Traits in Associations

gistfile1.txt

(rdb:1) p FactoryGirl.build(:user, :pro, :active)
ArgumentError Exception: Factory not registered: [:subscription, :pro]

(rdb:1) p FactoryGirl.build(:subscription, :pro)
#<Subscription id: nil, user_id: nil, plan: "pro", renew_on: "2012-12-13", charge_on: "2012-12-13", failures: 0, created_at: nil, updated_at: nil>

subscription_factory.rb

FactoryGirl.define do
  factory :subscription do
    plan      'free'
    renew_on  { 1.week.from_now.to_date }
    charge_on { 1.week.from_now.to_date }
    failures  0

    trait :pro do
      plan 'pro'
    end

    trait :trial do
      plan 'trial'
    end
  end
end

user_factory.rb

SPEC_DEFAULT_PASSWORD = 'super-secret'

FactoryGirl.define do
  factory :user do
    account_type          'free'
    sequence(:email)      {|n| "user_#{n}@example.com" }
    password              SPEC_DEFAULT_PASSWORD
    password_confirmation { password }
    listing               { create(:listing, :with_images) }

    trait :active do
      active true
    end

    trait :pro do
      account_type 'pro'
      listing      { create(:listing, :with_images, image_count: 6) }
      credit_card
      association  :subscription, factory: [:subscription, :pro]
    end

    trait :trial do
      account_type 'trial'
      listing      { create(:listing, :with_images, image_count: 6) }
      credit_card
      association  :subscription, factory: [:subscription, :trial]
    end
  end
end

Line 19 in user_factory.rb is unable to find the factory.