shortid-test.js

const shortid = require('shortid');
const redis = require("redis");
const client = redis.createClient();

function t() {
	const id = shortid.generate();
	client.sadd('sids', id, (err, res) => {
		if(err) throw err;
		if(res != 1) {  // redis will return the number of new items, so if we added anything other than 1, something broke
			throw new Error('gack, duplicate ' + id);
		}
		t();
	});
}

for(var i = 0; i < 50; i++) { // start multiple "workers" to add items
	t();
}

setInterval(() => {
	client.scard('sids', (err, res) => {
		console.log(res);
	});
}, 100);