feat: rate limit adding new payment methods by user

includes/reader-revenue/my-account/class-woocommerce-my-account.php

@@ -8,6 +8,7 @@
 namespace Newspack;
 
 use Newspack\Reader_Activation;
+use Newspack\WooCommerce_Connection;
 use WP_Error;
 
 defined( 'ABSPATH' ) || exit;
@@ -28,6 +29,7 @@ class WooCommerce_My_Account {
 	 * @codeCoverageIgnore
 	 */
 	public static function init() {
+		\add_action( 'rest_api_init', [ __CLASS__, 'register_routes' ] );
 		\add_filter( 'woocommerce_account_menu_items', [ __CLASS__, 'my_account_menu_items' ], 1000 );
 		\add_filter( 'woocommerce_default_address_fields', [ __CLASS__, 'required_address_fields' ] );
 		\add_filter( 'woocommerce_billing_fields', [ __CLASS__, 'required_address_fields' ] );
@@ -56,6 +58,36 @@ public static function init() {
 		}
 	}
 
+	/**
+	 * Register routes.
+	 */
+	public static function register_routes() {
+		\register_rest_route(
+			NEWSPACK_API_NAMESPACE,
+			'/check-rate',
+			[
+				'methods'             => \WP_REST_Server::READABLE,
+				'callback'            => [ __CLASS__, 'api_check_rate_limit' ],
+				'permission_callback' => '__return_true',
+			]
+		);
+	}
+
+	/**
+	 * REST API handler for rate limit check.
+	 */
+	public static function api_check_rate_limit() {
+		$is_rate_limited = WooCommerce_Connection::rate_limit_by_user( 'add_payment_method', __( 'Please wait a moment before trying to add a new payment method.', 'newspack-plugin' ), true );
+		$response        = [ 'success' => false ];
+		if ( ! \is_wp_error( $is_rate_limited ) && ! $is_rate_limited ) {
+			$response['success'] = true;
+		}
+		if ( \is_wp_error( $is_rate_limited ) ) {
+			$response['error'] = $is_rate_limited->get_error_message();
+		}
+		return new \WP_REST_Response( $response );
+	}
+
 	/**
 	 * Enqueue front-end scripts.
 	 */
@@ -72,9 +104,12 @@ public static function enqueue_scripts() {
 				'my-account',
 				'newspack_my_account',
 				[
-					'labels' => [
+					'labels'            => [
 						'cancel_subscription_message' => __( 'Are you sure you want to cancel this subscription?', 'newspack-plugin' ),
 					],
+					'rest_url'          => get_rest_url(),
+					'should_rate_limit' => WooCommerce_Connection::rate_limiting_enabled(),
+					'nonce'             => wp_create_nonce( 'wp_rest' ),
 				]
 			);
 			\wp_enqueue_style(

includes/reader-revenue/my-account/index.js

@@ -29,11 +29,12 @@ function domReady( callback ) {
 
 domReady( function () {
 	const cancelButton = document.querySelector( '.subscription_details .button.cancel' );
+	const { labels, nonce, rest_url, should_rate_limit } = newspack_my_account || {};
 
 	if ( cancelButton ) {
 		const confirmCancel = event => {
 			const message =
-				newspack_my_account?.labels?.cancel_subscription_message ||
+				labels?.cancel_subscription_message ||
 				'Are you sure you want to cancel this subscription?';
 
 			// eslint-disable-next-line no-alert
@@ -43,4 +44,53 @@ domReady( function () {
 		};
 		cancelButton.addEventListener( 'click', confirmCancel );
 	}
+
+	const addPaymentForm = document.getElementById( 'add_payment_method' );
+	if ( addPaymentForm && Boolean( should_rate_limit ) ) {
+		const errorContainer = document.querySelector( '.woocommerce-notices-wrapper' );
+		const submitButton = addPaymentForm.querySelector( 'input[type="submit"], button[type="submit"]' );
+		const rateLimit = function( e ) {
+			if ( addPaymentForm.hasAttribute( 'data-check-rate-limit' ) ) {
+				errorContainer.textContent = '';
+				submitButton.setAttribute( 'disabled', '' );
+				e.preventDefault();
+				const xhr = new XMLHttpRequest();
+				xhr.onreadystatechange = function() {
+					// Return if the request is completed.
+					if ( xhr.readyState !== 4 ) {
+						return;
+					}
+
+					// Call onSuccess with parsed JSON if the request is successful.
+					if ( xhr.status >= 200 && xhr.status < 300 ) {
+						submitButton.removeAttribute( 'disabled' );
+						const data = JSON.parse( xhr.responseText );
+						if ( data?.success ) {
+							addPaymentForm.removeAttribute( 'data-check-rate-limit' );
+							addPaymentForm.requestSubmit( submitButton );
+							addPaymentForm.setAttribute( 'data-check-rate-limit', '1' );
+						}
+						if ( data?.error ) {
+							const error = document.createElement( 'div' );
+							const errorUl = document.createElement( 'ul' );
+							const errorLi = document.createElement( 'li' );
+							errorUl.classList.add( 'woocommerce-error' );
+							errorLi.textContent = data.error;
+							error.appendChild( errorUl );
+							errorUl.appendChild( errorLi );
+							errorContainer.appendChild( error );
+							errorContainer.scrollIntoView( { behavior: 'smooth' } );
+						}
+					}
+				};
+
+				xhr.open( 'GET', rest_url + 'newspack/v1/check-rate' );
+				xhr.setRequestHeader( 'X-WP-Nonce', nonce );
+				xhr.send();
+			}
+		};
+		addPaymentForm.setAttribute( 'data-check-rate-limit', '1' );
+		addPaymentForm.addEventListener( 'submit' , rateLimit, true );
+		submitButton.addEventListener( 'click', rateLimit, true );
+	}
 } );

includes/reader-revenue/woocommerce/class-woocommerce-connection.php

@@ -177,6 +177,15 @@ private static function get_client_ip() {
 		return null;
 	}
 
+	/**
+	 * Check if rate limiting by user should be enabled for checkout and payment methods.
+	 *
+	 * @return bool
+	 */
+	public static function rate_limiting_enabled() {
+		return defined( 'NEWSPACK_CHECKOUT_RATE_LIMIT' ) && is_int( NEWSPACK_CHECKOUT_RATE_LIMIT ) && 0 !== NEWSPACK_CHECKOUT_RATE_LIMIT && class_exists( 'WC_Rate_Limiter' );
+	}
+
 	/**
 	 * Check the rate limit for the current user or IP.
 	 * Currently locked behind a NEWSPACK_CHECKOUT_RATE_LIMIT environment constant, for controlled rollout.
@@ -189,7 +198,7 @@ private static function get_client_ip() {
 	 */
 	public static function rate_limit_by_user( $action_name, $error_message = '', $return_error = false ) {
 		$rate_limited = false;
-		if ( ! defined( 'NEWSPACK_CHECKOUT_RATE_LIMIT' ) || ! class_exists( 'WC_Rate_Limiter' ) ) {
+		if ( ! self::rate_limiting_enabled() ) {
 			return $rate_limited;
 		}
 		if ( ! $error_message ) {