Creating a Factory association that defaults to nil?

Question

Using the FactoryGirl gem, inside the factories.rb file, how can I create a factory with an association that defaults to nil?

I am thinking something along these lines:

Factory.define :user do |factory|
  factory.association :post
  factory.association :comment, :default => nil
end

Would that be right and would that be ok to do?

Wouldn't it be `nil` by default if you do not mention this association in your factory definition at all? — KL-7, Dec 08 '11 at 21:31
Good point. I was worried that doing that would mean using Factory in the seeds.rb file wouldn't work, but I believe now that worrying was incorrect. — John, Dec 08 '11 at 22:38
Check http://stackoverflow.com/a/20407116/474597 if you want to override association to nil. — lulalala, Aug 16 '16 at 02:49

score 10 · Answer 1 · edited Feb 14 '19 at 03:22

10

FactoryGirl now benefits from a :null strategy. Therefore, you can define your association like this:

factory :user do
  association :post
  association :comment, strategy: :null
end

This will leave the association set to nil when using this factory. It's better to use this strategy than not defining the association altogether, because you can easily change strategies in traits/in the future.

edited Feb 14 '19 at 03:22

Jay Killeen

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answered Jan 17 '16 at 09:18

linkyndy

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gosh, it'd be nice if FactoryBot would mention this in their docs, no? – jayqui Mar 02 '23 at 03:02

score 0 · Accepted Answer · answered Dec 08 '11 at 21:33

0

Factory.define :user do |factory|
  factory.association :post
  factory.comment_id  nil
end

answered Dec 08 '11 at 21:33

Teddy

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Creating a Factory association that defaults to nil?

2 Answers2

Linked