Testing ActiveRecord callbacks with RSpec

Our preferred way of testing ActiveRecord is to simply create/update/destroy the record and then check if the expected behavior has happened.

We used to bend over backwards to avoid touching the database for this. For this we used a lot of stubbing and tricks like it_should_run_callbacks Show archive.org snapshot .

Today we would rather make a few database queries than have a fragile test full of stubs.

Example

Let's say your User model creates a first Project on creation, so the user doesn't see a blank application slate on her first visit:

Copyclass User < ActiveRecord::Base

  has_many :projects

  after_create :create_first_project
  
  private
  
  def create_first_project
    projects.create!(name: 'My first project')
  end

end

Note

Avoid having callbacks like this in your core User model. Prefer to use a form model Show archive.org snapshot like User::RegistrationForm. Read our book Growing Rails Applications in Practice Show archive.org snapshot for details.

Here is a test for the User model that automatically creates a Project:

Copydescribe 'User' do

  describe '#save' do
  
    it "creates a first project for the user" do
      user = FactoryBot.create(:user)
      user.projects.size.should == 1
      user.projects[0].name.should == 'My first project'
    end
  
  end

end