curl -i -H "Content-Type: application/json" -H "Accept: application/json" -X POST -d '{"user":{"username_or_email":"username","password":"password"}}' http://fas/test_json_post

module Rack
 
  # A Rack middleware for parsing POST/PUT body data when Content-Type is
  # not one of the standard supported types, like <tt>application/json</tt>.
  #
  # TODO: Find a better name.
  #
  class PostBodyContentTypeParser
 
    # Constants
    #
    CONTENT_TYPE = 'CONTENT_TYPE'.freeze
    POST_BODY = 'rack.input'.freeze
    FORM_INPUT = 'rack.request.form_input'.freeze
    FORM_HASH = 'rack.request.form_hash'.freeze
 
    # Supported Content-Types
    #
 
    ################## turned into regex so it matches type with encoding data...
    #APPLICATION_JSON = 'application/json'.freeze
    APPLICATION_JSON = /^application\/json/.freeze
 
    def initialize(app)
      @app = app
    end
 
    def call(env)
      case env[CONTENT_TYPE]
      when APPLICATION_JSON
        env.update(FORM_HASH => JSON.parse(env[POST_BODY].read), FORM_INPUT => env[POST_BODY])
      end
      @app.call(env)
    end
 
  end
end

def test_post_as_json_converts_to_params
  # sanity check that post with normal params works...
  post '/test_params_as_json', :param1=>"param one"
  assert_equal last_response.body,"params[:param1]=param one"
  post '/test_params_as_json', {:param1=>"param one"}.to_json, "CONTENT_TYPE"=>"application/json"
  assert_equal last_response.body,"params[:param1]=param one"
  # this is the problem, adding a charset to the content type seems to breaks rack-contrib/post_body_content_type_parser.rb
  post '/test_params_as_json', {:param1=>"param one"}.to_json, "CONTENT_TYPE"=>"application/json; charset=UTF-8"
  assert_equal last_response.body,"params[:param1]=param one"    
end

before do
  # remove and grab the file extension
  request.path_info.sub! %r{\.([^\./]+)$}, ''
  @format=$1 || 'html'
  @charset=mime_type($1) || 'text/html'
  content_type @charset, :charset => 'utf-8'
end

get "/home" do
  case @format
  when 'html'
    @stylesheet='home.css'
    haml :home, :layout=>:layout_simple
  when 'js'
    "{'js':true}"
  else
    pass
  end
end

require 'rack/contrib'

use Rack::PostBodyContentTypeParser

def test_json_creates_params_hash
  params_hash={"user"=>{"username"=>"testuser","email"=>"test@test.com","password"=>"pass1","password_confirmation"=>"pass1"}}
  post '/test_json', params_hash
  assert !last_request.params.blank?
  assert_equal params_hash, last_request.params
  assert last_response.ok?
  json_string="{\"user\":{\"password_confirmation\":\"pass1\",\"username\":\"testuser\",\"password\":\"pass1\",\"email\":\"test@test.com\"}}"
  post '/test_json', JSON(json_string)
  assert !last_request.params.blank?
  assert_equal params_hash, last_request.params
  assert last_response.ok?
  post '/test_json', json_string, "CONTENT_TYPE"=>"application/json"
  assert_equal last_request.env["CONTENT_TYPE"], "application/json"
  assert !last_request.params.blank?
  assert_equal params_hash, last_request.params
  assert last_response.ok?
end