tooling: Async/pathlib/mypy cleanups and utils

[phlax]

Signed-off-by: Ryan Northey ryan@synca.io

Commit Message: tooling: Improve async runner/test handling
Additional Description:

This Pr does a few things:

• adds an async_property decorator which is v handy for writing async classes
• switches pytest to -Werror which is kinda necessary for catching asyncio unawaited errors.
• adds a dep pin for setuptools to base/utils - some environments were still using older versions of setuptools which can cause issues with -Werror (as well as other incompatibilities)
• makes runner.catches work async
• improves the main plugin test to work async
• adds some tests for pytest plugin fixtures
• mypy fixes/cleanups
• os -> pathlib cleanups (Fix Use python pathlib more and clean up some existing code with it #17487 )

re the setuptools dep - i tried removing from docs requirements - but it wouldnt let me - setuptools works in mysterious ways

The decorator can be used as so:

import asyncio

from envoy.tools.base.functional import async_property


Class MyClass(object):

    @async_property
    async def myprop(self):
        return await some_other_coroutine()

    async def run(self):
        print(await self.myprop)

asyncio.run(MyClass().run())

it can also cache the results of the async call like so:

Class MyClass(object):

    @async_property(cache=True)
    async def myprop(self):
        return await some_other_coroutine()

in this case repeated awaits of the property will return the cached results.

Risk Level:
Testing:
Docs Changes:
Release Notes:
Platform Specific Features:
[Optional Runtime guard:]
[Optional Fixes #Issue]
[Optional Deprecated:]
[Optional API Considerations:]

[phlax]

coverage is here https://storage.googleapis.com/envoy-pr/17505/tooling/index.html

[repokitteh-read-only]

CC @envoyproxy/dependency-shepherds: Your approval is needed for changes made to (bazel/.*repos.*\.bzl)|(bazel/dependency_imports\.bzl)|(api/bazel/.*\.bzl)|(.*/requirements\.txt)|(.*\.patch).

🐱

Caused by: #17505 was synchronize by phlax.

see: more, trace.

[phlax]

ive figured out a better implementation that doesnt depend on gc for closing coroutines

WIP while i reimplement...

[htuch]

Looks good, generally prefer much smaller PRs but in this case it seems fine as a cleanup rollup.

[phlax]

generally prefer much smaller PRs but in this case it seems fine as a cleanup rollup.

yep, apologies, it kinda morphed

also, mypy can be a bit of rabbit hole of type safety, and changing only some of the paths to pathlib was making it unhappy (as do functions/methods that can return more than one type)

[phlax]

updated

as an aside @htuch writing/testing so many props is making reconsider not using attrs - that is what it kinda gives you free along with class/prop validation/mutators etc - and works out of the box with mypy

on my travels through the interwebs i read gvr saying somewhere that python was in the process of adopting some of the attrs features so i need to investigate this a bit further

[htuch]

Epic, thanks!

[htuch]

/lgtm deps