rack_test_thingy.rb

require 'rack'
require 'thin'

module Rack
  module Test
    class App
      # Attempt to run a Rack app server instance in the same process as the a
      # 'work' block. Came about because you can't see an unsaved DB transaction
      # inside the Rack app if it happens in another process.
      #
      # ==== Notes
      # Doesn't quite work because minitest failed assertions cause it to time
      # out and I don't know why.
      #
      # ==== Example
      # require 'minitest/spec'
      # require 'rack/test/app'
      #
      # describe 'MyApp'
      #   Rack::Test::App.run lambda{|env| [200, {'Content-Type' => 'text/plain'}, ['ok']]} do
      #     it 'must respond ok' do
      #       assert open('http://localhost:3000').read =~ /ok/
      #     end
      #   end 
      # end     
      #         
      # ==== Paramaters
      # app<Object>::   Rack 'app' responding to call.
      # options<Hash>:: Options include host: and port:.
      # work<Proc>::    Connect and work with the 'app'. When this block exits the app will stop.
      def self.run app, options = {}, &work
        host = options[:host] ||= '0.0.0.0'
        port = options[:port] ||= '3000'

        EM.run do
          Thin::Server.start(app, host, port)
          EM.defer(
            proc{ TCPSocket.new(host, port)},
            # TODO: Failed assertions do not return. Why?
            proc{ EM.defer(proc{ work.call; true}, proc{ EM.stop})}
          )
          EM.add_timer(5){ $stderr.puts 'Timed out completing work.'; EM.stop}
        end
      end
    end # App
  end # Test 
end # Rack