Adds an SVG inside of page nav items when using wp_nav_menu() in WordPress

wp_nav_add_icons.php

<?php
// Adds an SVG inside of page nav items when using wp_nav_menu()
add_filter('wp_nav_menu_objects', 'nav_add_icons', 10, 2);
function nav_add_icons($items, $args) {
  if ($args->menu->slug === 'header-navigation') {
    foreach ($items as $item) {
      if ($item->object === 'page') {
        $slug = get_post_field('post_name', $item->object_id);
        $icon = get_stylesheet_directory_uri() . "/img/svg/nav-$slug.svg";
        $item->title = "<img src='$icon' class='style-svg' /><span>{$item->title}</span>";
      }
    }
  }
  return $items;
}
?>