#268

backend/app/controllers/materials_controller.rb

@@ -89,13 +89,15 @@ class MaterialsController < ApplicationController
 
     begin
       Material.transaction do
-        tag = resolve_material_tag!(tag_name_raw)
+        tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
+        tag = tag_name.tag
+        tag = Tag.create!(tag_name:, category: :material) unless tag
+
         material = Material.new(tag:, url:,
                                 created_by_user: current_user,
                                 updated_by_user: current_user)
         material.file.attach(uploaded_blob) if uploaded_blob
         material.save!
-        TagVersioning.record_tag_snapshot!(tag, created_by_user: current_user)
         upsert_export_paths!(material)
         MaterialVersionRecorder.record!(material:, event_type: :create,
                                         created_by_user: current_user)
@@ -137,7 +139,10 @@ class MaterialsController < ApplicationController
     begin
       Material.transaction do
         MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: current_user)
-        tag = resolve_material_tag!(tag_name_raw)
+        tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
+        tag = tag_name.tag
+        tag = Tag.create!(tag_name:, category: :material) unless tag
+
         material.assign_attributes(tag:, url:, updated_by_user: current_user)
         if uploaded_blob
           material.file.attach(uploaded_blob)
@@ -145,7 +150,6 @@ class MaterialsController < ApplicationController
           material.file.detach
         end
         material.save!
-        TagVersioning.record_tag_snapshot!(tag, created_by_user: current_user)
         upsert_export_paths!(material)
         MaterialVersionRecorder.record!(material:, event_type: :update,
                                         created_by_user: current_user)
@@ -236,12 +240,6 @@ class MaterialsController < ApplicationController
     nil
   end
 
-  def resolve_material_tag! tag_name_raw
-    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
-    tag = tag_name.tag
-    tag || Tag.create!(tag_name:, category: :material)
-  end
-
   def material_index_needs_tag_name? filters
     filters[:q].present? || filters[:sort] == 'tag_name'
   end

backend/app/controllers/preview_controller.rb

@@ -1,57 +1,50 @@
 class PreviewController < ApplicationController
-  before_action :require_member!
-
   def title
-    return render_bad_request('URL は必須です．') if params[:url].blank?
+    # TODO: # 既知サイトなら決まったフォーマットで title 取得するやぅに．
+    return head :unauthorized unless current_user
 
-    render json: { title: Preview::ThumbnailFetcher.title(params[:url]) }
-  rescue Preview::UrlSafety::UnsafeUrl => e
+    url = params[:url]
+    return render_bad_request('URL は必須です．') unless url.present?
+
+    unless url.start_with?(/http(s)?:\/\//)
+      url = 'http://' + url
+    end
+
+    html = URI.open(url, open_timeout: 5, read_timeout: 5).read
+    doc = Nokogiri::HTML.parse(html)
+    title = doc.at('title')&.text&.strip
+
+    render json: { title: title }
+  rescue => e
     render_bad_request(e.message)
-  rescue Preview::HttpFetcher::FetchTimeout => e
-    render_preview_error(e.message, :gateway_timeout)
-  rescue Preview::HttpFetcher::ResponseTooLarge => e
-    render_preview_error(e.message, :payload_too_large)
-  rescue Preview::HttpFetcher::FetchFailed => e
-    render_preview_error(e.message, :bad_gateway)
   end
 
   def thumbnail
-    return render_bad_request('URL は必須です．') if params[:url].blank?
+    # TODO: 既知ドメインであれば指定のアドレスからサムネールを取得するやぅにする．
 
-    image = MiniMagick::Image.read(Preview::ThumbnailFetcher.fetch(params[:url]))
-    image.auto_orient
-    image.resize '180x180>'
-    image.format 'png'
-    width, height = image.dimensions
-    raise Preview::ThumbnailFetcher::GenerationFailed, 'サムネール画像の変換に失敗しました．' if width > 180 || height > 180
-
-    send_data image.to_blob, type: 'image/png', disposition: 'inline'
-  rescue Preview::UrlSafety::UnsafeUrl => e
-    render_bad_request(e.message)
-  rescue Preview::HttpFetcher::FetchTimeout => e
-    render_preview_error(e.message, :gateway_timeout)
-  rescue Preview::HttpFetcher::ResponseTooLarge => e
-    render_preview_error(e.message, :payload_too_large)
-  rescue Preview::HttpFetcher::FetchFailed => e
-    render_preview_error(e.message, :bad_gateway)
-  rescue Preview::ThumbnailFetcher::GenerationFailed, MiniMagick::Error => e
-    render_unprocessable_entity(e.message)
-  end
-
-  private
-
-  def require_member!
     return head :unauthorized unless current_user
-    return if current_user.gte_member?
 
-    head :forbidden
-  end
+    url = params[:url]
+    return render_bad_request('URL は必須です．') if url.blank?
 
-  def render_preview_error(message, status)
-    render json: { type: status.to_s,
-                   message:,
-                   errors: { },
-                   base_errors: [message] },
-           status:
+    unless url.start_with?(/http(s)?:\/\//)
+      url = 'http://' + url
+    end
+
+    path = Rails.root.join('tmp', "thumb_#{ SecureRandom.hex }.png")
+    system("node #{ Rails.root }/lib/screenshot.js #{ Shellwords.escape(url) } #{ path }")
+
+    if File.exist?(path)
+      image = MiniMagick::Image.open(path)
+      image.resize '180x180'
+      File.delete(path) rescue nil
+      send_file image.path, type: 'image/png', disposition: 'inline'
+    else
+      render json: { type: 'internal_server_error',
+                     message: 'サムネールを生成できませんでした．',
+                     errors: { },
+                     base_errors: ['サムネールを生成できませんでした．'] },
+             status: :internal_server_error
+    end
   end
 end

backend/app/models/post.rb

@@ -57,9 +57,9 @@ class Post < ApplicationRecord
 
   attribute :version_no, :integer, default: 1
 
-  before_validation :normalise_url, if: :will_save_change_to_url?
+  before_validation :normalise_url
 
-  validates :url, presence: true, uniqueness: true, length: { maximum: 768 }
+  validates :url, presence: true, uniqueness: true
   validates :video_ms, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
 
   validate :validate_original_created_range
@@ -180,7 +180,7 @@ class Post < ApplicationRecord
 
     u.host = u.host.downcase if u.host
     u.path = u.path.sub(/\/\Z/, '') if u.path.present?
-    self.url = PostUrlSanitisationRule.sanitise(u.to_s)
+    self.url = u.to_s
   rescue URI::InvalidURIError
     ;
   end

backend/app/models/post_url_sanitisation_rule.rb

@@ -1,163 +0,0 @@
-class PostUrlSanitisationRule < ApplicationRecord
-  include Discard::Model
-
-  class InvalidUrlError < StandardError
-    attr_reader :invalid_rows
-
-    def initialize(invalid_rows)
-      @invalid_rows = invalid_rows
-      ids = invalid_rows.map { _1.fetch(:post_id) }.join(', ')
-      super("post URL sanitisation produced invalid URLs for posts #{ ids }")
-    end
-  end
-
-  class UrlConflictError < StandardError
-    attr_reader :conflicts
-
-    def initialize(conflicts)
-      @conflicts = conflicts
-      urls = conflicts.map { _1.fetch(:url) }.uniq.join(', ')
-      super("post URL sanitisation conflicts detected for #{ urls }")
-    end
-  end
-
-  self.primary_key = :priority
-
-  default_scope -> { kept }
-
-  validates :source_pattern, presence: true, uniqueness: true
-
-  validate :source_pattern_must_be_regexp
-
-  class << self
-    def sanitise(url) = sanitise_with_rules(url, rules)
-
-    def apply!
-      rewrites = nil
-
-      Post.transaction do
-        compiled_rules = rules
-
-        rewrites = Post.order(:id)
-                       .lock('FOR UPDATE')
-                       .pluck(:id, :url)
-                       .map do |post_id, original_url|
-          { post_id:,
-            original_url:,
-            sanitised_url: sanitise_with_rules(original_url, compiled_rules) }
-        end
-
-        invalid_rows = rewrites.filter { invalid_sanitised_url?(_1.fetch(:sanitised_url)) }
-                               .map { { post_id: _1.fetch(:post_id),
-                                        original_url: _1.fetch(:original_url),
-                                        sanitised_url: _1.fetch(:sanitised_url) } }
-        raise InvalidUrlError.new(invalid_rows) if invalid_rows.present?
-
-        conflicts = build_conflicts(rewrites)
-        raise UrlConflictError.new(conflicts) if conflicts.present?
-
-        changed = rewrites.filter { _1.fetch(:original_url) != _1.fetch(:sanitised_url) }
-        return if changed.empty?
-
-        token = SecureRandom.hex(6)
-
-        changed.each do |row|
-          Post.where(id: row.fetch(:post_id))
-              .update_all(url: temporary_url_for(row.fetch(:post_id), token))
-        end
-
-        changed.each do |row|
-          Post.where(id: row.fetch(:post_id))
-              .update_all(url: row.fetch(:sanitised_url))
-        end
-      end
-    rescue ActiveRecord::RecordNotUnique => error
-      conflicts = build_persisted_conflicts(rewrites)
-      raise error if conflicts.empty?
-
-      raise UrlConflictError.new(conflicts), cause: error
-    end
-
-    private
-
-    def rules = kept.order(:priority).map { |r| [Regexp.new(r.source_pattern), r.replacement] }
-
-    def sanitise_with_rules(url, compiled_rules)
-      compiled_rules.reduce(url.dup) do |value, (pattern, replacement)|
-        value.sub(pattern, replacement)
-      end
-    end
-
-    def temporary_url_for(post_id, token) =
-        "https://post-url-sanitising.invalid/#{ token }/#{ post_id }"
-
-    def invalid_sanitised_url?(url)
-      return true if url.blank?
-      return true if url.length > 768
-
-      parsed = URI.parse(url)
-      return true if !(parsed in URI::HTTP)
-      return true if parsed.host.blank?
-
-      false
-    rescue URI::InvalidURIError
-      true
-    end
-
-    def build_conflicts(rewrites)
-      rewrites
-          .group_by { _1.fetch(:sanitised_url).downcase }
-          .values
-          .filter { _1.size > 1 }
-          .flatten
-          .map { { url: _1.fetch(:sanitised_url),
-                   post_id: _1.fetch(:post_id),
-                   original_url: _1.fetch(:original_url) } }
-    end
-
-    def build_persisted_conflicts(rewrites)
-      return [] if rewrites.blank?
-
-      target_rows = rewrites.filter { _1.fetch(:original_url) != _1.fetch(:sanitised_url) }
-      target_keys = target_rows.map { _1.fetch(:sanitised_url).downcase }.uniq
-      return [] if target_keys.empty?
-
-      target_pairs = target_rows.to_h do |row|
-        [row.fetch(:post_id), row.fetch(:sanitised_url).downcase]
-      end
-
-      persisted_rows = Post.order(:id)
-                           .where('LOWER(url) IN (?)', target_keys)
-                           .pluck(:id, :url)
-                           .reject { |post_id, original_url| target_pairs[post_id] == original_url.downcase }
-                           .map { |post_id, original_url|
-        { url: original_url,
-          post_id:,
-          original_url:,
-          conflict_key: original_url.downcase }
-      }
-
-      target_conflicts = target_rows.map { { url: _1.fetch(:sanitised_url),
-                                             post_id: _1.fetch(:post_id),
-                                             original_url: _1.fetch(:original_url),
-                                             conflict_key: _1.fetch(:sanitised_url).downcase } }
-
-      (persisted_rows + target_conflicts)
-          .group_by { _1.fetch(:conflict_key) }
-          .values
-          .filter { _1.size > 1 }
-          .flatten
-          .map { _1.except(:conflict_key) }
-    end
-  end
-
-  private
-
-  def source_pattern_must_be_regexp
-    return if source_pattern.blank?
-
-    Regexp.new(source_pattern)
-  rescue RegexpError
-    errors.add :source_pattern, '変な正規表現だね〜（笑）'
-  end
-end

backend/app/services/preview/html_metadata_extractor.rb

@@ -1,21 +0,0 @@
-module Preview
-  class HtmlMetadataExtractor
-    IMAGE_SELECTORS = [
-      'meta[property="og:image"]',
-      'meta[name="twitter:image"]',
-      'meta[name="thumbnail"]'
-    ].freeze
-
-    def self.extract(response)
-      document = Nokogiri::HTML.parse(response.body)
-      image_url = IMAGE_SELECTORS.filter_map {
-        document.at_css(_1)&.[]('content')&.strip.presence
-      }.first
-
-      { title: document.at_css('title')&.text&.strip,
-        image_url: image_url ? URI.join(response.url, image_url).to_s : nil }
-    rescue URI::InvalidURIError
-      { title: document.at_css('title')&.text&.strip, image_url: nil }
-    end
-  end
-end

backend/app/services/preview/http_fetcher.rb

@@ -1,122 +0,0 @@
-require 'net/http'
-require 'json'
-
-module Preview
-  class HttpFetcher
-    class FetchFailed < StandardError; end
-    class FetchTimeout < FetchFailed; end
-    class ResponseTooLarge < FetchFailed; end
-
-    MAX_REDIRECTS = 5
-    DEFAULT_MAX_BYTES = 5.megabytes
-
-    Response = Data.define(:body, :content_type, :url)
-
-    def self.fetch(raw_url, max_bytes: DEFAULT_MAX_BYTES, redirects: MAX_REDIRECTS)
-      uri, addresses = UrlSafety.validate(raw_url)
-      response = request(uri, addresses.first, max_bytes)
-
-      if response.is_a?(Net::HTTPRedirection)
-        location = response['location']
-        if redirects.zero?
-          log_failure(:redirect_limit,
-                      url: uri.to_s,
-                      redirects:,
-                      location:,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'])
-          raise FetchFailed, 'redirect が多すぎます．'
-        end
-
-        if location.blank?
-          log_failure(:blank_redirect_location,
-                      url: uri.to_s,
-                      redirects:,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'])
-          raise FetchFailed, 'redirect 先が不正です．'
-        end
-
-        redirect_url =
-            begin
-              URI.join(uri, location).to_s
-            rescue URI::InvalidURIError => e
-              log_failure(:invalid_redirect_location,
-                          url: uri.to_s,
-                          redirects:,
-                          location:,
-                          error: e.class.name,
-                          message: e.message)
-              raise FetchFailed, 'redirect 先が不正です．'
-            end
-
-        return fetch(redirect_url, max_bytes:, redirects: redirects - 1)
-      end
-
-      unless response.is_a?(Net::HTTPSuccess)
-        log_failure(:http_status,
-                    url: uri.to_s,
-                    code: response.code,
-                    content_type: response['content-type'],
-                    content_length: response['content-length'])
-        raise FetchFailed, "外部サーバーが HTTP #{ response.code } を返しました．"
-      end
-
-      Response.new(response.body, response['content-type'].to_s, uri.to_s)
-    rescue Net::OpenTimeout, Net::ReadTimeout, Timeout::Error => e
-      log_failure(:timeout, url: uri&.to_s || raw_url, error: e.class.name, message: e.message)
-      raise FetchTimeout, e.message
-    rescue SocketError, SystemCallError, OpenSSL::SSL::SSLError, EOFError => e
-      log_failure(:network_error, url: uri&.to_s || raw_url, error: e.class.name, message: e.message)
-      raise FetchFailed, e.message
-    end
-
-    def self.request(uri, ip_address, max_bytes)
-      http = Net::HTTP.new(uri.host, uri.port)
-      http.ipaddr = ip_address
-      http.use_ssl = uri.scheme == 'https'
-      http.open_timeout = 5
-      http.read_timeout = 8
-      http.write_timeout = 5
-
-      request = Net::HTTP::Get.new(uri)
-      request['User-Agent'] = 'BTRC-Hub thumbnail preview'
-      request['Accept'] = 'text/html,image/*;q=0.9,*/*;q=0.1'
-
-      http.request(request) do |response|
-        length = response['content-length'].to_i
-        if length > max_bytes
-          log_failure(:response_too_large,
-                      url: uri.to_s,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'],
-                      max_bytes:)
-          raise ResponseTooLarge, '外部データが大きすぎます．'
-        end
-
-        body = +''
-        response.read_body do |chunk|
-          body << chunk
-          next unless body.bytesize > max_bytes
-
-          log_failure(:response_too_large,
-                      url: uri.to_s,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'],
-                      bytes_read: body.bytesize,
-                      max_bytes:)
-          raise ResponseTooLarge, '外部データが大きすぎます．'
-        end
-        response.instance_variable_set(:@body, body)
-        response.instance_variable_set(:@read, true)
-        return response
-      end
-    end
-
-    def self.log_failure(reason, **payload)
-      Rails.logger.warn("preview_http_fetcher_failure #{ { reason:, **payload }.to_json }")
-    end
-
-    private_class_method :request, :log_failure
-  end
-end

backend/app/services/preview/known_site_extractor.rb

@@ -1,31 +0,0 @@
-module Preview
-  class KnownSiteExtractor
-    def self.thumbnail_url(uri)
-      youtube_thumbnail(uri)
-    end
-
-    def self.niconico_video_id(uri)
-      case uri.host&.downcase
-      when 'www.nicovideo.jp', 'nicovideo.jp'
-        uri.path[%r{\A/watch/(sm\d+)\z}, 1]
-      when 'nico.ms'
-        uri.path[%r{\A/(sm\d+)\z}, 1]
-      end
-    end
-
-    def self.youtube_thumbnail(uri)
-      id =
-          case uri.host&.downcase
-          when 'youtu.be'
-            uri.path.split('/').reject(&:blank?).first
-          when 'www.youtube.com', 'youtube.com', 'm.youtube.com'
-            uri.path == '/watch' ? URI.decode_www_form(uri.query.to_s).to_h['v'] : nil
-          end
-      return unless id&.match?(/\A[A-Za-z0-9_-]{6,20}\z/)
-
-      "https://i.ytimg.com/vi/#{ id }/hqdefault.jpg"
-    end
-
-    private_class_method :youtube_thumbnail
-  end
-end

backend/app/services/preview/thumbnail_fetcher.rb

@@ -1,95 +0,0 @@
-module Preview
-  class ThumbnailFetcher
-    class GenerationFailed < StandardError; end
-    ALLOWED_IMAGE_CONTENT_TYPES = [
-      'image/jpeg', 'image/png', 'image/gif', 'image/webp'
-    ].freeze
-    HTML_MAX_BYTES = 1.megabyte
-    NICONICO_XML_MAX_BYTES = 256.kilobytes
-
-    def self.fetch(raw_url)
-      uri, = UrlSafety.validate(raw_url)
-
-      known_url = KnownSiteExtractor.thumbnail_url(uri)
-      image = fetch_image_or_nil(known_url) if known_url
-      return image if image
-
-      niconico_url = niconico_thumbnail_url(uri)
-      image = fetch_image_or_nil(niconico_url) if niconico_url
-      return image if image
-
-      page = HttpFetcher.fetch(uri.to_s, max_bytes: HTML_MAX_BYTES)
-      metadata = HtmlMetadataExtractor.extract(page)
-      raise GenerationFailed, 'サムネール画像が見つかりませんでした．' if metadata[:image_url].blank?
-
-      fetch_image!(metadata[:image_url])
-    end
-
-    def self.title(raw_url)
-      uri, = UrlSafety.validate(raw_url)
-      HtmlMetadataExtractor.extract(
-          HttpFetcher.fetch(uri.to_s, max_bytes: HTML_MAX_BYTES))[:title]
-    end
-
-    def self.fetch_image_or_nil(url)
-      return nil if url.blank?
-
-      response = HttpFetcher.fetch(url)
-      return nil unless allowed_image_content_type?(response.content_type)
-
-      response.body
-    rescue HttpFetcher::FetchTimeout
-      raise
-    rescue HttpFetcher::FetchFailed
-      nil
-    end
-
-    def self.fetch_image!(url)
-      response = HttpFetcher.fetch(url)
-      unless allowed_image_content_type?(response.content_type)
-        raise GenerationFailed, 'サムネール画像が見つかりませんでした．'
-      end
-
-      response.body
-    rescue HttpFetcher::FetchTimeout
-      raise
-    rescue HttpFetcher::ResponseTooLarge
-      raise
-    rescue HttpFetcher::FetchFailed
-      raise GenerationFailed, 'サムネール画像を取得できませんでした．'
-    end
-
-    def self.niconico_thumbnail_url(uri)
-      video_id = KnownSiteExtractor.niconico_video_id(uri)
-      return nil if video_id.blank?
-
-      response = HttpFetcher.fetch("https://ext.nicovideo.jp/api/getthumbinfo/#{ video_id }",
-                                   max_bytes: NICONICO_XML_MAX_BYTES)
-      xml = Nokogiri::XML(response.body)
-      return nil unless xml.at_xpath('/nicovideo_thumb_response/@status')&.value == 'ok'
-
-      xml.at_xpath('//thumbnail_url')&.text&.strip.presence
-    rescue HttpFetcher::FetchFailed, HttpFetcher::FetchTimeout => e
-      Rails.logger.info("preview_niconico_getthumbinfo_fallback #{ { url: uri.to_s,
-                                                                     video_id:,
-                                                                     error: e.class.name,
-                                                                     message: e.message }.to_json }")
-      nil
-    rescue Nokogiri::XML::SyntaxError => e
-      Rails.logger.info("preview_niconico_getthumbinfo_fallback #{ { url: uri.to_s,
-                                                                     video_id:,
-                                                                     error: e.class.name,
-                                                                     message: e.message }.to_json }")
-      nil
-    end
-
-    def self.allowed_image_content_type?(content_type)
-      mime_type = content_type.to_s.split(';', 2).first.downcase.strip
-      ALLOWED_IMAGE_CONTENT_TYPES.include?(mime_type)
-    end
-
-    private_class_method :fetch_image_or_nil, :fetch_image!,
-                         :niconico_thumbnail_url,
-                         :allowed_image_content_type?
-  end
-end

backend/app/services/preview/url_safety.rb

@@ -1,55 +0,0 @@
-require 'resolv'
-require 'ipaddr'
-require 'uri'
-
-module Preview
-  class UrlSafety
-    class UnsafeUrl < StandardError; end
-
-    FORBIDDEN_NETWORKS = [
-      '0.0.0.0/8', '10.0.0.0/8', '100.64.0.0/10', '127.0.0.0/8',
-      '169.254.0.0/16', '172.16.0.0/12', '192.0.0.0/24',
-      '192.0.2.0/24', '192.168.0.0/16', '198.18.0.0/15',
-      '198.51.100.0/24', '203.0.113.0/24', '224.0.0.0/4',
-      '240.0.0.0/4', '::/128', '::1/128', 'fc00::/7', 'fe80::/10',
-      'ff00::/8', '2001:db8::/32', '::ffff:0:0/96'
-    ].map { IPAddr.new(_1) }.freeze
-
-    def self.validate(raw_url)
-      value = raw_url.to_s.strip
-      if value.match?(/\A[a-z][a-z0-9+\-.]*:/i)
-        unless value.match?(/\Ahttps?:\/\//i)
-          raise UnsafeUrl, 'http または https の URL を指定してください．'
-        end
-      else
-        value = "http://#{ value }"
-      end
-      uri = URI.parse(value)
-
-      unless ['http', 'https'].include?(uri.scheme&.downcase) && uri.host.present?
-        raise UnsafeUrl, 'http または https の URL を指定してください．'
-      end
-      raise UnsafeUrl, 'userinfo つき URL は使用できません．' if uri.userinfo.present?
-
-      addresses = Resolv.getaddresses(uri.host)
-      raise UnsafeUrl, 'URL のホストを解決できません．' if addresses.empty?
-
-      parsed_addresses = addresses.map { IPAddr.new(_1) }
-      if parsed_addresses.any? { |address| forbidden?(address) }
-        raise UnsafeUrl, '安全でない接続先は使用できません．'
-      end
-
-      [uri, parsed_addresses.map(&:to_s)]
-    rescue Resolv::ResolvError
-      raise UnsafeUrl, 'URL のホストを解決できません．'
-    rescue URI::InvalidURIError, IPAddr::InvalidAddressError
-      raise UnsafeUrl, 'URL が不正です．'
-    end
-
-    def self.forbidden?(address)
-      FORBIDDEN_NETWORKS.any? { _1.include?(address) }
-    end
-
-    private_class_method :forbidden?
-  end
-end

backend/db/migrate/20260713000000_create_post_url_sanitisation_rules.rb

@@ -1,61 +0,0 @@
-class CreatePostUrlSanitisationRules < ActiveRecord::Migration[8.0]
-  class PostUrlSanitisationRule < ActiveRecord::Base
-    self.table_name = 'post_url_sanitisation_rules'
-  end
-
-  def up
-    create_table :post_url_sanitisation_rules, id: :integer, primary_key: :priority do |t|
-      t.string :source_pattern, null: false
-      t.string :replacement, null: false
-      t.timestamps
-      t.datetime :discarded_at
-
-      t.index :source_pattern, unique: true
-      t.index :discarded_at
-    end
-
-    now = Time.current
-
-    PostUrlSanitisationRule.insert_all!([
-        { priority: 10,
-          source_pattern: '\Ahttps?://youtu\.be/([^/?#]+)(?:[?#].*)?\z',
-          replacement: 'https://www.youtube.com/watch?v=\1',
-          created_at: now,
-          updated_at: now },
-        { priority: 20,
-          source_pattern: '\Ahttps?://(?:www\.|m\.)?youtube\.com/live/([^/?#]+)(?:[?#].*)?\z',
-          replacement: 'https://www.youtube.com/watch?v=\1',
-          created_at: now,
-          updated_at: now },
-        { priority: 30,
-          source_pattern: '\Ahttps?://(?:www\.|m\.)?youtube\.com/shorts/([^/?#]+)(?:[?#].*)?\z',
-          replacement: 'https://www.youtube.com/watch?v=\1',
-          created_at: now,
-          updated_at: now },
-        { priority: 40,
-          source_pattern: '\Ahttps?://(?:www\.|m\.)?youtube\.com/embed/([^/?#]+)(?:[?#].*)?\z',
-          replacement: 'https://www.youtube.com/watch?v=\1',
-          created_at: now,
-          updated_at: now },
-        { priority: 50,
-          source_pattern:
-              '\Ahttps?://(?:www\.|m\.)?youtube\.com/watch\?(?:[^#&]+&)*v=([^&#]+)(?:[&#].*)?\z',
-          replacement: 'https://www.youtube.com/watch?v=\1',
-          created_at: now,
-          updated_at: now },
-        { priority: 60,
-          source_pattern: '\Ahttps?://nico\.ms/([^/?#]+)(?:[?#].*)?\z',
-          replacement: 'https://www.nicovideo.jp/watch/\1',
-          created_at: now,
-          updated_at: now },
-        { priority: 70,
-          source_pattern: '\Ahttps?://(?:www\.)?nicovideo\.jp/watch/([^?#/]+)(?:[?#].*)?\z',
-          replacement: 'https://www.nicovideo.jp/watch/\1',
-          created_at: now,
-          updated_at: now }])
-  end
-
-  def down
-    drop_table :post_url_sanitisation_rules
-  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_07_13_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_07_05_000000) 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
@@ -331,16 +331,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_07_13_000000) do
     t.index ["tag_id"], name: "index_post_tags_on_tag_id"
   end
 
-  create_table "post_url_sanitisation_rules", primary_key: "priority", id: :integer, charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.string "source_pattern", null: false
-    t.string "replacement", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.datetime "discarded_at"
-    t.index ["discarded_at"], name: "index_post_url_sanitisation_rules_on_discarded_at"
-    t.index ["source_pattern"], name: "index_post_url_sanitisation_rules_on_source_pattern", unique: true
-  end
-
   create_table "post_versions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.integer "version_no", null: false

backend/db/seeds.rb

@@ -8,43 +8,6 @@
 #     MovieGenre.find_or_create_by!(name: genre_name)
 #   end
 
-post_url_sanitisation_rules = [
-  { priority: 10,
-    source_pattern: '\Ahttps?://youtu\.be/([^/?#]+)(?:[?#].*)?\z',
-    replacement: 'https://www.youtube.com/watch?v=\1' },
-  { priority: 20,
-    source_pattern: '\Ahttps?://(?:www\.|m\.)?youtube\.com/live/([^/?#]+)(?:[?#].*)?\z',
-    replacement: 'https://www.youtube.com/watch?v=\1' },
-  { priority: 30,
-    source_pattern: '\Ahttps?://(?:www\.|m\.)?youtube\.com/shorts/([^/?#]+)(?:[?#].*)?\z',
-    replacement: 'https://www.youtube.com/watch?v=\1' },
-  { priority: 40,
-    source_pattern: '\Ahttps?://(?:www\.|m\.)?youtube\.com/embed/([^/?#]+)(?:[?#].*)?\z',
-    replacement: 'https://www.youtube.com/watch?v=\1' },
-  { priority: 50,
-    source_pattern:
-        '\Ahttps?://(?:www\.|m\.)?youtube\.com/watch\?(?:[^#&]+&)*v=([^&#]+)(?:[&#].*)?\z',
-    replacement: 'https://www.youtube.com/watch?v=\1' },
-  { priority: 60,
-    source_pattern: '\Ahttps?://nico\.ms/([^/?#]+)(?:[?#].*)?\z',
-    replacement: 'https://www.nicovideo.jp/watch/\1' },
-  { priority: 70,
-    source_pattern: '\Ahttps?://(?:www\.)?nicovideo\.jp/watch/([^?#/]+)(?:[?#].*)?\z',
-    replacement: 'https://www.nicovideo.jp/watch/\1' }
-]
-
-post_url_sanitisation_rule_scope = PostUrlSanitisationRule.unscoped
-
-post_url_sanitisation_rules.each do |attributes|
-  priority = attributes.fetch(:priority)
-  source_pattern = attributes.fetch(:source_pattern)
-
-  next if post_url_sanitisation_rule_scope.exists?(priority:)
-  next if post_url_sanitisation_rule_scope.exists?(source_pattern:)
-
-  post_url_sanitisation_rule_scope.create!(attributes)
-end
-
 material_sync_source_uri = ENV['MATERIAL_SYNC_SOURCE_URI']
 material_sync_source_file_id = ENV['MATERIAL_SYNC_SOURCE_FILE_ID']
 

backend/lib/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "lib",
+  "version": "1.0.0",
+  "main": "screenshot.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "description": "",
+  "dependencies": {
+    "puppeteer": "^24.10.0"
+  }
+}

backend/lib/screenshot.js

@@ -0,0 +1,18 @@
+const puppeteer = require ('puppeteer')
+const fs = require ('fs')
+
+
+void (async () => {
+  const url = process.argv[2]
+  const output = process.argv[3]
+
+  const browser = await puppeteer.launch ({
+      args: ['--no-sandbox', '--disable-setuid-sandbox'] })
+
+  const page = await browser.newPage ()
+  await page.setViewport ({ width: 960, height: 960 })
+  await page.goto (url, { waitUntil: 'networkidle2', timeout: 15000 })
+
+  await page.screenshot ({ path: output })
+  await browser.close ()
+}) ()

backend/spec/db/seeds_spec.rb

@@ -1,65 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe 'database seeds' do
-  before do
-    PostUrlSanitisationRule.unscoped.delete_all
-  end
-
-  it 'registers the initial post URL sanitisation rules' do
-    load_seeds
-
-    urls = {
-      'https://youtu.be/abc123?si=share' => youtube_url('abc123'),
-      'https://www.youtube.com/live/abc123?t=10' => youtube_url('abc123'),
-      'https://youtube.com/shorts/abc123?feature=share' => youtube_url('abc123'),
-      'https://m.youtube.com/embed/abc123' => youtube_url('abc123'),
-      'https://youtube.com/watch?feature=share&v=abc123&t=10' => youtube_url('abc123'),
-      'https://nico.ms/sm123?from=share#fragment' => nico_url('sm123'),
-      'https://www.nicovideo.jp/watch/sm123?ref=share#fragment' => nico_url('sm123')
-    }
-
-    expect(PostUrlSanitisationRule.count).to eq(7)
-    urls.each do |url, canonical_url|
-      expect(PostUrlSanitisationRule.sanitise(url)).to eq(canonical_url)
-    end
-  end
-
-  it 'does not overwrite or restore an existing rule' do
-    rule = PostUrlSanitisationRule.create!(
-      priority: 10,
-      source_pattern: '\Ahttps://example\.com/custom\z',
-      replacement: 'https://example.com/replacement'
-    )
-    rule.discard!
-    original_attributes = rule.reload.attributes
-
-    2.times { load_seeds }
-
-    persisted_rule = PostUrlSanitisationRule.unscoped.find(10)
-    expect(persisted_rule.attributes).to eq(original_attributes)
-    expect(PostUrlSanitisationRule.unscoped.count).to eq(7)
-  end
-
-  it 'does not duplicate a rule moved to another priority' do
-    source_pattern = '\Ahttps?://youtu\.be/([^/?#]+)(?:[?#].*)?\z'
-    PostUrlSanitisationRule.create!(
-      priority: 80,
-      source_pattern:,
-      replacement: 'https://example.com/custom/\1'
-    )
-
-    load_seeds
-
-    rules = PostUrlSanitisationRule.unscoped
-    expect(rules.where(source_pattern:).count).to eq(1)
-    expect(rules.find(80).replacement).to eq('https://example.com/custom/\1')
-  end
-
-  def load_seeds
-    load Rails.root.join('db/seeds.rb')
-  end
-
-  def youtube_url(video_id) = "https://www.youtube.com/watch?v=#{ video_id }"
-
-  def nico_url(video_id) = "https://www.nicovideo.jp/watch/#{ video_id }"
-end

backend/spec/models/post_spec.rb

@@ -1,68 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Post, type: :model do
-  before do
-    PostUrlSanitisationRule.unscoped.delete_all
-  end
-
-  describe 'URL normalisation' do
-    it 'normalises the HTTP URL before applying sanitisation rules' do
-      PostUrlSanitisationRule.create!(
-        priority: 10,
-        source_pattern: '\\Ahttps://example\\.com/videos/([^/]+)\\z',
-        replacement: 'https://example.com/watch/\\1'
-      )
-
-      post = described_class.create!(
-        title: 'normalised URL',
-        url: '  https://EXAMPLE.com/videos/123/  '
-      )
-
-      expect(post.url).to eq('https://example.com/watch/123')
-    end
-
-    it 'does not normalise an unchanged URL when another attribute changes' do
-      post = create(:post)
-      post.update_column(:url, 'https://EXAMPLE.com/unchanged/')
-
-      post.update!(title: 'updated title')
-
-      expect(post.reload.url).to eq('https://EXAMPLE.com/unchanged/')
-    end
-
-    it 'validates the sanitised URL length' do
-      path = 'a' * 375
-
-      PostUrlSanitisationRule.create!(
-        priority: 10,
-        source_pattern: '\\Ahttps://example\\.com/(a+)\\z',
-        replacement: 'https://example.com/\\1\\1'
-      )
-
-      post = described_class.new(
-        title: 'long URL',
-        url: "https://example.com/#{ path }"
-      )
-
-      expect(post).to be_invalid
-      expect(post.errors.details.fetch(:url)).to include(
-        error: :too_long,
-        count: 768
-      )
-    end
-
-    it 'validates uniqueness after sanitisation' do
-      PostUrlSanitisationRule.create!(
-        priority: 10,
-        source_pattern: '\\Ahttps://example\\.com/alias\\z',
-        replacement: 'https://example.com/canonical'
-      )
-      create(:post, url: 'https://example.com/canonical')
-
-      post = described_class.new(title: 'duplicate URL', url: 'https://example.com/alias')
-
-      expect(post).to be_invalid
-      expect(post.errors.details.fetch(:url)).to include(error: :taken, value: post.url)
-    end
-  end
-end

backend/spec/models/post_url_sanitisation_rule_spec.rb

@@ -1,265 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe PostUrlSanitisationRule, type: :model do
-  before do
-    described_class.unscoped.delete_all
-  end
-
-  describe 'validations' do
-    it 'requires a source pattern' do
-      rule = described_class.new(priority: 10, source_pattern: nil, replacement: '')
-
-      expect(rule).to be_invalid
-      expect(rule.errors.details.fetch(:source_pattern)).to eq([{ error: :blank }])
-    end
-
-    it 'requires a unique source pattern' do
-      described_class.create!(priority: 10, source_pattern: 'source', replacement: 'first')
-      rule = described_class.new(
-        priority: 20,
-        source_pattern: 'source',
-        replacement: 'second'
-      )
-
-      expect(rule).to be_invalid
-      expect(rule.errors.details.fetch(:source_pattern)).to include(
-        error: :taken,
-        value: 'source'
-      )
-    end
-
-    it 'rejects an invalid regexp' do
-      rule = described_class.new(priority: 10, source_pattern: '[', replacement: '')
-
-      expect(rule).to be_invalid
-      expect(rule.errors[:source_pattern]).to include('変な正規表現だね〜（笑）')
-    end
-  end
-
-  describe '.sanitise' do
-    it 'applies each active rule once in priority order' do
-      described_class.create!(priority: 30, source_pattern: 'c', replacement: 'd')
-      described_class.create!(priority: 10, source_pattern: 'a', replacement: 'aa')
-      described_class.create!(priority: 20, source_pattern: 'aa', replacement: 'c')
-      discarded = described_class.create!(
-        priority: 5,
-        source_pattern: '.',
-        replacement: 'discarded'
-      )
-      discarded.discard!
-
-      expect(described_class.sanitise('a')).to eq('d')
-    end
-
-    it 'canonicalises the initial YouTube and Nico URL forms' do
-      create_initial_rules
-
-      urls = {
-        'https://youtu.be/abc123?si=share' => youtube_url('abc123'),
-        'https://www.youtube.com/live/abc123?t=10' => youtube_url('abc123'),
-        'https://youtube.com/shorts/abc123?feature=share' => youtube_url('abc123'),
-        'https://m.youtube.com/embed/abc123' => youtube_url('abc123'),
-        'https://youtube.com/watch?feature=share&v=abc123&t=10' => youtube_url('abc123'),
-        'https://nico.ms/sm123?from=share#fragment' => nico_url('sm123'),
-        'https://www.nicovideo.jp/watch/sm123?ref=share#fragment' => nico_url('sm123')
-      }
-
-      urls.each do |url, canonical_url|
-        expect(described_class.sanitise(url)).to eq(canonical_url)
-      end
-    end
-  end
-
-  describe '.apply!' do
-    it 'locks posts in ID order and updates through temporary URLs' do
-      first = create(:post, url: 'https://example.com/source/1')
-      second = create(:post, url: 'https://example.com/source/2')
-      create_source_rule
-      sql = capture_sql { described_class.apply! }
-
-      lock_sql = sql.find { _1.match?(/SELECT .*posts.*FOR UPDATE/i) }
-      expect(lock_sql).to match(/ORDER BY .*posts.*id.* ASC/i)
-      expect(sql.grep(/post-url-sanitising\.invalid/).size).to eq(2)
-      expect(first.reload.url).to eq('https://example.com/canonical/1')
-      expect(second.reload.url).to eq('https://example.com/canonical/2')
-    end
-
-    it 'loads and compiles rules only once' do
-      create(:post, url: 'https://example.com/source/1')
-      create(:post, url: 'https://example.com/source/2')
-      create_source_rule
-
-      expect(described_class).to receive(:rules).once.and_call_original
-
-      described_class.apply!
-    end
-
-    it 'does not change post versions, version_no, or updated_at' do
-      post = create(:post, url: 'https://example.com/source/1')
-      post.update_columns(version_no: 7, updated_at: 1.day.ago)
-      original_updated_at = post.reload.updated_at
-      create_source_rule
-
-      expect { described_class.apply! }.not_to change(PostVersion, :count)
-
-      post.reload
-      expect(post.url).to eq('https://example.com/canonical/1')
-      expect(post.version_no).to eq(7)
-      expect(post.updated_at).to eq(original_updated_at)
-    end
-
-    invalid_urls = {
-      'a blank URL' => '',
-      'an unparseable URL' => 'https://[',
-      'a non-HTTP URL' => 'ftp://example.com/file',
-      'an HTTP URL without a host' => 'https:/path'
-    }
-
-    invalid_urls.each do |description, sanitised_url|
-      it "rolls back every update when sanitisation produces #{ description }" do
-        valid_post = create(:post, url: 'https://example.com/source/1')
-        invalid_post = create(:post, url: 'https://example.com/invalid')
-        create_source_rule
-        described_class.create!(
-          priority: 20,
-          source_pattern: '\\Ahttps://example\\.com/invalid\\z',
-          replacement: sanitised_url
-        )
-
-        expect { described_class.apply! }
-            .to raise_error(described_class::InvalidUrlError) { |error|
-          expect(error.invalid_rows).to eq([
-            { post_id: invalid_post.id,
-              original_url: 'https://example.com/invalid',
-              sanitised_url: }
-          ])
-        }
-        expect(valid_post.reload.url).to eq('https://example.com/source/1')
-        expect(invalid_post.reload.url).to eq('https://example.com/invalid')
-      end
-    end
-
-    it 'rolls back every update when sanitisation produces a URL longer than 768 characters' do
-      path = 'a' * 375
-      original_url = "https://example.com/#{ path }"
-      sanitised_url = "https://example.com/#{ path }#{ path }"
-      valid_post = create(:post, url: 'https://example.com/source/1')
-      invalid_post = create(:post, url: original_url)
-      create_source_rule
-      described_class.create!(
-        priority: 20,
-        source_pattern: '\\Ahttps://example\\.com/(a+)\\z',
-        replacement: 'https://example.com/\\1\\1'
-      )
-
-      expect { described_class.apply! }
-          .to raise_error(described_class::InvalidUrlError) { |error|
-        expect(error.invalid_rows).to eq([
-          { post_id: invalid_post.id,
-            original_url:,
-            sanitised_url: }
-        ])
-      }
-      expect(valid_post.reload.url).to eq('https://example.com/source/1')
-      expect(invalid_post.reload.url).to eq(original_url)
-    end
-
-    it 'rejects sanitised URL collisions case-insensitively without changing posts' do
-      source = create(:post, url: 'https://example.com/source/Foo')
-      canonical = create(:post, url: 'https://example.com/canonical/foo')
-      create_source_rule
-
-      expect { described_class.apply! }
-          .to raise_error(described_class::UrlConflictError) { |error|
-        expect(error.conflicts).to contain_exactly(
-          { url: 'https://example.com/canonical/Foo',
-            post_id: source.id,
-            original_url: 'https://example.com/source/Foo' },
-          { url: 'https://example.com/canonical/foo',
-            post_id: canonical.id,
-            original_url: 'https://example.com/canonical/foo' }
-        )
-      }
-      expect(source.reload.url).to eq('https://example.com/source/Foo')
-      expect(canonical.reload.url).to eq('https://example.com/canonical/foo')
-      expect(Post.count).to eq(2)
-    end
-
-    it 'converts a persisted URL constraint race into UrlConflictError' do
-      post = create(:post, url: 'https://example.com/source/1')
-      create_source_rule
-      conflict = { url: 'https://example.com/canonical/1',
-                   post_id: post.id,
-                   original_url: post.url }
-      database_error = ActiveRecord::RecordNotUnique.new('duplicate URL')
-      allow_any_instance_of(ActiveRecord::Relation)
-          .to receive(:update_all).and_raise(database_error)
-      allow(described_class).to receive(:build_persisted_conflicts).and_return([conflict])
-
-      expect { described_class.apply! }
-          .to raise_error(described_class::UrlConflictError) { |error|
-        expect(error.conflicts).to eq([conflict])
-        expect(error.cause).to equal(database_error)
-      }
-      expect(post.reload.url).to eq('https://example.com/source/1')
-    end
-
-    it 're-raises an unidentified RecordNotUnique error' do
-      post = create(:post, url: 'https://example.com/source/1')
-      create_source_rule
-      database_error = ActiveRecord::RecordNotUnique.new('another unique constraint')
-      allow_any_instance_of(ActiveRecord::Relation)
-          .to receive(:update_all).and_raise(database_error)
-      allow(described_class).to receive(:build_persisted_conflicts).and_return([])
-
-      expect { described_class.apply! }.to raise_error(database_error)
-      expect(post.reload.url).to eq('https://example.com/source/1')
-    end
-  end
-
-  def capture_sql
-    statements = []
-    subscriber = lambda do |_name, _start, _finish, _id, payload|
-      binds = payload.fetch(:binds, []).map { _1.value_for_database.to_s }
-      statements << ([payload.fetch(:sql)] + binds).join(' ')
-    end
-    ActiveSupport::Notifications.subscribed(subscriber, 'sql.active_record') { yield }
-    statements
-  end
-
-  def create_source_rule
-    described_class.create!(
-      priority: 10,
-      source_pattern: '\\Ahttps://example\\.com/source/(.+)\\z',
-      replacement: 'https://example.com/canonical/\\1'
-    )
-  end
-
-  def create_initial_rules
-    rules = [
-      ['\\Ahttps?://youtu\\.be/([^/?#]+)(?:[?#].*)?\\z', youtube_url('\\1')],
-      ['\\Ahttps?://(?:www\\.|m\\.)?youtube\\.com/live/([^/?#]+)(?:[?#].*)?\\z',
-       youtube_url('\\1')],
-      ['\\Ahttps?://(?:www\\.|m\\.)?youtube\\.com/shorts/([^/?#]+)(?:[?#].*)?\\z',
-       youtube_url('\\1')],
-      ['\\Ahttps?://(?:www\\.|m\\.)?youtube\\.com/embed/([^/?#]+)(?:[?#].*)?\\z',
-       youtube_url('\\1')],
-      ['\\Ahttps?://(?:www\\.|m\\.)?youtube\\.com/watch\\?(?:[^#&]+&)*' \
-       'v=([^&#]+)(?:[&#].*)?\\z', youtube_url('\\1')],
-      ['\\Ahttps?://nico\\.ms/([^/?#]+)(?:[?#].*)?\\z', nico_url('\\1')],
-      ['\\Ahttps?://(?:www\\.)?nicovideo\\.jp/watch/([^?#/]+)(?:[?#].*)?\\z',
-       nico_url('\\1')]
-    ]
-    rules.each_with_index do |(source_pattern, replacement), index|
-      described_class.create!(
-        priority: (index + 1) * 10,
-        source_pattern:,
-        replacement:
-      )
-    end
-  end
-
-  def youtube_url(video_id) = "https://www.youtube.com/watch?v=#{ video_id }"
-
-  def nico_url(video_id) = "https://www.nicovideo.jp/watch/#{ video_id }"
-end

backend/spec/requests/materials_spec.rb

@@ -287,25 +287,6 @@ RSpec.describe 'Materials API', type: :request do
         expect(json.dig('export_paths', 'legacy_drive')).to eq('伊地知ニジカ/created.png')
       end
 
-      it 'creates a create tag_version for a newly created material tag' do
-        expect do
-          post '/materials', params: {
-            tag: 'material_create_versioned_tag',
-            file: dummy_upload(filename: 'created.png')
-          }
-        end.to change(TagVersion, :count).by(1)
-
-        expect(response).to have_http_status(:created)
-
-        tag = Tag.joins(:tag_name).find_by!(tag_names: { name: 'material_create_versioned_tag' })
-        version = tag.tag_versions.order(:version_no).last
-
-        expect(version.event_type).to eq('create')
-        expect(version.name).to eq('material_create_versioned_tag')
-        expect(version.category).to eq('material')
-        expect(version.created_by_user).to eq(member_user)
-      end
-
       it 'snapshots attached file metadata and sha256' do
         post '/materials', params: {
           tag: 'material_create_file_version',
@@ -485,73 +466,6 @@ RSpec.describe 'Materials API', type: :request do
         expect(json.dig('tag', 'name')).to eq('material_update_new')
       end
 
-      it 'creates a create tag_version when update creates a new tag' do
-        expect do
-          put "/materials/#{ material.id }", params: {
-            tag: 'material_update_versioned_tag',
-            file: dummy_upload(filename: 'updated.png')
-          }
-        end.to change(Tag, :count).by(1)
-          .and change(TagName, :count).by(1)
-          .and change(TagVersion, :count).by(1)
-
-        expect(response).to have_http_status(:ok)
-
-        tag = Tag.joins(:tag_name).find_by!(tag_names: { name: 'material_update_versioned_tag' })
-        version = tag.tag_versions.order(:version_no).last
-
-        expect(version.event_type).to eq('create')
-        expect(version.name).to eq('material_update_versioned_tag')
-        expect(version.category).to eq('material')
-        expect(version.created_by_user).to eq(member_user)
-      end
-
-      it 'backfills a create tag_version for an existing material tag without history' do
-        existing_tag =
-            Tag.create!(tag_name: TagName.create!(name: 'material_update_existing_no_history'),
-                        category: :material)
-
-        expect(existing_tag.tag_versions).to be_empty
-
-        expect do
-          put "/materials/#{ material.id }", params: {
-            tag: 'material_update_existing_no_history',
-            file: dummy_upload(filename: 'updated.png')
-          }
-        end.to change(TagVersion, :count).by(1)
-
-        expect(response).to have_http_status(:ok)
-
-        version = existing_tag.reload.tag_versions.order(:version_no).last
-        expect(version.event_type).to eq('create')
-        expect(version.name).to eq('material_update_existing_no_history')
-        expect(version.category).to eq('material')
-        expect(version.created_by_user).to eq(member_user)
-      end
-
-      it 'backfills a create tag_version for an existing character tag without history' do
-        existing_tag =
-            Tag.create!(tag_name: TagName.create!(name: 'material_update_character_no_history'),
-                        category: :character)
-
-        expect(existing_tag.tag_versions).to be_empty
-
-        expect do
-          put "/materials/#{ material.id }", params: {
-            tag: 'material_update_character_no_history',
-            file: dummy_upload(filename: 'updated.png')
-          }
-        end.to change(TagVersion, :count).by(1)
-
-        expect(response).to have_http_status(:ok)
-
-        version = existing_tag.reload.tag_versions.order(:version_no).last
-        expect(version.event_type).to eq('create')
-        expect(version.name).to eq('material_update_character_no_history')
-        expect(version.category).to eq('character')
-        expect(version.created_by_user).to eq(member_user)
-      end
-
       it 'detaches the existing file without purging blob when url replaces file' do
         old_blob_id = material.file.blob.id
 
@@ -580,7 +494,6 @@ RSpec.describe 'Materials API', type: :request do
       it 'does not increase version for the same snapshot update' do
         MaterialVersionRecorder.record!(material:, event_type: :create,
                                         created_by_user: member_user)
-        TagVersioning.ensure_snapshot!(tag, created_by_user: member_user)
 
         expect do
           put "/materials/#{ material.id }", params: {
@@ -588,8 +501,6 @@ RSpec.describe 'Materials API', type: :request do
           }
         end.not_to change(MaterialVersion, :count)
 
-        expect(tag.reload.tag_versions.count).to eq(1)
-
         expect(response).to have_http_status(:ok)
         expect(material.reload.version_no).to eq(1)
       end

backend/spec/requests/preview_spec.rb

@@ -1,46 +1,28 @@
-require 'rails_helper'
+require "rails_helper"
 
 
-RSpec.describe 'Preview', type: :request do
-  describe 'GET /preview/title' do
-    it '401 unless logged in' do
+RSpec.describe "Preview", type: :request do
+  describe "GET /preview/title" do
+    it "401 unless logged in" do
       sign_out
-      get '/preview/title', params: { url: 'example.com' }
+      get "/preview/title", params: { url: "example.com" }
       expect(response).to have_http_status(:unauthorized)
     end
 
-    it '403 when logged in as guest' do
-      sign_in_as(create(:user, :guest))
-      get '/preview/title', params: { url: 'example.com' }
-      expect(response).to have_http_status(:forbidden)
-    end
-
-    it '400 when url blank' do
-      sign_in_as(create(:user, :member))
-      get '/preview/title', params: { url: '' }
+    it "400 when url blank" do
+      sign_in_as(create(:user))
+      get "/preview/title", params: { url: "" }
       expect(response).to have_http_status(:bad_request)
     end
 
-    it 'returns parsed title' do
-      sign_in_as(create(:user, :member))
-      allow(Preview::ThumbnailFetcher)
-          .to receive(:title)
-          .with('example.com')
-          .and_return('Hello')
+    it "returns parsed title (stubbing URI.open)" do
+      sign_in_as(create(:user))
+      fake_html = "<html><head><title>  Hello  </title></head></html>"
+      allow(URI).to receive(:open).and_return(StringIO.new(fake_html))
 
-      get '/preview/title', params: { url: 'example.com' }
+      get "/preview/title", params: { url: "example.com" }
       expect(response).to have_http_status(:ok)
-      expect(json['title']).to eq('Hello')
-    end
-
-    it '413 when fetched response is too large' do
-      sign_in_as(create(:user, :member))
-      allow(Preview::ThumbnailFetcher)
-          .to receive(:title)
-          .and_raise(Preview::HttpFetcher::ResponseTooLarge, '外部データが大きすぎます．')
-
-      get '/preview/title', params: { url: 'example.com' }
-      expect(response).to have_http_status(:payload_too_large)
+      expect(json["title"]).to eq("Hello")
     end
   end
 end

backend/spec/services/preview/http_fetcher_spec.rb

@@ -1,23 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Preview::HttpFetcher do
-  describe '.fetch' do
-    it 'raises FetchFailed when redirect location is invalid' do
-      redirect = Net::HTTPFound.new('1.1', '302', 'Found')
-      redirect['location'] = 'http://[invalid'
-
-      allow(Preview::UrlSafety).to receive(:validate)
-          .with('https://example.com/page')
-          .and_return([URI.parse('https://example.com/page'), ['203.0.113.10']])
-      allow(described_class).to receive(:request)
-          .and_return(redirect)
-      allow(Rails.logger).to receive(:warn)
-
-      expect {
-        described_class.fetch('https://example.com/page')
-      }.to raise_error(Preview::HttpFetcher::FetchFailed)
-      expect(Rails.logger).to have_received(:warn)
-          .with(/invalid_redirect_location/)
-    end
-  end
-end

backend/spec/services/preview/thumbnail_fetcher_spec.rb

@@ -1,51 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Preview::ThumbnailFetcher do
-  describe '.fetch' do
-    it 'rejects svg thumbnails' do
-      page = Preview::HttpFetcher::Response.new(
-          '<meta property="og:image" content="https://example.com/thumb.svg">',
-          'text/html',
-          'https://example.com/page')
-      svg = Preview::HttpFetcher::Response.new(
-          '<svg></svg>',
-          'image/svg+xml',
-          'https://example.com/thumb.svg')
-
-      allow(Preview::UrlSafety).to receive(:validate)
-          .and_return([URI.parse('https://example.com/page'), ['203.0.113.10']])
-      allow(Preview::HttpFetcher).to receive(:fetch)
-          .with('https://example.com/page', max_bytes: described_class::HTML_MAX_BYTES)
-          .and_return(page)
-      allow(Preview::HttpFetcher).to receive(:fetch)
-          .with('https://example.com/thumb.svg')
-          .and_return(svg)
-
-      expect {
-        described_class.fetch('https://example.com/page')
-      }.to raise_error(Preview::ThumbnailFetcher::GenerationFailed)
-    end
-
-    it 'accepts allowed image content type with parameters' do
-      page = Preview::HttpFetcher::Response.new(
-          '<meta property="og:image" content="https://example.com/thumb.jpg">',
-          'text/html',
-          'https://example.com/page')
-      image = Preview::HttpFetcher::Response.new(
-          'jpeg-bytes',
-          'image/jpeg; charset=binary',
-          'https://example.com/thumb.jpg')
-
-      allow(Preview::UrlSafety).to receive(:validate)
-          .and_return([URI.parse('https://example.com/page'), ['203.0.113.10']])
-      allow(Preview::HttpFetcher).to receive(:fetch)
-          .with('https://example.com/page', max_bytes: described_class::HTML_MAX_BYTES)
-          .and_return(page)
-      allow(Preview::HttpFetcher).to receive(:fetch)
-          .with('https://example.com/thumb.jpg')
-          .and_return(image)
-
-      expect(described_class.fetch('https://example.com/page')).to eq('jpeg-bytes')
-    end
-  end
-end

backend/spec/services/preview/url_safety_spec.rb

@@ -1,15 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe Preview::UrlSafety do
-  describe '.validate' do
-    it 'raises UnsafeUrl when DNS resolution fails' do
-      allow(Resolv).to receive(:getaddresses)
-          .with('missing.example')
-          .and_raise(Resolv::ResolvError)
-
-      expect {
-        described_class.validate('https://missing.example')
-      }.to raise_error(Preview::UrlSafety::UnsafeUrl)
-    end
-  end
-end

backend/spec/tasks/nico_export_spec.rb

@@ -62,7 +62,7 @@ RSpec.describe 'nico:export' do
 
     it 'deduplicates video ids' do
       create_post('https://www.nicovideo.jp/watch/sm12345')
-      create_post('https://sp.nicovideo.jp/watch/sm12345')
+      create_post('https://www.nicovideo.jp/watch/sm12345?from=1')
 
       expect(Open3).to receive(:capture3) do |_env, *args, **_kwargs|
         expect(args.drop(3)).to eq(['sm12345'])

frontend/src/index.css

@@ -239,11 +239,6 @@ body
   background: var(--top-nav-submenu-bg);
 }
 
-.top-nav-mobile-menu .top-nav-submenu
-{
-  background: var(--top-nav-mobile-active-bg);
-}
-
 .top-nav-mobile-menu
 {
   background: var(--top-nav-mobile-menu-bg);

frontend/src/index.test.ts

@@ -1,22 +0,0 @@
-import { readFileSync } from 'node:fs'
-import { resolve } from 'node:path'
-
-import { describe, expect, it } from 'vitest'
-
-
-const indexCss = readFileSync (
-    resolve (process.cwd (), 'src/index.css'),
-    'utf8')
-const compactIndexCss = indexCss.replace (/\s+/g, ' ')
-const mobileActiveRule = '.top-nav-mobile-active {'
-    + ' background: var(--top-nav-mobile-active-bg); }'
-const mobileSubmenuRule = '.top-nav-mobile-menu .top-nav-submenu {'
-    + ' background: var(--top-nav-mobile-active-bg); }'
-
-
-describe ('TopNav mobile menu colours', () => {
-  it ('uses one background variable for active rows and expanded submenus', () => {
-    expect (compactIndexCss).toContain (mobileActiveRule)
-    expect (compactIndexCss).toContain (mobileSubmenuRule)
-  })
-})

frontend/src/lib/settings.test.ts

@@ -89,12 +89,8 @@ describe ('settings', () => {
   })
 
   it ('derives TopNav colours without mixing mobile active backgrounds', () => {
-    const tokens = buildThemeTokens ('light', { })
-
-    expect (tokens.topNavMobileActiveBackground).toBe (
+    expect (buildThemeTokens ('light', { }).topNavMobileActiveBackground).toBe (
 	LIGHT_THEME_TOKENS.topNavRootBackgroundDesktop)
-    expect (tokens.topNavMobileActiveBackground).not.toBe (
-	tokens.topNavRootBackgroundMobile)
     expect (buildThemeTokens ('dark', { }).topNavMobileActiveBackground).toBe (
 	DARK_THEME_TOKENS.topNavActiveBackground)
   })