Rest API: add /revisions endpoint for global styles (#49974)

* Initial commit:
- adding /revisions endpoint to global styles API
- tests

* Updating tests to account for author and is_latest response properties

* There's an existing protected method called `prepare_links` in Gutenberg_REST_Global_Styles_Controller that we can overwrite in the subclass. It makes for less code and a neater abstraction.

* Refactored to extract revisions endpoint registration and associated classes into Gutenberg_REST_Global_Styles_Revisions_Controller
Returning revisions URL in prepare_links

* Update tests

* Removing unused comment and method.

lib/compat/wordpress-6.2/rest-api.php

@@ -84,15 +84,6 @@ function gutenberg_pattern_directory_collection_params_6_2( $query_params ) {
 }
 add_filter( 'rest_pattern_directory_collection_params', 'gutenberg_pattern_directory_collection_params_6_2' );
 
-/**
- * Registers the Global Styles REST API routes.
- */
-function gutenberg_register_global_styles_endpoints() {
-	$editor_settings = new Gutenberg_REST_Global_Styles_Controller_6_2();
-	$editor_settings->register_routes();
-}
-add_action( 'rest_api_init', 'gutenberg_register_global_styles_endpoints' );
-
 /**
  * Updates REST API response for the sidebars and marks them as 'inactive'.
  *

lib/compat/wordpress-6.3/class-gutenberg-rest-global-styles-controller-6-3.php

@@ -0,0 +1,51 @@
+<?php
+/**
+ * REST API: Gutenberg_REST_Global_Styles_Controller class
+ *
+ * @package    Gutenberg
+ * @subpackage REST_API
+ */
+
+/**
+ * Base Global Styles REST API Controller.
+ */
+class Gutenberg_REST_Global_Styles_Controller_6_3 extends Gutenberg_REST_Global_Styles_Controller_6_2 {
+	/**
+	 * Revision controller.
+	 *
+	 * @since 6.3.0
+	 * @var WP_REST_Revisions_Controller
+	 */
+	private $revisions_controller;
+
+	/**
+	 * Prepares links for the request.
+	 *
+	 * @since 5.9.0
+	 * @since 6.3 Adds revisions to version-history.
+	 *
+	 * @param integer $id ID.
+	 * @return array Links for the given post.
+	 */
+	protected function prepare_links( $id ) {
+		$base = sprintf( '%s/%s', $this->namespace, $this->rest_base );
+
+		$links = array(
+			'self' => array(
+				'href' => rest_url( trailingslashit( $base ) . $id ),
+			),
+		);
+
+		if ( post_type_supports( $this->post_type, 'revisions' ) ) {
+			$revisions                = wp_get_latest_revision_id_and_total_count( $id );
+			$revisions_count          = ! is_wp_error( $revisions ) ? $revisions['count'] : 0;
+			$revisions_base           = sprintf( '/%s/%s/%d/revisions', $this->namespace, $this->rest_base, $id );
+			$links['version-history'] = array(
+				'href'  => rest_url( $revisions_base ),
+				'count' => $revisions_count,
+			);
+		}
+
+		return $links;
+	}
+}

lib/compat/wordpress-6.3/rest-api.php

@@ -28,3 +28,37 @@ function gutenberg_update_templates_template_parts_rest_controller( $args, $post
 	return $args;
 }
 add_filter( 'register_post_type_args', 'gutenberg_update_templates_template_parts_rest_controller', 10, 2 );
+
+
+/**
+ * Registers the Global Styles Revisions REST API routes.
+ */
+function gutenberg_register_global_styles_revisions_endpoints() {
+	$global_styles_revisions_controller = new Gutenberg_REST_Global_Styles_Revisions_Controller();
+	$global_styles_revisions_controller->register_routes();
+}
+add_action( 'rest_api_init', 'gutenberg_register_global_styles_revisions_endpoints' );
+
+/**
+ * Registers the Global Styles REST API routes.
+ */
+function gutenberg_register_global_styles_endpoints() {
+	$global_styles_controller = new Gutenberg_REST_Global_Styles_Controller_6_3();
+	$global_styles_controller->register_routes();
+}
+add_action( 'rest_api_init', 'gutenberg_register_global_styles_endpoints' );
+
+/**
+ * Update `wp_global_styles` post type to use Gutenberg's REST controller.
+ *
+ * @param array  $args Array of arguments for registering a post type.
+ * @param string $post_type Post type key.
+ */
+function gutenberg_update_global_styles_rest_controller( $args, $post_type ) {
+	if ( in_array( $post_type, array( 'wp_global_styles' ), true ) ) {
+		$args['rest_controller_class'] = 'Gutenberg_REST_Templates_Controller_6_3';
+		$args['rest_base']             = 'global-styles';
+	}
+	return $args;
+}
+add_filter( 'register_post_type_args', 'gutenberg_update_global_styles_rest_controller', 10, 2 );