RSpec with Factory_girl - Destroy Object

I have not tested the connection between the two models. A course has many enrollments, an enrollment has one course.

When a course is destroyed, all records connected to it are set to active = false. This works with real objects, I just can't get the test to work, because no matter what I do, the course is not destroyed.

describe Enrollment do
  it "deactivates enrollment" do
    course = create(:a_course)
    user = create_user
    enrollment = build(:enrollment)
    enrollment.course = course
    enrollment.user = user
    enrollment.save

    # until now everything works as expected

    expect { course.destroy }.to change { enrollment.active }.to be_false

    # the course isn't being destroyed when calling course.destroy

  end
end

I couldn’t find anything about destroying the factory_girl object in the factory_girl docs, maybe I am doing it all wrong and should I use “real” objects? Thank!

Update Here is the model where the change occurs.

class Course < ActiveRecord::Base
  attr_accessible ...

  has_many :users, through: :enrollments
  has_many :enrollments

  before_destroy :deactivate_enrollments

  protected

  def deactivate_enrollments
    enrollments = self.enrollments

    enrollments.each do |e|
      e.active = false
      e.save
    end
  end
end

As I'm not sure about this, the course I use for testing is a factory_girl object. He was not created as follows: Course.create.... Does the factory_girl object have the same methods as the ActiveRecord object?

factory_girl:

FactoryGirl.define do
  factory :course, class: Course do
    titel "Course title"
  end
end

2 failure message

Enrollment
  deactivates enrolment (FAILED - 1)

Failures:

  1) Enrollment deactivates enrollment
     Failure/Error: expect { course.destroy }.to change(enrollment, :active).from(true).to(false)
       active should have been changed to false, but is now true
     # ./spec/models/enrollment_spec.rb:18:in `block (2 levels) in <top (required)>'

3

, . Course.destroy_all, course.destroy . , factory_girl . ?