index.js

const crawl = async url => {
  visited.add(url);
  const { data } = await axios.get(url);
  const $ = cheerio.load(data);
  const content = extractContent($);
  const links = extractLinks($);
  links
    .filter(link => !visited.has(link)) // Filter out already visited links
    .forEach(link => toVisit.add(link));
};

(async () => { // IIFE
  // Loop over a set's values
  for (const next of toVisit.values()) {
    if (visited.size >= maxVisits) {
      break;
    }

    toVisit.delete(next);
    await crawl(next);
  }

  console.log(visited);
  // Set { 'https://scrapeme.live/shop/page/1/', '.../2/', ... }
  console.log(toVisit);
  // Set { 'https://scrapeme.live/shop/page/47/', '.../48/', ... }
})(); // The final set of parenthesis will call the function