Get a tweet with OAuth

twitter.js

const OAuth = require('oauth-1.0a');
const crypto = require('crypto');
const fetch = require('isomorphic-unfetch');
const linkifyHTML = require('linkifyjs/html');
const sanitizeHtml = require('sanitize-html');

// Don't put your config where people can see it folks
const { Config } = require('../config');

// \n doesn't work in HTML :/
const nl2br = string => {
  const html = string.replace(/(?:\r\n|\r|\n)/g, '<br>');
  return sanitizeHtml(html, {
    allowedTags: ['br'],
  });
};

const populateHashtags = (text, hashtags) => {
  hashtags.forEach(hashtag => {
    // Add space around the search so we don't accidentally grab hashes
    // from a url (e.g. https://wearecreator.uk/#clients)
    text = text.replace(
      ` #${hashtag.text} `,
      ` <a href="https://twitter.com/hashtag/${
        hashtag.text
      }" target="_blank" rel="nofollow noopener">#${hashtag.text}</a> `
    );
  });

  return text;
};

const populateMentions = (text, mentions) => {
  mentions.forEach(mention => {
    text = text.replace(
      `@${mention.screen_name}`,
      `<a href="https://twitter.com/${
        mention.screen_name
      }" target="_blank" rel="nofollow noopener">@${mention.screen_name}</a>`
    );
  });

  return text;
};

const getLatestTweet = async screenName => {
  const oauth = OAuth({
    consumer: {
      key: Config.twitter.consumerKey,
      secret: Config.twitter.consumerSecret,
    },
    signature_method: 'HMAC-SHA1',
    hash_function(base_string, key) {
      return crypto
        .createHmac('sha1', key)
        .update(base_string)
        .digest('base64');
    },
  });

  const token = {
    key: Config.twitter.accessToken,
    secret: Config.twitter.accessTokenSecret,
  };

  const requestData = {
    url: `https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=${screenName}&count=1&tweet_mode=extended`,
    method: 'GET',
  };

  const headers = oauth.toHeader(oauth.authorize(requestData, token));

  const tweetRes = await fetch(requestData.url, {
    headers,
    mode: 'no-cors',
  });

  const [tweet] = await tweetRes.json();

  // If no tweet was returned, like for instance if
  // the twitter feed hasn't posted anything yet...
  if (typeof tweet === 'undefined') return '';

  const withLineBreaks = nl2br(tweet.full_text);
  const withLinks = linkifyHTML(withLineBreaks);

  const withHashtags = populateHashtags(withLinks, tweet.entities.hashtags);
  const withMentions = populateMentions(
    withHashtags,
    tweet.entities.user_mentions
  );

  return withMentions;
};

exports.getLatestTweet = getLatestTweet;