Started typing codebase

[WisdomPill]

Fixes #893

First of all, I want to point out that this is a process and maybe it will not be completed in every piece of code right away with just one pull request.
I started adding typing only on functions to the project but I have some questions about some parts of the code.

1. The user is always a Union[User, AnonymousUser]?

2. Is the message in Consumers always a dictionary?
   I have a problem with AsyncHttpConsumer that throws a strange exception

   TypeError: 'type' object is not subscriptable
   

3. Is it mandatory to put the output if there's no return value?

4. The code in close method of web sockets can be a number or a bool, not anything else?

By the way this is my first pull request to the project, so if there's anything else I should do

[WisdomPill]

Now only the last two points need some clarification.

1. Is it mandatory to put the output if there's no return value?

2. The code in close method of web sockets can be a number or a bool, not anything else?

[hishnash]

would it not make more sense to make the database_sync_to_async be generic

def database_sync_to_async(method: Callable[SomeGenericVar...]) -> Callable[ Awaitable[TheGenericReturnOfTHeCallable]]
....

[WisdomPill]

It's not that easy, database_sync_to_async inherits from SyncToAsync class from asgiref library.
Are you suggesting that I should inherit the call method to then type it like you wrote?

[hishnash]

good point, no lets just leave that as is.

[WisdomPill]

We'll see, in the mean time I have to keep in mind compatibility with python 3.5.

How should I deal with import sorting? Is there a tool for sorting them before a commit or a configuration in the editor to enable?

[WisdomPill]

Never mind I figured out how to use black and isort

[WisdomPill]

I'm waiting for someone to review the PR.

@matthiask @carltongibson @hishnash anyone?

Can you please give some feedback or just merge the PR?

[carltongibson]

HI @WisdomPill. I'm currently working on an update for Daphne. Then I'll cut back to channels. I'll have a look at this then.

[carltongibson]

Hi @WisdomPill.

This looks good. Thank you for the effort.

Can I ask a question? Is there any shorthand for this:

Dict[str, Any]

Can we define an alias so we can just pass, say StrDict — that's rubbish but you get the idea?

(Like 99% of Dicts are Dict[str, Any] so it seems quite boilerplatey...)

[WisdomPill]

@carltongibson done!

[carltongibson]

Hi @WisdomPill. That was quick. 🙂 Still not sure about StrDict per se but yes.

I'm looking at releases here for Sept, so will do something with this for then. Good work!

[carltongibson]

HI @WisdomPill.

Sorry for the slow follow-up here. This has been bugging me greatly, and I haven't had a chance to get to it. Anyhow...

Please create a types or typing module — What do Python folks do here? —

Then create proper type alias wherever you have something like Optional[Tuple[str, Tuple[str, Any], StrDict]]. I simply don't want to look at that. 🙂 Instead I want to see RouteMatch or such...

Then we'll hopefully get something meaningful. i.e. a scope is an AsgiScope (or just Scope), which if I'm interested I'll go and see is a Dict[Str: Any] — but only certain keys are allowed, so can we tighten that? (if we can't tighten it now, maybe we will over time. Maybe we'll get asgiref to declare that type, and so on...)

Liberal use of type aliases is the key to success here. (As they do in Haskell and friends.)

Make sense?

Thanks!

[auvipy]

fix the merge error plz

[WisdomPill]

@carltongibson is there anything left in order to merge the pull request?

[carltongibson]

@WisdomPill Just me getting another chance to review it. 🙂 Thank you for your efforts here!

[nscozzaro]

Stumbled upon this issue because I was looking to see the status of type hinting in Django, so I'd love to see these changes pulled!

[WisdomPill]

I should have fixed everything in the following commits, closing che changes request.

Sorry I just discovered this feature, I'm a noob in open source software

[WisdomPill]

@carltongibson just a friendly reminder to review the changes and to point out that I alligned the changes with channels/master.

[carltongibson]

Hi @WisdomPill. Thanks for your efforts here. I'm just waiting to see what happens with the discussion on Django before coming back here.

[carltongibson]

Gonna close this for now. Further discussion on #1819.