feat: Experimental editor assets REST API endpoint

lib/experimental/class-wp-rest-block-editor-assets-controller.php

@@ -0,0 +1,193 @@
+<?php
+/**
+ * REST API: WP_REST_Block_Editor_Assets_Controller class
+ *
+ * @package WordPress
+ * @subpackage REST_API
+ */
+
+if ( ! class_exists( 'WP_REST_Block_Editor_Assets_Controller' ) ) {
+
+	/**
+	 * Core class used to retrieve the block editor assets via the REST API.
+	 *
+	 * @see WP_REST_Controller
+	 */
+	class WP_REST_Block_Editor_Assets_Controller extends WP_REST_Controller {
+		/**
+		 * Constructor.
+		 */
+		public function __construct() {
+			$this->namespace = '__experimental/wp-block-editor/v1';
+			$this->rest_base = 'editor-assets';
+		}
+
+		/**
+		 * Registers the controller routes.
+		 */
+		public function register_routes() {
+			register_rest_route(
+				$this->namespace,
+				'/' . $this->rest_base,
+				array(
+					array(
+						'methods'             => WP_REST_Server::READABLE,
+						'callback'            => array( $this, 'get_items' ),
+						'permission_callback' => array( $this, 'get_items_permissions_check' ),
+					),
+					'schema' => array( $this, 'get_public_item_schema' ),
+				)
+			);
+		}
+
+		/**
+		 * Retrieves a collection of items.
+		 *
+		 * @param WP_REST_Request $request The request object.
+		 *
+		 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+		 */
+		public function get_items( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			global $wp_styles, $wp_scripts;
+
+			$current_wp_styles  = $wp_styles;
+			$current_wp_scripts = $wp_scripts;
+
+			$wp_styles  = new WP_Styles();
+			$wp_scripts = new WP_Scripts();
+
+			// Trigger an action frequently used by plugins to enqueue assets.
+			do_action( 'wp_loaded' );
+
+			// We generally do not need reset styles for the block editor. However, if
+			// it's a classic theme, margins will be added to every block, which is
+			// reset specifically for list items, so classic themes rely on these
+			// reset styles.
+			$wp_styles->done =
+				wp_theme_has_theme_json() ? array( 'wp-reset-editor-styles' ) : array();
+
+			wp_enqueue_script( 'wp-polyfill' );
+			// Enqueue the `editorStyle` handles for all core block, and dependencies.
+			wp_enqueue_style( 'wp-edit-blocks' );
+
+			if ( current_theme_supports( 'wp-block-styles' ) ) {
+				wp_enqueue_style( 'wp-block-library-theme' );
+			}
+
+			// Enqueue frequent dependent, admin-only `dashicon` asset.
+			wp_enqueue_style( 'dashicons' );
+
+			// Enqueue the admin-only `postbox` asset required for the block editor.
+			$suffix = wp_scripts_get_suffix();
+			wp_enqueue_script( 'postbox', "/wp-admin/js/postbox$suffix.js", array( 'jquery-ui-sortable', 'wp-a11y' ), false, 1 );
+
+			// Enqueue foundational post editor assets.
+			wp_enqueue_script( 'wp-edit-post' );
+			wp_enqueue_style( 'wp-edit-post' );
+
+			// Ensure the block editor scripts and styles are enqueued.
+			add_filter( 'should_load_block_editor_scripts_and_styles', '__return_true' );
+			do_action( 'enqueue_block_assets' );
+			do_action( 'enqueue_block_editor_assets' );
+			remove_filter( 'should_load_block_editor_scripts_and_styles', '__return_true' );
+
+			// Additionally, enqueue `editorStyle` and `editorScript` assets for all
+			// blocks, which contains editor-only styling for blocks (editor content).
+			$block_registry = WP_Block_Type_Registry::get_instance();
+			foreach ( $block_registry->get_all_registered() as $block_type ) {
+				if ( isset( $block_type->editor_style_handles ) && is_array( $block_type->editor_style_handles ) ) {
+					foreach ( $block_type->editor_style_handles as $style_handle ) {
+						wp_enqueue_style( $style_handle );
+					}
+				}
+				if ( isset( $block_type->editor_script_handles ) && is_array( $block_type->editor_script_handles ) ) {
+					foreach ( $block_type->editor_script_handles as $script_handle ) {
+						wp_enqueue_script( $script_handle );
+					}
+				}
+			}
+
+			// Remove the deprecated `print_emoji_styles` handler. It avoids breaking
+			// style generation with a deprecation message.
+			$has_emoji_styles = has_action( 'wp_print_styles', 'print_emoji_styles' );
+			if ( $has_emoji_styles ) {
+				remove_action( 'wp_print_styles', 'print_emoji_styles' );
+			}
+
+			ob_start();
+			wp_print_styles();
+			$styles = ob_get_clean();
+
+			if ( $has_emoji_styles ) {
+				add_action( 'wp_print_styles', 'print_emoji_styles' );
+			}
+
+			ob_start();
+			wp_print_head_scripts();
+			wp_print_footer_scripts();
+			$scripts = ob_get_clean();
+
+			$wp_styles  = $current_wp_styles;
+			$wp_scripts = $current_wp_scripts;
+
+			return array(
+				'styles'  => $styles,
+				'scripts' => $scripts,
+			);
+		}
+
+		/**
+		 * Checks the permissions for retrieving items.
+		 *
+		 * @param WP_REST_Request $request The REST request object.
+		 *
+		 * @return bool|WP_Error True if the request has permission, WP_Error object otherwise.
+		 */
+		public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+			if ( current_user_can( 'edit_posts' ) ) {
+				return true;
+			}
+
+			foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
+				if ( current_user_can( $post_type->cap->edit_posts ) ) {
+					return true;
+				}
+			}
+
+			return new WP_Error(
+				'rest_cannot_read_block_editor_assets',
+				__( 'Sorry, you are not allowed to read the block editor assets.', 'gutenberg' ),
+				array( 'status' => rest_authorization_required_code() )
+			);
+		}
+
+		/**
+		 * Retrieves the block editor assets schema, conforming to JSON Schema.
+		 *
+		 * @return array Item schema data.
+		 */
+		public function get_item_schema() {
+			if ( $this->schema ) {
+				return $this->add_additional_fields_schema( $this->schema );
+			}
+
+			$schema = array(
+				'type'       => 'object',
+				'properties' => array(
+					'styles'  => array(
+						'description' => esc_html__( 'Style link tags for the block editor.', 'gutenberg' ),
+						'type'        => 'string',
+					),
+					'scripts' => array(
+						'description' => esc_html__( 'Script tags for the block editor.', 'gutenberg' ),
+						'type'        => 'string',
+					),
+				),
+			);
+
+			$this->schema = $schema;
+
+			return $this->add_additional_fields_schema( $this->schema );
+		}
+	}
+}

lib/experimental/rest-api.php

@@ -19,6 +19,15 @@ function gutenberg_register_block_editor_settings() {
 }
 add_action( 'rest_api_init', 'gutenberg_register_block_editor_settings' );
 
+/**
+ * Registers the block editor assets REST API route.
+ */
+function gutenberg_register_block_editor_assets() {
+	$editor_assets = new WP_REST_Block_Editor_Assets_Controller();
+	$editor_assets->register_routes();
+}
+add_action( 'rest_api_init', 'gutenberg_register_block_editor_assets' );
+
 
 /**
  * Shim for get_sample_permalink() to add support for auto-draft status.

lib/load.php

@@ -34,6 +34,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 	if ( ! class_exists( 'WP_REST_Block_Editor_Settings_Controller' ) ) {
 		require_once __DIR__ . '/experimental/class-wp-rest-block-editor-settings-controller.php';
 	}
+	require_once __DIR__ . '/experimental/class-wp-rest-block-editor-assets-controller.php';
 
 	// WordPress 6.6 compat.
 	require __DIR__ . '/compat/wordpress-6.6/class-gutenberg-rest-global-styles-revisions-controller-6-6.php';

phpunit/experimental/class-wp-rest-block-editor-assets-controller-test.php

@@ -0,0 +1,136 @@
+<?php
+/**
+ * Unit tests covering WP_REST_Block_Editor_Assets_Controller functionality.
+ *
+ * @package gutenberg
+ */
+
+if ( ! defined( 'REST_REQUEST' ) ) {
+	define( 'REST_REQUEST', true );
+}
+
+class WP_REST_Block_Editor_Assets_Controller_Test extends WP_Test_REST_Controller_Testcase {
+	/**
+	 * @var int
+	 */
+	protected static $admin_id;
+
+	/**
+	 * @var int
+	 */
+	protected static $subscriber_id;
+
+	public function set_up() {
+		parent::set_up();
+	}
+
+	/**
+	 * Create fake data before test runs.
+	 *
+	 * @param WP_UnitTest_Factory $factory Helper that lets us create fake data.
+	 */
+	public static function wpSetupBeforeClass( $factory ) {
+		self::$admin_id = $factory->user->create(
+			array(
+				'role' => 'administrator',
+			)
+		);
+
+		self::$subscriber_id = $factory->user->create(
+			array(
+				'role' => 'subscriber',
+			)
+		);
+	}
+
+	/**
+	 * Clean up fake data.
+	 */
+	public static function wpTearDownAfterClass() {
+		self::delete_user( self::$admin_id );
+		self::delete_user( self::$subscriber_id );
+	}
+
+	public function tear_down() {
+		parent::tear_down();
+	}
+
+	public function test_register_routes() {
+		$routes = rest_get_server()->get_routes();
+
+		$this->assertArrayHasKey(
+			'/__experimental/wp-block-editor/v1/editor-assets',
+			$routes
+		);
+	}
+
+	public function test_get_items_without_user() {
+		wp_set_current_user( 0 );
+
+		$request  = new WP_REST_Request( 'GET', '/__experimental/wp-block-editor/v1/editor-assets' );
+		$response = rest_get_server()->dispatch( $request );
+
+		$this->assertErrorResponse( 'rest_cannot_read_block_editor_assets', $response, 401 );
+	}
+
+	public function test_get_items_without_permissions() {
+		wp_set_current_user( self::$subscriber_id );
+
+		$request  = new WP_REST_Request( 'GET', '/__experimental/wp-block-editor/v1/editor-assets' );
+		$response = rest_get_server()->dispatch( $request );
+
+		$this->assertErrorResponse( 'rest_cannot_read_block_editor_assets', $response, 403 );
+	}
+
+	public function test_get_items() {
+		wp_set_current_user( self::$admin_id );
+
+		$request  = new WP_REST_Request( 'GET', '/__experimental/wp-block-editor/v1/editor-assets' );
+		$response = rest_get_server()->dispatch( $request );
+		$data     = $response->get_data();
+
+		$this->assertArrayHasKey( 'styles', $data, 'Editor assets should include styles.' );
+		$this->assertArrayHasKey( 'scripts', $data, 'Editor assets should include scripts.' );
+	}
+
+	public function test_get_item_schema() {
+		$request    = new WP_REST_Request( 'OPTIONS', '/__experimental/wp-block-editor/v1/editor-assets' );
+		$response   = rest_get_server()->dispatch( $request );
+		$data       = $response->get_data();
+		$properties = $data['schema']['properties'];
+
+		$this->assertCount( 2, $properties, 'Schema properties array does not have exactly 2 elements' );
+		$this->assertArrayHasKey( 'styles', $properties, 'Schema properties array does not have "id" key' );
+		$this->assertArrayHasKey( 'scripts', $properties, 'Schema properties array does not have "styles" key' );
+	}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_create_item() {}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_update_item() {}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_get_item() {}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_delete_item() {}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_prepare_item() {}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_context_param() {}
+}