Use ApplicationWorkHistoryBreak#breakable column

app/models/application_form.rb

@@ -16,7 +16,7 @@ class ApplicationForm < ApplicationRecord
   has_many :application_volunteering_experiences, as: :experienceable
   has_many :application_qualifications
   has_many :application_references
-  has_many :application_work_history_breaks
+  has_many :application_work_history_breaks, as: :breakable
   has_many :emails
 
   belongs_to :previous_application_form, class_name: 'ApplicationForm', optional: true, inverse_of: 'subsequent_application_form'

app/models/application_work_history_break.rb

@@ -1,13 +1,18 @@
 class ApplicationWorkHistoryBreak < ApplicationRecord
   include TouchApplicationChoices
 
-  belongs_to :application_form, touch: true
-  belongs_to :breakable, polymorphic: true, optional: true
+  belongs_to :application_form, touch: true, optional: true
+  belongs_to :breakable, polymorphic: true
 
-  before_save -> { self.breakable = application_form }, if: -> { breakable.nil? }
+  before_save -> { self.application_form_id = breakable_id }, if: -> { application_form_id.nil? }
 
   audited associated_with: :application_form
 
+  def application_form=(value)
+    super
+    self.breakable = value
+  end
+
   def length
     ((end_date.year * 12) + end_date.month) - ((start_date.year * 12) + start_date.month) - 1
   end

spec/models/application_work_history_break_spec.rb

@@ -1,8 +1,8 @@
 require 'rails_helper'
 
 RSpec.describe ApplicationWorkHistoryBreak do
-  it { is_expected.to belong_to(:application_form).touch(true) }
-  it { is_expected.to belong_to(:breakable).optional }
+  it { is_expected.to belong_to(:application_form).touch(true).optional }
+  it { is_expected.to belong_to(:breakable) }
 
   describe 'auditing', :with_audited do
     it { is_expected.to be_audited.associated_with :application_form }