Update REST API field schema

src/wp-includes/rest-api/endpoints/class-wp-rest-block-types-controller.php

@@ -707,15 +707,17 @@ public function get_item_schema() {
 				'keywords'              => $keywords_definition,
 				'example'               => $example_definition,
 				'block_hooks'           => array(
-					'description' => __( 'Block hooks.' ),
-					'type'        => 'object',
-					'properties'  => array(),
-					'additionalProperties' => array(
-						'type' => 'string',
+					'description'       => __( 'This block is automatically inserted near any occurence of the block types used as keys of this map, into a relative position given by the corresponding value.' ),
+					'type'              => 'object',
+					'patternProperties' => array(
+						'^[a-zA-Z0-9-]+/[a-zA-Z0-9-]+$' => array(
+							'type' => 'string',
+							'enum' => array( 'before', 'after', 'first_child', 'last_child' ),
+						),
 					),
-					'default'     => array(),
-					'context'     => array( 'embed', 'view', 'edit' ),
-					'readonly'    => true,
+					'default'           => array(),
+					'context'           => array( 'embed', 'view', 'edit' ),
+					'readonly'          => true,
 				),
 			),
 		);