```ruby
FactoryGirl.define do
  # must use build()
  factory :stock_packer, class: Spree::Stock::Packer do
    transient do
      stock_location { build(:stock_location) }
      contents []
    end

    initialize_with { new(stock_location, contents) }
  end

  factory :stock_package, class: Spree::Stock::Package do
    transient do
      stock_location { build(:stock_location) }
      contents       { [] }
      variants_contents { {} }
    end

    initialize_with { new(stock_location, contents) }

    after(:build) do |package, evaluator|
      evaluator.variants_contents.each do |variant, count|
        package.add_multiple build_list(:inventory_unit, count, variant: variant)
      end
    end

    factory :stock_package_fulfilled do
      transient { variants_contents { { build(:variant) => 2 } } }
    end
  end
end
```

Add skip_create to stock packer and stock package
user
```ruby
FactoryGirl.define do
  factory :stock_packer, class: Spree::Stock::Packer do
    skip_create

    transient do
      stock_location { build(:stock_location) }
      contents []
    end

    initialize_with { new(stock_location, contents) }
  end

  factory :stock_package, class: Spree::Stock::Package do
    skip_create

    transient do
      stock_location { build(:stock_location) }
      contents       { [] }
      variants_contents { {} }
    end

    initialize_with { new(stock_location, contents) }

    after(:build) do |package, evaluator|
      evaluator.variants_contents.each do |variant, count|
        package.add_multiple build_list(:inventory_unit, count, variant: variant)
      end
    end

    factory :stock_package_fulfilled do
      transient { variants_contents { { build(:variant) => 2 } } }
    end
  end
end
```
assistant