test_helper.rb

def [your_conventional_method_name_here]
  @foo ||= Factory(:foo)
  @foo.authorize!
end

if you are using rspec you could use a shared behavior so that you have:

it_should_behave_like "an action that requires an authorized foo"

if not, maybe that gives you some more ideas to choose from :)

Shoulda, and Matchy. FactoryGirl has callbacks that seem to fit the use case, @mbleigh suggested trying that approach. Another suggestion was to make the factory return an authorized or confirmed user. Seems to me like taking that happy path approach, and creating a factory for unconfirmed/unauthorized users to test those cases (they are fewer in number) is a reasonable proposition.