How can i create an object inside of other object?

Question

I want to create a 'post' and a 'card', but to create an card its necessary have company_id

factory :post do
  first_title { Faker::Name.name }
  sub_title { Faker::Name.name }
  email { Faker::Internet.email }
  company_id {}
  card { FactoryBot.create(:card, company_id: company_id) }
end

But i am getting this error:

undefined local variable or method `company_id' for #<FactoryBot::SyntaxRunner:0x00007f629fb1b260

Answer 1

Ideally if your test needs to create a well defined ocntext for it self and not rely on the factories behaviour, so you should call the factories passing the associated objects as a param for each factory call.

But if you really want to achieve this using the id you can use transient attributes.

Using the card object:

factory :company do
  # whatever you need here
end

factory :card do
  company
end

factory :post do
  first_title { Faker::Name.name }
  sub_title { Faker::Name.name }
  email { Faker::Internet.email }
  card
end

let(:company) { FactoryBot.create :company }
let(:card) { FactoryBot.create(:card, company: company) }
let!(:post) { FactoryBot.create(:post, card: card) }

Using the transient attribute:

# factory:
factory :post do
  first_title { Faker::Name.name }
  sub_title { Faker::Name.name }
  email { Faker::Internet.email }

  transient do
    company_id { FactoryBot.create(:company).id }
  end

  after(:build) do |post, evaluator|
    card = FactoryBot.create(:card, company_id: evaluator.company_id)
    post.card = card
  end
end
# spec:
let(:company) { FactoryBot.create :company }
let!(:post) { FactoryBot.create(:post, company_id: company.id) }

Update: I have added a code for the factories in the first example