node-passport-example.js

const express = require('express');

// Passport
const passport = require('passport');
const GoogleStrategy = require('passport-google-oauth20').Strategy;

const keys = require('./config/keys');

const app = express();

// Creates a new instance of the GoogleStrategy
// In the constructor tell it how to handle this
// Client ID and Client Secret
// callbackURL - string is the route that the user
// is sent to after they grant permission to our app
passport.use(
  new GoogleStrategy(
    {
      clientID: keys.googleClientID,
      clientSecret: keys.googleClientSecret,
      callbackURL: '/auth/google/callback',
      proxy: true
    },
    (accessToken, refreshToken, profile, done) => {
      // Take identifying user information and save to db
      console.log('access token', accessToken);
      console.log('refresh token', refreshToken);
      console.log('profile', profile);
    }
  )
);

// Route handler for passport flow
// Internally GoogleStrategy has a string of 'google' we can use as the first argument
// of passport.authenticate
app.get(
  '/auth/google',
  passport.authenticate('google', {
    scope: ['profile', 'email']
  })
);

// When the user hits this route they have the auth code
app.get(
  '/auth/google/callback',
  passport.authenticate('google')
);

app.listen(3000);