WordPress Custom search Include All Custom Post Types

functions.php

<?php
function my_custom_search($query) {
  // Check to verify it's search page
  if( is_search( ) {
      $post_types = get_post_types(array('public' => true, 'exclude_from_search' => false), 'objects');
      $searchable_types = array();
      // Add available post types
      if( $post_types ) {
          foreach( $post_types as $type) {
              $searchable_types[] = $type->name;
          }
      }
      $query->set( 'post_type', $searchable_types );
  }
  return $query;
}
add_action( 'pre_get_posts', 'my_custom_search' );