https://nascar.nbcsports.com/wp-content/uploads/sites/9/2020...
Google Identity reference to NASCAR Login: https://developers.google.com/identity/toolkit/images/federa...
NASCAR logins are particularly great (easy entry to convert interested users) and at the same time having a huge number of super-ugly edge cases:
1. If you log in with john.q.doe@gmail.com but originally had registered your gmail as johnqdoe, then your login automatically changes to the non-dot form.
2. If you have already registered via email on john.q.doe@gmail.com, then you cannot login-with-Google in the above case, as both accounts are separate and distinct in the host system.
3. If you have two accounts under your school and work account, but log-in-with-Facebook, and Facebook has both your emails, it gets confused.
4. There are cases where you simply cannot log in due to the network of conflicts across the identity services.
...and yet this is also awesome because you get to convert a registered user ASAP in 95% of the cases.
