hadron

hadron is a library for dealing with HTTP at the protocol level. It is the home of HTTPRequest and HTTPResponse types as well as parsers and QuickCheck instances for same.

Motivation

hadron is a response to a lack of exposed or general-purpose functionality in other HTTP libraries in two primary areas. The first is HTTP message types and parsers; the second is QuickCheck generators for HTTP messages which achieve good coverage of what's permitted by the protocol, driven by a need for a high level of assurance of correctness of software which directly manipulates requests and responses.

Example usage

With raw bytestrings

import qualified Data.ByteString as BS
import qualified Data.Text as T
import           Hadron.Core.Request (parseHTTPRequest, renderHTTPRequest)

main = do
  BS.putStrLn "enter an HTTP request:"
  bs <- BS.getContents
  case parseHTTPRequest bs of
    Left e ->
      T.putStrLn $ "nope, try again: " <> renderRequestError e
        >> main
    Right r ->
      BS.putStrLn $ renderHTTPRequest r

From airship

import Hadron.Wai (toHTTPRequest)
import Hadron.Core.Data.Request (renderHTTPRequest)

hadronReq <- firstEitherT MyErrorType $ toHTTPRequest request
liftIO . BS.putStr $ renderHTTPRequest hadronReq

From the CLI

nc -l 8080 | hadron validate
curl -XPOST -H "foo: bar" localhost:8080/blah -d 42

In tests

import           Test.Hadron.Core.Gen

instance Arbitrary MyRequest where
  arbitrary = fmap MyRequest $ genHTTPRequest'
                                 genHTTPMethod
                                 genRequestTarget
                                 genHTTPRequestHeaders
                                 (elements ["{\"foo\":1}", "{\"bar\":2}"])

Conceptual warriors

• Sharif