website/_includes/debug/toc.html

{% include vars.html %}

{% assign shouldRender = false %}

{% if jekyll.environment == "development" %}
  {% assign shouldRender = true %}
{% endif %}

{% if include.forceRender %}
  {% assign shouldRender = true %}
{% endif %}

{% if shouldRender and vars_active_language.tag == 'en' %}
  {% assign lines = include.content | newline_to_br | strip_newlines | split: '<br />' %}

  {% assign insideCodeBlock = false %}

  {% for line in lines %}
    {% assign threeChar = line | slice: 0, 3 %}
    {% assign firstChar = line | slice: 0, 1 %}

    {% if threeChar == '```' %}
      {% if insideCodeBlock %}
        {% assign insideCodeBlock = false %}
      {% else %}
        {% assign insideCodeBlock = true %}
      {% endif %}
    {% endif %}

    {% unless insideCodeBlock %}
      {% if firstChar == '#' %}
        {% assign stripped = line | strip_html %}
        {% assign slug = stripped | slugify | prepend: 'toc-' %}
        {% assign link = '<a class="toc" id="' | append: slug | append: '" href="#' | append: slug | append: '"></a>' %}
        {% assign full = stripped | append: ' ' | append: link %}

        {% unless line contains link %}
          <div class="alert alert-danger">
            <h4>Yarn Website Internal Developer Warning!</h4>

            <p>This page contains this heading:</p>

            <pre><code>{{line | escape}}</code></pre>

            <p>
              All headings need a table of contents "toc" link, you have either
              left it out or are using the "wrong" one. Please use this one:
            </p>

            <pre><code>{{link | escape}}</code></pre>

            <p>
              Even if this is not your fault, please correct the error. Also
              if there is an existing toc, please check that any links on the
              website to this heading are correct (just search for the previous
              toc id).
            </p>

            <p>
              If you believe you are seeing this warning by mistake, please open
              an issue.
            </p>
          </div>
        {% endunless %}
      {% endif %}
    {% endunless %}
  {% endfor %}
{% endif %}