Visit Twitter user's Medium blog and vice versa

twitter_to_medium.js

var url = window.location.href;
var unRE = /\/\@?(\w+)$/;
var userName = '';
var unMatch = url.match(unRE);
if (unMatch && unMatch.length) {
    userName = (unMatch.length > 1) ? unMatch[1] : unMatch[0];
    userName = userName.replace('/', '').replace('@', '');
}
var mediumMatch = url.match(/medium/);
var twitterMatch = url.match(/twitter/);
var isMedium = !!(mediumMatch && mediumMatch.length);
var isTwitter = !!(twitterMatch && twitterMatch.length);
var next = 'https://' + ((!isMedium) ? 'medium.com/@' : 'twitter.com/') + userName; 
window.location.href = next;