danbooru/app/components/popup_menu_component/popup_menu_component.html.erb

<div class="popup-menu">
  <a class="popup-menu-button" href="javascript:void(0)">
    <i class="fas fa-ellipsis-h"></i>
  </a>

  <ul class="popup-menu-content">
    <% items.each do |item| %>
      <li><%= item %></li>
    <% end %>
  </ul>
</div>