How to specify the association with factory_bot?

For example I have two models a user and a post. A post belongs_to a user and a user has many posts

#spec/factories/post.rb FactoryBot.define do factory :post do user body Faker::Movie.quote posted_at "2018-04-03 13:33:05" end end #spec/factories/user.rb FactoryBot.define do factory :user do first_name 'Jake' end end 

Using Rspec in a test I want to do this:

user = create(:user, first_name: 'Barry') #id 1 post = create(:post, user: user) 

I would expect that the user_id of post to be 1 however it is creating another user prior and the user_id is 2.

How can you specify the association when you are creating the object with factory_bot / factory_girl?

3 Answers

You should use explicit associations instead of implicit ones:

#spec/factories/post.rb FactoryBot.define do factory :post do association :user # <<<--- here the change body Faker::Movie.quote posted_at "2018-04-03 13:33:05" end end #spec/factories/user.rb FactoryBot.define do factory :user do first_name 'Jake' end end 

Another option is to use #trait method within the parent.

FactoryBot.define do factory :post do user nil body Faker::Movie.quote posted_at "2018-04-03 13:33:05" end end FactoryBot.define do factory :user do first_name 'Jake' end trait :with_post do after(:create) do |user| create(:post, user_id: user.id) end end end FactoryBot.create(:user, :with_post) 

Here we have another solution in case your association name and factory name is different then you can follow below syntax.

#spec/factories/post.rb FactoryBot.define do factory :post do association :author, factory: :user body Faker::Movie.quote posted_at "2018-04-03 13:33:05" end end 

in case your factory name is author and model name is user then you can use above syntax