Document what responses result in exceptions

[aztecrex]

Suggest that the documentation be more explicit on what responses result in exception.

In particular, what status codes result in an exception? What statuses are the responsibility of client code?

I see a lens for checkResponse that I suspect gives some control. But in defaults the value for it is Nothing and yet get throws exceptions on non-200 statuses. I can't find much documentation of that option, either.

[jez]

Hey @aztecrex! I just ran into this too (I was very surprised that non 200 statuses were raised as exceptions). This is how I ended up using checkResponse:

noExceptions :: W.Options
noExceptions = W.defaults & W.checkResponse .~ (Just $ \_ _ -> return ())

When I started using this for requests, it didn't raise exceptions anymore.

@bos I'd love to see a quick section in <www.serpentine.com/wreq/tutorial.html> referencing this snippet. Most of the other http client's I'm familiar with (Python's requests, JavaScript's fetch, ...) don't raise. A quick note about how to get back to the no-raise behavior would be great.

---

Curious about what's going on here? It looks like the checkResponse option is just forwarded to the underlying http-client library that wreq abstracts over. In particular, if we look at that package's documentation, we see:

-- | Modify the request so that non-2XX status codes do not generate a runtime
-- 'StatusCodeException'.
--
-- @since 0.4.29
setRequestIgnoreStatus :: Request -> Request
setRequestIgnoreStatus req = req { checkResponse = \_ _ -> return () }

So that's where I got the idea for the snippet I posted above.

http://hackage.haskell.org/package/http-client-0.5.12.1/docs/Network-HTTP-Client.html#v:setRequestIgnoreStatus