auth/missing-identifier when sign-in through Microsoft IDP

[ihor-panasiuk95]

Last few weeks our customers complain about impossibility to sign-in through Microsoft IDP. By digging deeper we found out that Firebase throws auth/missing-identifier error after signing in with popup.
Google sign-in with popup works well.
In browser devtools we clearly see that the endpoint https://identitytoolkit.googleapis.com/v1/accounts:createAuthUri returns 400 status code upon sing-in with Microsoft.
This is the request payload:

What that could be and how we can debug/fix this issue?
Thanks in advance.

Our stack:
Angular 15
Firebase 9
@angular/fire 7.5

[ihor-panasiuk95]

For whom it may concern, I found the pattern.
This error is thrown during login through Microsoft when I use a third party email (in my case, gmail) that MS account created with. For such case I have to get auth/account-exists-with-different-credential thrown instead of this error but instead I get auth/missing-identifier. When I login with MS account that's created without any third-party email it works fine and does not throw any error, just signs me in.
The same flow through Google provider works fine.

If I use firebase/compat Microsoft login also works fine and for the email I described above it throws the expected auth/account-exists-with-different-credential error.
I'm pretty sure this is the issue of the modular Firebase@9.
Will create the repo with reproduction steps and will raise the bug.

[ihor-panasiuk95]

This is the expected error I should get:

But instead I get:

[baughmann]

This is a problem still. Was able to reproduce verbatim.

[IrinaGaly]

Also having same problem

[devops-naya]

Facing same issue when I am integrating firebase with workOS

[baughmann]

For anyone coming across this, it's best to just roll your own integration. If I remember I will post a minimal version of how I did it with Microsoft O365. However, there are some good videos from Firebase about it and there's a good section of the docs regarding it as well.

[user9747]

@baughmann can you point towards the firebase docs.

[baughmann]

Sorry:
https://firebase.google.com/docs/auth/web/custom-auth

And

https://firebase.google.com/docs/auth/admin/create-custom-tokens