Automatically mark orders as ‘complete’ in WooCommerce

Automatically mark orders as ‘complete’ in WooCommerce

add_filter( 'woocommerce_payment_complete_order_status', 'virtual_order_payment_complete_order_status', 10, 2 );
function virtual_order_payment_complete_order_status( $order_status, $order_id ) {
  $order = new WC_Order( $order_id );
  if ( 'processing' == $order_status &&
       ( 'on-hold' == $order->status || 'pending' == $order->status || 'failed' == $order->status ) ) {
    $virtual_order = null;
    if ( count( $order->get_items() ) > 0 ) {
      foreach( $order->get_items() as $item ) {
        if ( 'line_item' == $item['type'] ) {
          $_product = $order->get_product_from_item( $item );
          if ( ! $_product->is_virtual() ) {
            // once we've found one non-virtual product we know we're done, break out of the loop
            $virtual_order = false;
            break;
          } else {
            $virtual_order = true;
          }
        }
      }
    }
    // virtual order, mark as completed
    if ( $virtual_order ) {
      return 'completed';
    }
  }
  // non-virtual order, return original status
  return $order_status;
}