Testing an RSpec controller action that can't be accessed directly - ruby-on-rails

Question

I've got a controller that can't be accessed directly, in the traditional RESTful way, but rather only through a particular url.
Normally I'm used to using get and post in my controller specs to call controller actions. Is there a way that I can exercise my controller by visiting a particular url?
EDIT:
Here is my route:
Larzworld::Application.routes.draw do
match '/auth/:provider/callback' => 'authentications#create'
devise_for :users, :controllers => {:registrations => "registrations"}
root :to => 'pages#home'
end
Here is my spec:
require 'spec_helper'
describe AuthenticationsController do
before(:each) do
request.env["omniauth.auth"] = {"provider" => "twitter", "uid" => "12345678"}
end
describe 'POST create' do
it "should find the Authentication using the uid and provider from omniauth" do
Authentication.should_receive(:find_by_provider_and_uid)
post 'auth/twitter/callback'
end
end
end
and here is the error I receive:
Failures:
1) AuthenticationsController POST create should find the Authentication using the uid and provider from omniauth
Failure/Error: post 'auth/twitter/callback'
No route matches {:action=>"auth/twitter/callback", :controller=>"authentications"}
# ./spec/controllers/authentications_controller_spec.rb:13
Finished in 0.04878 seconds
1 example, 1 failure

Answer 1

Controller tests use the four HTTP verbs (GET, POST, PUT, DELETE), regardless of whether your controller is RESTful. So if you have a non-RESTful route (Rails3):
match 'example' => 'story#example'
the these two tests:
require 'spec_helper'
describe StoryController do
describe "GET 'example'" do
it "should be successful" do
get :example
response.should be_success
end
end
describe "POST 'example'" do
it "should be successful" do
post :example
response.should be_success
end
end
end
will both pass, since the route accepts any verb.
EDIT
I think you're mixing up controller tests and route tests. In the controller test you want to check that the logic for the action works correctly. In the route test you check that the URL goes to the right controller/action, and that the params hash is generated correctly.
So to test your controller action, simply do:
post :create, :provider => "twitter"`
To test the route, use params_from (for Rspec 1) or route_to (for Rspec 2):
describe "routing" do
it "routes /auth/:provider/callback" do
{ :post => "/auth/twitter/callback" }.should route_to(
:controller => "authentications",
:action => "create",
:provider => "twitter")
end
end