Firebase strips all request cookies

A painfully wasteful discovery today was that, when you are using Firebase Functions to serve your code, it strips all cookies from the request object.  The only hack around this is to use a specially named cookie, “__session” and fit any data you need into that.

For example, in the browser

document.cookie = “__session=some_value”;

and on the server

import {parse} from “cookie-parse”;

exports.myFunction = functions.https.onRequest((req, res) => {
const cookie = req.headers.cookie;
const sessionValue = parse(cookie)[“__session”];
console.log(“Should be some_value”, sessionValue);