Is there a way to get a firebase-authenticated github user's username

Question

I'm essentially trying to have a website which authenticates the user's GitHub account through firebase, and then saves their username in a database - I specifically need the username for this. I have the authentication working but it seems that firebase doesn't have a way to access the username, only things such as the email, display name, etc. Currently I just want to save the username as a variable

I've come across this: https://developer.github.com/v3/users/#get-the-authenticated-user I assume "login" is the username? I'm relatively new to things though, and can't find any clear examples of how I would access this information with my token from firebase. For reference, I have an index.html, linked to app.js, which contains all of my authentication code.

var provider = new firebase.auth.GithubAuthProvider();
    provider.addScope('read:user');
    //get elements
    const authenticateBtn = document.getElementById('authbtn');

    //add login event
    authenticateBtn.addEventListener('click', e=>{

        firebase.auth().signInWithPopup(provider).then(function(result) {
        // This gives you a GitHub Access Token. You can use it to access the GitHub API.
        var token = result.credential.accessToken;

        // The signed-in user info.
        var user = result.user;

        //what I want to get
        //var Username = ; 

        //some data I am able to get
        var displayName = user.displayName;
        var email = user.email;
        var emailVerified = user.emailVerified;
        var photoURL = user.photoURL;
        var isAnonymous = user.isAnonymous;
        var uid = user.uid;
        var providerData = user.providerData;

        //where I want to print the username
        //console.log(userName);


        // ...
        }).catch(function(error) {
        // Handle Errors here.
        var errorCode = error.code;
        var errorMessage = error.message;
        // The email of the user's account used.
        var email = error.email;
        // The firebase.auth.AuthCredential type that was used.
        var credential = error.credential;
        // ...
        });
    })

I really just need a beginners explanation of if what I want to do is possible and if so, exactly what code I'd need where in my project. Thanks!

Answer 1

So I ended up getting some help from a friend, here is my solution:

firebase.auth().signInWithPopup(provider).then(function(result) {

        // This gives you a GitHub Access Token. You can use it to access the GitHub API.
        var token = result.credential.accessToken;
        // The signed-in user info.

        var user = result.user;
        var username;
        var obj;

        const Http =  new XMLHttpRequest();
        Http.open("GET", "https://api.github.com/user?access_token="+token);
        Http.send();

        Http.onreadystatechange=function(){
            if(this.readyState==4 && this.status==200){
                obj = JSON.parse(Http.responseText);
                username = obj.login;
                console.log(username);

            }
        }
}