List of the 10 most repeated links on a HTML page

TenMostRepeatedLinksOnPage.js

function duplicateLinks(document) {
  const elements = Array.from(document.body.getElementsByTagName('a'));
  const linkElements = elements.filter((node, index) => {
    const href = node.getAttribute('href');
    const isRemote = href && href.match(/^http/);
    if (isRemote) {
      return true;
    }
  });

  const urls = linkElements.reduce((accu, el, index) => {
    const href = el.href;
    if (!accu[href]) {
      accu[href] = 0;
    }
    accu[href]++;
    return accu;
  }, {});

  const duplicates = {};
  for (const url in urls) {
    if (urls[url] > 1) {
      duplicates[url] = urls[url];
    }
  }
  const list = Object.entries(duplicates);
  const sorted = list.sort((u, v) => {
    const countDiff = Math.sign(v[1] - u[1]);
    const localeDiff = u[0].localeCompare(v[0]);
    return countDiff ? countDiff : localeDiff;
  });
  return sorted;
}

for (const dup of duplicateLinks(document).slice(0,10)) {
  console.log(`\t${dup[1]}\t${dup[0]}`);
}