Distinguishing an unsuccessful OAuth flow

[rxb]

Steps to reproduce

• a feathersjs backend and a react (web) frontend using feathersjs/client for authentication
• using feathersjs/authentication-local
• using feathersjs/authentication-oauth (google, in this case)
• calling .reAuthenticate() on frontend init to either:
  • read token saved in localstorage or
  • get oauth accessToken from location.hash
  • get oauth error from location.hash

Actual behavior

Currently, the feathers client throws a 401 not-authenticated for both...

• when reAuthenticate does not find a token in localstorage (normal occurrence for every pageload for a non-logged-in user)
• when reAuthenticate captures an OAuth error from the location.hash, returning from an oauth flow

Expected behavior

It would be useful if there was a way to distinguish the OAuth failure error specifically (for example: an Oauth attempts to create a user that fails validation because the email already exists as a local-auth user ) and show the user some helpful info for logging in to their original account with email/password.

It's also very possible I'm thinking about this in completely the wrong way and there's a simpler way to detect a bad OAuth on the client. Thanks so much for your help!

Module versions (especially the part that's not working):
5.0.0-pre.3

NodeJS version:
14.15.0

Operating System:
MacOS 11.3

Browser Version:
Chrome 90.0.4430.61

[daffl]

I just realised that this has been addressed a while ago in #2189