React - Firebase - GoogleAuthProvider is not a constructor

I ran into this "not a constructor" problem and some other errors as well. I was doing something like this:

var googleProvider = new myApp.auth.GoogleAuthProvider();

When it should have been

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

I was also initializing my app with a name like this:

var myApp = firebase.initializeApp(appConfig, "App");

Which didn't initialize a DEFAULT app & gave me more errors. I should have done this (since I only have one app)

var myApp = firebase.initializeApp(appConfig);

I ran into this issue as I was trying to store a reference to firebase.auth to use in multiple functions.

I found that the GoogleAuthProvider function is a property of the auth firebase function whereas the signInWithPopup, onAuthStateChanged, signOut, etc. are on the firebase.auth.Auth returned by the firebase.auth() function.

This is what my code now looks like.

    //constructor
    this.auth = firebase.auth;
    this.auth_ = firebase.auth();
    ...
    //sign in function
    var provider = new this.auth.GoogleAuthProvider();
    this.auth_.signInWithPopup(provider); 

The sample code at https://codelabs.developers.google.com/codelabs/firebase-web/#5 is correct but this is a hard to notice difference when you paste this code in your solution and start messing with it.

I also faced the same issue and now fortunately is working!

put this in firebase.js

export const provider = new firebase.auth.GoogleAuthProvider();

and import in login.js

import {firebaseApp,provider} from '../../../services/firebase_setup';

You're mixing namespaces with instance: the firebaseApp is just a container for configuration data. It is not how you create a provider instance.

The proper way is:

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