Nope, because the testmail controller now passes the id (which it should) rather than the User object.  Passing the User object is bad, as it breaks compatibility with asynchronous worker systems (Sidekiq, Resque, etc.) So we don't want Spree framework code doing that.

The backwards compatibility is only there for 3rd parties who may be using the method in their own code without using asynchronous workers.  We don't want to break their code, at least not without a deprecation warning.

BTW, this isn't theoretical - I ran the test with the double and it fails.