Improve catch_response feature (was previous: Remove catch_response feature from HttpBrowser)

To me - even though I was in favor of it when we implemented it - the catch_response feature is slightly odd, and I’m not sure it should be a feature in Locust. A web app should not return 200 OK if the request in fact failed. I also think it would be a mistake to keep locust features that are focused toward detecting errors in the app that should have been spotted by the app’s own unit/integration tests. Simply because it’s better to focus on one thing (in our case load testing and user simulation) and kick ass at that 😃.

If someone is wandering I’m talking about the following syntax:

from locust import ResponseError

with self.client.get("/inbox", catch_response=True) as response:
    if response.data == "fail":
        raise ResponseError("Request failed")

Part of the reason I’m bringing this up is that I’m currently working on a branch where I’m replacing Locust’s built in HttpBrowser with python requests lib (http://python-requests.org). I have now fully replaced the old client with requests, except for the catch_response feature, and not having to port that feature would save time and code lines 😃.

Does anyone use the catch_response feature extensively? Would anyone miss it 😃?

[heyman]

Actually this got me thinking if maybe we could use the above solution to also solve the allow_http_error use cases.

If the API looked something like this:

# normal request
client.get("/page")

# equivalent of the above
with client.get("/page", catch_response=True): pass

# the "catch_response" use case
# this one will be reported as failure if the content is empty or if the response code is anything else than 2XX
with client.get("/page", catch_response=True) as catched:
    if catched.response.content = "":
        catched.failure("Empty content")

# the allow_http_error use case
# this one will only be reported as success if the response code was 404
with client.get("/page404", catch_response=True) as catched:
    if catched.response.status_code = 404:
        catched.success()
    elif catched.response.status_code = 200:
        catched.failure("Expected 404")

# and if someone want to mark a request as successful no matter what
# i.e equivalent to client.get("/page", allow_http_error=True)
with client.get("/page") as catched:
    catched.success()

But then again maybe it’s weird to wrap the real response object in some other CatchedResponse object, but I do like the fact that it would also solve the use cases where one would want to use the allow_http_error argument.

What do you think?

[heyman]

Fixed by #40