[SOLVED] Firebase - check if user created with Google Account is signing up or logging in?

Firebase - check if user created with Google Account is signing up or logging in?

I'm trying to create a web application, where you can log-in and register an account with a google account. I have managed to make it so they can log-in with the signInWithPopup(provider), but not sure how to Implement the sign-up. Any suggestions? or know of any functions in firebase i can use?

Solution

There aren't any separate methods to login and sign up when using Google Sign-In or any other provider. If a user with that credential exists then user will be logged in else a new user account will be created. You can then use additionalUserInfo.isNewUser property from the result received from signInWithPopUp method to check if the user is new.

firebase.auth().signInWithPopup(provider).then(function (result) {
  const {additionalUserInfo: {isNewUser}} = result;

  console.log(isNewUser ? "This user just registered" : "Existing User")
})

For the new Modular SDK (V9.0.0+), the same can be written as:

import { signInWithPopup, getAdditionalUserInfo } from "firebase/auth"

const result = await signInWithPopup(auth, googleProvider);

// Pass the UserCredential   
const { isNewUser } = getAdditionalUserInfo(result)