WIP: adds types for user facing API

[sobolevn]

Related #305

Here's how it works:

from dramatiq import actor

@actor
def test(arg: int) -> str:
    return str(arg)

reveal_type(test)
reveal_type(test(1))

Output:

» mypy ex.py 
ex.py:7: note: Revealed type is 'dramatiq.actor.Actor[def (arg: builtins.int) -> builtins.str]'
ex.py:8: note: Revealed type is 'builtins.str'

[sobolevn]

@Bogdanp let's decide what "public API" is. Because project has lots of files and classes / methods. I would be very grateful if you can help me in this field.

[sobolevn]

I use # noqa: B950 because otherwise when I add new lines inside function definition python3.5 raises parsing errors. I don't know why.

[sobolevn]

Self notes: I need to parametrize Message as Generic on its result. And get_result() method will return the generic type.

This also means, that we need to somehow parametrize the result backend.

[Bogdanp]

@Bogdanp let's decide what "public API" is.

I would say anything that is documented in the Reference is part of the public API.

[sobolevn]

Hi, @Bogdanp! I don't have any more time to work on this.

What is going to be the future of this PR? Looks like it is a good start.

[Bogdanp]

I don't really have the time to carry it over either, but I'll happily make any necessary final adjustments and merge it if someone picks it up and finishes it.

[orsinium]

I'd be happy to take over it. However, since dramatic doesn't support Python 2 anymore, no need to use stubs. Would you mind having type annotations right in the code? That's much easier to maintain than a bunch of duplicated signatures in separate stub files.

UPD: now I see, stubs were used only for __init__.py. Interesting. I miss the historical context here, but I'm pretty sure it's not needed anymore.

[Bogdanp]

I'd be happy to take over it. However, since dramatic doesn't support Python 2 anymore, no need to use stubs. Would you mind having type annotations right in the code? That's much easier to maintain than a bunch of duplicated signatures in separate stub files.

UPD: now I see, stubs were used only for __init__.py. Interesting. I miss the historical context here, but I'm pretty sure it's not needed anymore.

Feel free to pick it up! I have no opinion on the stubs and, if they're no longer necessary, then you should feel free to get rid of them.

[orsinium]

Thank you :) Since I work at Sendcloud, I'm sure I can get some time to work on dramatiq. I'll pick it up in one of the upcoming sprints 👍🏿

[sobolevn]

@orsinium thanks! 👍

[Bogdanp]

I believe this is covered by @orsinium 's recent changes so I'm going to go ahead and close this. Thank you both!

[sobolevn]

@orsinium thank you for taking this over! Great work!