chess_app.rb

class ChessApp

  def self.routes
    @routes ||= ActionDispatch::Routing::RouteSet.new.tap do |r|
      r.draw do
        resources :games, :only => [:index, :create, :show, :update]
      end
    end
  end

  def call(env)
    env.update('POST_DATA' => Rack::Utils.parse_nested_query(env['rack.input'].read))
    env['rack.input'].rewind
   # above lines are to capture POST data in the env hash. No idea why Rack doesn't already do this.
    Router.new(self.class.routes, env).call
  end
end