hexo-theme-ayer/layout/categories.ejs

<section class="outer">
  <% if (site.categories.length){ %>
    <h1 class="page-type-title"><%= __('categories') %></h1>
    <!-- <%- list_categories({show_count: theme.show_count}) %> -->
    <ul class="category-list">
      <% site.categories.map(function(item){ %>
        <% if(item.posts.length){ %> 
          <a class="category-list-link" href="<%- config.root %><%- item.path %>" title="<%= item.name %>">
            <li class="category-list-item">
            <%= item.name %><i><%= item.posts.length %></i>
            </li>
          </a>
        <% } %>
      <% }); %>
      </ul>
  <% } %>
</section>