Syncing changes from Core https://core.trac.wordpress.org/ticket/61021 …

…for 6.6 compat (WordPress#62211)

Co-authored-by: ramonjd <ramonopoly@git.wordpress.org>
Co-authored-by: andrewserong <andrewserong@git.wordpress.org>

lib/compat/wordpress-6.6/rest-api.php

@@ -87,3 +87,73 @@ function gutenberg_register_global_styles_revisions_endpoints() {
 }
 
 add_action( 'rest_api_init', 'gutenberg_register_global_styles_revisions_endpoints' );
+
+if ( ! function_exists( 'gutenberg_register_wp_rest_themes_stylesheet_directory_uri_field' ) ) {
+	/**
+	 * Adds `stylesheet_uri` fields to WP_REST_Themes_Controller class.
+	 */
+	function gutenberg_register_wp_rest_themes_stylesheet_directory_uri_field() {
+		register_rest_field(
+			'theme',
+			'stylesheet_uri',
+			array(
+				'get_callback' => function ( $item ) {
+					if ( ! empty( $item['stylesheet'] ) ) {
+						$theme         = wp_get_theme( $item['stylesheet'] );
+						$current_theme = wp_get_theme();
+						if ( $theme->get_stylesheet() === $current_theme->get_stylesheet() ) {
+							return get_stylesheet_directory_uri();
+						} else {
+							return $theme->get_stylesheet_directory_uri();
+						}
+					}
+
+					return null;
+				},
+				'schema'       => array(
+					'type'        => 'string',
+					'description' => __( 'The uri for the theme\'s stylesheet directory.', 'gutenberg' ),
+					'format'      => 'uri',
+					'readonly'    => true,
+					'context'     => array( 'view', 'edit', 'embed' ),
+				),
+			)
+		);
+	}
+}
+add_action( 'rest_api_init', 'gutenberg_register_wp_rest_themes_stylesheet_directory_uri_field' );
+
+if ( ! function_exists( 'gutenberg_register_wp_rest_themes_template_directory_uri_field' ) ) {
+	/**
+	 * Adds `template_uri` fields to WP_REST_Themes_Controller class.
+	 */
+	function gutenberg_register_wp_rest_themes_template_directory_uri_field() {
+		register_rest_field(
+			'theme',
+			'template_uri',
+			array(
+				'get_callback' => function ( $item ) {
+					if ( ! empty( $item['stylesheet'] ) ) {
+						$theme         = wp_get_theme( $item['stylesheet'] );
+						$current_theme = wp_get_theme();
+						if ( $theme->get_stylesheet() === $current_theme->get_stylesheet() ) {
+							return get_template_directory_uri();
+						} else {
+							return $theme->get_template_directory_uri();
+						}
+					}
+
+					return null;
+				},
+				'schema'       => array(
+					'type'        => 'string',
+					'description' => __( 'The uri for the theme\'s template directory. If this is a child theme, this refers to the parent theme, otherwise this is the same as the theme\'s stylesheet directory.', 'gutenberg' ),
+					'format'      => 'uri',
+					'readonly'    => true,
+					'context'     => array( 'view', 'edit', 'embed' ),
+				),
+			)
+		);
+	}
+}
+add_action( 'rest_api_init', 'gutenberg_register_wp_rest_themes_template_directory_uri_field' );