Function processHeading

server/utils/readme.ts:515–544

(
    depth: number,
    displayHtml: string,
    plainText: string,
    slugSource: string,
    preservedAttrs = '',
  )

  // Shared heading processing for both markdown and HTML headings
  function processHeading(
    depth: number,
    displayHtml: string,
    plainText: string,
    slugSource: string,
    preservedAttrs = '',
  ) {
    const semanticLevel = calculateSemanticDepth(depth, lastSemanticLevel)
    lastSemanticLevel = semanticLevel

    let slug = slugify(slugSource)
    if (!slug) slug = 'heading'

    const count = usedSlugs.get(slug) ?? 0
    usedSlugs.set(slug, count + 1)
    const uniqueSlug = count === 0 ? slug : `${slug}-${count}`
    const id = toUserContentId(uniqueSlug)

    if (plainText) {
      toc.push({ text: plainText, id, depth })
    }

    // The browser doesn't support anchors within anchors and automatically extracts them from each other,
    // causing a hydration error. To prevent this from happening in such cases, we use the anchor separately
    if (htmlAnchorRe.test(displayHtml)) {
      return `<h${semanticLevel} id="${id}" data-level="${depth}"${preservedAttrs}>${displayHtml}<a href="#${id}"></a></h${semanticLevel}>\n`
    }

    return `<h${semanticLevel} id="${id}" data-level="${depth}"${preservedAttrs}><a href="#${id}">${displayHtml}</a></h${semanticLevel}>\n`
  }

  const anchorTokenRegex = /^<a(?:\s.+)?\/?>$/
  renderer.heading = function ({ tokens, depth }: Tokens.Heading) {