Creating multiple unique entries with transient FactoryGirl - ruby

Question

I have a FactoryGirl Object that creates a Category in my case (it is associated with an image)
class Image < ActiveRecord::Base
has_many :image_categories, dependent: :destroy
has_many :categories, through: :image_categories
validates :categories, presence: { message: 'Choose At Least 1 Category' }
end
class Category < ActiveRecord::Base
has_many :image_categories
has_many :images, through: :image_categories
validates :name, presence: { message: "Don't forget to add a Category" }
validates_uniqueness_of :name, message: 'Category name %{value} already exists'
end
FactoryGirl.define do
factory :category do
name 'My Category'
end
end
FactoryGirl.define do
factory :image do
title 'Test Title'
description 'Test Description'
transient do
categories_count 1
end
categories { build_list(:category, categories_count) }
end
end
When creating an image with 1 category everything is fine, but if i try and save with 2 categories the second entry gets saved as nil, I guess thats because of my validation of unique names.
So my question is how can I use transients to create a list of 2 unique categories
Hope this makes sense
Thanks

Answer 1

Direct from Factory Girl Documentation: http://www.rubydoc.info/gems/factory_girl/file/GETTING_STARTED.md#Transient_Attributes
FactoryGirl.define do
# post factory with a `belongs_to` association for the user
factory :post do
title "Through the Looking Glass"
user
end
# user factory without associated posts
factory :user do
name "John Doe"
# user_with_posts will create post data after the user has been created
factory :user_with_posts do
# posts_count is declared as a transient attribute and available in
# attributes on the factory, as well as the callback via the evaluator
transient do
posts_count 2
end
# the after(:create) yields two values; the user instance itself and the
# evaluator, which stores all values from the factory, including transient
# attributes; `create_list`'s second argument is the number of records
# to create and we make sure the user is associated properly to the post
after(:create) do |user, evaluator|
create_list(:post, evaluator.posts_count, user: user)
end
end
end
end