artisan-1.x-dev/components/nav-item/nav-item.twig

{% set attributes = attributes ?: create_attribute() %}

{% apply spaceless %}
  {% block nav_item %}
    <li {{ attributes.addClass('nav-item') }}>
      {{ link|add_class('nav-link', is_active ? 'active' : '') }}
    </li>
  {% endblock %}
{% endapply %}