machinist_matcher.rb

Spec::Matchers.define :have_a_machinist_blueprint do
  match do |model|
    model.class.respond_to?(:make)
  end
 
  description do
    "works if there's a valid blueprint"
  end
 
  failure_message_for_should do |model|
    "expected #{model} to have valid blueprint"
  end
 
  failure_message_for_should_not do |model|
    "wtf?"
  end
end