A/B testing middleware for express.js using cookies with a round-robin distribution.
You will need the cookie-parser set to make it work.
Usage:
app.use(cookieParser());
const test = setABCookies("test");
app.get("/", test(), (req, res) => res.send("Hello variant 1!"));
app.get("/", test(), (req, res) => res.send("Hello variant 2!"));