Example twitter api call including construction of the auth header

twitter.js

const CONSUMER_KEY="consumer_key";
const CONSUMER_SECRET="consumer_secret";

const ACCESS_TOKEN="access_token";
const ACCESS_TOKEN_SECRET="access_token_secret";

const crypto = require('crypto');
const qs = require("querystring")
const request = require("request");


function getTwitterFollowList(){
    return new Promise(function(resolve, reject){
        let url = "https://api.twitter.com/1.1/friends/list.json";
        let method = "GET";
        
        let oauthParams = {        
            oauth_consumer_key: CONSUMER_KEY,
            oauth_nonce: generateNonce(),
            oauth_signature_method: "HMAC-SHA1",
            oauth_timestamp: Math.round(Date.now()/1000),
            oauth_token: ACCESS_TOKEN,
            oauth_version: "1.0"
        };
    
        let requestParams = {}
        let baseStringParams = Object.assign({},requestParams,oauthParams);
        let baseString = `${method.toUpperCase()}&${encodeURIComponent(url)}&${encodeURIComponent(qs.stringify(baseStringParams))}`
        let signingKey = `${encodeURIComponent(CONSUMER_SECRET)}&${encodeURIComponent(ACCESS_TOKEN_SECRET)}`;
        let signature = crypto.createHmac('sha1', signingKey).update(baseString).digest('base64');
        let header = constructHeader(Object.assign({},oauthParams,{oauth_signature: signature}));
        let requestObj = {
            "url": url,
            "method": method,
            "headers":{
                "Authorization": header
            }
        }
        request(requestObj, (e, res, body)=>{
            if(e){
                return reject(e.message)
            }
            resolve({status: res.statusCode, data: JSON.parse(body)})
        })
    
    });
}

function constructHeader(options){
    let headerString = "OAuth ", headerParts=[];
    let keys = Object.keys(options);
    keys.sort();
    for (let index = 0; index < keys.length; index++) {
        const key = keys[index];
        headerParts.push(`${key}="${encodeURIComponent(options[key])}"`)
    }
    return headerString+headerParts.join(", ");
}

function generateNonce(){
    let nonceString = crypto.randomBytes(32).toString("base64")
    return nonceString.replace(/[^a-zA-Z0-9]/gi,"");
}

module.exports = {
    getTwitterFollowList: getTwitterFollowList
}