Pega e salva os conteúdos da MDN

getContentsFromMDN.js

const cheerio = require('cheerio') 
const rp = require('request-promise') 
 
const links = require('./links')
const createFile = require('./createFile')

const options = {
    uri: `https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/`,
    transform: (body) => cheerio.load(body),
}

const BASE = `https://developer.mozilla.org/`
rp(options)
    .then( ($) => {
                $(`#wikiArticle ul li a`)
                    .map(( index, element ) => element.attribs.href )
                    .get() // 
                    .map( ( el, i ) => {
                        const _name = el.split('Reference/')[1]
                        const name = (_name) ? _name.replace('/', '_') : i
                        const link = BASE+el 

                        return { name, link }
                    })
                    .map( content => 
                        rp( {
                            uri: content.link,
                            transform: (body) => cheerio.load(body),
                        })
                        .then( ($) => 
                            createFile(`conteudos/${content.name}.html`, 
                                            $(`#wikiArticle`).html()) )
                        .catch( (err) => 
                            console.log('err no request', err) )
                    )
                }
    )
    .catch( (err) => console.log('err no request', err) )

// } )

const fs = require('fs')

module.exports = (PATH, data) => fs.writeFile(PATH, data, (err) =>
(err)
? console.log('err em createFile', err)
: console.log('\n Salvei o conteúdo em : ', PATH))