class Comment < ApplicationRecord validates :author_id, :post_id, :body, presence: true belongs_to :author, foreign_key: :author_id, class_name: :User belongs_to :post, foreign_key: :post_id, class_name: :Post belongs_to :parent_comment, foreign_key: :parent_id, class_name: :Comment, optional: true has_many :child_comments, foreign_key: :parent_id, class_name: :Comment end