key
 * Fix - Update legacy checkout documentation links and deprecation notice display logic
+* Fix - Fixes an issue where the order signature retrieval method could throw a fatal error when the received order parameter is actually an OrderRefund object (instead of a WC_Order).
 * Fix - Fixes an error with the `filter_thankyou_order_received_text` filter when it does not receive a valid WC_Order instance.
 
 = 9.3.0 - 2025-03-13 =

includes/abstracts/abstract-wc-stripe-payment-gateway.php

@@ -1,4 +1,7 @@
 <?php
+
+use Automattic\WooCommerce\Admin\Overrides\OrderRefund;
+
 if ( ! defined( 'ABSPATH' ) ) {
 	exit;
 }
@@ -2389,10 +2392,12 @@ public function get_balance_transaction_id_from_charge( $charge ) {
 	 *
 	 * This signature is included as metadata in Stripe requests and used to identify the order when webhooks are received.
 	 *
-	 * @param WC_Order $order The Order object.
+	 * @param WC_Order|OrderRefund $order The Order object.
 	 * @return string The order's unique signature. Format: order_id:md5(order_id-order_key-customer_id-order_total).
 	 */
 	protected function get_order_signature( $order ) {
+		$order = ! is_a( $order, 'WC_Order' ) ? wc_get_order( $order ) : $order;
+
 		$signature = [
 			absint( $order->get_id() ),
 			$order->get_order_key(),

readme.txt

@@ -114,6 +114,7 @@ If you get stuck, you can ask for help in the [Plugin Forum](https://wordpress.o
 * Fix - Temporarily disables the subscriptions detached notice feature due to long loading times on stores with many subscriptions.
 * Fix - Update ACH capability check key
 * Fix - Update legacy checkout documentation links and deprecation notice display logic
+* Fix - Fixes an issue where the order signature retrieval method could throw a fatal error when the received order parameter is actually an OrderRefund object (instead of a WC_Order).
 * Fix - Fixes an error with the `filter_thankyou_order_received_text` filter when it does not receive a valid WC_Order instance.
 
 [See changelog for all versions](https://raw.githubusercontent.com/woocommerce/woocommerce-gateway-stripe/trunk/changelog.txt).