support aiohttp-3.8.0

[cmalek]

This fixes the rename of aiohttp.web_routedef._SimpleHandler to aiohttp.typedefs.Handler

[kammala]

this will break compatibility with aiohttp < 3.8.0
should we use some kind of conditional imports?

try:
  from aiohttp.typedefs import Handler
except ImportError:
  from aiohttp.web_routedef import _SimpleHandler as Handler

[kammala]

this one was also moved to aiohttp.typedefs, but wasn't released yet.
for future stability, I would recommend to use the same mechanic with conditional import.

[cmalek]

Duh, of course, sorry about that. I should have thought about backwards compatibility. I shall make your suggested changes.

[cmalek]

Ok, I've made the changes, amended the commit and pushed.

[kammala]

looks good, but I am not sure if mypy will be satisfied. did you run make lint against your code?

[cmalek]

Yes, mypy is not satisfied. make lint says:

> make lint
< linting using black...
All done! ✨ � ✨
22 files would be left unchanged.
> done

< linting using flake8...
> done

< linting using isort...
> done

< linting using mypy...
aiodogstatsd/contrib/aiohttp.py:7: error: Module "aiohttp.typedefs" has no attribute "Middleware"
aiodogstatsd/contrib/aiohttp.py:15: error: Module "aiohttp.web_routedef" has no attribute "_SimpleHandler"
aiodogstatsd/contrib/aiohttp.py:15: error: Name "Handler" already defined (possibly by an import)
Found 3 errors in 1 file (checked 22 source files)
make: *** [lint-mypy] Error 1

I don't know how to fix that since in 3.8.0 aiohttp.typedefs.Middleware certainly does exist, aiohttp.web_routedef._SimpleHandler definitely does not exist, and Handler is not imported twice.

I don't use mypy for linting in our codebases, so what do you suggest?

[kammala]

well, as far as I see, mypy doesn't recognize this try ... except ImportError pattern.
possible solutions would be:

• use # type: ignore

try:
  from aiohttp.typedefs import Handler  # type: ignore
except ImportError:
  from aiohttp.web_routedef import _SimpleHandler as Handler  # type: ignore

doesn't make much sense as we use these classes only for typing and ignoring types makes it kinda useless

• somehow detect aiohttp actual version(via pkg_resources, e.g.) and use if - else conditions.
  this option looks a little bit overcomplicated for type hints and I didn't check if it actually satisfies mypy.
• do not rely on aiohttp typedefs at all and use just Callable(or something more nested)

Handler = Callable
...

this is the simplest and the most stable solution, but it also kinda compromises idea of type checking.

as I am not a maintainer of this library, I can't make this decision :)
personally, I would go with the latest option(Callable instead of aiohttp internals).

[Gr1N]

Hi everyone, thanks for the contribution, but decided to go with another solution. Nevertheless, fix already in master.