#327

backend/app/models/tag.rb

@@ -84,7 +84,6 @@ class Tag < ApplicationRecord
   def self.no_deerjikist = find_or_create_by_tag_name!('ニジラー情報不詳', category: :meta)
   def self.video = find_or_create_by_tag_name!('動画', category: :meta)
   def self.niconico = find_or_create_by_tag_name!('ニコニコ', category: :meta)
-  def self.youtube = find_or_create_by_tag_name!('YouTube', category: :meta)
 
   def self.normalise_tags tag_names, with_tagme: true,
                                      with_no_deerjikist: true,

backend/app/services/youtube/api_client.rb

@@ -1,73 +0,0 @@
-require 'json'
-require 'net/http'
-require 'uri'
-
-
-module Youtube
-  class ApiClient
-    ENDPOINT = 'https://www.googleapis.com/youtube/v3'
-
-    def initialize api_key: ENV.fetch('YOUTUBE_API_KEY')
-      @api_key = api_key
-    end
-
-    def search_videos q:, published_after: nil, published_before: nil, page_token: nil
-      get_json('/search', {
-          part:           'snippet',
-          type:           'video',
-          q:,
-          order:          'date',
-          maxResults:     50,
-          regionCode:     'JP',
-          relevanceLanguage: 'ja',
-          publishedAfter: published_after&.iso8601,
-          publishedBefore: published_before&.iso8601,
-          pageToken:      page_token }.compact)
-    end
-
-    def videos ids
-      return { 'items' => [] } if ids.empty?
-
-      get_json('/videos', part: 'snippet,status,contentDetails', id: ids.join(','))
-    end
-
-    def playlist_items playlist_id:, page_token: nil
-      get_json('/playlistItems', {
-          part:       'snippet,contentDetails,status',
-          playlistId: playlist_id,
-          maxResults: 50,
-          pageToken:  page_token }.compact)
-    end
-
-    def channel id: nil, handle: nil
-      raise ArgumentError, 'id or handle is required' if id.present? == handle.present?
-
-      params = { part: 'snippet,contentDetails' }
-      params[:id] = id if id.present?
-      params[:forHandle] = handle if handle.present?
-
-      get_json('/channels', params)
-    end
-
-    private
-
-    def get_json path, params
-      uri = URI(ENDPOINT + path)
-      uri.query = URI.encode_www_form(params.merge(key: @api_key))
-
-      response = Net::HTTP.start(uri.host,
-                                 uri.port,
-                                 use_ssl: true,
-                                 open_timeout: 10,
-                                 read_timeout: 30) do |http|
-        http.get(uri)
-      end
-
-      unless response.is_a?(Net::HTTPSuccess)
-        raise "YouTube API error: #{ response.code } #{ response.body }"
-      end
-
-      JSON.parse(response.body)
-    end
-  end
-end

backend/app/services/youtube/sync.rb

@@ -1,168 +0,0 @@
-require 'open-uri'
-require 'set'
-require 'time'
-
-
-module Youtube
-  class Sync
-    def initialize client: ApiClient.new
-      @client = client
-    end
-
-    def sync!
-      video_ids = discover_video_ids
-      return if video_ids.empty?
-
-      video_ids.each_slice(50) do |ids|
-        @client.videos(ids).fetch('items', []).each do |item|
-          sync_video!(VideoItem.new(item))
-        end
-      end
-    end
-
-    private
-
-    def discover_video_ids
-      ids = Set.new
-
-      query_terms.each do |q|
-        response = @client.search_videos(q:, published_after: sync_since)
-
-        response.fetch('items', []).each do |item|
-          video_id = item.dig('id', 'videoId')
-          ids << video_id if video_id.present?
-        end
-      end
-
-      playlist_ids.each do |playlist_id|
-        each_playlist_item(playlist_id) do |item|
-          video_id = item.dig('contentDetails', 'videoId')
-          video_id ||= item.dig('snippet', 'resourceId', 'videoId')
-
-          ids << video_id if video_id.present?
-        end
-      end
-
-      ids.to_a
-    end
-
-    def sync_video! video
-      post = Post.where('url REGEXP ?', youtube_url_regexp(video.id)).first
-
-      original_created_from = video.published_at.change(sec: 0)
-      original_created_before = original_created_from + 1.minute
-
-      post_created = false
-      post_changed = false
-
-      if post
-        post.assign_attributes(title: video.title,
-                               original_created_from:,
-                               original_created_before:,
-                               thumbnail_base: video.thumbnail_url)
-
-        post_changed = post.changed?
-        post.save! if post_changed
-
-        attach_thumbnail_if_needed!(post, video.thumbnail_url)
-      else
-        post_created = true
-        post = Post.create!(
-            title: video.title,
-            url: video.url,
-            thumbnail_base: video.thumbnail_url,
-            uploaded_user_id: nil,
-            original_created_from:,
-            original_created_before:)
-
-        attach_thumbnail_if_needed!(post, video.thumbnail_url)
-
-        sync_post_tags!(post, [Tag.tagme.id, Tag.bot.id, Tag.youtube.id, Tag.video.id])
-      end
-
-      kept_tag_ids = post.tags.pluck(:id).to_set
-      desired_tag_ids = kept_tag_ids.to_a
-
-      deerjikist = Deerjikist.find_by(platform: :youtube, code: video.channel_id)
-      if deerjikist
-        desired_tag_ids.delete(Tag.no_deerjikist.id)
-        desired_tag_ids << deerjikist.tag_id
-      elsif post.tags.where(category: :deerjikist).none?
-        desired_tag_ids << Tag.no_deerjikist.id
-      end
-
-      desired_tag_ids.uniq!
-
-      sync_post_tags!(post, desired_tag_ids, current_tag_ids: kept_tag_ids)
-
-      if post_created
-        PostVersionRecorder.record!(post:, event_type: :create, created_by_user: nil)
-      elsif post_changed || kept_tag_ids != desired_tag_ids.to_set
-        PostVersionRecorder.ensure_snapshot!(post, created_by_user: nil)
-        PostVersionRecorder.record!(post:, event_type: :update, created_by_user: nil)
-      end
-    end
-
-    def sync_post_tags! post, desired_tag_ids, current_tag_ids: nil
-      current_tag_ids ||= PostTag.kept.where(post_id: post.id).pluck(:tag_id).to_set
-      desired_tag_ids = desired_tag_ids.compact.to_set
-
-      to_add = desired_tag_ids - current_tag_ids
-      to_remove = current_tag_ids - desired_tag_ids
-
-      Tag.where(id: to_add.to_a).find_each do |tag|
-        begin
-          PostTag.create!(post:, tag:)
-        rescue ActiveRecord::RecordNotUnique
-          ;
-        end
-      end
-
-      PostTag.where(post_id: post.id, tag_id: to_remove.to_a).kept.find_each do |pt|
-        pt.discard_by!(nil)
-      end
-    end
-
-    def attach_thumbnail_if_needed! post, thumbnail_url
-      return if post.thumbnail.attached?
-      return if thumbnail_url.blank?
-
-      post.thumbnail.attach(
-          io:           URI.open(thumbnail_url),
-          filename:     File.basename(URI.parse(thumbnail_url).path),
-          content_type: 'image/jpeg')
-
-      post.resized_thumbnail!
-    end
-
-    def youtube_url_regexp id
-      escaped = Regexp.escape(id)
-      "(youtube\\.com/watch\\?v=#{ escaped }|youtu\\.be/#{ escaped })([^A-Za-z0-9_-]|$)"
-    end
-
-    def query_terms = ['ぼざろクリーチャーシリーズ', '伊地知ニジカ', '伊地知虹鹿']
-
-    def playlist_ids
-      ['PLrOch4zHkI5vu29b-f9umUQQ4tQkuWLPX',
-       'PLrOch4zHkI5vOK0RaytQq6PbucxQkkL0K',
-       'PLrOch4zHkI5tdwm9vSegiDQJOM-hgpcOC']
-    end
-
-    def sync_since = 14.days.ago
-
-    def each_playlist_item playlist_id
-      page_token = nil
-
-      loop do
-        response = @client.playlist_items(playlist_id:, page_token:)
-
-        response.fetch('items', []).each do |item|
-          yield item
-        end
-
-        page_token = response['nextPageToken']
-        break if page_token.blank?
-      end
-    end
-  end
-end

backend/app/services/youtube/video_item.rb

@@ -1,32 +0,0 @@
-require 'time'
-
-
-module Youtube
-  class VideoItem
-    attr_reader :id, :title, :channel_id, :published_at, :thumbnail_url, :raw_tags
-
-    def initialize item
-      snippet = item.fetch('snippet')
-
-      @id = item.fetch('id')
-      @title = snippet['title']
-      @channel_id = snippet['channelId']
-      @published_at = Time.iso8601(snippet['publishedAt'])
-      @thumbnail_url = pick_thumbnail(snippet['thumbnails'] || { })
-      @raw_tags = snippet['tags'] || []
-    end
-
-    def url = "https://www.youtube.com/watch?v=#{ @id }"
-
-    private
-
-    def pick_thumbnail thumbnails
-      ['maxres', 'standard', 'high', 'medium', 'default'].each do |key|
-        url = thumbnails.dig(key, 'url')
-        return url if url.present?
-      end
-
-      nil
-    end
-  end
-end

backend/config/schedule.rb

@@ -17,11 +17,3 @@ every 1.day, at: '0:00 am' do
   rake 'post_similarity:calc', environment: 'production'
   rake 'tag_similarity:calc', environment: 'production'
 end
-
-every 1.day, at: '7:50 am' do
-  rake 'nico:export', environment: 'production'
-end
-
-every :hour do
-  rake 'post:sync', environment: 'production'
-end

backend/db/migrate/20260501153900_rename_banned_to_banned_at_in_users_and_ip_addresses.rb

@@ -0,0 +1,16 @@
+class RenameBannedToBannedAtInUsersAndIpAddresses < ActiveRecord::Migration[8.0]
+  def up
+    [:users, :ip_addresses].each do
+      add_column _1, :banned_at, :datetime, after: :banned
+      add_index _1, :banned_at
+      remove_column _1, :banned
+    end
+  end
+
+  def down
+    [:ip_addresses, :users].each do
+      add_column _1, :banned, :boolean, null: false, default: false, after: :banned_at
+      remove_column _1, :banned_at
+    end
+  end
+end

backend/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
+ActiveRecord::Schema[8.0].define(version: 2026_05_01_153900) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -50,9 +50,10 @@ ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
 
   create_table "ip_addresses", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.binary "ip_address", limit: 16, null: false
-    t.boolean "banned", default: false, null: false
+    t.datetime "banned_at"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.index ["banned_at"], name: "index_ip_addresses_on_banned_at"
     t.index ["ip_address"], name: "index_ip_addresses_on_ip_address", unique: true
   end
 
@@ -119,6 +120,15 @@ ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
     t.check_constraint "`version_no` > 0", name: "nico_tag_versions_version_no_positive"
   end
 
+  create_table "post_implications", primary_key: ["post_id", "parent_post_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.bigint "post_id", null: false
+    t.bigint "parent_post_id", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["parent_post_id"], name: "index_post_implications_on_parent_post_id"
+    t.check_constraint "`post_id` <> `parent_post_id`", name: "chk_post_implications_no_self"
+  end
+
   create_table "post_similarities", primary_key: ["post_id", "target_post_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.bigint "target_post_id", null: false
@@ -155,13 +165,12 @@ ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
     t.string "url", limit: 768, null: false
     t.string "thumbnail_base", limit: 2000
     t.text "tags", null: false
-    t.bigint "parent_id"
+    t.text "parent_post_ids", null: false
     t.datetime "original_created_from"
     t.datetime "original_created_before"
     t.datetime "created_at", null: false
     t.bigint "created_by_user_id"
     t.index ["created_by_user_id"], name: "index_post_versions_on_created_by_user_id"
-    t.index ["parent_id"], name: "index_post_versions_on_parent_id"
     t.index ["post_id", "version_no"], name: "index_post_versions_on_post_id_and_version_no", unique: true
     t.index ["post_id"], name: "index_post_versions_on_post_id"
     t.check_constraint "`event_type` in (_utf8mb4'create',_utf8mb4'update',_utf8mb4'discard',_utf8mb4'restore')", name: "post_versions_event_type_valid"
@@ -172,13 +181,11 @@ ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
     t.string "title"
     t.string "url", limit: 768, null: false
     t.string "thumbnail_base", limit: 2000
-    t.bigint "parent_id"
     t.bigint "uploaded_user_id"
     t.datetime "created_at", null: false
     t.datetime "original_created_from"
     t.datetime "original_created_before"
     t.datetime "updated_at", null: false
-    t.index ["parent_id"], name: "index_posts_on_parent_id"
     t.index ["uploaded_user_id"], name: "index_posts_on_uploaded_user_id"
     t.index ["url"], name: "index_posts_on_url", unique: true
   end
@@ -326,9 +333,10 @@ ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
     t.string "name"
     t.string "inheritance_code", limit: 64, null: false
     t.string "role", null: false
-    t.boolean "banned", default: false, null: false
+    t.datetime "banned_at"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.index ["banned_at"], name: "index_users_on_banned_at"
   end
 
   create_table "wiki_assets", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -428,6 +436,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
   add_foreign_key "nico_tag_relations", "tags", column: "nico_tag_id"
   add_foreign_key "nico_tag_versions", "tags"
   add_foreign_key "nico_tag_versions", "users", column: "created_by_user_id"
+  add_foreign_key "post_implications", "posts"
+  add_foreign_key "post_implications", "posts", column: "parent_post_id"
   add_foreign_key "post_similarities", "posts"
   add_foreign_key "post_similarities", "posts", column: "target_post_id"
   add_foreign_key "post_tags", "posts"
@@ -435,9 +445,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
   add_foreign_key "post_tags", "users", column: "created_user_id"
   add_foreign_key "post_tags", "users", column: "deleted_user_id"
   add_foreign_key "post_versions", "posts"
-  add_foreign_key "post_versions", "posts", column: "parent_id"
   add_foreign_key "post_versions", "users", column: "created_by_user_id"
-  add_foreign_key "posts", "posts", column: "parent_id"
   add_foreign_key "posts", "users", column: "uploaded_user_id"
   add_foreign_key "settings", "users"
   add_foreign_key "tag_implications", "tags"

backend/lib/tasks/sync_posts.rake

@@ -1,6 +0,0 @@
-namespace :post do
-  desc '投稿同期（ニコニコ以外）'
-  task sync: :environment do
-    Youtube::Sync.new.sync!
-  end
-end

backend/spec/services/youtube/api_client_spec.rb

@@ -1,130 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Youtube::ApiClient do
-  let(:api_key) { 'test-api-key' }
-  let(:client) { described_class.new(api_key:) }
-
-  describe '#search_videos' do
-    it 'calls YouTube search API with expected params' do
-      published_after = Time.zone.parse('2026-05-01 00:00:00')
-      published_before = Time.zone.parse('2026-05-02 00:00:00')
-
-      expect(client).to receive(:get_json).with(
-        '/search',
-        {
-          part: 'snippet',
-          type: 'video',
-          q: 'ぼざろクリーチャー',
-          order: 'date',
-          maxResults: 50,
-          regionCode: 'JP',
-          relevanceLanguage: 'ja',
-          publishedAfter: published_after.iso8601,
-          publishedBefore: published_before.iso8601,
-          pageToken: 'NEXT'
-        }
-      ).and_return({ 'items' => [] })
-
-      client.search_videos(
-        q: 'ぼざろクリーチャー',
-        published_after:,
-        published_before:,
-        page_token: 'NEXT'
-      )
-    end
-
-    it 'omits nil optional params' do
-      expect(client).to receive(:get_json).with(
-        '/search',
-        hash_excluding(:publishedAfter, :publishedBefore, :pageToken)
-      ).and_return({ 'items' => [] })
-
-      client.search_videos(q: 'ぼざろクリーチャー')
-    end
-  end
-
-  describe '#videos' do
-    it 'returns empty items when ids are empty' do
-      expect(client).not_to receive(:get_json)
-
-      expect(client.videos([])).to eq({ 'items' => [] })
-    end
-
-    it 'calls videos API with comma separated ids' do
-      expect(client).to receive(:get_json).with(
-        '/videos',
-        {
-          part: 'snippet,status,contentDetails',
-          id: 'video-1,video-2'
-        }
-      ).and_return({ 'items' => [] })
-
-      client.videos(['video-1', 'video-2'])
-    end
-  end
-
-  describe '#playlist_items' do
-    it 'calls playlistItems API with page token' do
-      expect(client).to receive(:get_json).with(
-        '/playlistItems',
-        {
-          part: 'snippet,contentDetails,status',
-          playlistId: 'PL123',
-          maxResults: 50,
-          pageToken: 'NEXT'
-        }
-      ).and_return({ 'items' => [] })
-
-      client.playlist_items(playlist_id: 'PL123', page_token: 'NEXT')
-    end
-
-    it 'omits page token when nil' do
-      expect(client).to receive(:get_json).with(
-        '/playlistItems',
-        {
-          part: 'snippet,contentDetails,status',
-          playlistId: 'PL123',
-          maxResults: 50
-        }
-      ).and_return({ 'items' => [] })
-
-      client.playlist_items(playlist_id: 'PL123')
-    end
-  end
-
-  describe '#channel' do
-    it 'calls channels API by id' do
-      expect(client).to receive(:get_json).with(
-        '/channels',
-        {
-          part: 'snippet,contentDetails',
-          id: 'UC123'
-        }
-      ).and_return({ 'items' => [] })
-
-      client.channel(id: 'UC123')
-    end
-
-    it 'calls channels API by handle' do
-      expect(client).to receive(:get_json).with(
-        '/channels',
-        {
-          part: 'snippet,contentDetails',
-          forHandle: '@some_handle'
-        }
-      ).and_return({ 'items' => [] })
-
-      client.channel(handle: '@some_handle')
-    end
-
-    it 'raises when neither id nor handle is given' do
-      expect { client.channel }.to raise_error(ArgumentError, 'id or handle is required')
-    end
-
-    it 'raises when both id and handle are given' do
-      expect do
-        client.channel(id: 'UC123', handle: '@some_handle')
-      end.to raise_error(ArgumentError, 'id or handle is required')
-    end
-  end
-end

backend/spec/services/youtube/sync_spec.rb

@@ -1,310 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Youtube::Sync do
-  let(:client) { instance_double(Youtube::ApiClient) }
-  let(:sync) { described_class.new(client:) }
-
-  before do
-    allow(PostVersionRecorder).to receive(:record!)
-    allow(PostVersionRecorder).to receive(:ensure_snapshot!)
-    allow(sync).to receive(:attach_thumbnail_if_needed!)
-  end
-
-  describe '#sync!' do
-    it 'returns without fetching video details when no video ids are discovered' do
-      allow(sync).to receive(:query_terms).and_return([])
-      allow(sync).to receive(:playlist_ids).and_return([])
-
-      expect(client).not_to receive(:videos)
-
-      sync.sync!
-    end
-
-    it 'discovers ids from search and all playlist pages' do
-      allow(sync).to receive(:query_terms).and_return(['ぼざろクリーチャー'])
-      allow(sync).to receive(:playlist_ids).and_return(['PL123'])
-      allow(sync).to receive(:sync_since).and_return(Time.zone.parse('2026-05-01 00:00:00'))
-
-      allow(client).to receive(:search_videos).with(
-        q: 'ぼざろクリーチャー',
-        published_after: Time.zone.parse('2026-05-01 00:00:00')
-      ).and_return({
-        'items' => [
-          {
-            'id' => {
-              'videoId' => 'search-video-1'
-            }
-          }
-        ]
-      })
-
-      allow(client).to receive(:playlist_items).with(
-        playlist_id: 'PL123',
-        page_token: nil
-      ).and_return({
-        'items' => [
-          {
-            'contentDetails' => {
-              'videoId' => 'playlist-video-1'
-            }
-          }
-        ],
-        'nextPageToken' => 'NEXT'
-      })
-
-      allow(client).to receive(:playlist_items).with(
-        playlist_id: 'PL123',
-        page_token: 'NEXT'
-      ).and_return({
-        'items' => [
-          {
-            'snippet' => {
-              'resourceId' => {
-                'videoId' => 'playlist-video-2'
-              }
-            }
-          }
-        ]
-      })
-
-      expect(client).to receive(:videos).with(
-        satisfy do |ids|
-          ids.sort == ['playlist-video-1', 'playlist-video-2', 'search-video-1']
-        end
-      ).and_return({ 'items' => [] })
-
-      sync.sync!
-    end
-
-    it 'creates a YouTube post with default tags and no_deerjikist when no deerjikist mapping exists' do
-      Tag.tagme
-      Tag.bot
-      Tag.youtube
-      Tag.video
-      Tag.no_deerjikist
-
-      allow(sync).to receive(:query_terms).and_return([])
-      allow(sync).to receive(:playlist_ids).and_return(['PL123'])
-
-      allow(client).to receive(:playlist_items).with(
-        playlist_id: 'PL123',
-        page_token: nil
-      ).and_return({
-        'items' => [
-          {
-            'contentDetails' => {
-              'videoId' => 'video-1'
-            }
-          }
-        ]
-      })
-
-      allow(client).to receive(:videos).with(['video-1']).and_return({
-        'items' => [
-          youtube_video_item(
-            id: 'video-1',
-            title: 'YouTube テスト動画',
-            channel_id: 'UC_NO_MAPPING'
-          )
-        ]
-      })
-
-      expect do
-        sync.sync!
-      end.to change(Post, :count).by(1)
-
-      post = Post.find_by!(url: 'https://www.youtube.com/watch?v=video-1')
-      tag_ids = post.tags.pluck(:id)
-
-      expect(post.title).to eq('YouTube テスト動画')
-      expect(post.uploaded_user_id).to be_nil
-      expect(post.original_created_from).to eq(Time.zone.parse('2026-05-01 12:34:00'))
-      expect(post.original_created_before).to eq(Time.zone.parse('2026-05-01 12:35:00'))
-
-      expect(tag_ids).to include(Tag.tagme.id)
-      expect(tag_ids).to include(Tag.bot.id)
-      expect(tag_ids).to include(Tag.youtube.id)
-      expect(tag_ids).to include(Tag.video.id)
-      expect(tag_ids).to include(Tag.no_deerjikist.id)
-
-      expect(PostVersionRecorder).to have_received(:record!).with(
-        post:,
-        event_type: :create,
-        created_by_user: nil
-      )
-    end
-
-    it 'uses deerjikist tag when channel id is mapped' do
-      Tag.tagme
-      Tag.bot
-      Tag.youtube
-      Tag.video
-      Tag.no_deerjikist
-
-      deerjikist_tag = Tag.find_or_create_by_tag_name!('テスト投稿者', category: :deerjikist)
-      Deerjikist.create!(
-        platform: 'youtube',
-        code: 'UC_MAPPED',
-        tag: deerjikist_tag
-      )
-
-      allow(sync).to receive(:query_terms).and_return([])
-      allow(sync).to receive(:playlist_ids).and_return(['PL123'])
-
-      allow(client).to receive(:playlist_items).with(
-        playlist_id: 'PL123',
-        page_token: nil
-      ).and_return({
-        'items' => [
-          {
-            'contentDetails' => {
-              'videoId' => 'video-1'
-            }
-          }
-        ]
-      })
-
-      allow(client).to receive(:videos).with(['video-1']).and_return({
-        'items' => [
-          youtube_video_item(
-            id: 'video-1',
-            title: 'YouTube テスト動画',
-            channel_id: 'UC_MAPPED'
-          )
-        ]
-      })
-
-      sync.sync!
-
-      post = Post.find_by!(url: 'https://www.youtube.com/watch?v=video-1')
-      tag_ids = post.tags.pluck(:id)
-
-      expect(tag_ids).to include(deerjikist_tag.id)
-      expect(tag_ids).not_to include(Tag.no_deerjikist.id)
-    end
-
-    it 'removes no_deerjikist when deerjikist mapping is added later' do
-      Tag.no_deerjikist
-
-      post = Post.create!(
-        title: '旧タイトル',
-        url: 'https://www.youtube.com/watch?v=video-1',
-        uploaded_user_id: nil,
-        original_created_from: Time.zone.parse('2026-05-01 00:00:00'),
-        original_created_before: Time.zone.parse('2026-05-01 00:01:00')
-      )
-      PostTag.create!(post:, tag: Tag.no_deerjikist)
-
-      deerjikist_tag = Tag.find_or_create_by_tag_name!('後から判明した投稿者', category: :deerjikist)
-      Deerjikist.create!(
-        platform: 'youtube',
-        code: 'UC_MAPPED_LATER',
-        tag: deerjikist_tag
-      )
-
-      allow(sync).to receive(:query_terms).and_return([])
-      allow(sync).to receive(:playlist_ids).and_return(['PL123'])
-
-      allow(client).to receive(:playlist_items).with(
-        playlist_id: 'PL123',
-        page_token: nil
-      ).and_return({
-        'items' => [
-          {
-            'contentDetails' => {
-              'videoId' => 'video-1'
-            }
-          }
-        ]
-      })
-
-      allow(client).to receive(:videos).with(['video-1']).and_return({
-        'items' => [
-          youtube_video_item(
-            id: 'video-1',
-            title: '新タイトル',
-            channel_id: 'UC_MAPPED_LATER'
-          )
-        ]
-      })
-
-      sync.sync!
-
-      post.reload
-      tag_ids = post.tags.pluck(:id)
-
-      expect(post.title).to eq('新タイトル')
-      expect(tag_ids).to include(deerjikist_tag.id)
-      expect(tag_ids).not_to include(Tag.no_deerjikist.id)
-
-      expect(PostVersionRecorder).to have_received(:ensure_snapshot!).with(
-        post,
-        created_by_user: nil
-      )
-      expect(PostVersionRecorder).to have_received(:record!).with(
-        post:,
-        event_type: :update,
-        created_by_user: nil
-      )
-    end
-
-    it 'matches existing youtu.be URL and does not create duplicate post' do
-      post = Post.create!(
-        title: '旧タイトル',
-        url: 'https://youtu.be/video-1',
-        uploaded_user_id: nil,
-        original_created_from: Time.zone.parse('2026-05-01 00:00:00'),
-        original_created_before: Time.zone.parse('2026-05-01 00:01:00')
-      )
-
-      allow(sync).to receive(:query_terms).and_return([])
-      allow(sync).to receive(:playlist_ids).and_return(['PL123'])
-
-      allow(client).to receive(:playlist_items).with(
-        playlist_id: 'PL123',
-        page_token: nil
-      ).and_return({
-        'items' => [
-          {
-            'contentDetails' => {
-              'videoId' => 'video-1'
-            }
-          }
-        ]
-      })
-
-      allow(client).to receive(:videos).with(['video-1']).and_return({
-        'items' => [
-          youtube_video_item(
-            id: 'video-1',
-            title: '新タイトル',
-            channel_id: 'UC_NO_MAPPING'
-          )
-        ]
-      })
-
-      expect do
-        sync.sync!
-      end.not_to change(Post, :count)
-
-      expect(post.reload.title).to eq('新タイトル')
-    end
-  end
-
-  def youtube_video_item(id:, title:, channel_id:)
-    {
-      'id' => id,
-      'snippet' => {
-        'title' => title,
-        'channelId' => channel_id,
-        'publishedAt' => '2026-05-01T12:34:56Z',
-        'thumbnails' => {
-          'high' => {
-            'url' => "https://img.youtube.com/#{id}.jpg"
-          }
-        },
-        'tags' => ['tag-a', 'tag-b']
-      }
-    }
-  end
-end

backend/spec/services/youtube/video_item_spec.rb

@@ -1,93 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Youtube::VideoItem do
-  describe '#initialize' do
-    it 'extracts fields from YouTube video API item' do
-      item = {
-        'id' => 'video-1',
-        'snippet' => {
-          'title' => 'テスト動画',
-          'channelId' => 'UC123',
-          'publishedAt' => '2026-05-01T12:34:56Z',
-          'tags' => ['tag-a', 'tag-b'],
-          'thumbnails' => {
-            'high' => {
-              'url' => 'https://img.youtube.com/high.jpg'
-            },
-            'medium' => {
-              'url' => 'https://img.youtube.com/medium.jpg'
-            }
-          }
-        }
-      }
-
-      video = described_class.new(item)
-
-      expect(video.id).to eq('video-1')
-      expect(video.title).to eq('テスト動画')
-      expect(video.channel_id).to eq('UC123')
-      expect(video.published_at).to eq(Time.iso8601('2026-05-01T12:34:56Z'))
-      expect(video.thumbnail_url).to eq('https://img.youtube.com/high.jpg')
-      expect(video.raw_tags).to eq(['tag-a', 'tag-b'])
-      expect(video.url).to eq('https://www.youtube.com/watch?v=video-1')
-    end
-
-    it 'uses highest priority thumbnail' do
-      item = {
-        'id' => 'video-1',
-        'snippet' => {
-          'title' => 'テスト動画',
-          'channelId' => 'UC123',
-          'publishedAt' => '2026-05-01T12:34:56Z',
-          'thumbnails' => {
-            'default' => {
-              'url' => 'https://img.youtube.com/default.jpg'
-            },
-            'standard' => {
-              'url' => 'https://img.youtube.com/standard.jpg'
-            },
-            'maxres' => {
-              'url' => 'https://img.youtube.com/maxres.jpg'
-            }
-          }
-        }
-      }
-
-      video = described_class.new(item)
-
-      expect(video.thumbnail_url).to eq('https://img.youtube.com/maxres.jpg')
-    end
-
-    it 'falls back to empty raw tags' do
-      item = {
-        'id' => 'video-1',
-        'snippet' => {
-          'title' => 'テスト動画',
-          'channelId' => 'UC123',
-          'publishedAt' => '2026-05-01T12:34:56Z',
-          'thumbnails' => {}
-        }
-      }
-
-      video = described_class.new(item)
-
-      expect(video.raw_tags).to eq([])
-    end
-
-    it 'returns nil thumbnail when no thumbnail exists' do
-      item = {
-        'id' => 'video-1',
-        'snippet' => {
-          'title' => 'テスト動画',
-          'channelId' => 'UC123',
-          'publishedAt' => '2026-05-01T12:34:56Z',
-          'thumbnails' => {}
-        }
-      }
-
-      video = described_class.new(item)
-
-      expect(video.thumbnail_url).to be_nil
-    end
-  end
-end

backend/spec/tasks/post_sync_spec.rb

@@ -1,25 +0,0 @@
-require 'rails_helper'
-require 'rake'
-
-RSpec.describe 'post:sync' do
-  around do |example|
-    original_application = Rake.application
-    Rake.application = Rake::Application.new
-
-    Rake::Task.define_task(:environment)
-    load Rails.root.join('lib/tasks/sync_posts.rake')
-
-    example.run
-  ensure
-    Rake.application = original_application
-  end
-
-  it 'runs Youtube::Sync' do
-    sync = instance_double(Youtube::Sync)
-
-    expect(Youtube::Sync).to receive(:new).once.and_return(sync)
-    expect(sync).to receive(:sync!).once
-
-    Rake::Task['post:sync'].invoke
-  end
-end