моя модель имеет default_scope (: order = > 'created_at') мои тесты (rspec, factory girl, shoulda и т.д.) являются:
require 'spec/spec_helper.rb'
describe CatMembership do
context "is valid" do
subject { Factory.build(:cat_membership) }
it { should be_valid }
it { should belong_to :cat}
it { should belong_to :cat_group}
it { should have_db_column(:start_date)}
it { should have_db_column(:end_date)}
end
end