Improve NullUser with implementation of UserEntityInterface

[AurelienPillevesse]

Add implementation of UserEntityInterface for NullUser to be aligned with OAuth2-Server library

[chalasr]

Could you please provide some link pointing to the related change on league/oauth2-server?

[AurelienPillevesse]

There is no update from league/oauth2-server but this class implements everything except this little update

[maxhelias]

The NullUser is related to the new security implementation #34

[maxhelias]

Shouldn't we respect the interface declaration with no return type and return a null value? https://github.com/thephpleague/oauth2-server/blob/master/src/Entities/UserEntityInterface.php#L19C7-L19C7

[X-Coder264]

The NullUser is supposed to be used only in the context of the Symfony security layer (as that's what it was added for in the first place - in order to be able to use the client credentials grant in Symfony apps as that grant does not have a real user associated with it). I'm not sure what exactly do you want to achieve by making it implement an unrelated non Symfony interface?

[chalasr]

As @X-Coder264 said, this is not desired as we have entities separated from security objects.
Thanks for proposing.