app/models/like.rb
class Like < ApplicationRecord
after_commit on: [:create] do
NotifierJob.perform_later(self)
end
validates :user_id, uniqueness: { scope: [ :likeable_id, :likeable_type ] }
belongs_to :user, inverse_of: :likes
belongs_to :likeable, polymorphic: true
has_many :notifications, as: :notifiable, dependent: :destroy
end