Gtk.TextIter.prototype.get_visible_text

function get_visible_text(end:Gtk.TextIter):String {
    // Gjs wrapper for gtk_text_iter_get_visible_text()
}

Like gtk_text_iter_get_text (), but invisible text is not included. Invisible text is usually invisible because a Gtk.TextTag with the "invisible" attribute turned on has been applied to it.