companion: use state in session in tests

packages/@uppy/companion/test/mockserver.js

@@ -2,7 +2,7 @@ const { app } = require('../src/standalone')
 
 const express = require('express')
 const session = require('express-session')
-var authServer = express()
+const authServer = express()
 
 authServer.use(session({ secret: 'grant', resave: true, saveUninitialized: true }))
 authServer.all('*/callback', (req, res, next) => {
@@ -11,7 +11,7 @@ authServer.all('*/callback', (req, res, next) => {
   }
   next()
 })
-authServer.all('*/send-token', (req, res, next) => {
+authServer.all(['*/send-token', '*/redirect'], (req, res, next) => {
   req.session.grant = { dynamic: { state: req.query.state || 'non-empty-value' } }
   next()
 })