add facebook login functionality and remove fb secret key

.env.example

@@ -0,0 +1,5 @@
+FACEBOOK_ID=SKIP
+FACEBOOK_SECRET=SKIP
+FACEBOOK_CALLBACK=http://localhost:3000/auth/facebook/callback
+SESSION_SECRET=ThisIsMySecret
+PORT=3000

.gitignore

@@ -11,4 +11,6 @@ Desktop.ini
 # npm
 node_modules
 *.log
-*.gz
+*.gz
+
+.env

app.js

@@ -5,18 +5,22 @@ const bodyParser = require('body-parser')
 const methodOverride = require('method-override')
 const flash = require('connect-flash')
 
+if (process.env.NODE_ENV !== 'production') {
+  require('dotenv').config()
+}
+
 const routes = require('./routes')
 
 const usePassport = require('./config/passport')
 
 const app = express()
-const PORT = 3000
+const PORT = process.env.PORT
 
 app.engine('hbs', exphbs({ defaultLayout: 'main', extname: '.hbs' }))
 app.set('view engine', 'hbs')
 
 app.use(session({
-  secret: 'ThisIsMySecret',
+  secret: process.env.SESSION_SECRET,
   resave: false,
   saveUninitialized: true
 }))

config/passport.js

@@ -1,5 +1,6 @@
 const passport = require('passport')
 const LocalStrategy = require('passport-local').Strategy
+const FacebookStrategy = require('passport-facebook').Strategy
 const bcrypt = require('bcryptjs')
 
 const db = require('../models')
@@ -25,6 +26,33 @@ module.exports = app => {
       .catch(err => done(err, false))
   }))
 
+  passport.use(new FacebookStrategy({
+    clientID: process.env.FACEBOOK_ID,
+    clientSecret: process.env.FACEBOOK_SECRET,
+    callbackURL: process.env.FACEBOOK_CALLBACK,
+    profileFields: ['email', 'displayName']
+  },
+  (accessToken, refreshToken, profile, done) => {
+    const { name, email } = profile._json
+    User.findOne({ where: { email } })
+      .then(user => {
+        if (user) return done(null, user)
+
+        const randomPassword = Math.random().toString(36).slice(-8)
+        bcrypt
+          .genSalt(10)
+          .then(salt => bcrypt.hash(randomPassword, salt))
+          .then(hash => User.create({
+            name,
+            email,
+            password: hash
+          }))
+          .then(user => done(null, user))
+          .catch(err => done(err, false))
+      })
+  }
+  ))
+
   passport.serializeUser((user, done) => {
     done(null, user.id)
   })

package.json

@@ -14,12 +14,14 @@
   "dependencies": {
     "bcryptjs": "^2.4.3",
     "connect-flash": "^0.1.1",
+    "dotenv": "^8.2.0",
     "express": "^4.17.1",
     "express-handlebars": "^4.0.4",
     "express-session": "^1.17.1",
     "method-override": "^3.0.0",
     "mysql2": "^2.1.0",
     "passport": "^0.4.1",
+    "passport-facebook": "^3.0.0",
     "passport-local": "^1.0.0",
     "sequelize": "^5.21.13",
     "sequelize-cli": "^5.5.1"

routes/index.js

@@ -4,11 +4,13 @@ const router = express.Router()
 const home = require('./modules/home')
 const users = require('./modules/users')
 const todos = require('./modules/todos')
+const auth = require('./modules/auth')
 
 const { authenticator } = require('../middleware/auth')
 
 router.use('/todos', authenticator, todos)
 router.use('/users', users)
+router.use('/auth', auth)
 router.use('/', authenticator, home)
 
 module.exports = router

routes/modules/auth.js

@@ -0,0 +1,15 @@
+const express = require('express')
+const router = express.Router()
+
+const passport = require('passport')
+
+router.get('/facebook', passport.authenticate('facebook', {
+  scope: ['email', 'public_profile']
+}))
+
+router.get('/facebook/callback', passport.authenticate('facebook', {
+  successRedirect: '/',
+  failureRedirect: 'users/login'
+}))
+
+module.exports = router