raise_for_status in event hooks raises exception for 301 even if follow_redirects flag is set to True

[cjcjcj]

Context: I've a lot of requests to one host which should normally return 200 code, if one of them returns 4xx or 5xx, I'm raising an error.
I decided to use event_hooks to reduce boilerplate of raise_for_status usage(basically, I've copy pasted example from documentation).
Using httpx.Client(follow_redirects=True, event_hooks={"response": [raise_4xx_5xx]}), leads to an error when a redirect is encountered.

Traceback

Traceback (most recent call last):
  File "client.py", line 23, in <module>
    print(request(f"http://{host}:{port}/301"))
  File "client.py", line 12, in request
    r = client.get(uri)
  File "/Users/aleksandr/tmp/httpx_301/.venv/lib/python3.8/site-packages/httpx/_client.py", line 1025, in get
    return self.request(
  File "/Users/aleksandr/tmp/httpx_301/.venv/lib/python3.8/site-packages/httpx/_client.py", line 802, in request
    return self.send(request, auth=auth, follow_redirects=follow_redirects)
  File "/Users/aleksandr/tmp/httpx_301/.venv/lib/python3.8/site-packages/httpx/_client.py", line 889, in send
    response = self._send_handling_auth(
  File "/Users/aleksandr/tmp/httpx_301/.venv/lib/python3.8/site-packages/httpx/_client.py", line 917, in _send_handling_auth
    response = self._send_handling_redirects(
  File "/Users/aleksandr/tmp/httpx_301/.venv/lib/python3.8/site-packages/httpx/_client.py", line 974, in _send_handling_redirects
    raise exc
  File "/Users/aleksandr/tmp/httpx_301/.venv/lib/python3.8/site-packages/httpx/_client.py", line 957, in _send_handling_redirects
    hook(response)
  File "client.py", line 5, in raise_4xx_5xx
    response.raise_for_status()
  File "/Users/aleksandr/tmp/httpx_301/.venv/lib/python3.8/site-packages/httpx/_models.py", line 1508, in raise_for_status
    raise HTTPStatusError(message, request=request, response=self)
httpx.HTTPStatusError: Redirect response '301 Moved Permanently' for url 'http://localhost:8000/301'
Redirect location: '/200'
For more information check: https://httpstatuses.com/301

Here is the code to reproduce this behaviour:

client side code

import httpx


def raise_4xx_5xx(response: httpx.Response):
    response.raise_for_status()


def request(uri: str):
    with httpx.Client(
        follow_redirects=True, event_hooks={"response": [raise_4xx_5xx]}
    ) as client:
        r = client.get(uri)
        r.raise_for_status()
        return r.content


if __name__ == "__main__":
    import os

    host = os.environ.get("HTTPX_TEST_HOST", "localhost")
    port = int(os.environ.get("HTTPX_TEST_PORT", "8000"))

    print(request(f"http://{host}:{port}/301"))

server side code

#!/usr/bin/env python

from http.server import BaseHTTPRequestHandler, HTTPServer


class HttpGetHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        if self.path == "/301":
            self._redirect()
        if self.path == "/200":
            self._ok()

    def _redirect(self):
        print("redirect")
        self.send_response(301)
        self.send_header("Location", "/200")
        self.end_headers()

    def _ok(self):
        print("ok")
        self.send_response(200)
        self.end_headers()
        self.wfile.write(b"OK")
        self.wfile.close()


def run(host: str, port: int):
    server_address = (host, port)
    httpd = HTTPServer(server_address, HttpGetHandler)
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        httpd.server_close()


if __name__ == "__main__":
    import os

    host = os.environ.get("HTTPX_TEST_HOST", "localhost")
    port = int(os.environ.get("HTTPX_TEST_PORT", "8000"))
    run(host, port)

Is it expected behaviour or issue candidate?

[lovelydinosaur]

Okay, so the event hook is firing on all responses. That's including the intermediary redirects (and any auth flow responses).

If you're using the event hooks to raise_for_status, then you'd need to do something like this I guess...

def raise_4xx_5xx(response: httpx.Response):
    if not response.is_redirect:
        response.raise_for_status()

I'm not sure how well our event hook behaviour is documented here.

It's also occurred to me in the past that we might want response.raise_for_status(allow_redirects=True). Not sure.

[cjcjcj]

It can work for me, thanks.

---

I'm not sure how well our event hook behaviour is documented here.

TBH there is another problem w/ documentation it says :

The HTTPStatusError class is raised by response.raise_for_status() on 4xx and 5xx responses. These exceptions include both a .request and a .response attribute.

which is not true, the error also rises for 300 codes.