Do fixtures trigger model callbacks?

Question

Say I have a User model with the following code in User.rb:

before_create :create_dependencies
after_create :build_inbox

And I also have a users.yml file with a bunch of user fixtures defined in it.

When I run rake db:fixtures:load, it doesn't appear to trigger the callbacks.

1. Is this how it is expected to work? If so, why did they design it this way?
2. Is there a way to force the triggering of the callbacks when loading fixtures?

Answer 1

Is this how it is expected to work? If so, why did they design it this way?

Yes, fixtures do not use callbacks. I'm assuming this is for performance reasons. It is quicker to load the data straight into the database without instantiating the model.

Is there a way to force the triggering of the callbacks when loading fixtures?

Not that I know of. You have a couple options. One is to build your fixtures as if the callbacks were already triggered. That is, manually create the data that the callbacks would. For example, if you have a callback which hashes a user's password you would need to hash the password manually and then store that hash in the fixture.

The second solution (and highly recommended!) is to use factories. Factories do trigger callbacks and allow you to use virtual attributes, etc. This is because they do instantiate the model each time. One popular gem is Factory Girl. Another one to try is Machinist. I have also created a Railscasts episode on the topic.

Answer 2

I have this problem as well. Our app calculates some totals before_save so it doesn't have to be done on the fly. Makes reporting faster and cuts out a few joins on certain reports.

In the tests for those objects we manually run the callbacks like this:

before do
  order.perform_callbacks
end

This works out well because it doesn't run all the time so other tests don't suffer.

We are using minitest and fixtures btw.