function genesis_post_author_shortcode( $atts ) {

  if ( ! post_type_supports( get_post_type(), 'author' ) ) {
    return '';
  }

  $author = get_the_author();

  if ( ! $author ) {
    return '';
  }

  $defaults = [
    'after'  => '',
    'before' => '',
  ];

  $atts = shortcode_atts( $defaults, $atts, 'post_author' );

  $output  = sprintf( '<span %s>', genesis_attr( 'entry-author' ) );
  $output .= $atts['before'];
  $output .= sprintf( '<span %s>', genesis_attr( 'entry-author-name' ) ) . esc_html( $author ) . '</span>';
  $output .= $atts['after'];
  $output .= '</span>';

  return apply_filters( 'genesis_post_author_shortcode', $output, $atts );

}