how to link to phone Auth? about snippets-web

[malcolmdeck]

Hey there, Malcolm from the Firebase team here!

You can link a phone credential to an existing account, but you can't do it using the #linkWithPopup() method. You can use either of:

1. #updatePhoneNumber()
2. #linkWithCredential()

The reason that you can't use #linkWithPopup() is that that method is specifically to launch a popup to show an OAuth login screen (for example, Google Sign-In), and then link the credential. For Phone Auth, you instead need to use the intermediary credential from the Phone Authentication flow, which you can get by calling

firebase.auth.PhoneAuthProvider.credential(confirmationResult.verificationId, code);

as mentioned in this guide.

I hope that that clears things up!
~Malcolm

[samtstern]

@cp-bwg is there something you tried that is not working?

[geek-at]

I have the same problem. When I'm initially logging in via Phone authentication, I can add another account (like a gmail) without a problem using snippets from https://github.com/firebase/snippets-web/blob/master/auth/link-multiple-accounts.js

But when I first log in via Email and want to link a phone number I get the error

code: "auth/invalid-oauth-provider"
message: "EmailAuthProvider is not supported for this operation. This operation only supports OAuth providers."

This is my the snipped that produces the error (while being logged in with only an email address):

var phoneProvider = new firebase.auth.PhoneAuthProvider();
firebase.auth().currentUser.linkWithPopup(phoneProvider).then(function(result) {
    // Accounts successfully linked.
    var credential = result.credential;
    var user = result.user;
    console.log(credential,user)
}).catch(function(error) {
    console.log(error)
});

[geek-at]

@samtstern is this a known problem or is it by design?