How to Parse (not get) an HTTP Request in Ruby - ruby

Question

I have an integration test which uses eventmachine to receive http requests. This is my eventmachine handler:
class NotificationRecipient < EM::Connection
def receive_data(data)
EM.stop
end
end
I need to test various properies of the received request, e.g. I want to extract a json payload from an HTTP POST request string I've received like this. Is there a nicely packaged way to do it?
Googling finds lots of ways to make a request and parse the response, e.g. rest-client will parse response automatically. However, since I'm receiving the request, not making it, none of these ways work for me.

Answer 1

I would make use of WEBrick. WEBrick::HTTPRequest has a serviceable parser, and all you need to do is pass an IO object to its parse method and you have yourself an object you can manipulate.
This example declares a POST request with a JSON body in a string and uses StringIO to make it accessible as an IO object.
require 'webrick'
require 'stringio'
Request = <<-HTTP
POST /url/path HTTP/1.1
Host: my.hostname.com
Content-Type: application/json
Content-Length: 62
{
"firstName": "John",
"lastName": "Smith",
"age": 25
}
HTTP
req = WEBrick::HTTPRequest.new(WEBrick::Config::HTTP)
req.parse(StringIO.new(Request))
puts req.path
req.each { |head| puts "#{head}: #{req[head]}" }
puts req.body
output
/url/path
host: my.hostname.com
content-type: application/json
content-length: 62
{
"firstName": "John",
"lastName": "Smith",
"age": 25
}