text: const cheerio = require('cheerio');
  const fs = require('fs');
  // walk through directory to collect html file paths, parse for links, and return array of link objects
  
  // create collection of HTML file addresses from directory
  const walk = (dir) => {
    let results = [];
    const list = fs.readdirSync(dir);
    list.forEach((file) => {
      file = `${dir}/${file}`;
      const stat = fs.statSync(file);
      if (stat && stat.isDirectory()) {
        /* Recurse into a subdirectory */
        results = results.concat(walk(file));
      } else {
        const fileType = file.split('.').pop();
        if (fileType === 'html') {
          results.push(file);
        }
      }
    });
    return results;
  };
  
  // get URLS from HTML in ./build/options using cheerio
  const getUrls = (htmlArray) => {
    // skip exact (rel and href) doubles of links
    const trackDoubles = {};
    const scrapedHTML = [];
  
    for (let i = 0; i < htmlArray.length; i += 1) {
      const $ = cheerio.load(fs.readFileSync(htmlArray[i]));
      const links = $('a');
  
      // create url object:
      // { 'AIRS - The AIRS instrument suite physical retrievals': 'http://airs.jpl.nasa.gov/data/physical_retrievals' }
      $(links).each((i, link) => {
        const linkRel = $(link).text() || 'EMPTY';
        const linkHref = $(link).attr('href');
  
        if (trackDoubles[linkRel] !== linkHref) {
          scrapedHTML.push({ [linkRel]: linkHref });
          trackDoubles[linkRel] = linkHref;
        }
      });
    }
    return scrapedHTML;
  };
  
  // get URLS from HTML files
  // scraped URLs are saved in an array of objects with a key value pair of link text and href:
  // 'Wildfire MB-CE042, Manitoba, Canada': 'https://eonet.gsfc.nasa.gov/api/v2.1/events/EONET_3518'
  const initExtractor = async() => {
    // any html file with a url will be scraped and added
    const htmlFiles = await walk('./build/options');
    const htmlUrls = await getUrls(htmlFiles);
    return htmlUrls;
  };
  
  module.exports = initExtractor;
  