Session in webSocket subscriptions

[frederikhors]

I'm using Apollo Server 2 and Express.js vanilla (with apollo-server-express).

Everything works good also with Subscriptions except the Express session mechanism.

The problem:

I'm using cookie-session (https://github.com/expressjs/cookie-session, but I think this is the same for express-session middleware) and when my browser start a new connection with my server the ApolloServer onConnect hook doesn't have the req attribute and neither req.session and so on...

What I can do is to parse the cookies from webSocket.upgradeReq.headers.cookie in onConnect lifecycle hook, but it seems to me very hacky.

The code:

const { ApolloServer } = require('apollo-server-express')

const typeDefs = require('../src/graphql/types')
const resolvers = require('../src/graphql/resolvers')
const models = require('../src/models')

const apolloServer = new ApolloServer({
  typeDefs,
  resolvers,
  context: ({ req, connection }) => {
    // connection exists only on webSocket connection
    if (connection) {
      return {
        currentUser: connection.context.currentUser // <-- I NEED THIS!
      }
    }
    // if not a (webSocket) connection it is a "default" HTTP call
    return {
      models,
      currentUser: { id: req.user.id }
    }
  },
  subscriptions: {
    onConnect: (connectionParams, webSocket) => {
      // "connectionParams" is from the client but I cannot use it because cookies are HTTP-Only
      // I can retrieve cookies from here: "webSocket.upgradeReq.headers.cookie" but then I need to parse them which seems a bit hacky to me
      // return { currentUser: req.user.id } // <-- I NEED THIS (req.user.id doesn't exists)!
    }
  }
})

module.exports = apolloServer

I can't find anything on Apollo Server Docs site (for other topics very well documented!).

Where am I doing wrong?

StackOverflow question: https://stackoverflow.com/questions/52280481/graphql-subscription-websocket-nodejs-express-session-with-apollo-server-2