AsyncHTTPPolicy's next attribute is Optional[Any]

[chlowell]

Looks like this should be Optional[AsyncHTTPPolicy] instead; would next ever be anything else?

[xiangyan99]

It should call transport as next. Close it. Will re-open if we see real requests.

[chlowell]

Reopening this for further consideration because it creates mypy errors in subclasses. For example, line 94 of this code gets "Item "None" of "Optional[Any]" has no attribute "send"":

azure-sdk-for-python/sdk/identity/azure-identity/azure/identity/aio/_credentials/azure_arc.py

Lines 89 to 94 in dc95dbf

	class ArcChallengeAuthPolicy(AsyncHTTPPolicy):
	"""Policy for handling Azure Arc's challenge authentication"""
	async def send(self, request: "PipelineRequest") -> "AsyncHttpResponse":
	request.http_request.headers["Metadata"] = "true"
	response = await self.next.send(request)

This can of course be worked around in the subclass but it would be better for AsyncHTTPPolicy to have the correct type.
Similar to HTTPPolicy, I think that type would be Union[AsyncHTTPPolicy, AsyncHttpTransport], which aligns with actual usage and the class's documentation. However, fixing this is more complicated than just changing the type because AsyncRedirectPolicy and AsyncRetryPolicy transitively inherit HTTPPolicy.

[xiangyan99]

@chlowell We refactored HttpPolicy & AsyncHttpPolicy in #15831. Now AsyncHTTPPolicy is not a sub-class of HTTPPolicy any longer. Could you help to check if this issue is fixed?

[chlowell]

Yes, that worked for my case.