Getting meta tags from multiple posts on NPR using Cheerio.js

cheerio_meta_posts.js

const cheerio = require('cheerio');
const request = require('request');
const fs = require('fs');
var interval = 500;
let data = new Array;

request({
    method: 'GET',
    url: 'https://www.npr.org/sections/national/'
}, (err, res, body) => {    
  if (err) return console.error(err);
    let $ = cheerio.load(body);
      $('div.imagewrap > a').each(function(index, elem) {
        setTimeout(function () {
            let link = $(elem).attr('href');
            request({
                method: 'GET',
                url: link
            }, (err, res, body) => {
                if (err) return console.error(err);
                let $ = cheerio.load(body);
                let post = {
                    title: $('h1').text(),
                    url: link,
                    canonical: $('link[rel="canonical"]').attr('href'),
                    description: $('meta[name="description"]').attr('content'),
                    // Get OG Values
                    og_title: $('meta[property="og:title"]').attr('content'),
                    og_url: $('meta[property="og:url"]').attr('content'),
                    og_img: $('meta[property="og:image"]').attr('content'),
                    og_type: $('meta[property="og:type"]').attr('content'),
                    // Get Twitter Values
                    twitter_site: $('meta[name="twitter:site"]').attr('content'),
                    twitter_domain: $('meta[name="twitter:domain"]').attr('content'),
                    twitter_img_src: $('meta[name="twitter:image:src"]').attr('content'),
                    // Get Facebook Values
                    fb_appid: $('meta[property="fb:app_id"]').attr('content'),
                    fb_pages: $('meta[property="fb:pages"]').attr('content'),
                }
                data.push(post)
            })
            fs.writeFile("log.json", JSON.stringify(data), function(err) {
                if (err) return console.error(err);
                console.log("Anoter post saved!");
            });
        }, index * interval);
    });
});