AI: address issue #149

backend/app/models/post_implication.rb

@@ -8,7 +8,6 @@ class PostImplication < ApplicationRecord
   validates :parent_post_id, presence: true
 
   validate :parent_post_mustnt_be_itself
-  validate :parent_post_mustnt_create_cycle
 
   private
 
@@ -17,24 +16,4 @@ class PostImplication < ApplicationRecord
       errors.add :parent_post_id, '親投稿に同じ投稿を設定することはできません．'
     end
   end
-
-  def parent_post_mustnt_create_cycle
-    return if post_id.blank? || parent_post_id.blank?
-    return if errors[:parent_post_id].present?
-
-    ancestor_ids = Set.new
-    frontier_ids = [parent_post_id]
-
-    until frontier_ids.empty?
-      if frontier_ids.include?(post_id)
-        errors.add :parent_post_id, :invalid
-        return
-      end
-
-      ancestor_ids.merge(frontier_ids)
-      frontier_ids = PostImplication.where(post_id: frontier_ids)
-          .distinct.pluck(:parent_post_id)
-          .reject { ancestor_ids.include?(_1) }
-    end
-  end
 end

backend/spec/models/post_implication_spec.rb

@@ -48,47 +48,4 @@ RSpec.describe PostImplication, type: :model do
     expect(duplicate).not_to be_valid
     expect(duplicate.errors[:post_id]).to be_present
   end
-
-  it 'rejects a parent that would create a two-post cycle' do
-    described_class.create!(post: post_record, parent_post:)
-
-    implication = described_class.new(
-        post: parent_post, parent_post: post_record)
-
-    expect(implication).not_to be_valid
-    expect(implication.errors.of_kind?(:parent_post_id, :invalid)).to be true
-  end
-
-  it 'rejects a parent that would create a three-post cycle' do
-    ancestor_post = create(:post)
-    described_class.create!(post: post_record, parent_post:)
-    described_class.create!(post: parent_post, parent_post: ancestor_post)
-
-    implication = described_class.new(
-        post: ancestor_post, parent_post: post_record)
-
-    expect(implication).not_to be_valid
-    expect(implication.errors.of_kind?(:parent_post_id, :invalid)).to be true
-  end
-
-  it 'allows a parent with an ancestor when no cycle would result' do
-    ancestor_post = create(:post)
-    described_class.create!(post: parent_post, parent_post: ancestor_post)
-
-    implication = described_class.new(post: post_record, parent_post:)
-
-    expect(implication).to be_valid
-  end
-
-  it 'terminates when existing ancestors already contain a cycle' do
-    ancestor_post = create(:post)
-    described_class.create!(post: parent_post, parent_post: ancestor_post)
-    legacy_implication = described_class.new(
-        post: ancestor_post, parent_post:)
-    legacy_implication.save!(validate: false)
-
-    implication = described_class.new(post: post_record, parent_post:)
-
-    expect(implication).to be_valid
-  end
 end

frontend/src/components/PostEmbed.tsx

@@ -196,6 +196,27 @@ const PostEmbed: FC<Props> = (
       return <TwitterEmbed userId={userId} statusId={statusId}/>
     }
 
+  case 'tiktok.com':
+    {
+      const videoId = url.pathname.match (/^\/@[^/]+\/video\/(\d+)\/?$/)?.[1]
+      if (!(videoId))
+	break
+
+      if (embedAutoLoadMode === 'off')
+	return externalLink
+      if (shouldLoadEmbed === false)
+	return manualLoadControl
+
+      return (
+	  <iframe
+	      src={`https://www.tiktok.com/player/v1/${ encodeURIComponent (videoId) }`}
+	      title={post.title || post.url}
+	      width={325}
+	      height={578}
+	      className="max-w-full"
+	      allowFullScreen/>)
+    }
+
   case 'youtube.com':
     {
       const videoId = url.searchParams.get ('v')