Fix Express Checkout buttons not appearing on order-pay pages due to script timing issue (#4446)

* Fix: Express Checkout buttons not appearing on order-pay pages.

* Refactor: Extract duplicated asset loading logic into reusable method

---------

Co-authored-by: Wesley Rosa <[email protected]>
Co-authored-by: Malith Senaweera <[email protected]>

Author: 3 people

includes/payment-methods/class-wc-stripe-express-checkout-element.php

@@ -466,6 +466,10 @@ function ( $field ) {
 	 * @param WC_Order $order The order that needs payment.
 	 */
 	public function localize_pay_for_order_page_scripts( $order ) {
+		// Ensure the script is registered before localizing
+		if ( ! wp_script_is( 'wc_stripe_express_checkout', 'registered' ) ) {
+			$this->register_express_checkout_script();
+		}
 		$currency = get_woocommerce_currency();
 		$data     = [];
 		$items    = [];
@@ -553,21 +557,15 @@ public function localize_pay_for_order_page_scripts( $order ) {
 	}
 
 	/**
-	 * Load scripts and styles.
+	 * Get asset file data (version and dependencies).
+	 *
+	 * @return array Array containing 'version' and 'dependencies' keys.
 	 */
-	public function scripts() {
-		// If page is not supported, bail.
-		if ( ! $this->express_checkout_helper->is_page_supported() ) {
-			return;
-		}
-
-		if ( ! $this->express_checkout_helper->should_show_express_checkout_button() ) {
-			return;
-		}
-
+	private function get_asset_data() {
 		$asset_path   = WC_STRIPE_PLUGIN_PATH . '/build/express-checkout.asset.php';
 		$version      = WC_STRIPE_VERSION;
 		$dependencies = [];
+
 		if ( file_exists( $asset_path ) ) {
 			$asset        = require $asset_path;
 			$version      = is_array( $asset ) && isset( $asset['version'] )
@@ -578,20 +576,53 @@ public function scripts() {
 				: $dependencies;
 		}
 
+		return [
+			'version'      => $version,
+			'dependencies' => $dependencies,
+		];
+	}
+
+	/**
+	 * Register the express checkout script without enqueuing it.
+	 */
+	private function register_express_checkout_script() {
+		$asset_data = $this->get_asset_data();
+
 		wp_register_script( 'stripe', 'https://js.stripe.com/v3/', '', '3.0', true );
 		wp_register_script(
 			'wc_stripe_express_checkout',
 			WC_STRIPE_PLUGIN_URL . '/build/express-checkout.js',
-			array_merge( [ 'jquery', 'stripe' ], $dependencies ),
-			$version,
+			array_merge( [ 'jquery', 'stripe' ], $asset_data['dependencies'] ),
+			$asset_data['version'],
 			true
 		);
+	}
+
+	/**
+	 * Load scripts and styles.
+	 */
+	public function scripts() {
+		// If page is not supported, bail.
+		if ( ! $this->express_checkout_helper->is_page_supported() ) {
+			return;
+		}
+
+		if ( ! $this->express_checkout_helper->should_show_express_checkout_button() ) {
+			return;
+		}
+
+		// Register the script if not already registered
+		if ( ! wp_script_is( 'wc_stripe_express_checkout', 'registered' ) ) {
+			$this->register_express_checkout_script();
+		}
+
+		$asset_data = $this->get_asset_data();
 
 		wp_enqueue_style(
 			'wc_stripe_express_checkout_style',
 			WC_STRIPE_PLUGIN_URL . '/build/express-checkout.css',
 			[],
-			$version
+			$asset_data['version']
 		);
 
 		wp_localize_script(