Add HTTPX support

[sarayourfriend]

Closes #71.

HTTPX documentation is here: https://www.python-httpx.org/

The current implementation supports everything, except HTTP2.

At first, I tried to implement this on the httpcore level, figuring that it'd be nice to go ahead and support anything that depended on httpcore. I still think that would be a good way to approach this, perhaps even supplanting the httpx-specific approach. However, httpcore's connection interfaces are significantly more complex to mock, if only because whereas httpx has only two entrypoints, httpcore technically has 8, an HTTP1, HTTP1.1 and HTTP2, and a connection pool connection for both sync and async requests (luckily all the supported proxy request types are implemented over top the other four and wouldn't require their own interceptors). Additionally, it wasn't entirely clear to me whether merely mocking the "handle request" method was sufficient to prevent outbound network connections for all 8 of these connection types.

For the sake of having support for HTTPX at least, and not holding it back by trying to support a broader, I chose to stick to just supporting HTTPX for the time being. The implementation luckily turned out to be pretty simple, and I took a helpful queue from the excellent https://github.com/Colin-b/pytest_httpx, specifically the idea to mock the _transport_for_url method, which prevents any of the httpcore complexity from leaking into this feature.

[tekumara]

Thanks @sarayourfriend! I've tried #91 and run into an error when trying to use @pook.on with @pytest.mark.asyncio, eg:

@pook.on
@pytest.mark.asyncio
async def test_pook():
    pass

errors with

    @functools.wraps(func)
    def inner(**kwargs):
        coro = func(**kwargs)
        if coro is not None:
>           task = asyncio.ensure_future(coro, loop=_loop)

.venv/lib/python3.11/site-packages/pytest_asyncio/plugin.py:193: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/opt/homebrew/Cellar/python@3.11/3.11.6_1/Frameworks/Python.framework/Versions/3.11/lib/python3.11/asyncio/tasks.py:659: in ensure_future
    return _ensure_future(coro_or_future, loop=loop)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

coro_or_future = <async_generator object test_pook at 0x1075b2e40>

    def _ensure_future(coro_or_future, *, loop=None):
        if futures.isfuture(coro_or_future):
            if loop is not None and loop is not futures._get_loop(coro_or_future):
                raise ValueError('The future belongs to a different loop than '
                                'the one specified as the loop argument')
            return coro_or_future
        called_wrap_awaitable = False
        if not coroutines.iscoroutine(coro_or_future):
            if inspect.isawaitable(coro_or_future):
                coro_or_future = _wrap_awaitable(coro_or_future)
                called_wrap_awaitable = True
            else:
>               raise TypeError('An asyncio.Future, a coroutine or an awaitable '
                                'is required')
E               TypeError: An asyncio.Future, a coroutine or an awaitable is required

This doesn't happen with pook 1.1.1

[sarayourfriend]

Thanks @tekumara! I need to rebase this branch, I believe it would fix the issue with the coroutine issue you're seeing. The problem was that the wrapped async function in async_activate was an async generator rather than a coroutine before, and this caused issues with the pook.on decorator on async tests.

Here is the code that was fixed:

pook/src/pook/activate_async.py

Lines 18 to 26 in 16ecba6

	async def wrapper(*args, **kw):
	_engine.activate()
	try:
	if iscoroutinefunction(fn):
	return await fn(*args, **kw)
	else:
	fn(*args, **kw)
	finally:
	_engine.disable()

Previously the wrapped function used the pre-async def notation of yielding in an async generator:

pook/pook/activate_async.py

Lines 17 to 26 in 3f2b818

	async def wrapper(*args, **kw):
	_engine.activate()
	try:
	if iscoroutinefunction(fn):
	async for v in fn(*args, **kw):
	yield v
	else:
	fn(*args, **kw)
	finally:
	_engine.disable()

[sarayourfriend]

Update: I've rebased the branch since the changes in master and that should fix the issue you mentioned with pook.on on async test functions.

[tekumara]

Thanks @sarayourfriend I can confirm it now works well on my code base!

[sarayourfriend]

Awesome, thanks 🙏 I'm very excited to add httpx support in the next release 🎉

[tekumara]

Thanks for adding this feature!

PS: I like pook over alternatives because the no match error message shows any unmatched mocks which is great for debugging.