How to get status of a StreamResponse?

[alexeyr-ci]

https://github.com/HoneyryderChuck/httpx/blob/master/doc/release_notes/0_14_0.md has this example:

session = HTTPX.plugin(:stream)
response = session.get(build_uri("/stream/3"), stream: true)

# before
response.status # this could block indefinitely, if the request truly streams infinitely.

# after
response.status # sends the request, and starts streaming the response until status is available.
response.each {|chunk|...} # and now you can start yielding the chunks...

and similarly in https://honeyryderchuck.gitlab.io/httpx/wiki/Stream:

http = HTTPX.plugin(:stream).plugin(:follow_redirects)
response = http.get("https://google.com", stream: true)
response.each_line do |line|
  # dodge redirects
  next if (300..399).cover?(response.status)
  # now you can do smth with line
end

But when I tried to call response.status in my code, I get NoSuchMethod; and indeed, looking at the StreamResponse code the method isn't there. I know it throws an exception for 4xx/5xx and I can get the status from the exception, but how to handle the redirect cases?

[alexeyr-ci]

looking at the StreamResponse code the method isn't there

No, wait. It should be provided by method_missing delegating to response. So something else is going wrong for me. Maybe in my case response is ErrorResponse and not Response, so it doesn't have status?

Anyway, closing.

[HoneyryderChuck]

So something else is going wrong for me. Maybe in my case response is ErrorResponse and not Response, so it doesn't have status?

That's possible. FWIW this works as expected:

require "httpx"

http =  HTTPX.plugin(:follow_redirects).plugin(:stream)
uri = "https://nghttp2.org/httpbin/redirect/2"
response.each_line do |line|
  if (300..399).cover?(response.status)
    puts "WOW, REDIRECT!"
    next
  end
end

stream responses will call .raise_for_status at the end. However, what's interesting about your report is that, if it were an ErrorResponse:

• I would not expect the block to be called (because there are no body chunks to yield)
• I would have expected it to fail early, as the stream response relies on existence of body being implemented, which is not for ErrorResponse.

So perhaps this is a bug, but not the bug you're pointing to. Could you please post the full backtrace of that NoSuchMethod error?

[alexeyr-ci]

Unfortunately, I already fixed the problem on my side which led to it.

But what I now think happened is that I was calling response.status (where response is a StreamResponse) before calling response.each_line, so response.response was still nil. If that's the problem:

1. I think it just needs a wiki update saying that status and other methods delegating to response are only available once you start streaming (and that there are other methods delegating to response?).
2. The example from 0.14 release notes is wrong, but probably it was right at the time.

If you want, I can still try to reproduce the error to provide the backtrace.

[HoneyryderChuck]

But what I now think happened is that I was calling response.status (where response is a StreamResponse) before calling response.each_line, so response.response was still nil

Don't think that's the problem. In such a scenario, the response will start stream until it has a status to show for. However, if it's an ErrorResponse, then it'd fail with NoMethodError.

If you manage to reproduce it again, keep the whole backtrace for report plz 🙏 then we can access whether that's an actual bug.