How to Parse (not get) an HTTP Request in 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
}