shopping cart

app/models/application_record.rb

@@ -15,4 +15,9 @@ class ApplicationRecord < ActiveRecord::Base
     AuditRecord.create(model: self.class, action: 'create', params: result.to_json)
     result
   end
+  def decrement!(*args)
+    result = super(*args)
+    AuditRecord.create(model: self.class, action: 'decrement!', params: self.to_json)
+    result
+  end
 end

app/models/user.rb

@@ -1,4 +1,6 @@
 class User < ApplicationRecord
+  has_and_belongs_to_many :books
+
   has_secure_password
   has_secure_password :recovery_password, validations: false
   enum role: [:customer, :admin], _default: :customer