Rack middleware?

# This file is used by Rack-based servers to start the application.

require ::File.expand_path('../config/environment',  __FILE__)

class TestMiddleware
  def initialize(app)
    @app = app
  end 
  
  def call(env)
    puts "------------------TestMiddleware--------------"
    puts env.to_yaml
    @app.call(env)
  end
end

run TestMiddleware.new(TestApp::Application)