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JavaScript Facebook Authentication

Emmanuel Nwogbo
PLUS
Emmanuel Nwogbo
Courses Plus Student 2,434 Points
Posted by Emmanuel Nwogbo
Emmanuel Nwogbo
Courses Plus Student 2,434 Points

OAuth Authentication With Passport course

I just finished the OAuth Authentication With Passport course, still trying to digest a few concepts. Everything works fine, until I actually try to login to my test app with Facebook or github. Instead of being routed to the profile page, I get this error: 

Cannot read property '0' of undefined

TypeError: Cannot read property '0' of undefined
    at Strategy.generateOrFindUser [as _verify] (C:\projects\Side         Projects\passyapp\app.js:16:19)
    at C:\projects\Side Projects\passyapp\node_modules\passport-  oauth2\lib\strategy.js:193:24
    at C:\projects\Side Projects\passyapp\node_modules\passport-  github\lib\strategy.js:174:7
    at passBackControl (C:\projects\Side Projects\passyapp\node_modules\oauth\lib\oauth2.js:134:9)
    at IncomingMessage.<anonymous> (C:\projects\Side Projects\passyapp\node_modules\oauth\lib\oauth2.js:157:7)
    at emitNone (events.js:91:20)
    at IncomingMessage.emit (events.js:185:7)
    at endReadableNT (_stream_readable.js:974:12)
    at _combinedTickCallback (internal/process/next_tick.js:74:11)
    at process._tickCallback (internal/process/next_tick.js:98:9)

BELOW IS A SNIPPET FROM MY APP.JS FILE:

function generateOrFindUser(accessToken, refreshToken, profile, done){
  if(profile.emails[0]) {
    User.findOneAndUpdate({
      email: profile.emails[0]},
    {
      name: profile.displayName || profile.username,
      email: profile.emails[0].value,
      photo: profile.photos[0].value
    },
    {
      upsert: true
    },
    done);
  }
  else {
    let noEmailError = new Error("Your email privacy setting prevent you from signing in");
    done(noEmailError, null);
  }
}

//configure github startegy
passport.use(new GitHubStrategy({
  clientID: process.env.GITHUB_CLIENT_ID,
  clientSecret: process.env.GITHUB_CLIENT_SECRET,
  callbackURL: "http://localhost:3000/auth/github/return",
  profileFields   : ['id', 'email']
}, generateOrFindUser));

//Configure facebook strategy
passport.use(new FacebookStrategy({
    clientID: process.env.FACEBOOK_APP_ID,
    clientSecret: process.env.FACEBOOK_APP_SECRET,
    callbackURL: "http://localhost:3000/auth/facebook/return",
    profileFields   : ['id', 'email']
  }, generateOrFindUser));

I've been stuck the whole day; any help would be nice.

1 Answer

Valeshan Naidoo
Valeshan Naidoo
27,008 Points
Valeshan Naidoo
Valeshan Naidoo
27,008 Points

Extremely late response, but for anybody else reading, you don't need a profileFields for the github strategy. And what worked for me was adding a scope to my github strategy like this:

scope: 'user:email'

I know Andrew didn't use this, but maybe this requirement was added later.