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

use getAdditionalUserInfo

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

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