Support Polymorphic for STI

manager.rb

class Manager < User
  
  def can_do_stuff
  end
  
end

profile.rb

class Profile < ApplicationRecord
  belongs_to :profileable, polymorphic: true

#   # if don't want to use blanket polymorphic
#   def profilable_type=(class_name)
#     super(class_name.constantize.base_class.to_s)
#   end

end

single_table_polymorphic.rb

# models/concerns/single_table_polymorphic.rb
module SingleTablePolymorphic
  extend ActiveSupport::Concern

  included do
    self.reflect_on_all_associations.select{|a| a.options[:polymorphic]}.map(&:name).each do |name|
      define_method "#{name.to_s}_type=" do |class_name|
        super(class_name.constantize.base_class.name)
      end
    end
  end
end

user.rb

class User < ApplicationRecord
  has_one :profile, as: :profileable, dependent: :destroy

end