HTTPX: type mismatch in values passed to the request/response hooks

[burritoatspoton]

Describe your environment

OS: MacOS 14.5
Python version: 3.12.7
Package version: 0.48.b0

What happened?

When instrumenting httpx clients e.g. via HTTPXClientInstrumentor.instrument_client, users can pass request_hook and response_hook callables which accept namedtuples RequestInfo/ResponseInfo (type definitions). These tuples contain a header field typed as Optional[List[Tuple[bytes, bytes]]]. However, at runtime this field seems to be copied verbatim from request.headers/response.headers, making it an instance of httpx.Headers. The same applies to a url field in RequestInfo (tuple of values vs httpx.URL). Should the typehints be updated?

Steps to Reproduce

def request_hook(span, request_info):
    print(f"{type(request_info.headers)=} {type(request_info.url)=}")

with httpx.Client() as client:
    HTTPXClientInstrumentor.instrument_client(client, request_hook=request_hook)
    client.get("https://example.com")

Expected Result

type(request_info.headers)=<class 'list'> type(request_info.url)=<class 'tuple'>

Actual Result

type(request_info.headers)=<class 'httpx.Headers'> type(request_info.url)=<class 'httpx.URL'>

Additional context

No response

Would you like to implement a fix?

None

[Kludex]

I've created the PR above to handle this.