frontend/middleware/passport.js

const Auth0Strategy = require("passport-auth0")
const passport = require("passport")
const config = require("../config")

//passport-auth0
const strategy = new Auth0Strategy({
  domain: config.auth0.domain,
  clientID: config.auth0.clientId,
  clientSecret: config.auth0.secret, // Replace this with the client secret for your app
  callbackURL: config.root + "/auth/callback"
  }, (accessToken, refreshToken, extraParams, profile, done) => {
    // accessToken is the token to call Auth0 API (not needed in the most cases)
    // extraParams.id_token has the JSON Web Token
    // profile has all the information from the user
    return done(null, profile);
  }
)

passport.use(strategy)

passport.serializeUser(function(user, done) {
  done(null, user);
});

passport.deserializeUser(function(user, done) {
  done(null, user);
});

module.exports = passport