feat: update actor_name assignment in decorator

[z0z0r4]

Close #640

[Bogdanp]

This isn't the right approach, since it would be a breaking change to any currently-deployed code. I would prefer it if we checked for duplicate actor names and raised an error instead.

[z0z0r4]

Indeed, I think checking for duplicate actor_name is necessary. But at the same time, it is reasonable to change the default value. We should support functions decorated with the same function name by default, right? This should also be a design mistake.

[Bogdanp]

I think it's more nuanced than a plain design mistake. At least, I remember thinking about this quite a bit when I made the original decision to use __name__. For example, even if we used __qualname__ here, renaming the module in which an actor is defined would then potentially lead to a production bug (actors are looked up by name, and messages already enqueued for mod1.foo would not be able to find mod2.foo). Using __qualname__ now is out of the question since it would break users' code for the same reason. So, the only good option is to keep using __name__ and to error when there are duplicates.

[z0z0r4]

actors are looked up by name, and messages already enqueued for mod1.foo would not be able to find mod2.foo

Will anyone who in the production environment keep the queue unemptied and update dramatiq? I don't think so, but there is no evidence.

I will keep this PR until I open another PR to add the exception you mentioned. Delay for a few days .

[z0z0r4]

@Bogdanp fixed

[z0z0r4]

fixed

[Bogdanp]

Thanks!