Enhance Jetpack integration for comment meta sync (#2233)

Author: obenland

.github/changelog/2233-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: changed
+
+Updated sync allowlist to add support for Jetpack notifications of likes and reposts.

integration/class-jetpack.php

@@ -21,6 +21,8 @@ class Jetpack {
 	 */
 	public static function init() {
 		\add_filter( 'jetpack_sync_post_meta_whitelist', array( self::class, 'add_sync_meta' ) );
+		\add_filter( 'jetpack_sync_comment_meta_whitelist', array( self::class, 'add_sync_comment_meta' ) );
+		\add_filter( 'jetpack_sync_whitelisted_comment_types', array( self::class, 'add_comment_types' ) );
 		\add_filter( 'jetpack_json_api_comment_types', array( self::class, 'add_comment_types' ) );
 		\add_filter( 'jetpack_api_include_comment_types_count', array( self::class, 'add_comment_types' ) );
 	}
@@ -39,13 +41,31 @@ public static function add_sync_meta( $allow_list ) {
 		return $allow_list;
 	}
 
+	/**
+	 * Add ActivityPub comment meta keys to the Jetpack sync allow list.
+	 *
+	 * @param array $allow_list The Jetpack sync allow list.
+	 *
+	 * @return array The Jetpack sync allow list with ActivityPub comment meta keys.
+	 */
+	public static function add_sync_comment_meta( $allow_list ) {
+		$allow_list[] = 'avatar_url';
+
+		return $allow_list;
+	}
+
 	/**
 	 * Add custom comment types to the list of comment types.
 	 *
 	 * @param array $comment_types Default comment types.
 	 * @return array
 	 */
 	public static function add_comment_types( $comment_types ) {
+		// jetpack_sync_whitelisted_comment_types runs on plugins_loaded, before comment types are registered.
+		if ( 'jetpack_sync_whitelisted_comment_types' === current_filter() ) {
+			Comment::register_comment_types();
+		}
+
 		return array_unique( \array_merge( $comment_types, Comment::get_comment_type_slugs() ) );
 	}
 }