Jupyter notebook & lab TOC generator bookmarklet

JupyterTOC.js

javascript:(() => {
  const anchors = Array.from(document.querySelectorAll('a.anchor-link,a.jp-InternalAnchorLink'));
  const linkData = anchors.map(
    a => [
      Number(a.parentElement.tagName[1]),
      a.parentElement.firstChild.textContent,
      new URL(a.href).hash
    ]
  );

  const links = linkData
    .filter(([level, ..._]) => level > 1)
    .map(([level, title, url]) => {
      const indent = '  '.repeat(level - 2);
      return `${indent} * [${title}](${url})`;
    });

  const toc = `**Table of contents**\n${links.join("\n")}`;
  console.log(toc);
})();