Fix fatal error on sites using WooCommerce Subscription versions below 4.0.0 (#6489)

Co-authored-by: James Allan <[email protected]>

Author: malithsen

changelog/fix-pre-wcs-4.0.0-fatal-error

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fix
+
+Fix a fatal error on sites using WC Subscriptions versions below 4.0.0

includes/subscriptions/class-wc-payments-subscriptions.php

@@ -129,6 +129,10 @@ public static function get_subscription_service() {
 	 * @return bool Whether the site is a duplicate URL or not.
 	 */
 	public static function is_duplicate_site() {
+		if ( class_exists( 'WC_Subscriptions' ) && version_compare( WC_Subscriptions::$version, '4.0.0', '<' ) ) {
+			return WC_Subscriptions::is_duplicate_site();
+		}
+
 		return class_exists( 'WCS_Staging' ) && WCS_Staging::is_duplicate_site();
 	}
 }

tests/unit/helpers/class-wc-helper-subscriptions.php

@@ -90,11 +90,11 @@ function wcs_order_contains_renewal() {
  */
 class WC_Subscriptions {
 	/**
-	 * Subscriptions version, defaults to 3.0.7
+	 * Subscriptions version, defaults to 4.0.0
 	 *
 	 * @var string
 	 */
-	public static $version = '3.0.7';
+	public static $version = '4.0.0';
 
 	/**
 	 * wcs_order_contains_subscription mock.
@@ -216,4 +216,8 @@ public static function wcs_create_renewal_order( $function ) {
 	public static function wcs_order_contains_renewal( $function ) {
 		self::$wcs_order_contains_renewal = $function;
 	}
+
+	public static function is_duplicate_site() {
+		return false;
+	}
 }