Using RSpec2 to test a controller's show action

I have a fairly simple Rails 3 project where I've defined a custom route:

get 'factions/:name' => 'factions#show', :as => :factions
get 'factions' => 'factions#index'

... which when running rails s gives me the expected page (http://localhost:3000/factions/xyz is HTTP 200 with the app/views/factions/show.html.haml being displayed). However I've tried multiple different ways of expressing a spec that will work, below is my latest incarnation:

require 'spec_helper'

describe FactionsController do
  render_views

  describe "GET 'show'" do
    before { get '/xyz' }
    subject { controller }
    it { should respond_with(:success) }
    it { should render_template(:show) }
  end

  describe "GET 'index'" do
    it "should be successful" do
      get 'index'
      response.should be_success
    end
  end

end

The GET 'index' spec passes without complaint but no matter what I do the GET 'show' specs cannot pass - even if they do succeed when I am browsing to them locally.

1) FactionsController GET 'show' 
     Failure/Error: before { get '/xyz' }
     ActionController::RoutingError:
       No route ma开发者_Python百科tches {:controller=>"factions", :action=>"/xyz"}
     # ./spec/controllers/factions_controller_spec.rb:7:in `block (3 levels) in <top (required)>'

The action really should be show but my routes.rb configuration must be incorrect or something. What gives?

(Additional context: I am using bundle exec spork for speeding up my specs and I have restarted the spork server multiple times just to make sure I'm not completely insane.)

---

Change:

before { get '/xyz' }

To:

before { get :show, :name => 'xyz' }