My Jetpack: register wp-build-polyfills so the app (and Boost) loads without Gutenberg on WP < 7.0

projects/packages/my-jetpack/changelog/fix-my-jetpack-wp-theme-polyfill

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Fix the My Jetpack app failing to load on WordPress installs without the Gutenberg plugin active, where the wp-theme script handle it depends on is otherwise unregistered.

projects/packages/my-jetpack/composer.json

@@ -20,7 +20,8 @@
 		"automattic/jetpack-plans": "@dev",
 		"automattic/jetpack-status": "@dev",
 		"automattic/jetpack-sync": "@dev",
-		"automattic/jetpack-protect-status": "@dev"
+		"automattic/jetpack-protect-status": "@dev",
+		"automattic/jetpack-wp-build-polyfills": "@dev"
 	},
 	"require-dev": {
 		"yoast/phpunit-polyfills": "^4.0.0",

projects/packages/my-jetpack/src/class-initializer.php

@@ -29,6 +29,7 @@
 use Automattic\Jetpack\Sync\Functions as Sync_Functions;
 use Automattic\Jetpack\Terms_Of_Service;
 use Automattic\Jetpack\Tracking;
+use Automattic\Jetpack\WP_Build_Polyfills\WP_Build_Polyfills;
 use Jetpack;
 use WP_Error;
 
@@ -247,12 +248,42 @@ public static function can_use_analytics() {
 		return $tracking->should_enable_tracking( new Terms_Of_Service(), $status );
 	}
 
+	/**
+	 * Register polyfills for the wp-notices / wp-private-apis / wp-theme handles the
+	 * My Jetpack app bundle depends on but WP < 7.0 does not ship (or ships with an
+	 * incomplete allowlist) when the Gutenberg plugin is not active.
+	 *
+	 * Without this, `my_jetpack_main_app` is enqueued with an unregistered `wp-theme`
+	 * dependency, so WP silently drops the script (no console error) and the My Jetpack
+	 * app — plus any consumer that hard-depends on it, such as Jetpack Boost — renders
+	 * a blank page. Only the handles the bundle actually uses are requested.
+	 *
+	 * @return void
+	 */
+	public static function register_wp_build_polyfills() {
+		if ( ! class_exists( WP_Build_Polyfills::class ) ) {
+			return;
+		}
+
+		WP_Build_Polyfills::register(
+			'my-jetpack',
+			array( 'wp-notices', 'wp-private-apis', 'wp-theme' )
+		);
+	}
+
 	/**
 	 * Enqueue admin page assets.
 	 *
 	 * @return void
 	 */
 	public static function enqueue_scripts() {
+		// Register the wp-build-polyfills shim before the extension hook below or
+		// the app script can enqueue against wp-theme / wp-private-apis / wp-notices.
+		// WP_Build_Polyfills registers synchronously on its first caller, so calling
+		// it after a hook consumer would leave our handles recorded but unregistered
+		// for this request.
+		self::register_wp_build_polyfills();
+
 		/**
 		 * Fires after the My Jetpack page is initialized.
 		 * Allows for enqueuing additional scripts only on the My Jetpack page.

projects/packages/my-jetpack/tests/php/Register_Wp_Build_Polyfills_Test.php

@@ -0,0 +1,83 @@
+<?php
+/**
+ * Tests for Initializer::register_wp_build_polyfills().
+ *
+ * @package automattic/my-jetpack
+ */
+
+namespace Automattic\Jetpack\My_Jetpack;
+
+use Automattic\Jetpack\WP_Build_Polyfills\WP_Build_Polyfills;
+use PHPUnit\Framework\TestCase;
+use ReflectionProperty;
+
+/**
+ * Verifies My Jetpack requests the wp-build-polyfills shim for the script handles
+ * its app bundle depends on but older WordPress (< 7.0, no Gutenberg) does not ship.
+ *
+ * @see \Automattic\Jetpack\My_Jetpack\Initializer::register_wp_build_polyfills
+ */
+class Register_Wp_Build_Polyfills_Test extends TestCase {
+
+	/**
+	 * The app bundle's polyfill-provided handles that must be requested.
+	 */
+	const EXPECTED_HANDLES = array( 'wp-notices', 'wp-private-apis', 'wp-theme' );
+
+	/**
+	 * Reset the WP_Build_Polyfills static registrar so tests do not inherit state.
+	 */
+	public function tearDown(): void {
+		foreach ( array(
+			'requested'            => array(),
+			'hooked'               => false,
+			'wp_version_threshold' => '7.0',
+		) as $name => $value ) {
+			$prop = new ReflectionProperty( WP_Build_Polyfills::class, $name );
+			if ( PHP_VERSION_ID < 80100 ) {
+				$prop->setAccessible( true );
+			}
+			$prop->setValue( null, $value );
+		}
+		parent::tearDown();
+	}
+
+	/**
+	 * Registering requests each required handle for the `my-jetpack` consumer.
+	 */
+	public function test_registers_required_polyfill_handles() {
+		Initializer::register_wp_build_polyfills();
+
+		$consumers = WP_Build_Polyfills::get_consumers();
+
+		foreach ( self::EXPECTED_HANDLES as $handle ) {
+			$this->assertArrayHasKey( $handle, $consumers, "$handle should be requested" );
+			$this->assertContains( 'my-jetpack', $consumers[ $handle ], "$handle should list the my-jetpack consumer" );
+		}
+	}
+
+	/**
+	 * Guards against bundle drift: if a future `@wordpress/*` bump makes the app
+	 * depend on another polyfill-covered handle (e.g. `wp-views`) that we do not
+	 * request, that page would blank out with no console error. Fail here instead.
+	 *
+	 * Skips when the package has not been built (no asset file to inspect).
+	 */
+	public function test_requested_handles_cover_polyfilled_bundle_dependencies() {
+		$asset_file = dirname( __DIR__, 2 ) . '/build/index.asset.php';
+		if ( ! is_readable( $asset_file ) ) {
+			$this->markTestSkipped( 'my_jetpack_main_app build asset not found; run the package build first.' );
+		}
+
+		$asset      = require $asset_file;
+		$deps       = $asset['dependencies'] ?? array();
+		$polyfilled = array_values( array_intersect( $deps, WP_Build_Polyfills::SCRIPT_HANDLES ) );
+		$missing    = array_values( array_diff( $polyfilled, self::EXPECTED_HANDLES ) );
+
+		$this->assertSame(
+			array(),
+			$missing,
+			'The app bundle depends on polyfill-covered handle(s) not requested by register_wp_build_polyfills(): ' . implode( ', ', $missing )
+		);
+	}
+}

projects/plugins/backup/changelog/fix-my-jetpack-wp-theme-polyfill

@@ -0,0 +1,3 @@
+Significance: patch
+Type: changed
+Comment: Update composer.lock.

projects/plugins/boost/changelog/fix-my-jetpack-wp-theme-polyfill

@@ -0,0 +1,4 @@
+Significance: patch
+Type: fixed
+
+Fix a blank Boost admin page on WordPress installs without the Gutenberg plugin active, where the wp-theme script handle the embedded My Jetpack app depends on was otherwise unregistered.

projects/plugins/jetpack/changelog/fix-my-jetpack-wp-theme-polyfill

@@ -0,0 +1,3 @@
+Significance: patch
+Type: other
+Comment: Update composer.lock.

projects/plugins/protect/changelog/fix-my-jetpack-wp-theme-polyfill

@@ -0,0 +1,3 @@
+Significance: patch
+Type: changed
+Comment: Update composer.lock.

projects/plugins/search/changelog/fix-my-jetpack-wp-theme-polyfill

@@ -0,0 +1,3 @@
+Significance: patch
+Type: changed
+Comment: Update composer.lock.