feat(models): extend claim with Claim and Comment

examples/blog/app/models/comment.rb

@@ -0,0 +1,34 @@
+class Comment < Prism::Orm::Model
+  # touch: true keeps Post#updated_at reflecting the most recent comment
+  # activity (created, edited, deleted), not just edits to the post itself -
+  # shown as "Last activity" on the post list/show pages.
+  belongs_to :post, counter_cache: true, touch: true
+  belongs_to :user
+  has_many :likes, as: :likeable, dependent: :destroy
+
+  # Paranoid so PostsController#restore(recursive: true) can bring a
+  # trashed post's comments back along with it - see Post#acts_as_paranoid.
+  acts_as_paranoid
+
+  # Every comment starts life pending (column default 0, see the
+  # add_status_to_comments migration) so a post's author gets a chance to
+  # approve or reject it before strangers can read it - see
+  # CommentsController#approve/#reject and the `visible_to` scope below.
+  enum :status, { pending: 0, approved: 1, rejected: 2 }
+
+  # Who gets to see a comment depends on who's asking, not just its status:
+  # everyone sees approved comments, the post's author (the moderator) sees
+  # everything on their own post regardless of status, and a signed-in
+  # commenter always sees their own comment even while it's still pending.
+  # `self` inside the block is whatever relation this scope was chained
+  # onto (e.g. already narrowed to one post's comments by `post.comments`),
+  # so `approved`/`where` compose with that instead of re-querying globally.
+  scope :visible_to, lambda { |user, post_author_id|
+    next self if user && user.id == post_author_id
+    next approved if user.nil?
+    approved.or(where(user_id: user.id))
+  }
+
+  validates :author, presence: true, length: { minimum: 2 }
+  validates :body, presence: true
+end