Integrate with WooCommerce to offload Google Analytics to Web Worker

package.json

@@ -7,7 +7,7 @@
     "npm": ">=10.2.3"
   },
   "dependencies": {
-    "@builder.io/partytown": "^0.10.2",
+    "@builder.io/partytown": "github:westonruter/partytown#add/wp-i18n-workaround",
     "web-vitals": "4.2.3"
   },
   "devDependencies": {

plugins.json

@@ -7,6 +7,7 @@
     "optimization-detective",
     "performance-lab",
     "speculation-rules",
+    "web-worker-offloading",
     "webp-uploads"
   ]
 }

plugins/web-worker-offloading/helper.php

@@ -0,0 +1,70 @@
+<?php
+/**
+ * Helpers for Web Worker Offloading.
+ *
+ * @since 0.1.0
+ * @package web-worker-offloading
+ */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit; // Exit if accessed directly.
+}
+
+/**
+ * Gets configuration for Web Worker Offloading.
+ *
+ * @since 0.1.0
+ * @link https://partytown.builder.io/configuration
+ * @link https://github.com/BuilderIO/partytown/blob/b292a14047a0c12ca05ba97df1833935d42fdb66/src/lib/types.ts#L393-L548
+ *
+ * @return array<string, mixed> Configuration for Partytown.
+ */
+function wwo_get_configuration(): array {
+	$config = array(
+		'lib' => wp_parse_url( plugin_dir_url( __FILE__ ), PHP_URL_PATH ) . 'build/',
+	);
+
+	if ( WP_DEBUG && SCRIPT_DEBUG ) {
+		$config['debug'] = true;
+	}
+
+	/**
+	 * Add configuration for Web Worker Offloading.
+	 *
+	 * Many of the configuration options are not documented publicly, so refer to the TypeScript definitions.
+	 * Additionally, not all of the configuration options (e.g. functions) can be serialized as JSON and must instead be
+	 * defined in JavaScript instead. To do so, use the following PHP code instead of filtering `wwo_configuration`:
+	 *
+	 *     add_action(
+	 *         'wp_enqueue_scripts',
+	 *         function () {
+	 *             wp_add_inline_script(
+	 *                 'web-worker-offloading',
+	 *                 <<<JS
+	 *                 window.partytown = {
+	 *                     ...(window.partytown || {}),
+	 *                     resolveUrl: (url, location, type) => {
+	 *                         if (type === 'script') {
+	 *                             const proxyUrl = new URL('https://my-reverse-proxy.example.com/');
+	 *                             proxyUrl.searchParams.append('url', url.href);
+	 *                             return proxyUrl;
+	 *                         }
+	 *                         return url;
+	 *                     },
+	 *                 };
+	 *                 JS,
+	 *                 'before'
+	 *             );
+	 *         }
+	 *     );
+	 *
+	 * There are also many configuration options which are not documented, so refer to the TypeScript definitions.
+	 *
+	 * @since 0.1.0
+	 * @link https://partytown.builder.io/configuration
+	 * @link https://github.com/BuilderIO/partytown/blob/b292a14047a0c12ca05ba97df1833935d42fdb66/src/lib/types.ts#L393-L548
+	 *
+	 * @param array<string, mixed> $config Configuration for Partytown.
+	 */
+	return (array) apply_filters( 'wwo_configuration', $config );
+}

plugins/web-worker-offloading/hooks.php

@@ -10,35 +10,11 @@
 	exit; // Exit if accessed directly.
 }
 
-/**
- * Gets configuration for Web Worker Offloading.
- *
- * @since 0.1.0
- * @link https://partytown.builder.io/configuration
- *
- * @return array{ debug?: bool, forward?: non-empty-string[], lib: non-empty-string, loadScriptsOnMainThread?: non-empty-string[], nonce?: non-empty-string } Configuration for Partytown.
- */
-function wwo_get_configuration(): array {
-	$config = array(
-		'lib'     => wp_parse_url( plugin_dir_url( __FILE__ ), PHP_URL_PATH ) . 'build/',
-		'forward' => array(),
-	);
-
-	/**
-	 * Add configuration for Web Worker Offloading.
-	 *
-	 * @since 0.1.0
-	 * @link https://partytown.builder.io/configuration
-	 *
-	 * @param array{ debug?: bool, forward?: non-empty-string[], lib: non-empty-string, loadScriptsOnMainThread?: non-empty-string[], nonce?: non-empty-string } $config Configuration for Partytown.
-	 */
-	return apply_filters( 'wwo_configuration', $config );
-}
-
 /**
  * Registers defaults scripts for Web Worker Offloading.
  *
  * @since 0.1.0
+ * @access private
  *
  * @param WP_Scripts $scripts WP_Scripts instance.
  */
@@ -59,7 +35,7 @@ function wwo_register_default_scripts( WP_Scripts $scripts ): void {
 	$scripts->add_inline_script(
 		'web-worker-offloading',
 		sprintf(
-			'window.partytown = %s;',
+			'window.partytown = {...(window.partytown || {}), ...%s};',
 			wp_json_encode( wwo_get_configuration() )
 		),
 		'before'
@@ -72,12 +48,8 @@ function wwo_register_default_scripts( WP_Scripts $scripts ): void {
 /**
  * Prepends web-worker-offloading to the list of scripts to print if one of the queued scripts is offloaded to a worker.
  *
- * This also marks their strategy as `async`. This is needed because scripts offloaded to a worker thread can be
- * considered async. However, they may include `before` and `after` inline scripts that need sequential execution. Once
- * marked as async, `filter_eligible_strategies()` determines if the script is eligible for async execution. If so, it
- * will be offloaded to the worker thread.
- *
  * @since 0.1.0
+ * @access private
  *
  * @param string[]|mixed $script_handles An array of enqueued script dependency handles.
  * @return string[] Script handles.
@@ -88,61 +60,62 @@ function wwo_filter_print_scripts_array( $script_handles ): array {
 		if ( true === (bool) $scripts->get_data( $handle, 'worker' ) ) {
 			$scripts->set_group( 'web-worker-offloading', false, 0 ); // Try to print in the head.
 			array_unshift( $script_handles, 'web-worker-offloading' );
-
-			// TODO: This should be reconsidered because scripts needing to be offloaded will often have after scripts. See <https://github.com/WordPress/performance/pull/1497/files#r1733538721>.
-			if ( false === wp_scripts()->get_data( $handle, 'strategy' ) ) {
-				wp_script_add_data( $handle, 'strategy', 'async' ); // The 'defer' strategy would work as well.
-				wp_script_add_data( $handle, 'wwo_strategy_added', true );
-			}
+			break;
 		}
 	}
 	return $script_handles;
 }
-add_filter( 'print_scripts_array', 'wwo_filter_print_scripts_array' );
+add_filter( 'print_scripts_array', 'wwo_filter_print_scripts_array', PHP_INT_MAX );
 
 /**
  * Updates script type for handles having `web-worker-offloading` as dependency.
  *
  * @since 0.1.0
+ * @access private
  *
  * @param string|mixed $tag    Script tag.
  * @param string       $handle Script handle.
  * @return string|mixed Script tag with type="text/partytown" for eligible scripts.
  */
 function wwo_update_script_type( $tag, string $handle ) {
 	if (
-		is_string( $tag ) &&
+		is_string( $tag )
+		&&
 		(bool) wp_scripts()->get_data( $handle, 'worker' )
 	) {
 		$html_processor = new WP_HTML_Tag_Processor( $tag );
-
 		while ( $html_processor->next_tag( array( 'tag_name' => 'SCRIPT' ) ) ) {
-			if ( $html_processor->get_attribute( 'id' ) !== "{$handle}-js" ) {
-				continue;
-			}
-			if ( null === $html_processor->get_attribute( 'async' ) && null === $html_processor->get_attribute( 'defer' ) ) {
-				_doing_it_wrong(
-					'wwo_update_script_type',
-					esc_html(
-						sprintf(
-							/* translators: %s: script handle */
-							__( 'Unable to offload "%s" script to a worker. Script will continue to load in the main thread.', 'web-worker-offloading' ),
-							$handle
-						)
-					),
-					'Web Worker Offloading 0.1.0'
-				);
-			} else {
+			if ( $html_processor->get_attribute( 'id' ) === "{$handle}-js" ) {
 				$html_processor->set_attribute( 'type', 'text/partytown' );
+				$tag = $html_processor->get_updated_html();
+				break;
 			}
-			if ( true === wp_scripts()->get_data( $handle, 'wwo_strategy_added' ) ) {
-				$html_processor->remove_attribute( 'async' );
-				$html_processor->remove_attribute( 'data-wp-strategy' );
-			}
-			$tag = $html_processor->get_updated_html();
 		}
 	}
-
 	return $tag;
 }
 add_filter( 'script_loader_tag', 'wwo_update_script_type', 10, 2 );
+
+/**
+ * Filters inline script attributes to offload to a worker if the script has been opted-in.
+ *
+ * @since 0.1.0
+ * @access private
+ *
+ * @param array<string, mixed>|mixed $attributes Attributes.
+ * @return array<string, mixed> Attributes.
+ */
+function wwo_filter_inline_script_attributes( $attributes ): array {
+	$attributes = (array) $attributes;
+	if (
+		isset( $attributes['id'] )
+		&&
+		1 === preg_match( '/^(?P<handle>.+)-js-(?:before|after)$/', $attributes['id'], $matches )
+		&&
+		(bool) wp_scripts()->get_data( $matches['handle'], 'worker' )
+	) {
+		$attributes['type'] = 'text/partytown';
+	}
+	return $attributes;
+}
+add_filter( 'wp_inline_script_attributes', 'wwo_filter_inline_script_attributes' );

plugins/web-worker-offloading/load.php

@@ -45,5 +45,6 @@
 
 define( 'WEB_WORKER_OFFLOADING_VERSION', '0.1.0' );
 
-// Load the hooks.
+require_once __DIR__ . '/helper.php';
 require_once __DIR__ . '/hooks.php';
+require_once __DIR__ . '/third-party.php';

plugins/web-worker-offloading/readme.txt

@@ -5,23 +5,95 @@ Tested up to:      6.6
 Stable tag:        0.1.0
 License:           GPLv2 or later
 License URI:       https://www.gnu.org/licenses/gpl-2.0.html
-Tags:              performance, JavaScript, web worker, partytown
+Tags:              performance, JavaScript, web worker, partytown, analytics
 
 Offload JavaScript execution to a Web Worker.
 
 == Description ==
 
-This plugin offloads JavaScript execution to a Web Worker, improving performance by freeing up the main thread.
+This plugin offloads JavaScript execution to a Web Worker, improving performance by freeing up the main thread. This should translate into improved [Interaction to Next Paint](https://web.dev/articles/inp) (INP) scores.
 
-In order to opt-in a script to be loaded in a worker, simply add `worker` script data to a registered script. For example,
+⚠ _This functionality is experimental._ ⚠
+
+In order to opt in a script to be loaded in a worker, simply add `worker` script data to a registered script. For example,
 if you have a script registered with the handle of `foo`, opt-in to offload it to a web worker by doing:
 
 `
 wp_script_add_data( 'foo', 'worker', true );
 `
 
+Unlike with the script loading strategies (async/defer), any inline before/after scripts associated with the worker-offloaded registered script will also be offloaded to the worker, whereas with the script strategies an inline after script would block the script from being delayed.
+
+Otherwise, the plugin currently ships with built-in integrations to offload Google Analytics to a web worker for the following plugin:
+
+* [WooCommerce](https://wordpress.org/plugins/woocommerce/)
+
+Support for [Site Kit by Google](https://wordpress.org/plugins/google-site-kit/) and [Rank Math SEO](https://wordpress.org/plugins/seo-by-rank-math/) are [planned](https://github.com/WordPress/performance/issues/1455).
+
+Please monitor your analytics once activating to ensure all the expected events are being logged. At the same time, monitor your INP scores to check for improvement.
+
+This plugin relies on the [Partytown 🎉](https://partytown.builder.io/) library by Builder.io, released under the MIT license. This library is in beta and there are quite a few [open bugs](https://github.com/BuilderIO/partytown/issues?q=is%3Aopen+is%3Aissue+label%3Abug).
+
+The [Partytown configuration](https://partytown.builder.io/configuration) can be modified via the `wwo_configuration` filter. For example:
+
+`
+<?php
+add_filter( 'wwo_configuration', function ( $config ) {
+	$config['mainWindowAccessors'][] = 'wp'; // Make the wp global available in the worker (e.g. wp.i18n and wp.hooks).
+	return $config;
+} );
+`
+
+However, not all of the configuration options can be serialized to JSON in this way, for example the `resolveUrl` configuration is a function. To specify this, you can add an inline script as follows.
+
+`
+<?php
+add_action(
+	'wp_enqueue_scripts',
+	function () {
+		wp_add_inline_script(
+			'web-worker-offloading',
+			<<<JS
+			window.partytown = {
+				...(window.partytown || {}),
+				resolveUrl: (url, location, type) => {
+					if (type === 'script') {
+						const proxyUrl = new URL('https://my-reverse-proxy.example.com/');
+						proxyUrl.searchParams.append('url', url.href);
+						return proxyUrl;
+					}
+					return url;
+				},
+			};
+			JS,
+			'before'
+		);
+	}
+);
+`
+
+There are also many configuration options which are not documented, so refer to the [TypeScript definitions](https://github.com/BuilderIO/partytown/blob/b292a14047a0c12ca05ba97df1833935d42fdb66/src/lib/types.ts#L393-L548).
+
 == Frequently Asked Questions ==
 
 = Why are my offloaded scripts not working and I see a 404 error in the console for `partytown-sandbox-sw.html`? =
 
 If you find that your offloaded scripts aren't working while also seeing a 404 error in the console for a file at `/wp-content/plugins/web-worker-offloading/build/partytown-sandbox-sw.html?1727389399791` then it's likely you have Chrome DevTools open with the "Bypass for Network" toggle enabled in the Application panel.
+
+= Where can I report security bugs? =
+
+The Performance team and WordPress community take security bugs seriously. We appreciate your efforts to responsibly disclose your findings, and will make every effort to acknowledge your contributions.
+
+To report a security issue, please visit the [WordPress HackerOne](https://hackerone.com/wordpress) program.
+
+= How can I contribute to the plugin? =
+
+Contributions are always welcome! Learn more about how to get involved in the [Core Performance Team Handbook](https://make.wordpress.org/performance/handbook/get-involved/).
+
+The [plugin source code](https://github.com/WordPress/performance/tree/trunk/plugins/web-worker-offloading) is located in the [WordPress/performance](https://github.com/WordPress/performance) repo on GitHub.
+
+== Changelog ==
+
+= 0.1.0 =
+
+* Initial release.