mask auction bidder display name

add_filter( 'woocommerce_simple_auctions_displayname', 'auction_mask_displayname' );
function auction_mask_displayname( $displayname ) {

    if ( current_user_can( 'editor' ) || current_user_can( 'administrator' ) ) {
            return $displayname;
    } else {
        $length      = strlen( $displayname );
        $displayname = $displayname[0] . str_repeat( '*', $length - 2 ) . $displayname[ $length - 1 ];
    }
    return $displayname;
}