A spec for a filter

privacy_filter.rb

class PrivacyFilter
  def self.filter(controller)
    [:first_article?,
     :authenticate_administrator!,
     :authenticate_user!
    ].find do |m|
      controller.send(m)
    end
  end
end

privacy_filter_spec.rb

require "app/models/privacy_filter"

describe PrivacyFilter do

  let(:controller) do
    double(:first_article? => false,
           :authenticate_administrator! => false,
           :authenticate_user! => false)
  end

  it "allows access to the root article" do
    controller.should_receive(:first_article?).and_return(true)
    PrivacyFilter.filter(controller).should be_true
  end

  it "allows access for administrators" do
    controller.should_receive(:authenticate_administrator!).and_return(true)
    PrivacyFilter.filter(controller).should be_true
  end

  it "allows access to users" do
    controller.should_receive(:authenticate_user!).and_return(true)
    PrivacyFilter.filter(controller).should be_true
  end

  it "denies all others" do
    PrivacyFilter.filter(controller).should be_false
  end
end

Yeah, that seems like the right API. Rails makes it awkward.

For the app, I just ended up using cancan, which is the Right Way anywaay...