WordPress - Timber Menu: set an archive menu item to 'current' when location is a single post

functions.php

<?php

/*
Suppose you have a custom content type called 'videos'
You have a menu item that points to the 'videos' archive page (http://yoursite.com/videos)
When on a single video page you want the 'videos' menu item to be styled as the current/active link

The following will make the Timber\MenuItem 'current' property to true on the archives menu item when on a single post
*/

// register the menu
function register_menus() {
  register_nav_menu('primary',__( 'Primary Navigation', 'theme_slug' ));
}
add_action( 'init', 'register_menus' );

function add_to_timber_context($context) {
  $context['primary_menu'] = array_map(function($item) {
    if(is_single()){
      $item->current = ($item->object === get_post_type()) ?: false;
    }
    return $item;
  }, (new TimberMenu('primary'))->get_items());
  return $context;
}
add_filter('timber_context', 'add_to_timber_context');

primary-nav.twig

<div class="c-nav">
  <nav class="c-nav__menu" role="navigation">
    <ul class="c-nav__menu-list">
      {% for item in items %}
        <li class="c-nav__menu-item">
          <a class="c-nav__menu-link {{ item.current ? 'active' : '' }}" href="{{ item.get_link }}">
            {{ item.title }}
          </a>
        </li>
      {% endfor %}
    </ul>
  </nav>
</div>