DEV: Delete reviewable associations when deleting (#18472)

app/models/reviewable.rb

@@ -28,8 +28,8 @@ class Reviewable < ActiveRecord::Base
   belongs_to :topic
   belongs_to :category
 
-  has_many :reviewable_histories
-  has_many :reviewable_scores, -> { order(created_at: :desc) }
+  has_many :reviewable_histories, dependent: :destroy
+  has_many :reviewable_scores, -> { order(created_at: :desc) }, dependent: :destroy
 
   enum :status, {
     pending: 0,

spec/models/reviewable_spec.rb

@@ -7,6 +7,9 @@ RSpec.describe Reviewable, type: :model do
 
     let(:reviewable) { Fabricate.build(:reviewable, created_by: admin) }
 
+    it { is_expected.to have_many(:reviewable_scores).dependent(:destroy) }
+    it { is_expected.to have_many(:reviewable_histories).dependent(:destroy) }
+
     it "can create a reviewable object" do
       expect(reviewable).to be_present
       expect(reviewable.pending?).to eq(true)