testing route constraints

route_constraints.rb

# I was upgrading an old rails 2 app to rails 3 and noticed that 
# http://rails.rubyonrails.org/classes/ActionController/Verification/ClassMethods.html
# was deprecated. I was using this in the controllers to verify that an action had to be triggered
# by an xhr request

# I am unable to test it from a functional test b/c it doesn't look like functional tests
# go through routes. However, it works fine in the app.  I could put this in an integration test,
# but I'm wonder if it makes more sense to have some way of testing the route constraint in
# a local way.

class XhrConstraint
  def matches?(request)
    request.xhr?
  end
end

Beerpad::Application.routes.draw do
  resources :beers do
    collection do
      get :autocomplete, :constraints => XhrConstraint.new
    end
  end
end