Documented ways of using Unix domain sockets and ratelimits do not properly interact with one another

[kchen]

Background:
I wanted to use a Unix domain socket and disable rate-limiting.

• For UDS, https://www.python-httpx.org/advanced/transports/ says I should create a Transport object and pass it to a new Client.
• For rate-limiting, https://www.python-httpx.org/advanced/resource-limits/ says I should create a new Limits object and pass it to a new Client.
• Given that documentation, the natural way to combine these appears to be to create a new Transport object, a new Limits object, and pass both objects to a new Client, like the following:

transport = httpx.HTTPTransport(uds="uds_endpoint")
limits = httpx.Limits(max_keepalive_connections=None, max_connections=None)
client = httpx.Client(transport=transport, limits=limits)

This does not work, however, because creating a new Client calls Client._init_transport, which immediately returns the Transport object if one was supplied, ignoring all other options. It appears that the proper way to do this would be to create a new Transport object specifying both the UDS and a Limits object, and then passing that Transport object when creating a new Client, like the following:

limits = httpx.Limits(max_keepalive_connections=None, max_connections=None)
transport = httpx.HTTPTransport(uds="uds_endpoint", limits=limits)
client = httpx.Client(transport=transport)

It would be helpful if the documentation were made more clear around this and similar interactions, although that seems like it might be hard to cleanly do. It would also be helpful if httpx threw an exception when a Transport is passed in to a Client and other options would otherwise be ignored.

[kchen]

Oh, I hadn't seen #1867 when I searched earlier, but that is the same problem.