WP_REST_Revisions_Controller::delete_item PHP Method

    public function delete_item($request)
    {
        $force = isset($request['force']) ? (bool) $request['force'] : false;
        // We don't support trashing for revisions.
        if (!$force) {
            return new WP_Error('rest_trash_not_supported', __('Revisions do not support trashing. Set force=true to delete.'), array('status' => 501));
        }
        $revision = get_post($request['id']);
        $previous = $this->prepare_item_for_response($revision, $request);
        $result = wp_delete_post($request['id'], true);
        /**
         * Fires after a revision is deleted via the REST API.
         *
         * @since 4.7.0
         *
         * @param (mixed) $result The revision object (if it was deleted or moved to the trash successfully)
         *                        or false (failure). If the revision was moved to to the trash, $result represents
         *                        its new state; if it was deleted, $result represents its state before deletion.
         * @param WP_REST_Request $request The request sent to the API.
         */
        do_action('rest_delete_revision', $result, $request);
        if (!$result) {
            return new WP_Error('rest_cannot_delete', __('The post cannot be deleted.'), array('status' => 500));
        }
        $response = new WP_REST_Response();
        $response->set_data(array('deleted' => true, 'previous' => $previous->get_data()));
        return $response;
    }