how to do testing of rails layouts, when they call url_for

I have a test case that tests a layout. It looks to see if certain links are present or absent for different kinds of users (admin links, for instance). This worked fine until we started to localize some of our interface.

describe "layouts/application" do
  include Devise::TestHelpers
  fixtures :users

  it "renders admin link for admin user" do
    @admin = users(:admin)
    sign_in(@admin)
    @locale = 'en'
    render
    rendered.should match(/Administration/)
  end
end

The layout now contains a call开发者_Go百科 to <%= toggle_language %>, which uses url_for to generate a URL like the current one, but with the :locale parameter changed:

def toggle_language
  case locale
  when :fr
    other=:en
  when :en
    other=:fr
  else
    other=:fr
  end
  link_to t(:other_language), url_for(:locale => other)
end

The problem is that since I have no controller called "layouts", the url_for can't generate what it needs.

1) layouts/application renders admin link for admin user
 Failure/Error: render
 ActionView::Template::Error:
   No route matches {:controller=>"layouts", :locale=>:fr, :action=>"application"}

I've looked to see if perhaps the rspec render command would take a :controller,:action, which I could point at a valid route. I haven't found such a thing yet.

Yes, stubbing this out works very well.