How to differentiate signin and signup user in firebase using google auth?

Question

I am using firebase to authenticate user. If new user signin using google/facebook provider, it creates a user and automatically sign in. After user signin, how to differentiate between signIn and signUp?

var provider = new firebase.auth.GoogleAuthProvider();

firebase.auth().signInWithPopup(provider).then(function(result) {
  var token = result.credential.accessToken;
  var user = result.user;
  // if new user i want to redirect to some other page.
  // if user already exist, i want to redirect to home page
}).catch(function(error) {
  // Handle Errors here.
});

Answer 1

The UserCredential object you get as result has an additionalUserInfo member that has an isNewUser property.

So result.additionalUserInfo.isNewUser will be true the first time the user signs in, and false afterwards.