Obtain OAuth token in Nodejs for SalesForce Commerce Cloud OCAPI (previously Demandware)

obtain_token.js

const https = require('https')

const headers = {
    'Authorization' : 'Basic YWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhOmFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYQ==',
    'Content-Type' : 'application/x-www-form-urlencoded'
}

const optionsget = {
    host : 'account.demandware.com',
    port : 443,
    path : '/dw/oauth2/access_token?grant_type=client_credentials',
    method : 'POST',
    headers: headers
}

let reqGet = https.request(optionsget, (res) => {

    res.on('data', (d) => {
        console.info('POST result:'+d.toString())
        console.info('Access token: \n')
        process.stdout.write(JSON.parse(d).access_token)
    })
})

reqGet.end()
reqGet.on('error', (e) => { console.error(e) })

// https://isolasoftware.it/2012/05/28/call-rest-api-with-node-js/

promised.js

const optionsget = {
    host : 'account.demandware.com',
    port : 443,
    path : '/dw/oauth2/access_token?grant_type=client_credentials',
    method : 'POST',
    headers: {
        'Authorization' : 'Basic YWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhOmFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYWFhYQ==',
        'Content-Type' : 'application/x-www-form-urlencoded'
    }
}

let getToken = () => {

    return new Promise((resolve, reject) => {

        try {

            require('https').get(optionsget, (res) => {

                let body = '';

                res.on('data', (chunk) => { body += chunk })
                res.on('end', () => {
                    let response = JSON.parse(body)
                    resolve( response )
                })

            }).on('error', (e) => { return reject(e + '') })

        } catch (e) { return reject(e + '') }
    })
}

getToken()
    .then((response) => {
        console.log('Access token (Expires in ' + response.expires_in + '): \n\n' + response.access_token)
    })
    .catch((e) => { console.error(e + '') })