Skip callbacks on Factory Girl and Rspec

I'm testing a model with an after create callback that I'd like to run only on some occasions while testing. How can I skip/run callbacks from a factory?

class User < ActiveRecord::Base
  after_create :run_something
  ...
end

Factory:

FactoryGirl.define do
  factory :user do
    first_name "Luiz"
    last_name "Branco"
    ...
    # skip callback

    factory :with_run_something do
      # run callback
  end
end

I'm not sure if it is the best solution, but I have successfully achieved this using:

FactoryGirl.define do
  factory :user do
    first_name "Luiz"
    last_name "Branco"
    #...

    after(:build) { |user| user.class.skip_callback(:create, :after, :run_something) }

    factory :user_with_run_something do
      after(:create) { |user| user.send(:run_something) }
    end
  end
end

Running without callback:

FactoryGirl.create(:user)

Running with callback:

FactoryGirl.create(:user_with_run_something)

When you don't want to run a callback do the following:

User.skip_callback(:create, :after, :run_something)
Factory.create(:user)

Be aware that skip_callback will be persistant across other specs after it is run therefore consider something like the following:

before do
  User.skip_callback(:create, :after, :run_something)
end

after do
  User.set_callback(:create, :after, :run_something)
end

None of these solutions are good. They deface the class by removing functionality that should be removed from the instance, not from the class.

factory :user do
  before(:create){|user| user.define_singleton_method(:send_welcome_email){}}

Instead of suppressing the callback, I am suppressing the functionality of the callback. In a way, I like this approach better because it is more explicit.

I'd like to make an improvement to @luizbranco 's answer to make after_save callback more reusable when creating other users.

FactoryGirl.define do
  factory :user do
    first_name "Luiz"
    last_name "Branco"
    #...

    after(:build) { |user| 
      user.class.skip_callback(:create, 
                               :after, 
                               :run_something1,
                               :run_something2) 
    }

    trait :with_after_save_callback do
      after(:build) { |user| 
        user.class.set_callback(:create, 
                                :after, 
                                :run_something1,
                                :run_something2) 
      }
    end
  end
end

Running without after_save callback:

FactoryGirl.create(:user)

Running with after_save callback:

FactoryGirl.create(:user, :with_after_save_callback)

In my test, I prefer to create users without the callback by default because the methods used run extra stuff I don't normally want in my test examples.

----------UPDATE------------ I stopped using skip_callback because there were some inconsistency issues in the test suite.

Alternative Solution 1 (use of stub and unstub):

after(:build) { |user| 
  user.class.any_instance.stub(:run_something1)
  user.class.any_instance.stub(:run_something2)
}

trait :with_after_save_callback do
  after(:build) { |user| 
    user.class.any_instance.unstub(:run_something1)
    user.class.any_instance.unstub(:run_something2)
  }
end

Alternative Solution 2 (my preferred approach):

after(:build) { |user| 
  class << user
    def run_something1; true; end
    def run_something2; true; end
  end
}

trait :with_after_save_callback do
  after(:build) { |user| 
    class << user
      def run_something1; super; end
      def run_something2; super; end
    end
  }
end

Rails 5 - skip_callback raising Argument error when skipping from a FactoryBot factory.

ArgumentError: After commit callback :whatever_callback has not been defined

There was a change in Rails 5 with how skip_callback handles unrecognized callbacks:

ActiveSupport::Callbacks#skip_callback now raises an ArgumentError if an unrecognized callback is remove

When skip_callback is called from the factory, the real callback in the AR model is not yet defined.

If you've tried everything and pulled your hair out like me, here is your solution (got it from searching FactoryBot issues) (NOTE the raise: false part):

after(:build) { YourSweetModel.skip_callback(:commit, :after, :whatever_callback, raise: false) }

Feel free to use it with whatever other strategies you prefer.