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n350071πŸ‡―πŸ‡΅
n350071πŸ‡―πŸ‡΅

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[RSpec] Factorybot transient & trait with argument

#rails

πŸ€” Situation

You want to make a user with a book that title is 'Ruby'.

 class User has_many: books end class Book belongs_to: user end
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πŸ‘ Solution

  • trait: you can run the process
  • trait with arguments: It is DEPRECATED, we should use transient instead.
  • transient: you can define and pass arguments with the block
 FactoryBot.define do factory :user, class: User do trait :with_book transient do # πŸ¦„1. default value when you use :with_book trait # πŸ¦„2. Dont't assign just 'Agile'. see also: https://thoughtbot.com/blog/deprecating-static-attributes-in-factory_bot-4-11 title { 'Agile' } end after(:build) do |user, evaluator| user.book = FactoryBot.create(:book, title: evaluator.title) end end end factory :book, class Book do sequence(:title) { |n| "book no.#{n}" } # πŸ¦„ default value end end
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 let!(:user) { create(:user, :with_book, title: 'Ruby') }
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πŸ”— Parent Note

n350071

my RSpec note

n350071πŸ‡―πŸ‡΅ ・ Oct 8 '19

#rails

Top comments (2)

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mxdavis profile image
Malki Davis •

Very helpful! Small thing -- there should be a do after trait :with_book

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samuelfaure profile image
Samuel-Zacharie FAURE •

Thank you for this small snippet, it was quite useful!