RSocket python over Websocket using aiohttp

[jell-o-fishi]

RSocket - Application protocol providing Reactive Streams semantics.

I am the maintainer of rsocket-py, a python implementation of the protocol.
There is integration with aiohttp using RSocket over Websocket, both server and client.

Would appreciate feedback.

Available on pypi.

[Dreamsorcerer]

Feedback on implementation?

[jell-o-fishi]

Specifically these:
examples:
https://github.com/rsocket/rsocket-py/blob/master/examples/server_aiohttp_websocket.py
https://github.com/rsocket/rsocket-py/blob/master/examples/client_websocket.py
RSocket transport adapter:
https://github.com/rsocket/rsocket-py/blob/master/rsocket/transports/aiohttp_websocket.py

[Dreamsorcerer]

OK, await web._run_app(app, port=6565). This is clearly a private function and should not be used. I think for your example, you should just use the standard web.run_app() function (with no call to asyncio.run()). (https://docs.aiohttp.org/en/stable/web_quickstart.html#run-a-simple-web-server)

As you only add 1 handler, I'd also consider using app.router.add_get() as a slightly more concise method.

Applies to both:
https://github.com/rsocket/rsocket-py/blob/master/examples/tutorial/step8/chat_server.py
https://github.com/rsocket/rsocket-py/blob/master/examples/server_aiohttp_websocket.py

I also wonder if the Transport class could have __aenter__() and __aexit__() to automatically call .connect()/.close().

Otherwise, looks like it should be good.

[jell-o-fishi]

Wouldn't it be reasonable to have a formal way to run the web server without it being in control of the event loop ? As part of another application ? For example in the tests, I had to use the private function to run it, because the test framework was already in charge of the event loop. And in the server_aiohttp_websocket.py I placed it inside asyncclick. Am i missing something ?

[jell-o-fishi]

Regarding the asynccontextmanager I thought about that, but requires some major refactoring of the package. Maybe in the future.

[Dreamsorcerer]

Wouldn't it be reasonable to have a formal way to run the web server without it being in control of the event loop?

https://docs.aiohttp.org/en/stable/web_advanced.html#application-runners

For most applications though, it's usually easier and more reliable to let aiohttp run the program, and hook other parts of your program into that (using on_startup/cleanup_ctx). This allows aiohttp to ensure those other parts are started/stopped alongside the web app.
See: https://docs.aiohttp.org/en/stable/web_advanced.html#complex-applications

I had to use the private function to run it, because the test framework was already in charge of the event loop.

I've not looked at the tests, but generally you want to use the testing utils we provide, which should run the application for you:
https://docs.aiohttp.org/en/stable/testing.html

And in the server_aiohttp_websocket.py I placed it inside asyncclick.

I'd suggest not using asynclick for that. Just use a regular function which calls run_app(). I'm not sure I'd want asyncclick to be controlling the event loop, I only see click as an entrypoint to start running the application (but, maybe you have something different in mind, I'm not familiar with the full capabilities of it).