#346

.gitea/ISSUE_TEMPLATE.md

@@ -1,3 +1,11 @@
+---
+name: 'Codex task'
+about: 'Codex に実装させるための課題'
+title: ''
+labels:
+  - codex-ready
+---
+
 ## 背景
 
 なぜ必要か。

AGENTS.md

@@ -12,21 +12,16 @@ BTRC Hub / タグ広場 is a split Rails API and React frontend repository.
 ## Stack
 
 - Backend: Ruby `3.2.2` from `backend/.ruby-version`, Rails `~> 8.0.2`.
-- Backend dependencies include `mysql2`, `sqlite3`, `rspec-rails`,
+- Backend dependencies include `mysql2`, `sqlite3`, `rspec-rails`, `factory_bot_rails`, `rack-cors`, `jwt`, `discard`, `gollum`, `whenever`, `aws-sdk-s3`, `brakeman`, and `rubocop-rails-omakase`.
-  `factory_bot_rails`, `rack-cors`, `jwt`, `discard`, `gollum`, `whenever`,
-  `aws-sdk-s3`, `brakeman`, and `rubocop-rails-omakase`.
 - Frontend: React `^19.1.0`, TypeScript `~5.8.3`, Vite `^6.3.5`.
-- Frontend data/UI dependencies include Axios, TanStack Query, Tailwind CSS,
+- Frontend data/UI dependencies include Axios, TanStack Query, Tailwind CSS, Framer Motion, Radix UI components, lucide-react, MDX/Markdown tooling, and Zustand.
-  Framer Motion, Radix UI components, lucide-react, MDX/Markdown tooling, and
-  Zustand.
 
 ## Main directories
 
 - `backend/app/controllers`: Rails API controllers.
 - `backend/app/models`: Active Record models.
 - `backend/app/representations`: API response representation classes.
-- `backend/app/services`: domain services such as version recording,
+- `backend/app/services`: domain services such as version recording, wiki commit, YouTube sync, and similarity calculation.
-  wiki commit, YouTube sync, and similarity calculation.
 - `backend/config/routes.rb`: API routes.
 - `backend/db/migrate`: migrations.
 - `backend/db/schema.rb`: current schema snapshot.
@@ -89,132 +84,52 @@ cd frontend
 npm run dev
 npm run build
 npm run lint
-npm run test
-npm run test:run
 npm run preview
 ```
 
-`npm run build` runs `tsc -b && vite build`, then `postbuild` runs
+`npm run build` runs `tsc -b && vite build`, then `postbuild` runs `node scripts/generate-sitemap.js`.
-`node scripts/generate-sitemap.js`.
 
-`npm run test` runs Vitest in watch mode. Use `npm run test:run` for a non-watch frontend test run.
+Do not write or report `npm test` as a repository command unless a `test` script is added to `frontend/package.json`.
 
 ## Coding style
 
 - Prefer precise, minimal changes.
 - Do not flatter or over-explain.
 - Explain risks directly.
-- Prefer single quotes for strings unless interpolation or escaping makes
+- Prefer single quotes for strings unless interpolation or escaping makes double quotes better.
-  double quotes better.
 - Ruby: never put a space before method-call parentheses.
-- Ruby: never put a line break immediately before `)`.
 - Ruby: do not use `%w` or `%i`.
-- Ruby hashes are not blocks; keep `}` on the same line as the final pair.
+- TypeScript and Python: use GNU-style spacing before parentheses where syntactically valid.
-- Ruby hashes keep the first pair on the same line as `{` unless line length
-  requires a break.
-- Ruby blocks use separate `{ ... }` rules from hashes, with 2-space body
-  indentation.
-- For arrays, never put whitespace or a line break immediately before `]`.
-- Keep the first element on the same line as `[` by default.
-- If an array would exceed the line limit, break after `[` and indent
-  elements by 4 spaces.
-- TypeScript and Python: use GNU-style spacing before parentheses where
-  syntactically valid.
-- Never write Ruby, TypeScript, or TSX lines longer than 99 characters.
-- Aim to keep Ruby, TypeScript, and TSX lines within 79 characters where practical.
-- TypeScript and TSX use 4-space logical indentation.
-- In TypeScript and TSX only, replace every leading run of 8 spaces with a tab.
-- Tabs are only for leading indentation, never for spaces after non-space text.
 - Do not add production dependencies without explicit approval.
 
 ## Backend rules
 
-- Inspect existing routes, controllers, models, services, and specs before
+- Inspect existing routes, controllers, models, services, and specs before editing backend behavior.
-  editing backend behavior.
 - For API behavior changes, add or update request specs under `backend/spec/requests`.
-- Prefer RSpec for new backend tests; existing minitest files under
+- Prefer RSpec for new backend tests; existing minitest files under `backend/test` do not make minitest the default for new coverage.
-  `backend/test` do not make minitest the default for new coverage.
 - Do not weaken authentication, BAN user checks, or IP BAN checks.
-- Preserve the `X-Transfer-Code` user identification flow unless the task
+- Preserve the `X-Transfer-Code` user identification flow unless the task explicitly changes authentication.
-  explicitly changes authentication.
+- Be careful with version tables, `version_no`, optimistic concurrency, wiki revisions, and restore/diff behavior.
-- Be careful with version tables, `version_no`, optimistic concurrency,
-  wiki revisions, and restore/diff behavior.
 - Be careful with tag names, tag normalization, implications, similarities, and discard behavior.
-- Be sensitive to N+1 queries; avoid introducing them and proactively fix
-  existing N+1 issues in the code path being edited.
 - Keep migration files and `backend/db/schema.rb` consistent when changing schema.
 
 ## Frontend rules
 
 - Use `frontend/src/lib/api.ts` for API calls so headers and camelCase conversion stay consistent.
-- Add or reuse TanStack Query keys through `frontend/src/lib/queryKeys.ts`;
+- Add or reuse TanStack Query keys through `frontend/src/lib/queryKeys.ts`; avoid ad hoc query key arrays.
-  avoid ad hoc query key arrays.
 - Encode URL path-segment values with `encodeURIComponent`.
 - React hooks must be called unconditionally.
-- Keep page-level code under `frontend/src/pages` and shared UI/feature code
+- Keep page-level code under `frontend/src/pages` and shared UI/feature code under `frontend/src/components` unless existing patterns point elsewhere.
-  under `frontend/src/components` unless existing patterns point elsewhere.
 - Match existing Tailwind, component, and import alias conventions.
 
-### Frontend TSX style
-
-- Preserve the local TSX formatting style.
-- Do not normalize TSX to common Prettier-style React formatting unless
-  explicitly asked.
-- Prefer `const` arrow functions for TypeScript/TSX component and helper declarations.
-- Put two blank lines before and after top-level `const` function
-  declarations, unless imports, exports, or file boundaries make that awkward.
-- In TSX, indent with 4-space logical indentation.
-- A leading tab is exactly equivalent to 8 leading spaces.
-- Keep a tag's closing marker on the same line as the final prop when the tag
-  spans multiple lines.
-- Do not put `/>` or `>` on its own line unless the existing surrounding code
-  does so.
-- Keep JSX closing parentheses in the existing compact style, for example
-  `</div>)` rather than moving `)` onto a separate line.
-- Do not add braces around `if`, `else`, or `for` bodies when the body is a
-  single physical line.
-- Always add braces around `if`, `else`, or `for` bodies when the body spans
-  two or more physical lines, even if it is one statement.
-
-Preferred:
-
-```tsx
-const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
-  return (
-      <TextArea
-	  {...rest}
-	  ref={ref}
-	  value={tags}
-	  invalid={errors && errors.length > 0}
-	  onChange={ev => setTags (ev.target.value)}/>)
-}
-```
-
-Avoid:
-
-```tsx
-function PostFormTagsArea ({ tags, setTags }: Props) {
-  return (
-    <TextArea
-      value={tags}
-      onChange={ev => setTags (ev.target.value)}
-    />
-  )
-}
-```
-
 ## Codex workflow
 
 - First inspect existing patterns; do not invent new architecture when a local convention exists.
 - Keep changes scoped to the requested issue.
-- Do not scan or summarize dependency/generated/runtime directories such as
+- Do not scan or summarize dependency/generated/runtime directories such as `node_modules`, `dist`, `tmp`, `log`, and `storage` unless explicitly needed.
-  `node_modules`, `dist`, `tmp`, `log`, and `storage` unless explicitly needed.
+- Before touching wiki, tag, versioning, BAN, IP BAN, or authentication behavior, inspect the related request specs and service objects.
-- Before touching wiki, tag, versioning, BAN, IP BAN, or authentication
+- If frontend code changes, run the existing frontend verification commands that apply: `npm run build` and `npm run lint`.
-  behavior, inspect the related request specs and service objects.
+- If backend code changes, run the relevant RSpec command; for broad backend changes, run `bundle exec rspec`.
-- If frontend code changes, run the existing frontend verification commands
-  that apply: `npm run build`, `npm run lint`, and `npm run test:run`.
-- If backend code changes, run the relevant RSpec command; for broad backend
-  changes, run `bundle exec rspec`.
 - If a verification command cannot be run or fails, report the exact command and failure.
 
 ## Completion criteria

backend/AGENTS.md

@@ -4,9 +4,7 @@
 
 These rules apply to work under `backend/`.
 
-This is a Rails API app using Active Record, RSpec, request specs,
+This is a Rails API app using Active Record, RSpec, request specs, service objects, representation classes, and version tables for post/tag/wiki history.
-service objects, representation classes, and version tables for post/tag/wiki
-history.
 
 ## Commands
 
@@ -52,57 +50,32 @@ If a command cannot be run or fails, report the exact command and failure.
 - `app/controllers`: API controllers.
 - `app/models`: Active Record models and concerns.
 - `app/representations`: JSON response shaping.
-- `app/services`: domain services such as version recorders, wiki commit,
+- `app/services`: domain services such as version recorders, wiki commit, YouTube sync, and similarity calculation.
-  YouTube sync, and similarity calculation.
 - `config/routes.rb`: public API routes.
 - `db/migrate`: migrations.
 - `db/schema.rb`: schema snapshot.
 - `lib/tasks`: custom Rake tasks.
 - `spec`: RSpec tests.
 
-Before changing behavior, inspect the matching route, controller, model,
+Before changing behavior, inspect the matching route, controller, model, service, representation, and spec.
-service, representation, and spec.
 
 ## Ruby style
 
 - Prefer precise, minimal changes.
 - Use single quotes unless interpolation or escaping makes double quotes better.
 - Do not put a space before Ruby method-call parentheses.
-- Never put a line break immediately before `)` in Ruby.
 - Do not use `%w` or `%i` in new Ruby code.
-- Never write a Ruby line longer than 99 characters.
-- Aim to keep Ruby lines within 79 characters where practical.
-- For small Ruby method definitions that take keyword arguments, match the
-  local no-parentheses style when nearby code uses it.
-- Treat Ruby hash `{ ... }` style and Ruby block `{ ... }` style as separate
-  rules.
-- Do not format Ruby hashes like Ruby blocks.
-- For Ruby hashes, keep the closing `}` on the same line as the final pair.
-- Keep the first pair on the same line as `{` by default.
-- If the hash would exceed the line limit, break after `{` and indent pairs
-  by 4 spaces.
-- Put one logical pair per line when the expression would otherwise become
-  dense.
-- For Ruby arrays, never put whitespace or a line break immediately before `]`.
-- Keep the first element on the same line as `[` by default.
-- If an array would exceed the line limit, break after `[` and indent
-  elements by 4 spaces.
-- For Ruby blocks, use 2-space indentation for the block body.
 - Keep comments short and useful; avoid narrating obvious code.
 - Do not add production dependencies without approval.
 
 ## Authentication and authorization
 
-- Authentication is handled through the `X-Transfer-Code` header in
+- Authentication is handled through the `X-Transfer-Code` header in `ApplicationController#authenticate_user`.
-  `ApplicationController#authenticate_user`.
 - `current_user` is set by looking up `User.inheritance_code`.
-- Do not bypass or weaken the `X-Transfer-Code` flow unless the task
+- Do not bypass or weaken the `X-Transfer-Code` flow unless the task explicitly changes authentication.
-  explicitly changes authentication.
+- Unauthenticated write actions should return `:unauthorized` consistently with existing controllers.
-- Unauthenticated write actions should return `:unauthorized` consistently
-  with existing controllers.
 - Role checks use `User` enum roles: `guest`, `member`, and `admin`.
-- Use `current_user.gte_member?` for member-or-admin write permissions where
+- Use `current_user.gte_member?` for member-or-admin write permissions where existing controllers do so.
-  existing controllers do so.
 - Use `current_user.admin?` only for admin-only paths, such as tag child relationship changes.
 - Do not replace role checks with looser presence checks.
 
@@ -115,8 +88,7 @@ service, representation, and spec.
 - User and IP bans use `banned_at`, not a boolean `banned` column.
 - `User#banned?` and `IpAddress#banned?` check `banned_at.present?`.
 - Do not weaken BAN or IP BAN behavior.
-- If changing request authentication or controller before actions, add or
+- If changing request authentication or controller before actions, add or update request specs covering banned users and banned IP addresses.
-  update request specs covering banned users and banned IP addresses.
 
 ## RSpec
 
@@ -127,86 +99,49 @@ service, representation, and spec.
 - Put Rake task coverage under `spec/tasks`.
 - `spec/rails_helper.rb` loads `spec/support/**/*.rb`.
 - Request specs include `AuthHelper` and `JsonHelper`.
-- `AuthHelper#sign_in_as(user)` stubs
+- `AuthHelper#sign_in_as(user)` stubs `ApplicationController#current_user`; use it when matching existing request spec style.
-  `ApplicationController#current_user`; use it when matching existing
+- Add or update request specs for API behavior changes, especially status codes, permissions, response shape, and version conflict behavior.
-  request spec style.
-- Add or update request specs for API behavior changes, especially status
-  codes, permissions, response shape, and version conflict behavior.
 
 ## Migrations
 
 - Keep migrations and `db/schema.rb` consistent.
 - Use reversible migrations where practical; otherwise define explicit `up` and `down`.
-- For data backfills inside migrations, follow the existing pattern of
+- For data backfills inside migrations, follow the existing pattern of defining migration-local `ActiveRecord::Base` classes with `self.table_name`.
-  defining migration-local `ActiveRecord::Base` classes with
-  `self.table_name`.
 - Preserve existing indexes, foreign keys, check constraints, and null constraints.
 - Be careful with MySQL-specific options already present in migrations, such as `after:`.
-- Do not edit old migrations just to change current behavior unless
+- Do not edit old migrations just to change current behavior unless explicitly requested; add a new migration.
-  explicitly requested; add a new migration.
 
 ## Version tables
 
 - Versioned records include posts, tags, nico tags, and wiki pages.
-- Current records have `version_no`; version tables have positive
+- Current records have `version_no`; version tables have positive `version_no` with unique indexes scoped to the parent record.
-  `version_no` with unique indexes scoped to the parent record.
 - Version event types are `create`, `update`, `discard`, and `restore`.
 - Version rows are readonly through the `VersionRecord` concern.
-- Use the existing recorder services instead of manually inserting version
+- Use the existing recorder services instead of manually inserting version rows in application code:
-  rows in application code:
   - `PostVersionRecorder`
   - `TagVersionRecorder`
   - `NicoTagVersionRecorder`
   - `WikiVersionRecorder`
   - `TagVersioning`
-- `VersionRecorder` locks the current record, validates sequence consistency,
+- `VersionRecorder` locks the current record, validates sequence consistency, skips unchanged update snapshots, creates the next version row, and updates the record `version_no`.
-  skips unchanged update snapshots, creates the next version row, and updates
-  the record `version_no`.
 - Do not update versioned records without considering whether a version snapshot must be created.
-- For optimistic concurrency paths, preserve `base_version_no`, `force`, and
+- For optimistic concurrency paths, preserve `base_version_no`, `force`, and `merge` semantics and cover conflicts in request specs.
-  `merge` semantics and cover conflicts in request specs.
 
 ## Domain cautions
 
-- Posts have tag snapshots, parent post implications, original-created ranges,
+- Posts have tag snapshots, parent post implications, original-created ranges, viewed state, and version conflict behavior.
-  viewed state, and version conflict behavior.
+- Tags have canonical names, aliases through `TagName`, categories, parent implications, discard behavior, and version snapshots.
-- Tags have canonical names, aliases through `TagName`, categories, parent
+- Nico tags have separate relation/version behavior; do not treat them like normal editable tags without checking existing code.
-  implications, discard behavior, and version snapshots.
+- Wiki pages involve page content, revisions/history, version rows, title/tag-name behavior, and diff/restore paths.
-- Nico tags have separate relation/version behavior; do not treat them like
+- Materials, theatres, and comments have user and permission checks; inspect the controller before changing them.
-  normal editable tags without checking existing code.
-- Wiki pages involve page content, revisions/history, version rows,
-  title/tag-name behavior, and diff/restore paths.
-- Materials, theatres, and comments have user and permission checks; inspect
-  the controller before changing them.
 
 ## API responses
 
 - Use representation classes under `app/representations` when existing endpoints do.
-- Keep response keys consistent with existing JSON contracts.
+- Keep response keys consistent with existing JSON contracts; frontend code expects camelCase conversion client-side, while Rails params and JSON keys are generally snake_case.
-- Frontend code expects camelCase conversion client-side, while Rails params
+- Preserve existing HTTP status conventions: `:unauthorized` for no user, `:forbidden` for insufficient role or banned user, `:not_found` for missing records, and `:unprocessable_entity` for validation failures.
-  and JSON keys are generally snake_case.
-- Preserve existing HTTP status conventions:
-  `:unauthorized` for no user, `:forbidden` for insufficient role or banned
-  user, `:not_found` for missing records, and `:unprocessable_entity` for
-  validation failures.
-- For diagnostic or internal helper JSON, prefer a deliberately light response
-  shape over full representation classes when callers only need identifiers,
-  labels, URLs, or weights.
-
-## Active Record performance
-
-- When a controller action serializes nested associations, preload the
-  associations it will touch instead of allowing N+1 queries.
-- Be sensitive to N+1 queries in all backend work.
-- Avoid introducing N+1 queries, and proactively fix existing N+1 issues when
-  you find them in the code path you are editing.
-- When an association may already be preloaded, prefer loaded-association
-  checks that reuse the preloaded data without losing the efficient database
-  path.
 
 ## Files to avoid in routine work
 
-- Do not inspect or edit `tmp/`, `log/`, `storage/`, `vendor/`, or dependency
+- Do not inspect or edit `tmp/`, `log/`, `storage/`, `vendor/`, or dependency directories unless explicitly needed.
-  directories unless explicitly needed.
+- Do not modify generated schema or migration output without the corresponding migration when schema changes are made.
-- Do not modify generated schema or migration output without the corresponding
-  migration when schema changes are made.

backend/Gemfile

@@ -69,5 +69,3 @@ gem 'discard'
 gem "rspec-rails", "~> 8.0", :groups => [:development, :test]
 
 gem 'aws-sdk-s3', require: false
-
-gem 'rails-i18n', '~> 8.0.0'

backend/Gemfile.lock

@@ -306,9 +306,6 @@ GEM
     rails-html-sanitizer (1.6.2)
       loofah (~> 2.21)
       nokogiri (>= 1.15.7, != 1.16.7, != 1.16.6, != 1.16.5, != 1.16.4, != 1.16.3, != 1.16.2, != 1.16.1, != 1.16.0.rc1, != 1.16.0)
-    rails-i18n (8.0.2)
-      i18n (>= 0.7, < 2)
-      railties (>= 8.0.0, < 9)
     railties (8.0.2)
       actionpack (= 8.0.2)
       activesupport (= 8.0.2)
@@ -480,7 +477,6 @@ DEPENDENCIES
   puma (>= 5.0)
   rack-cors
   rails (~> 8.0.2)
-  rails-i18n (~> 8.0.0)
   rspec-rails (~> 8.0)
   rubocop-rails-omakase
   sprockets-rails

backend/app/controllers/application_controller.rb

@@ -1,7 +1,4 @@
 class ApplicationController < ActionController::API
-  rescue_from ActiveRecord::RecordInvalid, with: :render_record_invalid
-  rescue_from ActiveRecord::RecordNotUnique, with: :render_record_not_unique
-
   before_action :reject_banned_ip_address!
   before_action :authenticate_user
   before_action :reject_banned_user!
@@ -28,27 +25,6 @@ class ApplicationController < ActionController::API
     end
   end
 
-  def render_bad_request message = 'リクエストが不正です．'
-    render json: { type: 'bad_request',
-                   message:,
-                   errors: { },
-                   base_errors: [message] },
-           status: :bad_request
-  end
-
-  def render_unprocessable_entity message = '入力を確認してください．', field: nil
-    render_validation_error(fields: field ? { field => [message] } : { },
-                            base: field ? [] : [message])
-  end
-
-  def render_record_invalid error
-    render_validation_error error.record
-  end
-
-  def render_record_not_unique _error = nil
-    render_validation_error base: ['すでに存在してゐます．']
-  end
-
   def reject_banned_ip_address!
     ip_address = IpAddress.find_by(ip_address: IPAddr.new(request.remote_ip).hton)
     return unless ip_address&.banned?
@@ -61,28 +37,4 @@ class ApplicationController < ActionController::API
 
     head :forbidden
   end
-
-  def render_validation_error record = nil, fields: { }, base: [], status: :unprocessable_entity
-    errors = { }
-
-    if record
-      record.errors.each do |error|
-        errors[error.attribute] ||= []
-        errors[error.attribute] << error.message
-      end
-    end
-
-    fields.each do |attr, messages|
-      errors[attr.to_sym] ||= []
-      errors[attr.to_sym].concat(Array(messages))
-    end
-
-    base_errors = Array(base) + Array(errors.delete(:base))
-
-    render json: { type: 'validation_error',
-                   message: '入力内容を確認してください．',
-                   errors:,
-                   base_errors: },
-           status:
-  end
 end

backend/app/controllers/deerjikists_controller.rb

@@ -2,8 +2,7 @@ class DeerjikistsController < ApplicationController
   def show
     platform = params[:platform].to_s.strip
     code = params[:code].to_s.strip
-    return render_bad_request('platform は必須です．') if platform.blank?
+    return head :bad_request if platform.blank? || code.blank?
-    return render_bad_request('code は必須です．') if code.blank?
 
     deerjikist = Deerjikist
                  .joins(:tag)
@@ -23,9 +22,7 @@ class DeerjikistsController < ApplicationController
     platform = params[:platform].to_s.strip
     code = params[:code].to_s.strip
     tag_id = params[:tag_id].to_i
-    return render_bad_request('platform は必須です．') if platform.blank?
+    return head :bad_request if platform.blank? || code.blank? || tag_id <= 0
-    return render_bad_request('code は必須です．') if code.blank?
-    return render_bad_request('tag_id が不正です．') if tag_id <= 0
 
     deerjikist = Deerjikist.find_or_initialize_by(platform:, code:).tap do |d|
       d.tag_id = tag_id
@@ -41,8 +38,7 @@ class DeerjikistsController < ApplicationController
 
     platform = params[:platform].to_s.strip
     code = params[:code].to_s.strip
-    return render_bad_request('platform は必須です．') if platform.blank?
+    return head :bad_request if platform.blank? || code.blank?
-    return render_bad_request('code は必須です．') if code.blank?
 
     Deerjikist.find([platform, code]).destroy!
 

backend/app/controllers/materials_controller.rb

@@ -40,11 +40,7 @@ class MaterialsController < ApplicationController
     tag_name_raw = params[:tag].to_s.strip
     file = params[:file]
     url = params[:url].to_s.strip.presence
-    return render_unprocessable_entity('タグは必須です．', field: :tag) if tag_name_raw.blank?
+    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
-    if file.blank? && url.blank?
-      return render_validation_error fields: { file: ['ファイルまたは URL は必須です．'],
-                                               url: ['ファイルまたは URL は必須です．'] }
-    end
 
     tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
     tag = tag_name.tag
@@ -58,7 +54,7 @@ class MaterialsController < ApplicationController
     if material.save
       render json: MaterialRepr.base(material, host: request.base_url), status: :created
     else
-      render_validation_error material
+      render json: { errors: material.errors.full_messages }, status: :unprocessable_entity
     end
   end
 
@@ -72,11 +68,7 @@ class MaterialsController < ApplicationController
     tag_name_raw = params[:tag].to_s.strip
     file = params[:file]
     url = params[:url].to_s.strip.presence
-    return render_unprocessable_entity('タグは必須です．', field: :tag) if tag_name_raw.blank?
+    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
-    if file.blank? && url.blank?
-      return render_validation_error fields: { file: ['ファイルまたは URL は必須です．'],
-                                               url: ['ファイルまたは URL は必須です．'] }
-    end
 
     tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
     tag = tag_name.tag
@@ -92,7 +84,7 @@ class MaterialsController < ApplicationController
     if material.save
       render json: MaterialRepr.base(material, host: request.base_url)
     else
-      render_validation_error material
+      render json: { errors: material.errors.full_messages }, status: :unprocessable_entity
     end
   end
 

backend/app/controllers/nico_tags_controller.rb

@@ -1,69 +1,26 @@
 class NicoTagsController < ApplicationController
   def index
-    name = params[:name].presence
+    limit = (params[:limit] || 20).to_i
-    linked_tag = params[:linked_tag].presence
+    cursor = params[:cursor].presence
-    link_status = params[:link_status].presence
-    order = params[:order].to_s.split(':', 2).map(&:strip)
-    order[0] = 'updated_at' unless order[0].in?(['name', 'created_at', 'updated_at'])
-    unless order[1].in?(['asc', 'desc'])
-      order[1] = order[0] == 'name' ? 'asc' : 'desc'
-    end
-    page = (params[:page].presence || 1).to_i
-    limit = (params[:limit].presence || 20).to_i
-
-    page = 1 if page < 1
-    limit = 1 if limit < 1
-
-    post_tag_max_sql =
-        PostTag
-        .select('tag_id, MAX(created_at) AS max_created_at')
-        .group('tag_id')
-        .to_sql
 
     q = Tag.nico_tags
-           .joins(:tag_name)
-           .joins("LEFT JOIN (#{ post_tag_max_sql }) post_tag_max " \
-                  'ON post_tag_max.tag_id = tags.id')
            .includes(:tag_name, tag_name: :wiki_page, linked_tags: { tag_name: :wiki_page })
-    q = q.where('tag_names.name LIKE ?', "%#{ name }%") if name
+           .order(updated_at: :desc)
-    if linked_tag
+    q = q.where('tags.updated_at < ?', Time.iso8601(cursor)) if cursor
-      linked_tag_ids =
-        Tag
-        .joins(:tag_name)
-        .where('tag_names.name LIKE ?', "%#{ linked_tag }%")
-        .pluck(:id)
-      linked_nico_tag_ids = NicoTagRelation.where(tag_id: linked_tag_ids).pluck(:nico_tag_id)
-      q = q.where(id: linked_nico_tag_ids)
-    end
-    if link_status.in?(['linked', 'unlinked'])
-      exists_sql =
-          'EXISTS (SELECT 1 FROM nico_tag_relations ' \
-          'WHERE nico_tag_relations.nico_tag_id = tags.id)'
-      q = link_status == 'linked' ? q.where(exists_sql) : q.where("NOT #{ exists_sql }")
-    end
 
-    count = q.count
+    tags = q.limit(limit + 1).to_a
-    sort_sql =
+
-        case order[0]
+    next_cursor = nil
-        when 'name'
+    if tags.size > limit
-          'tag_names.name'
+      next_cursor = tags.last.updated_at.iso8601(6)
-        when 'updated_at'
+      tags = tags.first(limit)
-          'post_tag_max.max_created_at'
-        else
-          "tags.#{ order[0] }"
     end
-    tags = q.reselect('tags.*',
-                      Arel.sql('post_tag_max.max_created_at AS recent_post_tag_created_at'))
-            .order(Arel.sql("#{ sort_sql } #{ order[1] }, tags.id #{ order[1] }"))
-            .limit(limit)
-            .offset((page - 1) * limit)
-            .to_a
 
     render json: { tags: tags.map { |tag|
-      TagRepr.base(tag).merge(
+      TagRepr.base(tag).merge(linked_tags: tag.linked_tags.map { |lt|
-          recent_post_tag_created_at: tag.recent_post_tag_created_at,
+        TagRepr.base(lt)
-          linked_tags: tag.linked_tags.map { |lt| TagRepr.base(lt) })
+      })
-    }, count: }
+    }, next_cursor: }
   end
 
   def update
@@ -73,18 +30,14 @@ class NicoTagsController < ApplicationController
     id = params[:id].to_i
 
     tag = Tag.find(id)
-    return render_bad_request('ニコニコ・タグを指定してください．') unless tag.nico?
+    return head :bad_request unless tag.nico?
 
     linked_tag_names = params[:tags].to_s.split
-    linked_tags = nil
-
-    ApplicationRecord.transaction do
     linked_tags = Tag.normalise_tags!(linked_tag_names, with_tagme: false,
                                                         with_no_deerjikist: false)
-      if linked_tags.any? { |t| t.nico? }
+    return head :bad_request if linked_tags.any? { |t| t.nico? }
-        raise Tag::NicoTagNormalisationError
-      end
 
+    ApplicationRecord.transaction do
       TagVersioning.record_tag_snapshots!(linked_tags, created_by_user: current_user)
 
       tag.linked_tags = linked_tags
@@ -94,21 +47,5 @@ class NicoTagsController < ApplicationController
     end
 
     render json: tag.linked_tags.map { |t| TagRepr.base(t) }, status: :ok
-  rescue Tag::NicoTagNormalisationError
-    render_validation_error fields: { tags: ['ニコニコ・タグ同士は連携できません．'] }
-  rescue ActiveRecord::RecordInvalid => e
-    render_nico_tag_form_record_invalid e.record
-  end
-
-  private
-
-  def render_nico_tag_form_record_invalid record
-    if record.is_a?(TagName) || record.is_a?(Tag)
-      render_validation_error fields: { tags: record.errors.full_messages.map { |message|
-        "タグ名 “#{ record.name }”: #{ message }"
-      } }
-    else
-      render_validation_error record
-    end
   end
 end

backend/app/controllers/posts_controller.rb

@@ -44,8 +44,7 @@ class PostsController < ApplicationController
         filtered_posts
         .joins("LEFT JOIN (#{ pt_max_sql }) pt_max ON pt_max.post_id = posts.id")
         .reselect('posts.*', Arel.sql("#{ updated_at_all_sql } AS updated_at_all"))
-        .preload(:uploaded_user, :parents, :children,
+        .preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
-                 tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
         .with_attached_thumbnail
 
     q = q.where('posts.url LIKE ?', "%#{ url }%") if url
@@ -96,9 +95,7 @@ class PostsController < ApplicationController
   end
 
   def random
-    post = filtered_posts.preload(:uploaded_user, :parents, :children,
+    post = filtered_posts.preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
-                                  tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
-                         .with_attached_thumbnail
                          .order('RAND()')
                          .first
     return head :not_found unless post
@@ -107,25 +104,12 @@ class PostsController < ApplicationController
   end
 
   def show
-    post =
+    post = Post.includes(tags: [:deerjikists, :materials, { tag_name: :wiki_page }]).find_by(id: params[:id])
-        Post
-        .includes(:uploaded_user, :parents, :children,
-                  tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
-        .with_attached_thumbnail
-        .find_by(id: params[:id])
     return head :not_found unless post
 
-    parent_posts = post.parents.with_attached_thumbnail.order(:id).to_a
+    render json: PostRepr.base(post, current_user)
-    child_posts = post.children.with_attached_thumbnail.order(:id).to_a
+                         .merge(tags: build_tag_tree_for(post.tags),
-    sibling_posts = sibling_posts_by_parent(parent_posts.map(&:id))
+                                related: PostRepr.many(post.related(limit: 20)))
-    related = post.related(limit: 20).to_a
-
-    render json: PostRepr.detail(post, current_user,
-                                 parent_posts:,
-                                 child_posts:,
-                                 sibling_posts:,
-                                 related:)
-                         .merge(tags: build_tag_tree_for(post.tags))
   end
 
   def create
@@ -164,11 +148,11 @@ class PostsController < ApplicationController
     post.reload
     render json: PostRepr.base(post), status: :created
   rescue Tag::NicoTagNormalisationError
-    render_validation_error fields: { tags: 'ニコニコ・タグは直接指定できません．' }
+    head :bad_request
   rescue ArgumentError => e
-    render_validation_error fields: { parent_post_ids: [e.message] }
+    render json: { errors: [e.message] }, status: :unprocessable_entity
   rescue ActiveRecord::RecordInvalid => e
-    render_post_form_record_invalid e.record
+    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
   end
 
   def viewed
@@ -191,10 +175,10 @@ class PostsController < ApplicationController
 
     force = bool?(:force)
     merge = bool?(:merge)
-    return render_bad_request('force と merge は同時に指定できません．') if force && merge
+    return head :bad_request if force && merge
 
     base_version_no = parse_base_version_no
-    return render_bad_request('base_version_no は必須です．') if !(force) && !(base_version_no)
+    return head :bad_request if !(force) && !(base_version_no)
 
     title = params[:title].presence
     tag_names = params[:tags].to_s.split
@@ -254,11 +238,11 @@ class PostsController < ApplicationController
     json['tags'] = build_tag_tree_for(post.tags)
     render json:, status: :ok
   rescue Tag::NicoTagNormalisationError
-    render_validation_error fields: { tags: ['ニコニコ・タグは直接指定できません．'] }
+    head :bad_request
   rescue ArgumentError => e
-    render_validation_error fields: { parent_post_ids: [e.message] }
+    render json: { errors: [e.message] }, status: :unprocessable_entity
   rescue ActiveRecord::RecordInvalid => e
-    render_post_form_record_invalid e.record
+    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
   end
 
   def changes
@@ -401,7 +385,7 @@ class PostsController < ApplicationController
       return nil unless tag
 
       if path.include?(tag_id)
-        return TagRepr.inline(tag).merge(children: [])
+        return TagRepr.base(tag).merge(children: [])
       end
 
       if memo.key?(tag_id)
@@ -413,26 +397,12 @@ class PostsController < ApplicationController
 
       children = child_ids.filter_map { |cid| build_node.(cid, new_path) }
 
-      memo[tag_id] = TagRepr.inline(tag).merge(children:)
+      memo[tag_id] = TagRepr.base(tag).merge(children:)
     end
 
     root_ids.filter_map { |id| build_node.call(id, []) }
   end
 
-  def sibling_posts_by_parent parent_post_ids
-    return { } if parent_post_ids.blank?
-
-    implications =
-        PostImplication
-        .where(parent_post_id: parent_post_ids)
-        .includes(post: { thumbnail_attachment: :blob })
-        .order(:parent_post_id, :post_id)
-
-    implications.group_by(&:parent_post_id).transform_values { |items|
-      items.map(&:post)
-    }
-  end
-
   def parse_parent_post_ids
     raise ArgumentError, 'parent_post_ids は必須です．' unless params.key?(:parent_post_ids)
 
@@ -446,7 +416,7 @@ class PostsController < ApplicationController
 
   def sync_parent_posts! post, parent_post_ids
     if parent_post_ids.include?(post.id)
-      post.errors.add :parent_post_ids, '自分自身を親投稿にはできません．'
+      post.errors.add(:base, '自分自身を親投稿にはできません．')
       raise ActiveRecord::RecordInvalid, post
     end
 
@@ -454,8 +424,7 @@ class PostsController < ApplicationController
     missing_ids = parent_post_ids - existing_ids
 
     if missing_ids.present?
-      post.errors.add :parent_post_ids,
+      post.errors.add(:base, "存在しない親投稿 ID があります: #{ missing_ids.join(' ') }")
-                      "存在しない親投稿 Id. があります: #{ missing_ids.join(' ') }"
       raise ActiveRecord::RecordInvalid, post
     end
 
@@ -671,14 +640,4 @@ class PostsController < ApplicationController
 
     merged.uniq.sort
   end
-
-  def render_post_form_record_invalid record
-    if record.is_a?(TagName) || record.is_a?(Tag)
-      render_validation_error fields: { tags: record.errors.full_messages.map { |message|
-        "タグ名 “#{ record.name }”: #{ message }"
-      } }
-    else
-      render_validation_error record
-    end
-  end
 end

backend/app/controllers/preview_controller.rb

@@ -4,7 +4,7 @@ class PreviewController < ApplicationController
     return head :unauthorized unless current_user
 
     url = params[:url]
-    return render_bad_request('URL は必須です．') unless url.present?
+    return head :bad_request unless url.present?
 
     unless url.start_with?(/http(s)?:\/\//)
       url = 'http://' + url
@@ -16,7 +16,7 @@ class PreviewController < ApplicationController
 
     render json: { title: title }
   rescue => e
-    render_bad_request(e.message)
+    render json: { error: e.message }, status: :bad_request
   end
 
   def thumbnail
@@ -25,7 +25,7 @@ class PreviewController < ApplicationController
     return head :unauthorized unless current_user
 
     url = params[:url]
-    return render_bad_request('URL は必須です．') if url.blank?
+    return head :bad_request if url.blank?
 
     unless url.start_with?(/http(s)?:\/\//)
       url = 'http://' + url
@@ -40,11 +40,7 @@ class PreviewController < ApplicationController
       File.delete(path) rescue nil
       send_file image.path, type: 'image/png', disposition: 'inline'
     else
-      render json: { type: 'internal_server_error',
+      render json: { error: 'Failed to generate thumbnail' }, status: :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/controllers/tag_children_controller.rb

@@ -5,12 +5,11 @@ class TagChildrenController < ApplicationController
 
     parent_id = params[:parent_id]
     child_id = params[:child_id]
-    return render_bad_request('parent_id は必須です．') if parent_id.blank?
+    return head :bad_request if parent_id.blank? || child_id.blank?
-    return render_bad_request('child_id は必須です．') if child_id.blank?
 
     parent = Tag.find(parent_id)
     child = Tag.find(child_id)
-    return render_bad_request('ニコニコ・タグの階層は変更できません．') if parent.nico? || child.nico?
+    return head :bad_request if parent.nico? || child.nico?
 
     ApplicationRecord.transaction do
       TagVersioning.ensure_snapshot!(child, created_by_user: current_user)
@@ -28,12 +27,11 @@ class TagChildrenController < ApplicationController
 
     parent_id = params[:parent_id]
     child_id = params[:child_id]
-    return render_bad_request('parent_id は必須です．') if parent_id.blank?
+    return head :bad_request if parent_id.blank? || child_id.blank?
-    return render_bad_request('child_id は必須です．') if child_id.blank?
 
     parent = Tag.find(parent_id)
     child = Tag.find(child_id)
-    return render_bad_request('ニコニコ・タグの階層は変更できません．') if parent.nico? || child.nico?
+    return head :bad_request if parent.nico? || child.nico?
 
     ApplicationRecord.transaction do
       TagVersioning.ensure_snapshot!(child, created_by_user: current_user)

backend/app/controllers/tags_controller.rb

@@ -168,7 +168,7 @@ class TagsController < ApplicationController
 
   def show_by_name
     name = params[:name].to_s.strip
-    return render_bad_request('name は必須です．') if name.blank?
+    return head :bad_request if name.blank?
 
     tag = Tag.joins(:tag_name)
              .includes(:tag_name, :materials, tag_name: :wiki_page)
@@ -192,7 +192,7 @@ class TagsController < ApplicationController
 
   def deerjikists_by_name
     name = params[:name].to_s.strip
-    return render_bad_request('name は必須です．') if name.blank?
+    return head :bad_request if name.blank?
 
     tag = Tag.joins(:tag_name)
              .includes(:tag_name, tag_name: :wiki_page)
@@ -214,24 +214,21 @@ class TagsController < ApplicationController
 
     ApplicationRecord.transaction do
       tag.deerjikists = []
-      params[:_json].each.with_index do |item, i|
+      params[:_json].each do
-        platform = item[:platform]
+        platform = _1[:platform]
-        code = normalise_deerjikist_code(platform, item[:code])
+        code = normalise_deerjikist_code(platform, _1[:code])
         deerjikist = Deerjikist.find_or_initialize_by(platform:, code:)
         deerjikist.tag = tag
-        render_deerjikist_form_record_invalid(deerjikist, i) unless deerjikist.save
+        deerjikist.save!
-        raise ActiveRecord::Rollback if performed?
       end
     end
 
-    return if performed?
-
     render json: DeerjikistRepr.many(tag.reload.deerjikists)
   end
 
   def materials_by_name
     name = params[:name].to_s.strip
-    return render_bad_request('name は必須です．') if name.blank?
+    return head :bad_request if name.blank?
 
     tag = Tag.joins(:tag_name)
              .includes(:tag_name, :materials, tag_name: :wiki_page)
@@ -250,16 +247,17 @@ class TagsController < ApplicationController
 
     name = params[:name].to_s.strip
     category = params[:category].to_s.strip
-    return render_unprocessable_entity('名前は必須です．', field: :name) if name.blank?
+    return head :unprocessable_entity if name.blank? || category.blank?
-    return render_unprocessable_entity('カテゴリは必須です．', field: :category) if category.blank?
 
     if name != tag.name &&
         tag.in?([Tag.tagme, Tag.bot, Tag.no_deerjikist, Tag.video, Tag.niconico])
-      return render_unprocessable_entity('システム・タグの名称は変更できません．', field: :name)
+      return render json: { error: 'システム・タグの名称は変更できません．' },
+                    status: :unprocessable_entity
     end
 
     if tag.nico? || category == 'nico'
-      return render_unprocessable_entity('ニコタグは変更できません．', field: :category)
+      return render json: { error: 'ニコタグは変更できません．' },
+                    status: :unprocessable_entity
     end
 
     alias_names = params[:aliases].to_s.split.uniq
@@ -304,7 +302,8 @@ class TagsController < ApplicationController
     tag = Tag.find(params[:id])
 
     if tag.nico? || (category.present? && category == 'nico')
-      return render_unprocessable_entity('ニコタグは変更できません．', field: :category)
+      return render json: { error: 'ニコタグは変更できません．' },
+                    status: :unprocessable_entity
     end
 
     ApplicationRecord.transaction do
@@ -438,23 +437,4 @@ class TagsController < ApplicationController
   rescue
     nil
   end
-
-  def render_deerjikist_form_record_invalid deerjikist, index
-    fields = { }
-
-    deerjikist.errors.each do |error|
-      field =
-          case error.attribute
-          when :platform, :code
-            "deerjikists.#{ index }.#{ error.attribute }"
-          else
-            :deerjikists
-          end
-
-      fields[field] ||= []
-      fields[field] << error.full_message
-    end
-
-    render_validation_error fields:
-  end
 end

backend/app/controllers/theatre_comments_controller.rb

@@ -1,28 +1,21 @@
 class TheatreCommentsController < ApplicationController
   def index
-    limit = params[:limit].to_i
-    limit = 20 if limit <= 0
-
     no_gt = params[:no_gt].to_i
-    no_gt = 0 if no_gt < 0
+    no_gt = 0 if no_gt.negative?
 
     comments = TheatreComment
                .where(theatre_id: params[:theatre_id])
                .where('no > ?', no_gt)
                .order(no: :desc)
-               .limit(limit)
 
-    render json: comments.map {
+    render json: comments.as_json(include: { user: { only: [:id, :name] } })
-      _1.as_json(include: { user: { only: [:id, :name] } })
-          .merge(content: _1.discarded? ? nil : _1.content, deleted: _1.discarded?)
-    }
   end
 
   def create
     return head :unauthorized unless current_user
 
     content = params[:content]
-    return render_unprocessable_entity('本文は必須です．', field: :content) if content.blank?
+    return head :unprocessable_entity if content.blank?
 
     theatre = Theatre.find_by(id: params[:theatre_id])
     return head :not_found unless theatre
@@ -36,19 +29,4 @@ class TheatreCommentsController < ApplicationController
 
     render json: comment, status: :created
   end
-
-  def destroy
-    return head :unauthorized unless current_user
-
-    theatre_id = params[:theatre_id].to_i
-    no = params[:id].to_i
-
-    comment = TheatreComment.find_by(theatre_id:, no:)
-    return head :not_found unless comment
-    return head :forbidden unless comment.user == current_user
-
-    comment.discard!
-
-    head :no_content
-  end
 end

backend/app/controllers/theatre_programmes_controller.rb

@@ -1,22 +0,0 @@
-class TheatreProgrammesController < ApplicationController
-  def index
-    limit = params[:limit].to_i
-    limit = 100 if limit <= 0
-
-    position_gt = params[:position_gt].to_i
-    position_gt = 0 if position_gt < 0
-
-    programmes = TheatreProgramme
-                 .where(theatre_id: params[:theatre_id])
-                 .where('position > ?', position_gt)
-                 .includes(:post)
-                 .order(position: :desc).limit(100)
-                 .limit(limit)
-
-    render json: programmes.map { |programme|
-      programme.as_json.merge(post: { id: programme.post.id,
-                                      title: programme.post.title,
-                                      url: programme.post.url })
-    }
-  end
-end

backend/app/controllers/theatre_skip_events_controller.rb

@@ -1,22 +0,0 @@
-class TheatreSkipEventsController < ApplicationController
-  def index
-    limit = params[:limit].to_i
-    limit = 50 if limit <= 0
-
-    events =
-        TheatreSkipEvent
-        .where(theatre_id: params[:theatre_id])
-        .includes(:post, tags: :tag_name)
-        .order(created_at: :desc)
-        .limit(limit)
-
-    render json: events.map { |event|
-      { id: event.id,
-        theatre_id: event.theatre_id,
-        post: { id: event.post.id, title: event.post.title, url: event.post.url },
-        tags: event.tags.map { |tag| { id: tag.id, name: tag.name } },
-        programme_position: event.programme_position,
-        created_at: event.created_at }
-    }
-  end
-end

backend/app/controllers/theatres_controller.rb

@@ -31,7 +31,9 @@ class TheatresController < ApplicationController
       post_started_at = theatre.current_post_started_at
     end
 
-    render json: theatre_info_json(theatre, host_flg:, post_id:, post_started_at:)
+    render json: {
+        host_flg:, post_id:, post_started_at:,
+        watching_users: theatre.watching_users.as_json(only: [:id, :name]) }
   end
 
   def next_post
@@ -41,119 +43,12 @@ class TheatresController < ApplicationController
     return head :not_found unless theatre
     return head :forbidden if theatre.host_user != current_user
 
-    ApplicationRecord.transaction do
+    post = Post.where("url LIKE '%nicovideo.jp%'")
-      theatre.lock!
+           .or(Post.where("url LIKE '%youtube.com%'"))
-      TheatrePostAdvancer.call(theatre:)
+           .order('RAND()')
-    end
+           .first
+    theatre.update!(current_post: post, current_post_started_at: Time.current)
 
     head :no_content
   end
-
-  def skip_vote
-    return head :unauthorized unless current_user
-
-    theatre = Theatre.find_by(id: params[:id])
-    return head :not_found unless theatre
-    requested_post_id = params[:post_id].to_i
-    return head :unprocessable_entity if requested_post_id <= 0
-
-    skipped = false
-    conflicted = false
-
-    ApplicationRecord.transaction do
-      theatre.lock!
-      if theatre.current_post
-        TheatreWatchingUser.find_or_initialize_by(theatre:, user: current_user).tap {
-          _1.expires_at = 30.seconds.from_now
-        }.save!
-
-        if theatre.current_post_id != requested_post_id
-          conflicted = true
-          next
-        end
-
-        TheatreSkipVote.find_or_create_by!(theatre:, post_id: requested_post_id, user: current_user)
-
-        vote_status = skip_vote_status(theatre)
-        if vote_status[:votes_count] >= vote_status[:required_count]
-          TheatreSkipFinalizer.call(theatre:, user: current_user)
-          TheatrePostAdvancer.call(theatre:)
-          skipped = true
-        end
-      end
-    end
-
-    theatre.reload
-    return render json: theatre_info_json(theatre, skipped: false), status: :conflict if conflicted
-
-    render json: theatre_info_json(theatre, skipped:)
-  end
-
-  def unskip_vote
-    return head :unauthorized unless current_user
-
-    theatre = Theatre.find_by(id: params[:id])
-    return head :not_found unless theatre
-    requested_post_id = params[:post_id].to_i
-    return head :unprocessable_entity if requested_post_id <= 0
-
-    conflicted = false
-
-    theatre.with_lock do
-      if theatre.current_post
-        if theatre.current_post_id != requested_post_id
-          conflicted = true
-        else
-          TheatreSkipVote.where(theatre:, post_id: requested_post_id, user: current_user).delete_all
-        end
-      end
-    end
-
-    theatre.reload
-    return render json: theatre_info_json(theatre, skipped: false), status: :conflict if conflicted
-
-    render json: theatre_info_json(theatre, skipped: false)
-  end
-
-  def post_selection_weights
-    theatre = Theatre.find_by(id: params[:id])
-    return head :not_found unless theatre
-
-    render json: TheatrePostSelector.new(theatre:).weight_json
-  end
-
-  private
-
-  def theatre_info_json(theatre, host_flg: nil, post_id: nil, post_started_at: nil, skipped: nil)
-    host_flg = theatre.host_user_id == current_user&.id if host_flg.nil?
-    post_id = theatre.current_post_id if post_id.nil?
-    post_started_at = theatre.current_post_started_at if post_started_at.nil?
-
-    json = { host_flg:,
-             post_id:,
-             post_started_at:,
-             post_elapsed_ms: post_started_at ? ((Time.current - post_started_at) * 1000).floor : nil,
-             watching_users: theatre.watching_users.as_json(only: [:id, :name]),
-             skip_vote: skip_vote_status(theatre) }
-    json[:skipped] = skipped unless skipped.nil?
-    json
-  end
-
-  def skip_vote_status(theatre)
-    watching_user_ids = theatre.watching_users.ids
-    watching_users_count = watching_user_ids.size
-    required_count = (watching_users_count / 2) + 1
-    post = theatre.current_post
-    votes =
-        if post
-          TheatreSkipVote.where(theatre:, post:, user_id: watching_user_ids)
-        else
-          TheatreSkipVote.none
-        end
-
-    { votes_count: post ? votes.count : 0,
-      required_count:,
-      watching_users_count:,
-      voted: post && current_user ? votes.exists?(user_id: current_user.id) : false }
-  end
 end

backend/app/controllers/users_controller.rb

@@ -42,12 +42,12 @@ class UsersController < ApplicationController
     return head :unauthorized if user&.id != params[:id].to_i
 
     name = params[:name]
-    return render_unprocessable_entity('名前は必須です．', field: :name) if name.blank?
+    return head :bad_request if name.blank?
 
     if user.update(name:)
       render json: user.slice(:id, :name, :inheritance_code, :role), status: :ok
     else
-      render_validation_error user
+      render json: user.errors, status: :unprocessable_entity
     end
   end
 

backend/app/controllers/wiki_pages_controller.rb

@@ -46,7 +46,7 @@ class WikiPagesController < ApplicationController
 
   def diff
     id = params[:id]
-    return render_bad_request('id は必須です．') if id.blank?
+    return head :bad_request if id.blank?
 
     from = params[:from].presence
     to = params[:to].presence
@@ -56,7 +56,7 @@ class WikiPagesController < ApplicationController
     from_rev = from && page.wiki_revisions.find(from)
     to_rev = to ? page.wiki_revisions.find(to) : page.current_revision
     if ((from_rev && !(from_rev.content?)) || !(to_rev&.content?))
-      return render_unprocessable_entity('差分を表示できない版です．')
+      return head :unprocessable_entity
     end
 
     diffs = Diff::LCS.sdiff(from_rev&.body&.lines || [], to_rev.body.lines)
@@ -89,8 +89,7 @@ class WikiPagesController < ApplicationController
     body = params[:body].to_s
     message = params[:message].presence
 
-    return render_unprocessable_entity('タイトルは必須です．', field: :title) if title.blank?
+    return head :unprocessable_entity if title.blank? || body.blank?
-    return render_unprocessable_entity('本文は必須です．', field: :body) if body.blank?
 
     tag_name = TagName.find_undiscard_or_create_by!(name: title)
 
@@ -102,10 +101,8 @@ class WikiPagesController < ApplicationController
             message:)
 
     render json: WikiPageRepr.base(page), status: :created
-  rescue ActiveRecord::RecordInvalid => e
+  rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
-    render_validation_error e.record
+    head :unprocessable_entity
-  rescue ActiveRecord::RecordNotUnique
-    render_record_not_unique
   end
 
   def update
@@ -115,8 +112,7 @@ class WikiPagesController < ApplicationController
     title = params[:title]&.strip
     body = params[:body].to_s
 
-    return render_unprocessable_entity('タイトルは必須です．', field: :title) if title.blank?
+    return head :unprocessable_entity if title.blank? || body.blank?
-    return render_unprocessable_entity('本文は必須です．', field: :body) if body.blank?
 
     page = WikiPage.find(params[:id])
     base_revision_id = params[:base_revision_id].presence

backend/app/models/post.rb

@@ -94,7 +94,7 @@ class Post < ApplicationRecord
     return if !(f) || !(b)
 
     if f >= b
-      errors.add :original_created_at, 'オリジナルの作成日時の順番がをかしぃです．'
+      errors.add :original_created_before, 'オリジナルの作成日時の順番がをかしぃです．'
     end
   end
 

backend/app/models/tag.rb

@@ -81,7 +81,7 @@ class Tag < ApplicationRecord
 
   def material_id = materials.first&.id
 
-  def has_deerjikists = deerjikists.loaded? ? deerjikists.any? : deerjikists.exists?
+  def has_deerjikists = deerjikists.present?
 
   def self.tagme = find_or_create_by_tag_name!('タグ希望', category: :meta)
   def self.bot = find_or_create_by_tag_name!('bot操作', category: :meta)

backend/app/models/theatre.rb

@@ -7,10 +7,6 @@ class Theatre < ApplicationRecord
            class_name: 'TheatreWatchingUser', inverse_of: :theatre
   has_many :watching_users, through: :active_theatre_watching_users, source: :user
 
-  has_many :programmes, class_name: 'TheatreProgramme'
-  has_many :skip_votes, class_name: 'TheatreSkipVote', dependent: :delete_all
-  has_many :skip_events, class_name: 'TheatreSkipEvent', dependent: :delete_all
-
   belongs_to :host_user, class_name: 'User', optional: true
   belongs_to :current_post, class_name: 'Post', optional: true
   belongs_to :created_by_user, class_name: 'User'

backend/app/models/theatre_programme.rb

@@ -1,6 +0,0 @@
-class TheatreProgramme < ApplicationRecord
-  self.primary_key = :theatre_id, :position
-
-  belongs_to :theatre
-  belongs_to :post
-end

backend/app/models/theatre_skip_event.rb

@@ -1,10 +0,0 @@
-class TheatreSkipEvent < ApplicationRecord
-  belongs_to :theatre
-  belongs_to :post
-  belongs_to :skipped_by_user, class_name: 'User'
-
-  has_many :voters, class_name: 'TheatreSkipEventVoter', dependent: :delete_all
-  has_many :event_tags, class_name: 'TheatreSkipEventTag', dependent: :delete_all
-  has_many :users, through: :voters
-  has_many :tags, through: :event_tags
-end

backend/app/models/theatre_skip_event_tag.rb

@@ -1,6 +0,0 @@
-class TheatreSkipEventTag < ApplicationRecord
-  self.primary_key = :theatre_skip_event_id, :tag_id
-
-  belongs_to :theatre_skip_event
-  belongs_to :tag
-end

backend/app/models/theatre_skip_event_voter.rb

@@ -1,6 +0,0 @@
-class TheatreSkipEventVoter < ApplicationRecord
-  self.primary_key = :theatre_skip_event_id, :user_id
-
-  belongs_to :theatre_skip_event
-  belongs_to :user
-end

backend/app/models/theatre_skip_vote.rb

@@ -1,7 +0,0 @@
-class TheatreSkipVote < ApplicationRecord
-  self.primary_key = :theatre_id, :post_id, :user_id
-
-  belongs_to :theatre
-  belongs_to :post
-  belongs_to :user
-end

backend/app/representations/post_repr.rb

@@ -2,65 +2,20 @@
 
 
 module PostRepr
-  BASE_FIELDS = [
+  BASE = { include: { tags: TagRepr::BASE, uploaded_user: UserRepr::BASE },
-      :id,
+           methods: [:parent_posts, :child_posts, :sibling_posts] }.freeze
-      :version_no,
-      :url,
-      :title,
-      :thumbnail_base,
-      :original_created_from,
-      :original_created_before,
-      :created_at,
-      :updated_at
-  ].freeze
 
   module_function
 
   def base post, current_user = nil
-    json = common(post)
+    json = post.as_json(BASE)
-    json['tags'] = tag_json(post.tags)
+    return json.merge(viewed: false) unless current_user
-    json['uploaded_user'] = post.uploaded_user && UserRepr.base(post.uploaded_user)
-    json['viewed'] = current_user ? current_user.viewed?(post) : false
-    json
-  end
 
-  def detail post, current_user = nil, parent_posts: [], child_posts: [],
+    viewed = current_user.viewed?(post)
-             sibling_posts: { }, related: []
+    json.merge(viewed:)
-    base(post, current_user).merge(
-        'parent_posts' => cards(parent_posts),
-        'child_posts' => cards(child_posts),
-        'sibling_posts' => sibling_posts.transform_keys(&:to_s).transform_values { |posts|
-          cards(posts)
-        },
-        'related' => cards(related))
-  end
-
-  def card post
-    common(post).merge('parent_posts' => [], 'child_posts' => [])
-  end
-
-  def cards posts
-    posts.map { |post| card(post) }
   end
 
   def many posts, current_user = nil
     posts.map { |p| base(p, current_user) }
   end
-
-  def common post
-    BASE_FIELDS.to_h { |field| [field.to_s, post.public_send(field)] }
-               .merge('thumbnail' => thumbnail_url(post))
-  end
-
-  def tag_json tags
-    tags.map { |tag| TagRepr.inline(tag) }
-  end
-
-  def thumbnail_url post
-    return nil unless post.thumbnail.attached?
-
-    Rails.application.routes.url_helpers.rails_blob_url(post.thumbnail, only_path: false)
-  rescue
-    nil
-  end
 end

backend/app/representations/tag_repr.rb

@@ -12,9 +12,5 @@ module TagRepr
                             parents: tag.parents.map { _1.as_json(BASE) })
   end
 
-  def inline tag
-    tag.as_json(BASE).merge(aliases: [], parents: [])
-  end
-
   def many(tags) = tags.map { |t| base(t) }
 end

backend/app/services/theatre_post_advancer.rb

@@ -1,29 +0,0 @@
-class TheatrePostAdvancer
-  def self.call(theatre:)
-    new(theatre:).call
-  end
-
-  def initialize(theatre:)
-    @theatre = theatre
-  end
-
-  def call
-    previous_post = theatre.current_post
-    post = TheatrePostSelector.new(theatre:).select
-
-    TheatreSkipVote.where(theatre:, post: previous_post).delete_all if previous_post
-
-    theatre.update!(current_post: post, current_post_started_at: post ? Time.current : nil)
-
-    if post
-      position = (theatre.programmes.maximum(:position) || 0) + 1
-      theatre.programmes.create!(position:, post:)
-    end
-
-    post
-  end
-
-  private
-
-  attr_reader :theatre
-end

backend/app/services/theatre_post_selector.rb

@@ -1,119 +0,0 @@
-class TheatrePostSelector
-  Candidate = Struct.new(:post, :weight, :penalty, :tags, keyword_init: true)
-  ELIGIBLE_POST_URL_CONDITION =
-      ["url LIKE '%nicovideo.jp%'",
-       "url LIKE '%youtube.com/watch%'",
-       "url LIKE '%youtu.be/%'"]
-      .join(' OR ')
-
-  def initialize theatre:
-    @theatre = theatre
-  end
-
-  def select
-    candidates = weighted_candidates
-    return nil if candidates.empty?
-
-    total = candidates.sum(&:weight)
-    target = rand * total
-
-    candidates.each do |candidate|
-      target -= candidate.weight
-      return candidate.post if target <= 0
-    end
-
-    candidates.last.post
-  end
-
-  def weight_json limit: 20
-    candidates = weighted_candidates
-    sorted = candidates.sort_by { |candidate| [candidate.weight, candidate.post.id] }
-
-    { tag_penalties: tag_penalty_json,
-      lightest_posts: post_weight_json(sorted.first(limit)),
-      heaviest_posts: post_weight_json(sorted.reverse.first(limit)) }
-  end
-
-  private
-
-  attr_reader :theatre
-
-  def weighted_candidates
-    @weighted_candidates ||= begin
-      penalties = tag_penalties
-      posts = eligible_posts.includes(tags: :tag_name).to_a
-
-      posts.map do |post|
-        post_tags = post.tags.to_a
-        penalty = post_tags.sum { |tag| penalties[tag.id].to_i }
-
-        Candidate.new(
-            post:,
-            penalty:,
-            tags: post_tags,
-            weight: 1.0 / (1.0 + penalty))
-      end
-    end
-  end
-
-  def eligible_posts
-    posts = Post.where(ELIGIBLE_POST_URL_CONDITION)
-    posts = posts.where.not(id: theatre.current_post_id) if theatre.current_post_id
-    posts
-  end
-
-  def active_user_ids
-    @active_user_ids ||= theatre.watching_users.ids
-  end
-
-  def tag_penalties
-    @tag_penalties ||=
-      if active_user_ids.empty?
-        {}
-      else
-        TheatreSkipEventVoter
-          .joins(theatre_skip_event: :event_tags)
-          .where(user_id: active_user_ids)
-          .group('theatre_skip_event_tags.tag_id')
-          .count
-      end
-  end
-
-  def tag_penalty_json
-    return [] if tag_penalties.empty?
-
-    tags = Tag.where(id: tag_penalties.keys).includes(:tag_name).index_by(&:id)
-
-    tag_penalties
-      .map { |tag_id, penalty|
-        tag = tags[tag_id]
-        next unless tag
-
-        { tag: light_tag_json(tag),
-          penalty: }
-      }
-      .compact
-      .sort_by { |row| [-row[:penalty], row[:tag][:name].to_s] }
-  end
-
-  def post_weight_json candidates
-    candidates.map { |candidate|
-      { post: light_post_json(candidate.post),
-        weight: candidate.weight,
-        penalty: candidate.penalty,
-        tags: candidate.tags.map { |tag| light_tag_json(tag) } }
-    }
-  end
-
-  def light_post_json post
-    { id: post.id,
-      title: post.title,
-      url: post.url }
-  end
-
-  def light_tag_json tag
-    { id: tag.id,
-      name: tag.name,
-      category: tag.category }
-  end
-end

backend/app/services/theatre_skip_finalizer.rb

@@ -1,40 +0,0 @@
-class TheatreSkipFinalizer
-  def self.call(theatre:, user:)
-    new(theatre:, user:).call
-  end
-
-  def initialize(theatre:, user:)
-    @theatre = theatre
-    @user = user
-  end
-
-  def call
-    return unless theatre.current_post
-
-    post = theatre.current_post
-    voters = TheatreSkipVote.where(theatre:, post:).includes(:user).map(&:user)
-    return if voters.empty?
-
-    event = TheatreSkipEvent.create!(
-        theatre:,
-        post:,
-        skipped_by_user: user,
-        programme_position: theatre.programmes.maximum(:position))
-
-    voters.uniq(&:id).each do |voter|
-      TheatreSkipEventVoter.create!(theatre_skip_event: event, user: voter)
-    end
-
-    post.tags.find_each do |tag|
-      TheatreSkipEventTag.create!(theatre_skip_event: event, tag:)
-    end
-
-    TheatreSkipVote.where(theatre:, post:).delete_all
-
-    event
-  end
-
-  private
-
-  attr_reader :theatre, :user
-end

backend/config/routes.rb

@@ -85,14 +85,9 @@ Rails.application.routes.draw do
     member do
       put :watching
       patch :next_post
-      put :skip_vote
-      delete :skip_vote, action: :unskip_vote
-      get :post_selection_weights
     end
 
-    resources :comments, controller: :theatre_comments, only: [:index, :create, :destroy]
+    resources :comments, controller: :theatre_comments, only: [:index, :create]
-    resources :programmes, controller: :theatre_programmes, only: [:index]
-    resources :skip_events, controller: :theatre_skip_events, only: [:index]
   end
 
   resources :materials, only: [:index, :show, :create, :update, :destroy]

backend/db/migrate/20260514221900_create_theatre_programmes.rb

@@ -1,10 +0,0 @@
-class CreateTheatreProgrammes < ActiveRecord::Migration[8.0]
-  def change
-    create_table :theatre_programmes, primary_key: [:theatre_id, :position] do |t|
-      t.references :theatre, null: false, foreign_key: true
-      t.integer :position, null: false
-      t.references :post, null: false, foreign_key: true
-      t.datetime :created_at, null: false
-    end
-  end
-end

backend/db/migrate/20260606000000_create_theatre_skip_votes_and_events.rb

@@ -1,36 +0,0 @@
-class CreateTheatreSkipVotesAndEvents < ActiveRecord::Migration[8.0]
-  def change
-    create_table :theatre_skip_votes, primary_key: [:theatre_id, :post_id, :user_id] do |t|
-      t.references :theatre, null: false, foreign_key: true
-      t.references :post, null: false, foreign_key: true
-      t.references :user, null: false, foreign_key: true
-      t.timestamps
-    end
-
-    create_table :theatre_skip_events do |t|
-      t.references :theatre, null: false, foreign_key: true
-      t.references :post, null: false, foreign_key: true
-      t.references :skipped_by_user, null: false, foreign_key: { to_table: :users }
-      t.integer :programme_position
-      t.datetime :created_at, null: false
-    end
-
-    create_table :theatre_skip_event_voters, primary_key: [:theatre_skip_event_id, :user_id] do |t|
-      t.references :theatre_skip_event, null: false, foreign_key: true
-      t.references :user, null: false, foreign_key: true
-    end
-
-    create_table :theatre_skip_event_tags, primary_key: [:theatre_skip_event_id, :tag_id] do |t|
-      t.references :theatre_skip_event, null: false, foreign_key: true
-      t.references :tag, null: false, foreign_key: true
-    end
-
-    add_index :theatre_skip_events, [:theatre_id, :created_at]
-    add_index :theatre_skip_votes, [:theatre_id, :post_id, :created_at],
-              name: 'idx_theatre_skip_votes_theatre_post_created'
-    add_index :theatre_skip_event_voters, [:user_id, :theatre_skip_event_id],
-              name: 'idx_theatre_skip_event_voters_user_event'
-    add_index :theatre_skip_event_tags, [:tag_id, :theatre_skip_event_id],
-              name: 'idx_theatre_skip_event_tags_tag_event'
-  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_06_06_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) 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
@@ -283,55 +283,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_06_000000) do
     t.index ["user_id"], name: "index_theatre_comments_on_user_id"
   end
 
-  create_table "theatre_programmes", primary_key: ["theatre_id", "position"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_id", null: false
-    t.integer "position", null: false
-    t.bigint "post_id", null: false
-    t.datetime "created_at", null: false
-    t.index ["post_id"], name: "index_theatre_programmes_on_post_id"
-    t.index ["theatre_id"], name: "index_theatre_programmes_on_theatre_id"
-  end
-
-  create_table "theatre_skip_event_tags", primary_key: ["theatre_skip_event_id", "tag_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_skip_event_id", null: false
-    t.bigint "tag_id", null: false
-    t.index ["tag_id", "theatre_skip_event_id"], name: "idx_theatre_skip_event_tags_tag_event"
-    t.index ["tag_id"], name: "index_theatre_skip_event_tags_on_tag_id"
-    t.index ["theatre_skip_event_id"], name: "index_theatre_skip_event_tags_on_theatre_skip_event_id"
-  end
-
-  create_table "theatre_skip_event_voters", primary_key: ["theatre_skip_event_id", "user_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_skip_event_id", null: false
-    t.bigint "user_id", null: false
-    t.index ["theatre_skip_event_id"], name: "index_theatre_skip_event_voters_on_theatre_skip_event_id"
-    t.index ["user_id", "theatre_skip_event_id"], name: "idx_theatre_skip_event_voters_user_event"
-    t.index ["user_id"], name: "index_theatre_skip_event_voters_on_user_id"
-  end
-
-  create_table "theatre_skip_events", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_id", null: false
-    t.bigint "post_id", null: false
-    t.bigint "skipped_by_user_id", null: false
-    t.integer "programme_position"
-    t.datetime "created_at", null: false
-    t.index ["post_id"], name: "index_theatre_skip_events_on_post_id"
-    t.index ["skipped_by_user_id"], name: "index_theatre_skip_events_on_skipped_by_user_id"
-    t.index ["theatre_id", "created_at"], name: "index_theatre_skip_events_on_theatre_id_and_created_at"
-    t.index ["theatre_id"], name: "index_theatre_skip_events_on_theatre_id"
-  end
-
-  create_table "theatre_skip_votes", primary_key: ["theatre_id", "post_id", "user_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_id", null: false
-    t.bigint "post_id", null: false
-    t.bigint "user_id", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["post_id"], name: "index_theatre_skip_votes_on_post_id"
-    t.index ["theatre_id", "post_id", "created_at"], name: "idx_theatre_skip_votes_theatre_post_created"
-    t.index ["theatre_id"], name: "index_theatre_skip_votes_on_theatre_id"
-    t.index ["user_id"], name: "index_theatre_skip_votes_on_user_id"
-  end
-
   create_table "theatre_watching_users", primary_key: ["theatre_id", "user_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "theatre_id", null: false
     t.bigint "user_id", null: false
@@ -513,18 +464,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_06_000000) do
   add_foreign_key "tags", "tag_names"
   add_foreign_key "theatre_comments", "theatres"
   add_foreign_key "theatre_comments", "users"
-  add_foreign_key "theatre_programmes", "posts"
-  add_foreign_key "theatre_programmes", "theatres"
-  add_foreign_key "theatre_skip_event_tags", "tags"
-  add_foreign_key "theatre_skip_event_tags", "theatre_skip_events"
-  add_foreign_key "theatre_skip_event_voters", "theatre_skip_events"
-  add_foreign_key "theatre_skip_event_voters", "users"
-  add_foreign_key "theatre_skip_events", "posts"
-  add_foreign_key "theatre_skip_events", "theatres"
-  add_foreign_key "theatre_skip_events", "users", column: "skipped_by_user_id"
-  add_foreign_key "theatre_skip_votes", "posts"
-  add_foreign_key "theatre_skip_votes", "theatres"
-  add_foreign_key "theatre_skip_votes", "users"
   add_foreign_key "theatre_watching_users", "theatres"
   add_foreign_key "theatre_watching_users", "users"
   add_foreign_key "theatres", "posts", column: "current_post_id"

backend/spec/requests/error_responses_spec.rb

@@ -1,47 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe 'error responses', type: :request do
-  describe 'manual input errors' do
-    it 'returns a stable payload for bad requests' do
-      get '/tags/name/%20/deerjikists'
-
-      expect(response).to have_http_status(:bad_request)
-      expect(json).to include(
-          'type' => 'bad_request',
-          'message' => be_present,
-          'errors' => {},
-          'base_errors' => [be_present])
-    end
-
-    it 'returns a stable field-error payload for unprocessable requests' do
-      member = create(:user, :member)
-      tag = create(:tag, :general, name: 'error_response_tag')
-      sign_in_as(member)
-
-      patch "/tags/#{ tag.id }", params: { category: 'nico' }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json).to include(
-          'type' => 'validation_error',
-          'message' => '入力内容を確認してください．',
-          'base_errors' => [])
-      expect(json.fetch('errors')).to include(
-          'category' => ['ニコタグは変更できません．'])
-    end
-  end
-
-  describe 'model validation errors' do
-    it 'returns field messages for model errors' do
-      user = create(:user)
-      sign_in_as(user)
-
-      put "/users/#{ user.id }", params: { name: 'a' * 256 }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json).to include(
-          'type' => 'validation_error',
-          'message' => '入力内容を確認してください．')
-      expect(json.fetch('errors').fetch('name')).to include(be_present)
-    end
-  end
-end

backend/spec/requests/materials_spec.rb

@@ -141,21 +141,16 @@ RSpec.describe 'Materials API', type: :request do
     context 'when logged in' do
       before { sign_in_as(guest_user) }
 
-      it 'returns 422 when tag is blank' do
+      it 'returns 400 when tag is blank' do
         post '/materials', params: { tag: '   ', file: dummy_upload }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:bad_request)
-        expect(json.fetch('errors')).to include(
-            'tag' => ['タグは必須です．'])
       end
 
-      it 'returns 422 when both file and url are blank' do
+      it 'returns 400 when both file and url are blank' do
         post '/materials', params: { tag: 'material_create_blank' }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:bad_request)
-        expect(json.fetch('errors')).to include(
-            'file' => ['ファイルまたは URL は必須です．'],
-            'url' => ['ファイルまたは URL は必須です．'])
       end
 
       it 'creates a material with an attached file' do
@@ -266,26 +261,21 @@ RSpec.describe 'Materials API', type: :request do
         expect(response).to have_http_status(:not_found)
       end
 
-      it 'returns 422 when tag is blank' do
+      it 'returns 400 when tag is blank' do
         put "/materials/#{ material.id }", params: {
           tag: '   ',
           file: dummy_upload
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:bad_request)
-        expect(json.fetch('errors')).to include(
-            'tag' => ['タグは必須です．'])
       end
 
-      it 'returns 422 when both file and url are blank' do
+      it 'returns 400 when both file and url are blank' do
         put "/materials/#{ material.id }", params: {
           tag: 'material_update_no_payload'
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
+        expect(response).to have_http_status(:bad_request)
-        expect(json.fetch('errors')).to include(
-            'file' => ['ファイルまたは URL は必須です．'],
-            'url' => ['ファイルまたは URL は必須です．'])
       end
 
       it 'updates tag, url, file, and updated_by_user' do

backend/spec/requests/nico_tags_spec.rb

@@ -3,68 +3,12 @@ require 'rails_helper'
 
 RSpec.describe 'NicoTags', type: :request do
   describe 'GET /tags/nico' do
-    it 'returns paginated tags and total count' do
+    it 'returns tags and next_cursor when overflowing limit' do
-      create_list(:tag, 3, :nico)
+      create_list(:tag, 21, :nico)
-
+      get '/tags/nico', params: { limit: 20 }
-      get '/tags/nico', params: { page: 2, limit: 2 }
-
       expect(response).to have_http_status(:ok)
-      expect(json['tags'].size).to eq(1)
+      expect(json['tags'].size).to eq(20)
-      expect(json['count']).to eq(3)
+      expect(json['next_cursor']).to be_present
-    end
-
-    it 'filters by nico tag name, linked tag name, and link status' do
-      linked = create(:tag, :nico)
-      linked.tag_name.update!(name: 'nico:search_linked')
-      unlinked = create(:tag, :nico)
-      unlinked.tag_name.update!(name: 'nico:search_unlinked')
-      other = create(:tag, :nico)
-      other.tag_name.update!(name: 'nico:other')
-      destination = create(:tag, :general)
-      destination.tag_name.update!(name: 'destination_search')
-      NicoTagRelation.create!(nico_tag: linked, tag: destination)
-      NicoTagRelation.create!(nico_tag: other, tag: create(:tag, :general))
-
-      get '/tags/nico', params: {
-        name: 'search_',
-        linked_tag: 'destination_',
-        link_status: 'linked'
-      }
-
-      expect(response).to have_http_status(:ok)
-      expect(json['count']).to eq(1)
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([linked.id])
-
-      get '/tags/nico', params: { name: 'search_', link_status: 'unlinked' }
-
-      expect(json['count']).to eq(1)
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([unlinked.id])
-    end
-
-    it 'sorts by name and timestamps' do
-      older = create(:tag, :nico)
-      older.tag_name.update!(name: 'nico:a')
-      older.update_columns(created_at: 2.days.ago)
-      newer = create(:tag, :nico)
-      newer.tag_name.update!(name: 'nico:b')
-      newer.update_columns(created_at: 1.day.ago)
-      older_post_tag =
-        PostTag.create!(post: Post.create!(url: 'https://example.com/nico-older'), tag: older)
-      older_post_tag.update_columns(created_at: 1.hour.ago)
-      newer_post_tag =
-        PostTag.create!(post: Post.create!(url: 'https://example.com/nico-newer'), tag: newer)
-      newer_post_tag.update_columns(created_at: 2.hours.ago)
-
-      get '/tags/nico', params: { order: 'name:desc' }
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([newer.id, older.id])
-
-      get '/tags/nico', params: { order: 'created_at:asc' }
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([older.id, newer.id])
-
-      get '/tags/nico', params: { order: 'updated_at:desc' }
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([older.id, newer.id])
-      expect(Time.zone.parse(json.fetch('tags').first.fetch('recent_post_tag_created_at')))
-        .to be_within(1.second).of(older_post_tag.created_at)
     end
   end
 
@@ -131,7 +75,7 @@ RSpec.describe 'NicoTags', type: :request do
       expect(versions.last.created_by_user_id).to eq(admin.id)
     end
 
-    it 'returns 422 when linked tag normalises to nico tag' do
+    it '400 when linked tag normalises to nico tag' do
       sign_in_as(member)
 
       other_nico = create(:tag, :nico, name: 'nico:linked_ng')
@@ -143,37 +87,7 @@ RSpec.describe 'NicoTags', type: :request do
         patch "/tags/nico/#{nico_tag.id}", params: { tags: 'linked_ng_alias' }
       }.not_to change(NicoTagVersion, :count)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:bad_request)
-      expect(json.fetch('errors')).to include(
-          'tags' => ['ニコニコ・タグ同士は連携できません．'])
-    end
-
-    it 'returns the tags field error when a nico tag is specified directly' do
-      sign_in_as(member)
-
-      patch "/tags/nico/#{nico_tag.id}", params: { tags: 'nico:linked_ng' }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json.fetch('errors')).to include(
-          'tags' => ['ニコニコ・タグ同士は連携できません．'])
-    end
-
-    it 'returns tag name validation errors on the tags field and rolls back created tags' do
-      sign_in_as(member)
-      TagNameSanitisationRule.create!(
-        priority: 1,
-        source_pattern: 'invalid',
-        replacement: 'valid'
-      )
-      nico_tag
-
-      expect {
-        patch "/tags/nico/#{nico_tag.id}", params: { tags: 'created_first invalid' }
-      }.not_to change(TagName, :count)
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json.fetch('errors').fetch('tags')).to include(
-          a_string_including('タグ名 “invalid”:', '名前に使用できない文字が含まれてゐます．'))
     end
   end
 end

backend/spec/requests/posts_spec.rb

@@ -57,23 +57,6 @@ RSpec.describe 'Posts API', type: :request do
     post_write_params({ base_version_no: base_version.version_no }.merge(params))
   end
 
-  def count_sql_queries
-    count = 0
-
-    callback = lambda do |_name, _started, _finished, _id, payload|
-      next if payload[:cached]
-      next if ['SCHEMA', 'TRANSACTION'].include?(payload[:name])
-
-      count += 1
-    end
-
-    ActiveSupport::Notifications.subscribed(callback, 'sql.active_record') do
-      yield
-    end
-
-    count
-  end
-
   let!(:tag_name) { TagName.create!(name: 'spec_tag') }
   let!(:tag)      { Tag.create!(tag_name: tag_name, category: :general) }
 
@@ -575,59 +558,6 @@ RSpec.describe 'Posts API', type: :request do
           expect(sibling_ids).to include(sibling_post.id)
         end
       end
-
-      it 'does not issue a query per tag or related post' do
-        user = create_member_user!
-
-        tags =
-            15.times.map do |i|
-              tag_name = TagName.create!(name: "show_query_tag_#{ i }")
-              tag = Tag.create!(tag_name:, category: :general)
-              TagName.create!(name: "show_query_alias_#{ i }", canonical: tag_name)
-              PostTag.create!(post: post_record, tag:)
-              tag
-            end
-
-        tags.each_cons(2) do |parent_tag, child_tag|
-          TagImplication.create!(parent_tag:, tag: child_tag)
-        end
-
-        parent_post = Post.create!(
-          title: 'query parent post',
-          url: 'https://example.com/query-parent-post'
-        )
-        sibling_post = Post.create!(
-          title: 'query sibling post',
-          url: 'https://example.com/query-sibling-post'
-        )
-        child_post = Post.create!(
-          title: 'query child post',
-          url: 'https://example.com/query-child-post'
-        )
-
-        PostImplication.create!(post: post_record, parent_post:)
-        PostImplication.create!(post: sibling_post, parent_post:)
-        PostImplication.create!(post: child_post, parent_post: post_record)
-
-        20.times do |i|
-          related_post = Post.create!(
-            title: "query related post #{ i }",
-            url: "https://example.com/query-related-post-#{ i }"
-          )
-          PostSimilarity.create!(post: post_record,
-                                 target_post: related_post,
-                                 cos: 1.0 - (i / 100.0))
-        end
-
-        query_count =
-            count_sql_queries do
-              get "/posts/#{ post_record.id }",
-                  headers: { 'X-Transfer-Code' => user.inheritance_code }
-            end
-
-        expect(response).to have_http_status(:ok)
-        expect(query_count).to be <= 45
-      end
     end
 
     context 'when post does not exist' do
@@ -704,7 +634,7 @@ RSpec.describe 'Posts API', type: :request do
             category: :nico)
       end
 
-      it 'returns 422 with tag field errors' do
+      it 'return 400' do
         sign_in_as(member)
 
         post '/posts', params: post_write_params(
@@ -714,13 +644,7 @@ RSpec.describe 'Posts API', type: :request do
           thumbnail: dummy_upload
         )
 
-        expect(response).to have_http_status(:unprocessable_entity), response.body
+        expect(response).to have_http_status(:bad_request), response.body
-        expect(json).to include(
-            'type' => 'validation_error',
-            'message' => '入力内容を確認してください．',
-            'base_errors' => [])
-        expect(json.fetch('errors')).to include(
-            'tags' => ['ニコニコ・タグは直接指定できません．'])
       end
     end
 
@@ -937,7 +861,7 @@ RSpec.describe 'Posts API', type: :request do
             category: :nico)
       end
 
-      it 'returns 422 with tag field errors' do
+      it 'return 400' do
         sign_in_as(member)
 
         put "/posts/#{post_record.id}", params: post_update_params(
@@ -945,13 +869,7 @@ RSpec.describe 'Posts API', type: :request do
             title: 'updated title',
             tags: 'nico:nico_tag')
 
-        expect(response).to have_http_status(:unprocessable_entity), response.body
+        expect(response).to have_http_status(:bad_request), response.body
-        expect(json).to include(
-            'type' => 'validation_error',
-            'message' => '入力内容を確認してください．',
-            'base_errors' => [])
-        expect(json.fetch('errors')).to include(
-            'tags' => ['ニコニコ・タグは直接指定できません．'])
       end
     end
 

backend/spec/requests/tags_deerjikists_spec.rb

@@ -275,30 +275,6 @@ RSpec.describe 'Tags deerjikists API', type: :request do
         end
       end
 
-      context 'when a row is invalid' do
-        let(:payload) do
-          [
-            { platform: '', code: code1 },
-          ]
-        end
-
-        it 'returns 422 with indexed field errors and does not replace existing deerjikists' do
-          Deerjikist.create!(platform: platform1, code: code1, tag: tag)
-
-          expect {
-            do_request
-          }.not_to change { Deerjikist.where(tag: tag).map { |d| [d.platform, d.code] } }
-
-          expect(response).to have_http_status(:unprocessable_entity)
-          expect(json).to include(
-              'type' => 'validation_error',
-              'message' => '入力内容を確認してください．',
-              'base_errors' => [])
-          expect(json.fetch('errors')).to include(
-              'deerjikists.0.platform' => [be_present])
-        end
-      end
-
       context 'when youtube code is handle' do
         let(:channel_id) { 'UCabcdefghijklmnopqrstuv' }
         let(:payload) do

backend/spec/requests/theatre_comments_spec.rb

@@ -80,26 +80,6 @@ RSpec.describe 'TheatreComments', type: :request do
       expect(response).to have_http_status(:ok)
       expect(response.parsed_body.map { |row| row['no'] }).to eq([3, 2, 1])
     end
-
-    it '削除済みコメントは deleted として返し、本文を隠す' do
-      comment_2.discard!
-
-      get "/theatres/#{theatre.id}/comments", params: { no_gt: 1 }
-
-      expect(response).to have_http_status(:ok)
-
-      deleted_comment = response.parsed_body.find { _1['no'] == 2 }
-      expect(deleted_comment).to include(
-        'deleted' => true,
-        'content' => nil
-      )
-
-      visible_comment = response.parsed_body.find { _1['no'] == 3 }
-      expect(visible_comment).to include(
-        'deleted' => false,
-        'content' => 'third comment'
-      )
-    end
   end
 
   describe 'POST /theatres/:theatre_id/comments' do
@@ -167,44 +147,4 @@ RSpec.describe 'TheatreComments', type: :request do
       })
     end
   end
-
-  describe 'DELETE /theatres/:theatre_id/comments/:id' do
-    let(:theatre) { create(:theatre) }
-    let(:alice) { create(:user, name: 'Alice') }
-    let(:bob) { create(:user, name: 'Bob') }
-    let!(:comment) do
-      create(
-        :theatre_comment,
-        theatre: theatre,
-        no: 1,
-        user: alice,
-        content: 'delete target'
-      )
-    end
-
-    it 'returns 401 when not logged in' do
-      delete "/theatres/#{theatre.id}/comments/#{comment.no}"
-
-      expect(response).to have_http_status(:unauthorized)
-      expect(comment.reload.discarded?).to eq(false)
-    end
-
-    it 'allows the comment owner to delete it' do
-      sign_in_as(alice)
-
-      delete "/theatres/#{theatre.id}/comments/#{comment.no}"
-
-      expect(response).to have_http_status(:no_content)
-      expect(comment.reload.discarded?).to eq(true)
-    end
-
-    it 'returns 403 when another user tries to delete it' do
-      sign_in_as(bob)
-
-      delete "/theatres/#{theatre.id}/comments/#{comment.no}"
-
-      expect(response).to have_http_status(:forbidden)
-      expect(comment.reload.discarded?).to eq(false)
-    end
-  end
 end

backend/spec/requests/theatre_programmes_spec.rb

@@ -1,38 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe 'TheatreProgrammes', type: :request do
-  describe 'GET /theatres/:theatre_id/programmes' do
-    let(:theatre) { create(:theatre) }
-    let(:other_theatre) { create(:theatre) }
-    let(:post_1) { Post.create!(title: 'first', url: 'https://www.nicovideo.jp/watch/sm1') }
-    let(:post_2) { Post.create!(title: 'second', url: 'https://www.nicovideo.jp/watch/sm2') }
-    let(:other_post) { Post.create!(title: 'other', url: 'https://www.nicovideo.jp/watch/sm3') }
-
-    before do
-      TheatreProgramme.create!(theatre:, position: 1, post: post_1, created_at: 2.minutes.ago)
-      TheatreProgramme.create!(theatre:, position: 2, post: post_2, created_at: 1.minute.ago)
-      TheatreProgramme.create!(
-        theatre: other_theatre,
-        position: 1,
-        post: other_post,
-        created_at: 1.minute.ago
-      )
-    end
-
-    it 'returns programmes for the theatre in descending position with post json' do
-      get "/theatres/#{theatre.id}/programmes"
-
-      expect(response).to have_http_status(:ok)
-      expect(json.map { _1['position'] }).to eq([2, 1])
-      expect(json.map { _1.dig('post', 'title') }).to eq(['second', 'first'])
-      expect(json.first['post']).to include('id' => post_2.id, 'url' => post_2.url)
-    end
-
-    it 'filters programmes by position_gt' do
-      get "/theatres/#{theatre.id}/programmes", params: { position_gt: 1 }
-
-      expect(response).to have_http_status(:ok)
-      expect(json.map { _1['position'] }).to eq([2])
-    end
-  end
-end

backend/spec/requests/theatres_spec.rb

@@ -14,24 +14,10 @@ RSpec.describe 'Theatres API', type: :request do
   let(:member) { create(:user, :member, name: 'member user') }
   let(:other_user) { create(:user, :member, name: 'other user') }
 
-  let!(:niconico_post) do
-    Post.create!(
-      title: 'niconico post',
-      url: 'https://www.nicovideo.jp/watch/sm123'
-    )
-  end
-
-  let!(:second_niconico_post) do
-    Post.create!(
-      title: 'second niconico post',
-      url: 'https://www.nicovideo.jp/watch/sm456'
-    )
-  end
-
   let!(:youtube_post) do
     Post.create!(
       title: 'youtube post',
-      url: 'https://www.youtube.com/watch?v=yt123'
+      url: 'https://www.youtube.com/watch?v=spec123'
     )
   end
 
@@ -134,8 +120,7 @@ RSpec.describe 'Theatres API', type: :request do
         expect(json).to include(
           'host_flg' => true,
           'post_id' => nil,
-          'post_started_at' => nil,
+          'post_started_at' => nil
-          'post_elapsed_ms' => nil
         )
 
         expect(json.fetch('watching_users')).to contain_exactly(
@@ -192,8 +177,7 @@ RSpec.describe 'Theatres API', type: :request do
         expect(json).to include(
           'host_flg' => false,
           'post_id' => nil,
-          'post_started_at' => nil,
+          'post_started_at' => nil
-          'post_elapsed_ms' => nil
         )
 
         expect(json.fetch('watching_users')).to contain_exactly(
@@ -220,7 +204,7 @@ RSpec.describe 'Theatres API', type: :request do
         )
         theatre.update!(
           host_user: other_user,
-          current_post: niconico_post,
+          current_post: youtube_post,
           current_post_started_at: started_at
         )
         sign_in_as(member)
@@ -236,11 +220,9 @@ RSpec.describe 'Theatres API', type: :request do
         expect(theatre.host_user_id).to eq(member.id)
 
         expect(json['host_flg']).to eq(true)
-        expect(json['post_id']).to eq(niconico_post.id)
+        expect(json['post_id']).to eq(youtube_post.id)
         expect(Time.zone.parse(json['post_started_at']))
           .to be_within(1.second).of(started_at)
-        expect(json['post_elapsed_ms'])
-          .to be_within(1_000).of(120_000)
       end
     end
   end
@@ -291,36 +273,16 @@ RSpec.describe 'Theatres API', type: :request do
       it 'sets current_post to an eligible post and updates current_post_started_at' do
         expect { do_request }
           .to change { theatre.reload.current_post_id }
+          .from(nil).to(youtube_post.id)
 
         expect(response).to have_http_status(:no_content)
-        expect([niconico_post.id, second_niconico_post.id, youtube_post.id])
-          .to include(theatre.reload.current_post_id)
         expect(theatre.reload.current_post_started_at)
           .to be_within(1.second).of(Time.current)
-        expect(theatre.programmes.count).to eq(1)
-      end
-    end
-
-    context 'when only a YouTube post is eligible' do
-      before do
-        niconico_post.destroy!
-        second_niconico_post.destroy!
-        theatre.update!(host_user: member)
-        sign_in_as(member)
-      end
-
-      it 'sets current_post to the YouTube post' do
-        do_request
-
-        expect(response).to have_http_status(:no_content)
-        expect(theatre.reload.current_post_id).to eq(youtube_post.id)
       end
     end
 
     context 'when current user is host and no eligible post exists' do
       before do
-        niconico_post.destroy!
-        second_niconico_post.destroy!
         youtube_post.destroy!
         theatre.update!(
           host_user: member,
@@ -337,189 +299,9 @@ RSpec.describe 'Theatres API', type: :request do
 
         theatre.reload
         expect(theatre.current_post_id).to be_nil
-        expect(theatre.current_post_started_at).to be_nil
+        expect(theatre.current_post_started_at)
+          .to be_within(1.second).of(Time.current)
       end
     end
   end
-
-  describe 'PUT /theatres/:id/skip_vote' do
-    subject(:do_request) do
-      put "/theatres/#{theatre.id}/skip_vote", params: { post_id: requested_post_id }
-    end
-
-    let(:third_user) { create(:user, :member, name: 'third user') }
-    let(:requested_post_id) { niconico_post.id }
-
-    before do
-      theatre.update!(current_post: niconico_post, current_post_started_at: 10.seconds.ago)
-      [member, other_user, third_user].each do |user|
-        TheatreWatchingUser.create!(
-          theatre:,
-          user:,
-          expires_at: 10.seconds.from_now
-        )
-      end
-    end
-
-    it 'returns 401 when not logged in' do
-      sign_out
-
-      expect { do_request }.not_to change(TheatreSkipVote, :count)
-
-      expect(response).to have_http_status(:unauthorized)
-    end
-
-    it 'returns 422 when post_id is invalid' do
-      sign_in_as(member)
-
-      expect {
-        put "/theatres/#{theatre.id}/skip_vote", params: { post_id: 'invalid' }
-      }.not_to change(TheatreSkipVote, :count)
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'records a vote and returns the current vote status before majority' do
-      sign_in_as(member)
-
-      expect { do_request }.to change(TheatreSkipVote, :count).by(1)
-
-      expect(response).to have_http_status(:ok)
-      expect(json['skipped']).to eq(false)
-      expect(json['post_id']).to eq(niconico_post.id)
-      expect(json['skip_vote']).to include(
-        'votes_count' => 1,
-        'required_count' => 2,
-        'watching_users_count' => 3,
-        'voted' => true
-      )
-    end
-
-    it 'finalizes skip when votes reach majority and stores voters and tag snapshots' do
-      tag = create(:tag, name: 'skip-target')
-      PostTag.create!(post: niconico_post, tag:)
-
-      TheatreSkipVote.create!(theatre:, post: niconico_post, user: member)
-      sign_in_as(other_user)
-
-      expect { do_request }
-        .to change(TheatreSkipEvent, :count).by(1)
-        .and change(TheatreSkipEventVoter, :count).by(2)
-        .and change(TheatreSkipEventTag, :count).by(1)
-
-      expect(response).to have_http_status(:ok)
-      expect(json['skipped']).to eq(true)
-      expect([second_niconico_post.id, youtube_post.id]).to include(json['post_id'])
-
-      event = TheatreSkipEvent.last
-      expect(event.post).to eq(niconico_post)
-      expect(event.users).to contain_exactly(member, other_user)
-      expect(event.tags).to contain_exactly(tag)
-      expect(TheatreSkipVote.where(theatre:, post: niconico_post)).to be_empty
-    end
-
-    it 'does not record a vote when requested post is no longer current' do
-      theatre.update!(current_post: second_niconico_post)
-      sign_in_as(member)
-
-      expect { do_request }.not_to change(TheatreSkipVote, :count)
-
-      expect(response).to have_http_status(:conflict)
-      expect(json['post_id']).to eq(second_niconico_post.id)
-      expect(json['skip_vote']).to include(
-        'votes_count' => 0,
-        'voted' => false
-      )
-    end
-  end
-
-  describe 'DELETE /theatres/:id/skip_vote' do
-    let(:requested_post_id) { niconico_post.id }
-
-    before do
-      theatre.update!(current_post: niconico_post, current_post_started_at: 10.seconds.ago)
-      TheatreWatchingUser.create!(theatre:, user: member, expires_at: 10.seconds.from_now)
-      TheatreSkipVote.create!(theatre:, post: niconico_post, user: member)
-      sign_in_as(member)
-    end
-
-    it 'removes the current user vote' do
-      expect {
-        delete "/theatres/#{theatre.id}/skip_vote", params: { post_id: requested_post_id }
-      }.to change(TheatreSkipVote, :count).by(-1)
-
-      expect(response).to have_http_status(:ok)
-      expect(json['skip_vote']).to include(
-        'votes_count' => 0,
-        'required_count' => 1,
-        'watching_users_count' => 1,
-        'voted' => false
-      )
-    end
-
-    it 'does not remove a vote when requested post is no longer current' do
-      theatre.update!(current_post: second_niconico_post)
-
-      expect {
-        delete "/theatres/#{theatre.id}/skip_vote", params: { post_id: requested_post_id }
-      }.not_to change(TheatreSkipVote, :count)
-
-      expect(response).to have_http_status(:conflict)
-      expect(json['post_id']).to eq(second_niconico_post.id)
-    end
-  end
-
-  describe 'GET /theatres/:id/skip_events' do
-    before do
-      sign_in_as(member)
-    end
-
-    it 'does not expose skip voters' do
-      event = TheatreSkipEvent.create!(
-        theatre:,
-        post: niconico_post,
-        skipped_by_user: member,
-        created_at: Time.current
-      )
-      TheatreSkipEventVoter.create!(theatre_skip_event: event, user: member)
-
-      get "/theatres/#{theatre.id}/skip_events"
-
-      expect(response).to have_http_status(:ok)
-      expect(json.first).to include(
-        'id' => event.id,
-        'theatre_id' => theatre.id
-      )
-      expect(json.first).not_to have_key('voters')
-      expect(json.first).not_to have_key('skipped_by_user')
-    end
-  end
-
-  describe 'GET /theatres/:id/post_selection_weights' do
-    before do
-      theatre.update!(current_post: niconico_post)
-      TheatreWatchingUser.create!(theatre:, user: member, expires_at: 10.seconds.from_now)
-      sign_in_as(member)
-    end
-
-    it 'returns tag penalties and candidate weights for the current watchers' do
-      tag = create(:tag, name: 'heavy-tag')
-      PostTag.create!(post: second_niconico_post, tag:)
-      event = TheatreSkipEvent.create!(
-        theatre:,
-        post: niconico_post,
-        skipped_by_user: member,
-        created_at: Time.current
-      )
-      TheatreSkipEventVoter.create!(theatre_skip_event: event, user: member)
-      TheatreSkipEventTag.create!(theatre_skip_event: event, tag:)
-
-      get "/theatres/#{theatre.id}/post_selection_weights"
-
-      expect(response).to have_http_status(:ok)
-      expect(json['tag_penalties'].first['penalty']).to eq(1)
-      expect(json['lightest_posts'].first['post']['id']).to eq(second_niconico_post.id)
-      expect(json['lightest_posts'].first['penalty']).to eq(1)
-    end
-  end
 end

backend/spec/requests/users_spec.rb

@@ -90,14 +90,12 @@ RSpec.describe 'Users', type: :request do
       expect(response).to have_http_status(:unauthorized)
     end
 
-    it 'returns 422 when name is blank' do
+    it 'returns 400 when name is blank' do
       put "/users/#{user.id}",
           params: { name: '   ' },
           headers: auth_headers(user)
 
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect(response).to have_http_status(:bad_request)
-      expect(json.fetch('errors')).to include(
-          'name' => ['名前は必須です．'])
     end
 
     it 'updates name and returns user slice' do

docs/commands.md

@@ -18,13 +18,12 @@ npm install
 npm run dev
 npm run build
 npm run lint
-npm run test
+npm test
-npm run test:run
 ```
 
 ### Full verification
 
 ```sh
 cd backend && bundle exec rspec
-cd ../frontend && npm run test:run && npm run build && npm run lint
+cd ../frontend && npm run build && npm run lint
 ```

frontend/AGENTS.md

@@ -4,8 +4,7 @@
 
 These rules apply to work under `frontend/`.
 
-This is a Vite + React + TypeScript app using TanStack Query, Tailwind CSS,
+This is a Vite + React + TypeScript app using TanStack Query, Tailwind CSS, Framer Motion, Radix UI-style components, MDX, and Zustand.
-Framer Motion, Radix UI-style components, MDX, and Zustand.
 
 ## Commands
 
@@ -18,11 +17,9 @@ npm run lint
 npm run preview
 ```
 
-`npm run build` runs `tsc -b && vite build`, and `postbuild` runs
+`npm run build` runs `tsc -b && vite build`, and `postbuild` runs `node scripts/generate-sitemap.js`.
-`node scripts/generate-sitemap.js`.
 
-There is currently no `test` script in `package.json`. Do not run or report
+There is currently no `test` script in `package.json`. Do not run or report `npm test` unless a test script is added.
-`npm test` unless a test script is added.
 
 After frontend changes, run:
 
@@ -35,37 +32,18 @@ If either command cannot be run or fails, report the exact command and failure.
 
 ## TypeScript
 
-- TypeScript is strict. `tsconfig.app.json` enables `strict`,
+- TypeScript is strict. `tsconfig.app.json` enables `strict`, `noUnusedLocals`, `noUnusedParameters`, `erasableSyntaxOnly`, `noFallthroughCasesInSwitch`, and `noUncheckedSideEffectImports`.
-  `noUnusedLocals`, `noUnusedParameters`, `erasableSyntaxOnly`,
-  `noFallthroughCasesInSwitch`, and `noUncheckedSideEffectImports`.
 - Keep types explicit at module boundaries, API helpers, and exported utilities.
 - Use `import type` for type-only imports.
 - Prefer existing shared types from `src/types.ts` before adding local duplicate types.
-- Preserve the repository's existing spacing style in TypeScript, including
+- Preserve the repository's existing spacing style in TypeScript, including GNU-style spacing before call parentheses where it is already used.
-  GNU-style spacing before call parentheses where it is already used.
 - Prefer single quotes for strings unless interpolation or escaping makes double quotes better.
-- Never write a TypeScript or TSX line longer than 99 characters.
-- Aim to keep TypeScript and TSX lines within 79 characters where practical.
-- Use 4-space logical indentation in TypeScript and TSX.
-- For arrays, never put whitespace or a line break immediately before `]`.
-- Keep the first element on the same line as `[` by default.
-- If an array would exceed the line limit, break after `[` and indent
-  elements by 4 spaces.
-- In TypeScript and TSX only, replace every leading run of 8 spaces with a tab
-  to reduce bytes.
-- Treat one leading tab as exactly equivalent to 8 leading spaces.
-- Use tabs only for leading indentation. Never replace spaces that occur after
-  a non-space character on the same line.
 
 ## React
 
 - Use function components.
-- Existing page components commonly export an anonymous function satisfying
+- Existing page components commonly export an anonymous function satisfying `FC`; match nearby file style when editing.
-  `FC`; match nearby file style when editing.
 - React hooks must be called unconditionally and at the top level of components or custom hooks.
-- Gate editing and other privileged controls with shared permission helpers
-  such as `canEditContent`, instead of showing controls and relying only on a
-  later API failure.
 - Keep page-level components under `src/pages`.
 - Keep shared and feature components under `src/components`.
 - Use `react-router-dom` route params and navigation patterns already present in `src/App.tsx`.
@@ -74,23 +52,17 @@ If either command cannot be run or fails, report the exact command and failure.
 ## TanStack Query
 
 - Use `@tanstack/react-query` for server state.
-- Query keys should come from `src/lib/queryKeys.ts`; add key builders there
+- Query keys should come from `src/lib/queryKeys.ts`; add key builders there instead of using ad hoc arrays in components.
-  instead of using ad hoc arrays in components.
+- Fetch functions should live in domain helpers under `src/lib`, such as `posts.ts`, `tags.ts`, or `wiki.ts`.
-- Fetch functions should live in domain helpers under `src/lib`, such as
+- Use `useQueryClient().invalidateQueries` with the shared root keys when mutations affect cached lists or detail views.
-  `posts.ts`, `tags.ts`, or `wiki.ts`.
+- The app-wide `QueryClient` is configured in `src/main.tsx`; do not create additional clients in feature code.
-- Use `useQueryClient().invalidateQueries` with the shared root keys when
-  mutations affect cached lists or detail views.
-- The app-wide `QueryClient` is configured in `src/main.tsx`; do not create
-  additional clients in feature code.
 
 ## API calls
 
 - Use `src/lib/api.ts` for HTTP calls.
-- The API wrapper attaches `X-Transfer-Code` from `localStorage` and converts
+- The API wrapper attaches `X-Transfer-Code` from `localStorage` and converts non-blob responses to camelCase.
-  non-blob responses to camelCase.
 - Send Rails snake_case params and request body keys where the backend expects them.
-- Do not bypass the API wrapper unless there is a specific reason, such as a
+- Do not bypass the API wrapper unless there is a specific reason, such as a third-party request outside the Rails API.
-  third-party request outside the Rails API.
 - For blob responses, pass `responseType: 'blob'` so the wrapper does not camelCase the body.
 
 ## Imports and aliases
@@ -104,41 +76,17 @@ If either command cannot be run or fails, report the exact command and failure.
 
 - Tailwind scans `src/**/*.{html,js,ts,jsx,tsx,mdx}`.
 - Use `cn` from `src/lib/utils.ts` for conditional class names and class merging.
-- Reuse components from `src/components/common`, `src/components/layout`, and
+- Reuse components from `src/components/common`, `src/components/layout`, and `src/components/ui` before adding new primitives.
-  `src/components/ui` before adding new primitives.
 - Keep Tailwind classes consistent with nearby components.
-- Prefer restrained, content-first UI chrome: avoid adding card backgrounds,
+- When adding dynamic tag color classes, update `tailwind.config.js` safelist if the class cannot be statically detected.
-  heavy borders, or nested panel decoration unless the surrounding screen
-  already uses them.
-- Keep operational screens dense and direct; trim explanatory copy and use
-  short Japanese labels that fit the control.
-- Preserve existing Japanese tone and orthography in nearby UI text, including
-  old-kana wording where the file already uses it.
-- When adding dynamic tag color classes, update `tailwind.config.js` safelist
-  if the class cannot be statically detected.
 - Do not introduce new UI libraries or production dependencies without approval.
 
-## TSX formatting
-
-- Preserve compact TSX expression shapes such as inline ternary branches and
-  closing `</div>)` forms when nearby code uses them.
-- For long Tailwind `className` strings, wrap across lines only when needed.
-- Keep continuation indentation aligned with the 4-space logical indentation
-  rule, using tabs only as leading 8-space compression.
-- Do not add braces around `if`, `else`, or `for` bodies when the body is a
-  single physical line.
-- Always add braces around `if`, `else`, or `for` bodies when the body spans
-  two or more physical lines, even if it is one statement.
-- Avoid reformatting unrelated JSX.
-
 ## Lint and build constraints
 
-- ESLint uses `@eslint/js`, `typescript-eslint`, `eslint-plugin-react-hooks`,
+- ESLint uses `@eslint/js`, `typescript-eslint`, `eslint-plugin-react-hooks`, and `eslint-plugin-react-refresh`.
-  and `eslint-plugin-react-refresh`.
 - The hooks rules are enforced; fix hook ordering instead of disabling the rule.
 - `react-refresh/only-export-components` is enabled as a warning with `allowConstantExport`.
-- Build failures from unused locals or unused parameters are TypeScript
+- Build failures from unused locals or unused parameters are TypeScript errors, not lint-only issues.
-  errors, not lint-only issues.
 
 ## Files to avoid in routine work
 

frontend/eslint.config.js

@@ -5,7 +5,7 @@ import reactRefresh from 'eslint-plugin-react-refresh'
 import tseslint from 'typescript-eslint'
 
 export default tseslint.config(
-  { ignores: ['dist', 'tailwind.config.js'] },
+  { ignores: ['dist'] },
   {
     extends: [js.configs.recommended, ...tseslint.configs.recommended],
     files: ['**/*.{ts,tsx}'],

frontend/package.json

@@ -8,8 +8,6 @@
     "build": "tsc -b && vite build",
     "postbuild": "node scripts/generate-sitemap.js",
     "lint": "eslint .",
-    "test": "vitest",
-    "test:run": "vitest run",
     "preview": "vite preview"
   },
   "dependencies": {
@@ -47,10 +45,6 @@
   "devDependencies": {
     "@eslint/js": "^9.25.0",
     "@tailwindcss/typography": "^0.5.19",
-    "@testing-library/dom": "^10.4.1",
-    "@testing-library/jest-dom": "^6.9.1",
-    "@testing-library/react": "^16.3.2",
-    "@testing-library/user-event": "^14.6.1",
     "@types/axios": "^0.14.4",
     "@types/markdown-it": "^14.1.2",
     "@types/mdx": "^2.0.13",
@@ -64,13 +58,11 @@
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-refresh": "^0.4.19",
     "globals": "^16.0.0",
-    "jsdom": "^26.1.0",
     "postcss": "^8.5.3",
     "tailwindcss": "^3.4.13",
     "typescript": "~5.8.3",
     "typescript-eslint": "^8.30.1",
-    "vite": "^6.3.5",
+    "vite": "^6.3.5"
-    "vitest": "^4.1.5"
   },
   "description": "This template provides a minimal setup to get React working in Vite with HMR and some ESLint rules.",
   "main": "eslint.config.js",

frontend/src/App.tsx

@@ -62,9 +62,8 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	  <Route path="/tags/:id" element={<TagDetailPage/>}/>
 	  <Route path="/tags/:id/deerjikists" element={<DeerjikistDetailPage/>}/>
 	  <Route path="/tags/nico" element={<NicoTagListPage user={user}/>}/>
-	  <Route path="/nico/tags" element={<NicoTagListPage user={user}/>}/>
 	  <Route path="/tags/changes" element={<TagHistoryPage/>}/>
-	  <Route path="/theatres/:id" element={<TheatreDetailPage user={user}/>}/>
+	  <Route path="/theatres/:id" element={<TheatreDetailPage/>}/>
 	  <Route path="/materials" element={<MaterialBasePage/>}>
 	    <Route index element={<MaterialListPage/>}/>
 	    <Route path="new" element={<MaterialNewPage/>}/>
@@ -94,7 +93,7 @@ const PostDetailRoute = ({ user }: { user: User | null }) => {
 }
 
 
-const App: FC = () => {
+export default (() => {
   const [user, setUser] = useState<User | null> (null)
   const [status, setStatus] = useState (200)
 
@@ -157,6 +156,4 @@ const App: FC = () => {
 	  </DialogueProvider>
 	</BrowserRouter>
       </>)
-}
+}) satisfies FC
-
-export default App

frontend/src/components/DraggableDroppableTagRow.tsx

@@ -19,7 +19,7 @@ type Props = {
     sp?:              boolean }
 
 
-const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTagId, suppressClickRef, sp }) => {
+export default (({ tag, nestLevel, pathKey, parentTagId, suppressClickRef, sp }: Props) => {
   const dndId = `tag-node:${ pathKey }`
 
   const downPosRef = useRef<{ x: number; y: number } | null> (null)
@@ -96,6 +96,4 @@ const DraggableDroppableTagRow: FC<Props> = ({ tag, nestLevel, pathKey, parentTa
 	  <TagLink tag={tag} nestLevel={nestLevel}/>
 	</motion.div>
       </div>)
-}
+}) satisfies FC<Props>
-
-export default DraggableDroppableTagRow

frontend/src/components/ErrorScreen.test.tsx

@@ -1,32 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import { HelmetProvider } from 'react-helmet-async'
-import { describe, expect, it } from 'vitest'
-
-import ErrorScreen from '@/components/ErrorScreen'
-
-describe ('ErrorScreen', () => {
-  it.each ([
-    [403, '権限ないよ（笑）'],
-    [404, 'ページないよ（笑）'],
-    [500, '鯖でエラー出たって（嘲笑）'],
-    [503, '鯖死んでるよ（泣）'],
-  ]) ('renders status %s', (status, message) => {
-    render (
-        <HelmetProvider>
-          <ErrorScreen status={status}/>
-        </HelmetProvider>,
-    )
-
-    expect (screen.getByText (String (status))).toBeInTheDocument ()
-    expect (screen.getByText (message)).toBeInTheDocument ()
-    expect (screen.getByAltText ('逃げたギター')).toBeInTheDocument ()
-  })
-
-  it ('throws for unsupported statuses', () => {
-    expect (() => render (
-        <HelmetProvider>
-          <ErrorScreen status={418}/>
-        </HelmetProvider>,
-    )).toThrow ()
-  })
-})

frontend/src/components/ErrorScreen.tsx

@@ -10,7 +10,7 @@ import type { FC } from 'react'
 type Props = { status: number }
 
 
-const ErrorScreen: FC<Props> = ({ status }) => {
+export default (({ status }: Props) => {
   const [message, rightMsg, leftMsg]: [string, string, string] = (() => {
     switch (status)
     {
@@ -58,6 +58,4 @@ const ErrorScreen: FC<Props> = ({ status }) => {
 	  <p className="mr-[-.5em]">{message}</p>
 	</div>
       </MainArea>)
-}
+}) satisfies FC<Props>
-
-export default ErrorScreen

frontend/src/components/MaterialSidebar.tsx

@@ -31,7 +31,7 @@ const setChildrenById = (
     }))
 
 
-const MaterialSidebar: FC = () => {
+export default (() => {
   const [tags, setTags] = useState<TagWithDepth[]> ([])
   const [openTags, setOpenTags] = useState<Record<number, boolean>> ({ })
   const [tagFetchedFlags, setTagFetchedFlags] = useState<Record<number, boolean>> ({ })
@@ -94,6 +94,4 @@ const MaterialSidebar: FC = () => {
 	  {renderTags (tags)}
 	</ul>
       </SidebarComponent>)
-}
+}) satisfies FC
-
-export default MaterialSidebar

frontend/src/components/MenuSeparator.tsx

@@ -1,11 +1,9 @@
 import type { FC } from 'react'
 
 
-const MenuSeparator: FC = () => (
+export default (() => (
     <>
       <span className="hidden md:inline flex items-center px-2">|</span>
       <hr className="block md:hidden w-full opacity-25
 		     border-t border-black dark:border-white"/>
-    </>)
+    </>)) satisfies FC
-
-export default MenuSeparator

frontend/src/components/NicoViewer.test.tsx

@@ -1,83 +0,0 @@
-import { act, fireEvent, render } from '@testing-library/react'
-import { afterEach, describe, expect, it, vi } from 'vitest'
-import { createRef } from 'react'
-
-import NicoViewer from '@/components/NicoViewer'
-
-import type { NiconicoViewerHandle } from '@/types'
-
-
-describe ('NicoViewer', () => {
-  afterEach (() => {
-    vi.useRealTimers ()
-  })
-
-  it ('does not time out after metadata reports a playable duration', () => {
-    vi.useFakeTimers ()
-
-    const onError = vi.fn ()
-    const onMetadataChange = vi.fn ()
-    const { container } = render (
-        <NicoViewer
-            id="sm12345"
-            width={640}
-            height={360}
-            onMetadataChange={onMetadataChange}
-            onError={onError}/>,
-    )
-    const iframe = container.querySelector ('iframe')
-    expect (iframe).not.toBeNull ()
-
-    fireEvent.load (iframe!)
-    act (() => {
-      window.dispatchEvent (new MessageEvent ('message', {
-        origin: 'https://embed.nicovideo.jp',
-        source: iframe!.contentWindow,
-        data:   {
-          eventName: 'playerMetadataChange',
-          data:      {
-            currentTime:           7,
-            duration:              120,
-            isVideoMetaDataLoaded: true,
-            maximumBuffered:       30,
-            muted:                 false,
-            showComment:           true,
-            volume:                1,
-          },
-        },
-      }))
-    })
-
-    act (() => {
-      vi.advanceTimersByTime (8_000)
-    })
-
-    expect (onMetadataChange).toHaveBeenCalled ()
-    expect (onError).not.toHaveBeenCalled ()
-  })
-
-  it ('seeks with milliseconds', () => {
-    const ref = createRef<NiconicoViewerHandle> ()
-    const { container } = render (
-        <NicoViewer
-            ref={ref}
-            id="sm12345"
-            width={640}
-            height={360}/>,
-    )
-    const iframe = container.querySelector ('iframe')!
-    const postMessage = vi.spyOn (iframe.contentWindow!, 'postMessage')
-
-    act (() => {
-      ref.current!.seek (7_000)
-    })
-
-    expect (postMessage).toHaveBeenCalledWith (
-        expect.objectContaining ({
-          eventName: 'seek',
-          data:      { time: 7_000 },
-        }),
-        'https://embed.nicovideo.jp',
-    )
-  })
-})

frontend/src/components/NicoViewer.tsx

@@ -14,20 +14,10 @@ import type { NiconicoMetadata, NiconicoVideoInfo, NiconicoViewerHandle } from '
 type NiconicoPlayerMessage =
     | { eventName: 'enterProgrammaticFullScreen' }
     | { eventName: 'exitProgrammaticFullScreen' }
-    | { eventName: 'loadComplete'
+    | { eventName: 'loadComplete'; playerId?: string; data: { videoInfo: NiconicoVideoInfo } }
-	playerId?:  string
+    | { eventName: 'playerMetadataChange'; playerId?: string; data: NiconicoMetadata }
-	data:       { videoInfo: NiconicoVideoInfo } }
+    | { eventName: 'playerStatusChange' | 'statusChange'; playerId?: string; data?: unknown }
-    | { eventName: 'playerMetadataChange'
+    | { eventName: 'error'; playerId?: string; data?: unknown; code?: string; message?: string }
-	playerId?:  string
-	data:       NiconicoMetadata }
-    | { eventName: 'playerStatusChange' | 'statusChange'
-	playerId?:  string
-	data?:      unknown }
-    | { eventName: 'error'
-	playerId?:  string
-	data?:      unknown
-	code?:      string
-	message?:   string }
 
 type NiconicoCommand =
     | { eventName: 'play'; sourceConnectorType: 1; playerId: string }
@@ -40,7 +30,6 @@ type NiconicoCommand =
 	data: { commentVisibility: boolean } }
 
 const EMBED_ORIGIN = 'https://embed.nicovideo.jp'
-const LOAD_COMPLETE_TIMEOUT_MS = 8_000
 
 type Props = {
     id:                 string
@@ -48,18 +37,14 @@ type Props = {
     height:             number
     style?:             CSSProperties
     onLoadComplete?:    (info: NiconicoVideoInfo) => void
-    onMetadataChange?:  (meta: NiconicoMetadata) => void
+    onMetadataChange?:  (meta: NiconicoMetadata) => void }
-    onError?:           (data: unknown) => void }
 
 
 export default forwardRef ((props: Props, ref: ForwardedRef<NiconicoViewerHandle>) => {
-  const { id, width, height, style = { }, onLoadComplete, onMetadataChange, onError } = props
+  const { id, width, height, style = { }, onLoadComplete, onMetadataChange } = props
 
   const iframeRef = useRef<HTMLIFrameElement> (null)
-  const loadCompleteTimerRef = useRef<ReturnType<typeof setTimeout> | null> (null)
+  const playerId = useMemo (() => `nico-${ id }-${ Math.random ().toString (36).slice (2) }`, [id])
-  const playerId = useMemo (
-      () => `nico-${ id }-${ Math.random ().toString (36).slice (2) }`,
-      [id])
 
   const [screenWidth, setScreenWidth] = useState<CSSProperties['width']> ()
   const [screenHeight, setScreenHeight] = useState<CSSProperties['height']> ()
@@ -94,24 +79,6 @@ export default forwardRef ((props: Props, ref: ForwardedRef<NiconicoViewerHandle
   const margedStyle: CSSProperties =
       { border: 'none', maxWidth: '100%', ...style, ...styleFullScreen }
 
-  const clearLoadCompleteTimer = useCallback (() => {
-    if (!(loadCompleteTimerRef.current))
-      return
-
-    clearTimeout (loadCompleteTimerRef.current)
-    loadCompleteTimerRef.current = null
-  }, [])
-
-  const startLoadCompleteTimer = useCallback (() => {
-    clearLoadCompleteTimer ()
-    loadCompleteTimerRef.current = setTimeout (() => {
-      onError?.({
-	  eventName: 'loadCompleteTimeout',
-	  reason:    'niconico video length was not reported by embed',
-      })
-    }, LOAD_COMPLETE_TIMEOUT_MS)
-  }, [clearLoadCompleteTimer, onError])
-
   const postToPlayer = useCallback ((message: NiconicoCommand) => {
     const win = iframeRef.current?.contentWindow
     if (!(win))
@@ -129,9 +96,7 @@ export default forwardRef ((props: Props, ref: ForwardedRef<NiconicoViewerHandle
   }, [playerId, postToPlayer])
 
   const seek = useCallback ((time: number) => {
-    postToPlayer (
+    postToPlayer ({ eventName: 'seek', sourceConnectorType: 1, playerId, data: { time } })
-	{ eventName: 'seek', sourceConnectorType: 1, playerId,
-	  data: { time } })
   }, [playerId, postToPlayer])
 
   const mute = useCallback (() => {
@@ -197,34 +162,24 @@ export default forwardRef ((props: Props, ref: ForwardedRef<NiconicoViewerHandle
 
       if (data.eventName === 'loadComplete')
 	{
-	  clearLoadCompleteTimer ()
 	  onLoadComplete?.(data.data.videoInfo)
 	  return
 	}
 
       if (data.eventName === 'playerMetadataChange')
 	{
-	  if (Number.isFinite (data.data.duration) && data.data.duration > 0)
-	    clearLoadCompleteTimer ()
-
 	  onMetadataChange?.(data.data)
 	  return
 	}
 
       if (data.eventName === 'error')
-	{
-	  clearLoadCompleteTimer ()
         console.error ('niconico player error:', data)
-	  onError?.(data)
-	}
     }
 
     addEventListener ('message', onMessage)
 
     return () => removeEventListener ('message', onMessage)
-  }, [clearLoadCompleteTimer, onError, onLoadComplete, onMetadataChange, playerId])
+  }, [onLoadComplete, onMetadataChange, playerId])
-
-  useEffect (() => clearLoadCompleteTimer, [clearLoadCompleteTimer])
 
   useLayoutEffect (() => {
     if (!(fullScreen))
@@ -279,7 +234,6 @@ export default forwardRef ((props: Props, ref: ForwardedRef<NiconicoViewerHandle
 	  width={width}
 	  height={height}
 	  style={margedStyle}
-		  onLoad={startLoadCompleteTimer}
 	  allowFullScreen
 	  allow="autoplay"/>)
 })

frontend/src/components/PostEditForm.test.tsx

@@ -1,69 +0,0 @@
-import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
-
-import PostEditForm from '@/components/PostEditForm'
-import { buildPost, buildTag } from '@/test/factories'
-
-const postsApi = vi.hoisted (() => ({
-  updatePost: vi.fn (),
-}))
-
-const api = vi.hoisted (() => ({
-  isApiError: vi.fn (() => false),
-}))
-
-const toastApi = vi.hoisted (() => ({
-  toast: vi.fn (),
-}))
-
-vi.mock ('@/lib/posts', () => postsApi)
-vi.mock ('@/lib/api', () => api)
-vi.mock ('@/components/ui/use-toast', () => toastApi)
-vi.mock ('@/components/dialogues/DialogueProvider', () => ({
-  useDialogue: () => ({
-    choice: vi.fn (),
-  }),
-}))
-
-describe ('PostEditForm', () => {
-  it ('submits edited post fields with the current base version', async () => {
-    const onSave = vi.fn ()
-    const post = buildPost ({
-      id:        8,
-      versionNo: 4,
-      title:     'old',
-      tags:      [
-        buildTag ({ name: 'general-tag', category: 'general' }),
-        buildTag ({ id: 2, name: 'nico-tag', category: 'nico' }),
-      ],
-      parentPosts: [buildPost ({ id: 2, title: 'parent' })],
-    })
-    postsApi.updatePost.mockResolvedValueOnce ({
-      ...post,
-      versionNo: 5,
-      title:     'new',
-      tags:      [buildTag ({ name: 'new-tag' })],
-    })
-
-    render (<PostEditForm post={post} onSave={onSave}/>)
-
-    const [title, parentIds] = screen.getAllByRole ('textbox')
-    fireEvent.change (title, { target: { value: 'new' } })
-    fireEvent.change (parentIds, { target: { value: '3 4' } })
-    fireEvent.submit (screen.getByRole ('button', { name: '更新' }).closest ('form')!)
-
-    await waitFor (() => {
-      expect (postsApi.updatePost).toHaveBeenCalledWith (
-          expect.objectContaining ({
-            id:            8,
-            title:         'new',
-            parentPostIds: '3 4',
-            tags:          'general-tag',
-          }),
-          { baseVersionNo: 4 },
-      )
-    })
-    expect (onSave).toHaveBeenCalledWith (expect.objectContaining ({ versionNo: 5 }))
-    expect (toastApi.toast).toHaveBeenCalledWith ({ description: '更新しました．' })
-  })
-})

frontend/src/components/PostEditForm.tsx

@@ -2,23 +2,16 @@ import { useEffect, useState } from 'react'
 
 import PostFormTagsArea from '@/components/PostFormTagsArea'
 import PostOriginalCreatedTimeField from '@/components/PostOriginalCreatedTimeField'
-import FieldError from '@/components/common/FieldError'
+import Label from '@/components/common/Label'
-import FormField from '@/components/common/FormField'
 import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
-import { isApiError } from '@/lib/api'
 import { updatePost } from '@/lib/posts'
-import { inputClass } from '@/lib/utils'
-import { useValidationErrors } from '@/lib/useValidationErrors'
 
 import type { FC, FormEvent } from 'react'
 
 import type { Post, Tag } from '@/types'
 
-type PostFormField =
-    'parentPostIds' | 'tags' | 'originalCreatedAt'
-
 
 const tagsToStr = (tags: Tag[]): string => {
   const result: Tag[] = []
@@ -39,10 +32,8 @@ type Props = { post:    Post
 	       onSave:  (newPost: Post) => void }
 
 
-const PostEditForm: FC<Props> = ({ post, onSave }) => {
+export default (({ post, onSave }: Props) => {
   const [disabled, setDisabled] = useState (false)
-  const { baseErrors, fieldErrors, clearValidationErrors, applyValidationError } =
-      useValidationErrors<PostFormField> ()
   const [originalCreatedBefore, setOriginalCreatedBefore] =
       useState<string | null> (post.originalCreatedBefore)
   const [originalCreatedFrom, setOriginalCreatedFrom] =
@@ -55,8 +46,6 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
   const dialogue = useDialogue ()
 
   const update = async (...args: Parameters<typeof updatePost>) => {
-    clearValidationErrors ()
-
     try
     {
       const data = await updatePost (...args)
@@ -73,21 +62,14 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
     }
     catch (e)
     {
-      const response = isApiError<{ mergeable?: boolean }> (e) ? e.response : undefined
+      const response = (e as any)?.response
 
       if (response?.status !== 409)
-	{
-	  if (applyValidationError (e))
 	{
 	  toast ({ description: '更新はできなかったよ……' })
 	  return
 	}
 
-	  toast ({ title: '失敗……', description: '入力を確認してください．' })
-
-	  return
-	}
-
       const action = await dialogue.choice ({
 	  title: '競合が発生しました．',
 	  description: (
@@ -139,38 +121,33 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 
   return (
       <form onSubmit={handleSubmit} className="max-w-xl pt-2 space-y-4">
-	<FieldError messages={baseErrors}/>
-
 	{/* タイトル */}
-	<FormField label="タイトル">
+	<div>
-	  {({ invalid }) => (
+	  <Label>タイトル</Label>
 	  <input
 	      type="text"
 	      disabled={disabled}
-		  className={inputClass (invalid)}
+	      className="w-full border rounded p-2"
 	      value={title ?? ''}
-		  onChange={ev => setTitle (ev.target.value)}/>)}
+	      onChange={ev => setTitle (ev.target.value)}/>
-	</FormField>
+	</div>
 
 	{/* 親投稿 */}
-	<FormField label="親投稿" messages={fieldErrors.parentPostIds}>
+	<div>
-	  {({ describedBy, invalid }) => (
+	  <Label>親投稿</Label>
 	  <input
 	      type="text"
 	      disabled={disabled}
 	      value={parentPostIds}
 	      onChange={e => setParentPostIds (e.target.value)}
-		  aria-describedby={describedBy}
+	      className="w-full border p-2 rounded"/>
-		  aria-invalid={invalid}
+	</div>
-		  className={inputClass (invalid)}/>)}
-	</FormField>
 
 	{/* タグ */}
 	<PostFormTagsArea
 	    disabled={disabled}
 	    tags={tags}
-	    setTags={setTags}
+	    setTags={setTags}/>
-	    errors={fieldErrors.tags}/>
 
 	{/* オリジナルの作成日時 */}
 	<PostOriginalCreatedTimeField
@@ -178,14 +155,13 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 	    originalCreatedFrom={originalCreatedFrom}
 	    setOriginalCreatedFrom={setOriginalCreatedFrom}
 	    originalCreatedBefore={originalCreatedBefore}
-	    setOriginalCreatedBefore={setOriginalCreatedBefore}
+	    setOriginalCreatedBefore={setOriginalCreatedBefore}/>
-	    errors={fieldErrors.originalCreatedAt}/>
 
 	{/* 送信 */}
-	<Button type="submit" disabled={disabled}>
+	<Button
+	    type="submit"
+	    disabled={disabled}>
 	  更新
 	</Button>
       </form>)
-}
+}) satisfies FC<Props>
-
-export default PostEditForm

frontend/src/components/PostEmbed.test.tsx

@@ -1,128 +0,0 @@
-import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import { beforeEach, describe, expect, it, vi } from 'vitest'
-
-import PostEmbed from '@/components/PostEmbed'
-import { buildPost } from '@/test/factories'
-
-const dialogue = vi.hoisted (() => ({
-  confirm: vi.fn (),
-}))
-
-const nicoViewer = vi.hoisted (() => ({
-  props: vi.fn (),
-}))
-
-vi.mock ('@/components/dialogues/DialogueProvider', () => ({
-  useDialogue: () => dialogue,
-}))
-
-vi.mock ('@/components/NicoViewer', () => ({
-  default: (props: { id: string }) => {
-    nicoViewer.props (props)
-    return <div>Nico:{props.id}</div>
-  },
-}))
-
-vi.mock ('react-youtube', () => ({
-  default: ({ videoId }: { videoId: string }) => <div>YouTube:{videoId}</div>,
-}))
-
-describe ('PostEmbed', () => {
-  beforeEach (() => {
-    vi.clearAllMocks ()
-  })
-
-  it ('embeds nicovideo watch URLs', () => {
-    render (<PostEmbed post={buildPost ({ url: 'https://www.nicovideo.jp/watch/sm12345' })}/>)
-
-    expect (screen.getByText ('Nico:sm12345')).toBeInTheDocument ()
-  })
-
-  it ('reports niconico metadata as milliseconds', () => {
-    const onVideoReady = vi.fn ()
-    const onPlaybackChange = vi.fn ()
-    render (
-        <PostEmbed
-            post={buildPost ({ url: 'https://www.nicovideo.jp/watch/sm12345' })}
-            onVideoReady={onVideoReady}
-            onPlaybackChange={onPlaybackChange}/>,
-    )
-
-    nicoViewer.props.mock.calls[0][0].onMetadataChange ({
-      currentTime:            7_000,
-      duration:               120_000,
-      isVideoMetaDataLoaded:  true,
-      maximumBuffered:        30,
-      muted:                  false,
-      showComment:            true,
-      volume:                 1,
-    })
-
-    expect (onVideoReady).toHaveBeenCalledWith (120_000)
-    expect (onPlaybackChange).toHaveBeenCalledWith (7_000)
-  })
-
-  it ('reports niconico video readiness only once', () => {
-    const onVideoReady = vi.fn ()
-    render (
-        <PostEmbed
-            post={buildPost ({ url: 'https://www.nicovideo.jp/watch/sm12345' })}
-            onVideoReady={onVideoReady}/>,
-    )
-
-    nicoViewer.props.mock.calls[0][0].onLoadComplete ({
-      title:           '動画',
-      videoId:         'sm12345',
-      lengthInSeconds: 120,
-      thumbnailUrl:    'https://example.com/thumb.jpg',
-      description:     '',
-      viewCount:       1,
-      commentCount:    2,
-      mylistCount:     3,
-      postedAt:        '2026-01-02T03:04:05.000Z',
-      watchId:         12345,
-    })
-    nicoViewer.props.mock.calls[0][0].onMetadataChange ({
-      currentTime:            7_000,
-      duration:               120_000,
-      isVideoMetaDataLoaded:  true,
-      maximumBuffered:        30,
-      muted:                  false,
-      showComment:            true,
-      volume:                 1,
-    })
-
-    expect (onVideoReady).toHaveBeenCalledTimes (1)
-    expect (onVideoReady).toHaveBeenCalledWith (120_000)
-  })
-
-  it ('embeds x/twitter status URLs', () => {
-    render (<PostEmbed post={buildPost ({ url: 'https://x.com/someone/status/12345' })}/>)
-
-    expect (screen.getByRole ('link', { name: '@someone' })).toBeInTheDocument ()
-  })
-
-  it ('embeds youtube watch URLs', () => {
-    render (<PostEmbed post={buildPost ({ url: 'https://www.youtube.com/watch?v=abc123' })}/>)
-
-    expect (screen.getByText ('YouTube:abc123')).toBeInTheDocument ()
-  })
-
-  it ('asks before framing unknown external pages', async () => {
-    dialogue.confirm.mockResolvedValueOnce (true)
-    render (
-        <PostEmbed
-            post={buildPost ({ url: 'https://example.com/page', title: 'external' })}/>,
-    )
-
-    fireEvent.click (screen.getByRole ('link', { name: '外部ページを表示' }))
-
-    await waitFor (() => {
-      expect (dialogue.confirm).toHaveBeenCalled ()
-    })
-    expect (await screen.findByTitle ('external')).toHaveAttribute (
-        'src',
-        'https://example.com/page',
-    )
-  })
-})

frontend/src/components/PostEmbed.tsx

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useRef, useState } from 'react'
+import { useState } from 'react'
 import YoutubeEmbed from 'react-youtube'
 
 import NicoViewer from '@/components/NicoViewer'
@@ -8,113 +8,16 @@ import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import type { FC, RefObject } from 'react'
 
 import type { NiconicoMetadata, NiconicoVideoInfo, NiconicoViewerHandle, Post } from '@/types'
-import type { YouTubePlayer } from 'react-youtube'
-
-type YouTubeEvent<T = unknown> = {
-    data:    T
-    target:  YouTubePlayer }
 
 type Props = {
     ref?:               RefObject<NiconicoViewerHandle | null>
     post:               Post
     onLoadComplete?:    (info: NiconicoVideoInfo) => void
-    onMetadataChange?:  (meta: NiconicoMetadata) => void
+    onMetadataChange?:  (meta: NiconicoMetadata) => void }
-    onVideoReady?:      (durationMs: number) => void
-    onPlaybackChange?:  (currentTimeMs: number) => number | void
-    onError?:           (data: unknown) => void }
 
 
-const PostEmbed: FC<Props> = ({
+export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
-    ref,
-    post,
-    onLoadComplete,
-    onMetadataChange,
-    onVideoReady,
-    onPlaybackChange,
-    onError,
-}) => {
   const dialogue = useDialogue ()
-  const [framed, setFramed] = useState (false)
-  const [youtubePlayer, setYoutubePlayer] = useState<YouTubePlayer | null> (null)
-  const niconicoVideoReadyRef = useRef (false)
-
-  const notifyNiconicoVideoReady = useCallback ((durationMs: number) => {
-    if (niconicoVideoReadyRef.current
-	|| !(Number.isFinite (durationMs))
-	|| durationMs <= 0)
-      return
-
-    niconicoVideoReadyRef.current = true
-    onVideoReady?.(durationMs)
-  }, [onVideoReady])
-
-  const reportYoutubePlayback = useCallback (async (player: YouTubePlayer) => {
-    const currentTime = await player.getCurrentTime ()
-    const currentTimeMs = currentTime * 1_000
-    const targetTimeMs = onPlaybackChange?.(currentTimeMs)
-
-    if (typeof targetTimeMs !== 'number')
-      return
-
-    if (Math.abs (currentTimeMs - targetTimeMs) > 5_000)
-      await player.seekTo (targetTimeMs / 1_000, true)
-  }, [onPlaybackChange])
-
-  const handleYoutubeReady = async (event: YouTubeEvent) => {
-    setYoutubePlayer (event.target)
-
-    try
-    {
-      await event.target.playVideo ()
-
-      const duration = await event.target.getDuration ()
-      const durationMs = duration * 1_000
-      onVideoReady?.(durationMs)
-
-      if (!(Number.isFinite (durationMs)) || durationMs <= 0)
-	return
-
-      await reportYoutubePlayback (event.target)
-    }
-    catch (error)
-    {
-      onError?.({ platform: 'youtube', error })
-    }
-  }
-
-  const handleYoutubeStateChange = (event: YouTubeEvent<number>) => {
-    void reportYoutubePlayback (event.target)
-  }
-
-  const handleYoutubeError = (event: YouTubeEvent<number>) => {
-    onError?.({ platform: 'youtube', code: event.data })
-  }
-
-  const handleNiconicoLoadComplete = (info: NiconicoVideoInfo) => {
-    notifyNiconicoVideoReady (info.lengthInSeconds * 1_000)
-    onLoadComplete?.(info)
-  }
-
-  const handleNiconicoMetadataChange = (meta: NiconicoMetadata) => {
-    notifyNiconicoVideoReady (meta.duration)
-    onPlaybackChange?.(meta.currentTime)
-    onMetadataChange?.(meta)
-  }
-
-  useEffect (() => {
-    niconicoVideoReadyRef.current = false
-  }, [post.url])
-
-  useEffect (() => {
-    if (!(youtubePlayer) || !(onPlaybackChange))
-      return
-
-    const timer = setInterval (
-	() => void reportYoutubePlayback (youtubePlayer),
-	1_000)
-
-    return () => clearInterval (timer)
-  }, [onPlaybackChange, reportYoutubePlayback, youtubePlayer])
 
   const url = new URL (post.url)
 
@@ -134,15 +37,14 @@ const PostEmbed: FC<Props> = ({
 	      id={videoId}
 	      width={640}
 	      height={360}
-	      onLoadComplete={handleNiconicoLoadComplete}
+	      onLoadComplete={onLoadComplete}
-	      onMetadataChange={handleNiconicoMetadataChange}
+	      onMetadataChange={onMetadataChange}/>)
-	      onError={onError}/>)
     }
 
   case 'twitter.com':
   case 'x.com':
     {
-      const mUserId = url.pathname.match (/(?<=\/)[^/]+?(?=\/|$|\?)/)
+      const mUserId = url.pathname.match (/(?<=\/)[^\/]+?(?=\/|$|\?)/)
       const mStatusId = url.pathname.match (/(?<=\/status\/)\d+?(?=\/|$|\?)/)
       if (!(mUserId) || !(mStatusId))
 	break
@@ -166,13 +68,12 @@ const PostEmbed: FC<Props> = ({
 	      mute:         0,
 	      loop:         1,
 	      width:        '640',
-	      height:       '360' } }}
+	      height:       '360' } }}/>)
-	      onReady={handleYoutubeReady}
-	      onStateChange={handleYoutubeStateChange}
-	      onError={handleYoutubeError}/>)
     }
   }
 
+  const [framed, setFramed] = useState (false)
+
   return (
       <>
 	{framed
@@ -200,6 +101,4 @@ const PostEmbed: FC<Props> = ({
 	      </a>
 	    </div>)}
       </>)
-}
+}) satisfies FC<Props>
-
-export default PostEmbed

frontend/src/components/PostFormTagsArea.test.tsx

@@ -1,34 +0,0 @@
-import { fireEvent, screen, waitFor } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
-
-import PostFormTagsArea from '@/components/PostFormTagsArea'
-import { buildTag } from '@/test/factories'
-import { renderWithProviders } from '@/test/render'
-
-const api = vi.hoisted (() => ({
-  apiGet: vi.fn (),
-}))
-
-vi.mock ('@/lib/api', () => api)
-
-describe ('PostFormTagsArea', () => {
-  it ('updates text and fetches autocomplete for the selected token', async () => {
-    const setTags = vi.fn ()
-    api.apiGet.mockResolvedValueOnce ([buildTag ({ name: '虹夏', postCount: 3 })])
-
-    renderWithProviders (<PostFormTagsArea tags="虹" setTags={setTags}/>)
-
-    const textarea = screen.getByRole ('textbox')
-    fireEvent.focus (textarea)
-    fireEvent.select (textarea, { target: { selectionStart: 1, selectionEnd: 1 } })
-    fireEvent.change (textarea, { target: { value: '虹夏' } })
-
-    await waitFor (() => {
-      expect (api.apiGet).toHaveBeenCalledWith (
-          '/tags/autocomplete',
-          { params: { q: '虹', nico: '0' } },
-      )
-    })
-    expect (setTags).toHaveBeenCalledWith ('虹夏')
-  })
-})

frontend/src/components/PostFormTagsArea.tsx

@@ -3,7 +3,7 @@
 import { useRef, useState } from 'react'
 
 import TagSearchBox from '@/components/TagSearchBox'
-import FormField from '@/components/common/FormField'
+import Label from '@/components/common/Label'
 import TextArea from '@/components/common/TextArea'
 import { apiGet } from '@/lib/api'
 
@@ -33,11 +33,10 @@ const replaceToken = (value: string, start: number, end: number, text: string) =
 
 type Props = Omit<ComponentPropsWithoutRef<'textarea'>, 'value' | 'onChange' | 'onBlur'> & {
     tags:     string
-    setTags:  (tags: string) => void
+    setTags:  (tags: string) => void }
-    errors?:  string[] }
 
 
-const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
+export default (({ tags, setTags, ...rest }: Props) => {
   const ref = useRef<HTMLTextAreaElement> (null)
 
   const [bounds, setBounds] = useState<{ start: number; end: number }> ({ start: 0, end: 0 })
@@ -74,15 +73,12 @@ const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
   }
 
   return (
-      <FormField className="relative w-full" label="タグ" messages={errors}>
+      <div className="relative w-full">
-	{({ describedBy, invalid }) => (
+	<Label>タグ</Label>
-	    <>
 	<TextArea
 	    {...rest}
 	    ref={ref}
 	    value={tags}
-		  aria-describedby={describedBy}
-		  invalid={invalid}
 	    onChange={ev => setTags (ev.target.value)}
 	    onSelect={async (ev: SyntheticEvent<HTMLTextAreaElement>) => {
 	      const pos = (ev.target as HTMLTextAreaElement).selectionStart
@@ -100,8 +96,5 @@ const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
 			     : [] as Tag[]}
 		activeIndex={-1}
 		onSelect={handleTagSelect}/>)}
-	    </>)}
+      </div>)
-      </FormField>)
+}) satisfies FC<Props>
-}
-
-export default PostFormTagsArea

frontend/src/components/PostList.test.tsx

@@ -1,44 +0,0 @@
-import { fireEvent, screen } from '@testing-library/react'
-import { beforeEach, describe, expect, it, vi } from 'vitest'
-
-import PostList from '@/components/PostList'
-import { buildPost } from '@/test/factories'
-import { renderWithProviders } from '@/test/render'
-
-const prefetchers = vi.hoisted (() => ({
-  prefetchForURL: vi.fn (),
-}))
-
-vi.mock ('@/lib/prefetchers', () => prefetchers)
-
-describe ('PostList', () => {
-  beforeEach (() => {
-    prefetchers.prefetchForURL.mockResolvedValue (undefined)
-  })
-
-  it ('renders post thumbnails as links to post details', () => {
-    renderWithProviders (
-        <PostList posts={[
-          buildPost ({ id: 1, title: 'First', thumbnail: 'first.jpg' }),
-          buildPost ({ id: 2, title: null, url: 'https://example.com/second' }),
-        ]}/>,
-    )
-
-    expect (screen.getByRole ('link', { name: 'First' })).toHaveAttribute (
-        'href',
-        '/posts/1',
-    )
-    expect (
-        screen.getByRole ('link', { name: 'https://example.com/second' }),
-    ).toHaveAttribute ('href', '/posts/2')
-  })
-
-  it ('calls the optional click handler', () => {
-    const onClick = vi.fn ()
-    renderWithProviders (<PostList posts={[buildPost ()]} onClick={onClick}/>)
-
-    fireEvent.click (screen.getByRole ('link', { name: 'テスト投稿' }))
-
-    expect (onClick).toHaveBeenCalledTimes (1)
-  })
-})

frontend/src/components/PostList.tsx

@@ -14,7 +14,7 @@ type Props = { posts:     Post[]
 	       onClick?:  (event: MouseEvent<HTMLElement>) => void }
 
 
-const PostList: FC<Props> = ({ posts, onClick }) => {
+export default (({ posts, onClick }: Props) => {
   const location = useLocation ()
 
   const setForLocationKey = useSharedTransitionStore (s => s.setForLocationKey)
@@ -70,6 +70,4 @@ const PostList: FC<Props> = ({ posts, onClick }) => {
 	      </PrefetchLink>)
 	})}
       </div>)
-}
+}) satisfies FC<Props>
-
-export default PostList

frontend/src/components/PostOriginalCreatedTimeField.test.tsx

@@ -1,63 +0,0 @@
-import { fireEvent, render, screen } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
-
-import PostOriginalCreatedTimeField from '@/components/PostOriginalCreatedTimeField'
-
-describe ('PostOriginalCreatedTimeField', () => {
-  it ('updates from and before values', () => {
-    const setFrom = vi.fn ()
-    const setBefore = vi.fn ()
-
-    render (
-        <PostOriginalCreatedTimeField
-            originalCreatedFrom={null}
-            setOriginalCreatedFrom={setFrom}
-            originalCreatedBefore={null}
-            setOriginalCreatedBefore={setBefore}/>,
-    )
-
-    const inputs = screen.getAllByDisplayValue ('')
-    fireEvent.change (inputs[0], { target: { value: '2026-01-02T03:04' } })
-    fireEvent.change (inputs[1], { target: { value: '2026-01-03T03:04' } })
-
-    expect (setFrom).toHaveBeenCalledWith (expect.any (String))
-    expect (setBefore).toHaveBeenCalledWith (expect.any (String))
-  })
-
-  it ('infers an exclusive before value on blur', () => {
-    const setBefore = vi.fn ()
-
-    render (
-        <PostOriginalCreatedTimeField
-            originalCreatedFrom={null}
-            setOriginalCreatedFrom={vi.fn ()}
-            originalCreatedBefore={null}
-            setOriginalCreatedBefore={setBefore}/>,
-    )
-
-    const input = screen.getAllByDisplayValue ('')[0]
-    fireEvent.blur (input, { target: { value: '2026-01-02T03:04' } })
-
-    expect (setBefore).toHaveBeenCalledWith (expect.any (String))
-  })
-
-  it ('resets both values', () => {
-    const setFrom = vi.fn ()
-    const setBefore = vi.fn ()
-
-    render (
-        <PostOriginalCreatedTimeField
-            originalCreatedFrom="2026-01-01T00:00:00Z"
-            setOriginalCreatedFrom={setFrom}
-            originalCreatedBefore="2026-01-02T00:00:00Z"
-            setOriginalCreatedBefore={setBefore}/>,
-    )
-
-    const buttons = screen.getAllByRole ('button', { name: 'リセット' })
-    fireEvent.click (buttons[0])
-    fireEvent.click (buttons[1])
-
-    expect (setFrom).toHaveBeenCalledWith (null)
-    expect (setBefore).toHaveBeenCalledWith (null)
-  })
-})

frontend/src/components/PostOriginalCreatedTimeField.tsx

@@ -1,5 +1,5 @@
 import DateTimeField from '@/components/common/DateTimeField'
-import FormField from '@/components/common/FormField'
+import Label from '@/components/common/Label'
 import { Button } from '@/components/ui/button'
 
 import type { FC } from 'react'
@@ -9,29 +9,21 @@ type Props = {
     originalCreatedFrom:      string | null
     setOriginalCreatedFrom:   (x: string | null) => void
     originalCreatedBefore:    string | null
-    setOriginalCreatedBefore: (x: string | null) => void
+    setOriginalCreatedBefore: (x: string | null) => void }
-    errors?:                  string[] }
 
 
-const PostOriginalCreatedTimeField: FC<Props> = (
+export default (({ disabled,
-    { disabled,
 		   originalCreatedFrom,
 		   setOriginalCreatedFrom,
 		   originalCreatedBefore,
-      setOriginalCreatedBefore,
+		   setOriginalCreatedBefore }: Props) => (
-      errors }: Props,
+    <div>
-) => (
+      <Label>オリジナルの作成日時</Label>
-    <FormField label="オリジナルの作成日時" messages={errors}>
-      {({ describedBy, invalid }) => (
-	  <>
       <div className="my-1 flex">
 	<div className="w-80">
 	  <DateTimeField
 	      className="mr-2"
 	      disabled={disabled ?? false}
-		    aria-describedby={describedBy}
-		    aria-invalid={invalid}
-		    invalid={invalid}
 	      value={originalCreatedFrom ?? undefined}
 	      onChange={setOriginalCreatedFrom}
 	      onBlur={ev => {
@@ -59,15 +51,11 @@ const PostOriginalCreatedTimeField: FC<Props> = (
 	  </Button>
 	</div>
       </div>
-
       <div className="my-1 flex">
 	<div className="w-80">
 	  <DateTimeField
 	      className="mr-2"
 	      disabled={disabled}
-		    aria-describedby={describedBy}
-		    aria-invalid={invalid}
-		    invalid={invalid}
 	      value={originalCreatedBefore ?? undefined}
 	      onChange={setOriginalCreatedBefore}/>
 	  より前
@@ -83,7 +71,4 @@ const PostOriginalCreatedTimeField: FC<Props> = (
 	  </Button>
 	</div>
       </div>
-	  </>)}
+    </div>)) satisfies FC<Props>
-    </FormField>)
-
-export default PostOriginalCreatedTimeField

frontend/src/components/RouteBlockerOverlay.test.tsx

@@ -1,30 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import { afterEach, describe, expect, it } from 'vitest'
-
-import RouteBlockerOverlay, { useOverlayStore } from '@/components/RouteBlockerOverlay'
-
-describe ('RouteBlockerOverlay', () => {
-  afterEach (() => {
-    useOverlayStore.setState ({ active: false })
-    document.body.style.overflow = ''
-    document.body.removeAttribute ('aria-busy')
-  })
-
-  it ('renders nothing while inactive', () => {
-    useOverlayStore.setState ({ active: false })
-
-    const { container } = render (<RouteBlockerOverlay/>)
-
-    expect (container).toBeEmptyDOMElement ()
-  })
-
-  it ('renders a blocking progressbar and marks the body busy while active', () => {
-    useOverlayStore.setState ({ active: true })
-
-    render (<RouteBlockerOverlay/>)
-
-    expect (screen.getByRole ('progressbar', { name: 'Loading' })).toBeInTheDocument ()
-    expect (document.body).toHaveAttribute ('aria-busy', 'true')
-    expect (document.body.style.overflow).toBe ('hidden')
-  })
-})

frontend/src/components/RouteBlockerOverlay.tsx

@@ -13,7 +13,7 @@ export const useOverlayStore = create<OverlayStore> (set => ({
     setActive:  v => set ({ active: v }) }))
 
 
-const RouteBlockerOverlay: FC = () => {
+export default (() => {
   const active = useOverlayStore (s => s.active)
 
   useEffect (() => {
@@ -43,6 +43,4 @@ const RouteBlockerOverlay: FC = () => {
 	  </div>
 	</div>
       </div>)
-}
+}) satisfies FC
-
-export default RouteBlockerOverlay

frontend/src/components/SortHeader.test.tsx

@@ -1,39 +0,0 @@
-import { screen } from '@testing-library/react'
-import { describe, expect, it } from 'vitest'
-
-import SortHeader from '@/components/SortHeader'
-import { renderWithProviders } from '@/test/render'
-
-describe ('SortHeader', () => {
-  it ('toggles the active sort direction and resets the page', () => {
-    renderWithProviders (
-        <SortHeader
-            by="title"
-            label="タイトル"
-            currentOrder="title:asc"
-            defaultDirection={{ title: 'asc' }}/>,
-        { route: '/posts?tags=x&page=4&order=title%3Aasc' },
-    )
-
-    expect (screen.getByRole ('link', { name: 'タイトル ▲' })).toHaveAttribute (
-        'href',
-        '/posts?tags=x&page=1&order=title%3Adesc',
-    )
-  })
-
-  it ('uses default direction for inactive fields', () => {
-    renderWithProviders (
-        <SortHeader
-            by="updated_at"
-            label="更新"
-            currentOrder="title:desc"
-            defaultDirection={{ title: 'asc', updated_at: 'desc' }}/>,
-        { route: '/posts?page=2' },
-    )
-
-    expect (screen.getByRole ('link', { name: '更新' })).toHaveAttribute (
-        'href',
-        '/posts?page=1&order=updated_at%3Adesc',
-    )
-  })
-})

frontend/src/components/TagDetailSidebar.tsx

@@ -151,7 +151,7 @@ const DropSlot = ({ cat }: { cat: Category }) => {
 type Props = { post: Post; sp?: boolean }
 
 
-const TagDetailSidebar: FC<Props> = ({ post, sp }) => {
+export default (({ post, sp }: Props) => {
   sp = Boolean (sp)
 
   const qc = useQueryClient ()
@@ -376,6 +376,4 @@ const TagDetailSidebar: FC<Props> = ({ post, sp }) => {
 	  </DragOverlay>
 	</DndContext>
       </SidebarComponent>)
-}
+}) satisfies FC<Props>
-
-export default TagDetailSidebar

frontend/src/components/TagLink.test.tsx

@@ -1,45 +0,0 @@
-import { screen } from '@testing-library/react'
-import { describe, expect, it } from 'vitest'
-
-import TagLink from '@/components/TagLink'
-import { buildTag } from '@/test/factories'
-import { renderWithProviders } from '@/test/render'
-
-describe ('TagLink', () => {
-  it ('links tag names to post search and shows counts', () => {
-    renderWithProviders (
-        <TagLink tag={buildTag ({ name: '虹 夏', postCount: 4 })}/>,
-    )
-
-    expect (screen.getByRole ('link', { name: '虹 夏' })).toHaveAttribute (
-        'href',
-        '/posts?tags=%E8%99%B9+%E5%A4%8F',
-    )
-    expect (screen.getByText ('4')).toBeInTheDocument ()
-  })
-
-  it ('links wiki markers to the correct detail route', () => {
-    renderWithProviders (
-        <TagLink tag={buildTag ({ hasWiki: true, name: 'a/b' })}/>,
-    )
-
-    expect (screen.getByRole ('link', { name: '?' })).toHaveAttribute (
-        'href',
-        '/wiki/a%2Fb',
-    )
-  })
-
-  it ('renders aliases and non-link tags when requested', () => {
-    renderWithProviders (
-        <TagLink
-            tag={buildTag ({ matchedAlias: '別名', name: '正式名' })}
-            linkFlg={false}
-            withWiki={false}
-            withCount={false}/>,
-    )
-
-    expect (screen.getByText ('別名')).toBeInTheDocument ()
-    expect (screen.getByText ('正式名')).toBeInTheDocument ()
-    expect (screen.queryByRole ('link')).not.toBeInTheDocument ()
-  })
-})

frontend/src/components/TagLink.tsx

@@ -27,12 +27,12 @@ type Props =
     | PropsWithoutLink
 
 
-const TagLink: FC<Props> = ({ tag,
+export default (({ tag,
 		   nestLevel = 0,
 		   linkFlg   = true,
 		   withWiki  = true,
 		   withCount = true,
-		   ...props }) => {
+		   ...props }: Props) => {
   const spanClass = cn (
       `text-${ TAG_COLOUR[tag.category] }-${ LIGHT_COLOUR_SHADE }`,
       `dark:text-${ TAG_COLOUR[tag.category] }-${ DARK_COLOUR_SHADE }`)
@@ -126,6 +126,4 @@ const TagLink: FC<Props> = ({ tag,
 	{withCount && (
 	    <span className="ml-1">{tag.postCount}</span>)}
       </>)
-}
+}) satisfies FC<Props>
-
-export default TagLink

frontend/src/components/TagSearch.tsx

@@ -4,7 +4,6 @@ import { useEffect, useState } from 'react'
 import { useNavigate, useLocation } from 'react-router-dom'
 
 import { apiGet } from '@/lib/api'
-import { inputClass } from '@/lib/utils'
 
 import TagSearchBox from './TagSearchBox'
 
@@ -13,7 +12,7 @@ import type { ChangeEvent, FC, KeyboardEvent } from 'react'
 import type { Tag } from '@/types'
 
 
-const TagSearch: FC = () => {
+export default (() => {
   const location = useLocation ()
   const navigate = useNavigate ()
 
@@ -111,12 +110,9 @@ const TagSearch: FC = () => {
 	       onFocus={() => setSuggestionsVsbl (true)}
 	       onBlur={() => setSuggestionsVsbl (false)}
 	       onKeyDown={handleKeyDown}
-	       className={inputClass (false,
+	       className="w-full px-3 py-2 border rounded dark:border-gray-600 dark:bg-gray-800 dark:text-white"/>
-				      'px-3 py-2 dark:border-gray-600 dark:bg-gray-800 dark:text-white')}/>
 	<TagSearchBox suggestions={suggestionsVsbl && suggestions.length ? suggestions : [] as Tag[]}
 		      activeIndex={activeIndex}
 		      onSelect={handleTagSelect}/>
       </div>)
-}
+}) satisfies FC
-
-export default TagSearch

frontend/src/components/TagSearchBox.test.tsx

@@ -1,30 +0,0 @@
-import { fireEvent, screen } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
-
-import TagSearchBox from '@/components/TagSearchBox'
-import { buildTag } from '@/test/factories'
-import { renderWithProviders } from '@/test/render'
-
-describe ('TagSearchBox', () => {
-  it ('renders suggestions and selects tags on mouse down', () => {
-    const handleSelect = vi.fn ()
-    const tag = buildTag ({ id: 9, name: '候補', postCount: 2 })
-
-    renderWithProviders (
-        <TagSearchBox suggestions={[tag]} activeIndex={0} onSelect={handleSelect}/>,
-    )
-
-    fireEvent.mouseDown (screen.getByText ('候補'))
-
-    expect (handleSelect).toHaveBeenCalledWith (tag)
-    expect (screen.getByText ('2')).toBeInTheDocument ()
-  })
-
-  it ('renders nothing when suggestions are empty', () => {
-    const { container } = renderWithProviders (
-        <TagSearchBox suggestions={[]} activeIndex={-1} onSelect={vi.fn ()}/>,
-    )
-
-    expect (container).toBeEmptyDOMElement ()
-  })
-})

frontend/src/components/TagSearchBox.tsx

@@ -10,7 +10,7 @@ type Props = { suggestions: Tag[]
 	       onSelect:    (tag: Tag) => void }
 
 
-const TagSearchBox: FC<Props> = ({ suggestions, activeIndex, onSelect }) => {
+export default (({ suggestions, activeIndex, onSelect }: Props) => {
   if (suggestions.length === 0)
     return
 
@@ -26,6 +26,4 @@ const TagSearchBox: FC<Props> = ({ suggestions, activeIndex, onSelect }) => {
 	      <TagLink tag={tag} linkFlg={false} withWiki={false}/>
 	    </li>))}
       </ul>)
-}
+}) satisfies FC<Props>
-
-export default TagSearchBox

frontend/src/components/TagSidebar.tsx

@@ -19,7 +19,7 @@ type Props = { posts:     Post[]
 	       onClick?:  (event: MouseEvent<HTMLElement>) => void }
 
 
-const TagSidebar: FC<Props> = ({ posts, onClick }) => {
+export default (({ posts, onClick }: Props) => {
   const navigate = useNavigate ()
 
   const [tagsVsbl, setTagsVsbl] = useState (false)
@@ -126,6 +126,4 @@ const TagSidebar: FC<Props> = ({ posts, onClick }) => {
 	  {tagsVsbl ? '▲▲▲ タグ一覧を閉じる ▲▲▲' : '▼▼▼ タグ一覧を表示 ▼▼▼'}
 	</a>
       </SidebarComponent>)
-}
+}) satisfies FC<Props>
-
-export default TagSidebar

frontend/src/components/TopNav.tsx

@@ -26,7 +26,7 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
     pathName: string }): Menu => {
   const postCount = tag?.postCount ?? 0
 
-  const wikiPageFlg = Boolean (/^\/wiki\/(?!new|changes)[^/]+/.test (pathName) && wikiId)
+  const wikiPageFlg = Boolean (/^\/wiki\/(?!new|changes)[^\/]+/.test (pathName) && wikiId)
   const wikiTitle = pathName.split ('/')[2] ?? ''
 
   const tagFlg = /^\/tags\/\d+/.test (pathName)
@@ -55,6 +55,12 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 	  { name: '追加', to: '/materials/new' },
 	  { name: '全体履歴', to: '/materials/changes', visible: false },
 	  { name: 'ヘルプ', to: '/wiki/ヘルプ:素材集' }] },
+      { name: '上映会', to: '/theatres/1', base: '/theatres', subMenu: [
+	  { name: <>第&thinsp;1&thinsp;会場</>, to: '/theatres/1' },
+	  { name: 'CyTube', to: '//cytube.mm428.net/r/deernijika' },
+	  { name: <>ニジカ放送局第&thinsp;1&thinsp;チャンネル</>,
+	    to: '//www.youtube.com/watch?v=DCU3hL4Uu6A' },
+	  { name: 'ヘルプ', to: '/wiki/ヘルプ:上映会' }] },
       { name: 'Wiki', to: '/wiki/ヘルプ:ホーム', base: '/wiki', subMenu: [
 	  { name: '検索', to: '/wiki' },
 	  { name: '新規', to: '/wiki/new' },
@@ -65,8 +71,6 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 	    visible: wikiPageFlg },
 	  { name: '履歴', to: `/wiki/changes?id=${ wikiId }`, visible: wikiPageFlg },
 	  { name: '編輯', to: `/wiki/${ wikiId || wikiTitle }/edit`, visible: wikiPageFlg }] },
-      { name: 'おたのしみ', visible: false, subMenu: [
-	  { name: '上映会 (β)', to: '/theatres/1' }] },
       { name: 'ユーザ', to: '/users/settings', visible: false, subMenu: [
 	  { name: '一覧', to: '/users', visible: false },
 	  { name: 'お前', to: `/users/${ user?.id }`, visible: false },
@@ -76,7 +80,7 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 }
 
 
-const TopNav: FC<Props> = ({ user }) => {
+export default (({ user }: Props) => {
   const location = useLocation ()
 
   const dirRef = useRef<(-1) | 1> (1)
@@ -128,12 +132,8 @@ const TopNav: FC<Props> = ({ user }) => {
 
   const menu = menuOutline ({ tag, wikiId, user, pathName: location.pathname })
   const visibleMenu = menu.filter ((item): item is MenuVisibleItem => item.visible ?? true)
-  const moreMenu = menu.filter (item =>
-      !(item.visible ?? true)
-      || item.subMenu.filter (subItem => subItem.visible ?? true).length > 0)
   const activeIdx =
       visibleMenu.findIndex (item => location.pathname.startsWith (item.base || item.to))
-  const submenuHeight = moreVsbl ? 40 * moreMenu.length : (activeIdx < 0 ? 0 : 40)
 
   const prevActiveIdxRef = useRef<number> (activeIdx)
 
@@ -159,12 +159,12 @@ const TopNav: FC<Props> = ({ user }) => {
   useEffect (() => {
     const unsubscribe = WikiIdBus.subscribe (setWikiId)
     return () => unsubscribe ()
-  }, [])
+  }, [activeIdx])
 
   useEffect (() => {
     setMenuOpen (false)
     setOpenItemIdx (activeIdx)
-  }, [activeIdx, location])
+  }, [location])
 
   return (
       <>
@@ -244,9 +244,9 @@ const TopNav: FC<Props> = ({ user }) => {
 	  <motion.div
 	      key="submenu-shell"
 	      layout
-	      className="relative z-20 hidden md:block overflow-hidden
+	      className="relative hidden md:block overflow-hidden
 			 bg-yellow-200 dark:bg-red-950"
-	      animate={{ height: submenuHeight }}
+	      style={{ height: moreVsbl ? 40 * menu.length : (activeIdx < 0 ? 0 : 40) }}
 	      onMouseLeave={() => {
 		if (moreVsbl)
 		  setMoreVsbl (false)
@@ -257,7 +257,7 @@ const TopNav: FC<Props> = ({ user }) => {
 	      }}>
 	  {moreVsbl
 	   ? (
-	      moreMenu.map ((item, i) => (
+	      menu.map ((item, i) => (
 		  <div key={i} className="relative h-[40px]">
 		    <div className="absolute inset-0 flex items-center px-3">
 		      <motion.div
@@ -267,7 +267,7 @@ const TopNav: FC<Props> = ({ user }) => {
 			       : { initial: { x: 40, y: -40, opacity: 0 },
 				   animate: { x: 0, y: 0, opacity: 1 },
 				   exit: { x: 40, y: -40, opacity: 0 } })}
-			  className="z-10 h-full flex items-center px-3 font-bold w-28">
+			  className="z-10 h-full flex items-center px-3 font-bold w-24">
 			<h2>{item.name}</h2>
 		      </motion.div>
 		      {item.subMenu
@@ -433,6 +433,4 @@ const TopNav: FC<Props> = ({ user }) => {
 	      </motion.div>)}
 	</AnimatePresence>
       </>)
-}
+}) satisfies FC<Props>
-
-export default TopNav

frontend/src/components/TopNavUser.test.tsx

@@ -1,29 +0,0 @@
-import { screen } from '@testing-library/react'
-import { describe, expect, it } from 'vitest'
-
-import TopNavUser from '@/components/TopNavUser'
-import { buildUser } from '@/test/factories'
-import { renderWithProviders } from '@/test/render'
-
-describe ('TopNavUser', () => {
-  it ('renders nothing without a user', () => {
-    const { container } = renderWithProviders (<TopNavUser user={null}/>)
-
-    expect (container).toBeEmptyDOMElement ()
-  })
-
-  it ('links named users to settings', () => {
-    renderWithProviders (<TopNavUser user={buildUser ({ name: '山田' })}/>)
-
-    expect (screen.getByRole ('link', { name: '山田' })).toHaveAttribute (
-        'href',
-        '/users/settings',
-    )
-  })
-
-  it ('uses the anonymous display name', () => {
-    renderWithProviders (<TopNavUser user={buildUser ({ name: null })}/>)
-
-    expect (screen.getByRole ('link', { name: '名もなきニジラー' })).toBeInTheDocument ()
-  })
-})

frontend/src/components/TopNavUser.tsx

@@ -10,7 +10,7 @@ type Props = { user:  User | null,
 	       sp?:   boolean }
 
 
-const TopNavUser: FC<Props> = ({ user, sp }) => {
+export default (({ user, sp }: Props) => {
   if (!(user))
     return
 
@@ -28,6 +28,4 @@ const TopNavUser: FC<Props> = ({ user, sp }) => {
 	  {user.name || '名もなきニジラー'}
 	</PrefetchLink>
       </>)
-}
+}) satisfies FC<Props>
-
-export default TopNavUser

frontend/src/components/TwitterEmbed.test.tsx

@@ -1,19 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import { describe, expect, it } from 'vitest'
-
-import TwitterEmbed from '@/components/TwitterEmbed'
-
-describe ('TwitterEmbed', () => {
-  it ('renders tweet and user links', () => {
-    render (<TwitterEmbed userId="user_name" statusId="12345"/>)
-
-    expect (screen.getByRole ('link', { name: '@user_name' })).toHaveAttribute (
-        'href',
-        'https://twitter.com/user_name?ref_src=twsrc%3Etfw',
-    )
-    expect (screen.getByRole ('link', { name: /\d/ })).toHaveAttribute (
-        'href',
-        'https://twitter.com/user_name/status/12345?ref_src=twsrc%5Etfw',
-    )
-  })
-})

frontend/src/components/TwitterEmbed.tsx

@@ -5,7 +5,7 @@ type Props = {
     statusId: string }
 
 
-const TwitterEmbed: FC<Props> = ({ userId, statusId }) => {
+export default (({ userId, statusId }: Props) => {
   const now = (new Date).toLocaleDateString ()
 
   return (
@@ -18,6 +18,4 @@ const TwitterEmbed: FC<Props> = ({ userId, statusId }) => {
 	</blockquote>
 	<script async src="https://platform.twitter.com/widgets.js" charSet="utf-8"/>
       </div>)
-}
+}) satisfies FC<Props>
-
-export default TwitterEmbed

frontend/src/components/WikiBody.tsx

@@ -25,7 +25,7 @@ const mdComponents = { a: (({ href, children }) => (
 				  </a>))) } as const satisfies Components
 
 
-const WikiBody: FC<Props> = ({ title, body }) => {
+export default (({ title, body }: Props) => {
   const { data } = useQuery ({
       enabled: Boolean (body),
       queryKey: wikiKeys.index ({ }),
@@ -39,6 +39,4 @@ const WikiBody: FC<Props> = ({ title, body }) => {
       <ReactMarkdown components={mdComponents} remarkPlugins={remarkPlugins}>
 	{body || `このページは存在しません。[新規作成してください](/wiki/new?title=${ encodeURIComponent (title) })。`}
       </ReactMarkdown>)
-}
+}) satisfies FC<Props>
-
-export default WikiBody

frontend/src/components/common/DateTimeField.test.tsx

@@ -1,27 +0,0 @@
-import { fireEvent, render, screen } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
-
-import DateTimeField from '@/components/common/DateTimeField'
-
-describe ('DateTimeField', () => {
-  it ('renders an ISO value as a datetime-local value', () => {
-    render (<DateTimeField aria-label="日時" value="2026-01-02T03:04:05.000Z"/>)
-
-    const input = screen.getByLabelText ('日時')
-
-    expect (input).toHaveValue ('2026-01-02T12:04')
-  })
-
-  it ('reports local changes as ISO strings and empty values as null', () => {
-    const handleChange = vi.fn ()
-    render (<DateTimeField aria-label="日時" onChange={handleChange}/>)
-
-    const input = screen.getByLabelText ('日時')
-    fireEvent.change (input, { target: { value: '2026-01-02T03:04' } })
-    fireEvent.change (input, { target: { value: '' } })
-
-    const first = handleChange.mock.calls[0]?.[0]
-    expect (new Date (first).getFullYear ()).toBe (2026)
-    expect (handleChange).toHaveBeenLastCalledWith (null)
-  })
-})

frontend/src/components/common/DateTimeField.tsx

@@ -22,11 +22,10 @@ type Props = Omit<ComponentPropsWithoutRef<'input'>, 'onChange'> & {
     value?:     string
     onChange?:  (isoUTC: string | null) => void
     className?: string
-    onBlur?:    (ev: FocusEvent<HTMLInputElement>) => void
+    onBlur?:    (ev: FocusEvent<HTMLInputElement>) => void }
-    invalid?:   boolean }
 
 
-const DateTimeField: FC<Props> = ({ value, onChange, className, onBlur, invalid, ...rest }) => {
+export default (({ value, onChange, className, onBlur, ...rest }: Props) => {
   const [local, setLocal] = useState ('')
 
   useEffect (() => {
@@ -36,25 +35,13 @@ const DateTimeField: FC<Props> = ({ value, onChange, className, onBlur, invalid,
   return (
       <input
 	  {...rest}
-	  className={cn ('border rounded p-2',
+	  className={cn ('border rounded p-2', className)}
-			 (invalid
-			  ? ['border-red-500 bg-red-50 text-red-900',
-			     'focus:border-red-500 focus:outline-none',
-			     'focus:ring-2 focus:ring-red-200',
-			     'dark:border-red-500 dark:bg-red-950/30 dark:text-red-100']
-			  : ['border-gray-300',
-			     'focus:border-blue-500 focus:outline-none',
-			     'focus:ring-2 focus:ring-blue-200']),
-			 className)}
 	  type="datetime-local"
 	  value={local}
-	  aria-invalid={invalid}
 	  onChange={ev => {
 	    const v = ev.target.value
 	    setLocal (v)
 	    onChange?.(v ? (new Date (v)).toISOString () : null)
 	  }}
 	  onBlur={onBlur}/>)
-}
+}) satisfies FC<Props>
-
-export default DateTimeField

frontend/src/components/common/FieldError.tsx

@@ -1,18 +0,0 @@
-import type { FC } from 'react'
-
-type Props = { id?:        string
-	       messages?:  string[] }
-
-
-export const FieldError: FC<Props> = ({ id, messages }: Props) => {
-  if (!(messages) || messages.length === 0)
-    return null
-
-  return (
-      <ul id={id} className="mt-1 space-y-1 text-red-700 dark:text-red-300">
-	{messages.map ((message, i) => <li key={i}>{message}</li>)}
-      </ul>)
-}
-
-
-export default FieldError

frontend/src/components/common/Form.tsx

@@ -3,9 +3,7 @@ import type { FC, ReactNode } from 'react'
 type Props = { children: ReactNode }
 
 
-const Form: FC<Props> = ({ children }) => (
+export default (({ children }: Props) => (
     <div className="max-w-xl mx-auto p-4 space-y-4">
       {children}
-    </div>)
+    </div>)) satisfies FC<Props>
-
-export default Form

frontend/src/components/common/FormField.tsx

@@ -1,36 +0,0 @@
-import { useId } from 'react'
-
-import FieldError from '@/components/common/FieldError'
-import Label from '@/components/common/Label'
-import { cn } from '@/lib/utils'
-
-import type { FC, ReactNode } from 'react'
-
-type FieldState = { describedBy?: string
-		    invalid:      boolean }
-
-type Props = {
-    children:   (state: FieldState) => ReactNode
-    checkBox?:   { label:    string
-		   checked:  boolean
-		   onChange: (event: React.ChangeEvent<HTMLInputElement>) => void }
-    className?:  string
-    label:      ReactNode
-    messages?:  string[] }
-
-
-const FormField: FC<Props> = ({ children, checkBox, className, label, messages }: Props) => {
-  const id = useId ()
-  const invalid = messages != null && messages.length > 0
-  const errorId = invalid ? `${ id }-error` : undefined
-
-  return (
-      <div className={cn (className)}>
-	<Label checkBox={checkBox} invalid={invalid}>{label}</Label>
-	{children ({ describedBy: errorId, invalid })}
-	<FieldError id={errorId} messages={messages}/>
-      </div>)
-}
-
-
-export default FormField

frontend/src/components/common/Label.test.tsx

@@ -1,26 +0,0 @@
-import { fireEvent, render, screen } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
-
-import Label from '@/components/common/Label'
-
-describe ('Label', () => {
-  it ('renders a plain label', () => {
-    render (<Label>名前</Label>)
-
-    expect (screen.getByText ('名前')).toBeInTheDocument ()
-  })
-
-  it ('renders and toggles the optional checkbox', () => {
-    const handleChange = vi.fn ()
-
-    render (
-        <Label checkBox={{ label: '不明', checked: false, onChange: handleChange }}>
-          日時
-        </Label>,
-    )
-
-    fireEvent.click (screen.getByRole ('checkbox', { name: '不明' }))
-
-    expect (handleChange).toHaveBeenCalledTimes (1)
-  })
-})

frontend/src/components/common/Label.tsx

@@ -1,24 +1,16 @@
 import React from 'react'
 
-import { cn } from '@/lib/utils'
-
-import type { FC } from 'react'
-
 type Props = { children:  React.ReactNode
                checkBox?: { label:    string
                             checked:  boolean
-			    onChange: (event: React.ChangeEvent<HTMLInputElement>) => void }
+                            onChange: (event: React.ChangeEvent<HTMLInputElement>) => void } }
-	       invalid?:  boolean }
 
 
-const Label: FC<Props> = ({ children, checkBox, invalid }: Props) => {
+export default ({ children, checkBox }: Props) => {
-  const labelClassName = cn ('block font-semibold mb-1',
-			     invalid && 'text-red-700 dark:text-red-300')
-
   if (!(checkBox))
     {
       return (
-	  <label className={labelClassName}>
+          <label className="block font-semibold mb-1">
             {children}
           </label>)
     }
@@ -34,6 +26,3 @@ const Label: FC<Props> = ({ children, checkBox, invalid }: Props) => {
         </label>
       </div>)
 }
-
-
-export default Label

frontend/src/components/common/PageTitle.test.tsx

@@ -1,15 +0,0 @@
-import { render, screen } from '@testing-library/react'
-import { describe, expect, it } from 'vitest'
-
-import PageTitle from '@/components/common/PageTitle'
-
-
-describe ('PageTitle', () => {
-  it ('renders children as a level 1 heading', () => {
-    render (<PageTitle>Test title</PageTitle>)
-
-    const heading = screen.getByRole ('heading', { level: 1 })
-
-    expect (heading.textContent).toBe ('Test title')
-  })
-})

frontend/src/components/common/PageTitle.tsx

@@ -1,13 +1,9 @@
 import React from 'react'
 
-import type { FC } from 'react'
-
 type Props = { children: React.ReactNode }
 
 
-const PageTitle: FC<Props> = ({ children }) => (
+export default ({ children }: Props) => (
     <h1 className="text-2xl font-bold mb-2">
       {children}
     </h1>)
-
-export default PageTitle

frontend/src/components/common/Pagination.test.tsx

@@ -1,38 +0,0 @@
-import { screen } from '@testing-library/react'
-import { describe, expect, it } from 'vitest'
-
-import Pagination from '@/components/common/Pagination'
-import { renderWithProviders } from '@/test/render'
-
-describe ('Pagination', () => {
-  it ('builds page links while preserving existing query parameters', () => {
-    renderWithProviders (
-        <Pagination page={3} totalPages={5} siblingCount={1}/>,
-        { route: '/posts?tags=abc&page=3' },
-    )
-
-    expect (screen.getByLabelText ('前のページ')).toHaveAttribute (
-        'href',
-        '/posts?tags=abc&page=2',
-    )
-    expect (screen.getByLabelText ('次のページ')).toHaveAttribute (
-        'href',
-        '/posts?tags=abc&page=4',
-    )
-    expect (screen.getByText ('3')).toHaveAttribute ('aria-current', 'page')
-  })
-
-  it ('does not render active previous and next controls at the edges', () => {
-    const { rerender } = renderWithProviders (
-        <Pagination page={1} totalPages={1}/>,
-        { route: '/tags' },
-    )
-
-    expect (screen.queryByLabelText ('前のページ')).not.toBeInTheDocument ()
-    expect (screen.queryByLabelText ('次のページ')).not.toBeInTheDocument ()
-
-    rerender (<Pagination page={1} totalPages={2}/>)
-
-    expect (screen.getByLabelText ('次のページ')).toHaveAttribute ('href', '/tags?page=2')
-  })
-})

frontend/src/components/common/Pagination.tsx

@@ -48,7 +48,7 @@ const getPages = (
 }
 
 
-const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
+export default (({ page, totalPages, siblingCount = 3 }) => {
   const location = useLocation ()
 
   const buildTo = (p: number) => {
@@ -124,6 +124,4 @@ const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
 	      </>)}
 	</div>
       </nav>)
-}
+}) satisfies FC<Props>
-
-export default Pagination

frontend/src/components/common/SectionTitle.tsx

@@ -5,9 +5,7 @@ import type { ComponentPropsWithoutRef, FC } from 'react'
 type Props = ComponentPropsWithoutRef<'h2'>
 
 
-const SectionTitle: FC<Props> = ({ children, className, ...rest }) => (
+export default (({ children, className, ...rest }: Props) => (
     <h2 {...rest} className={cn ('text-xl my-4', className)}>
       {children}
-    </h2>)
+    </h2>)) satisfies FC<Props>
-
-export default SectionTitle

frontend/src/components/common/SubsectionTitle.tsx

@@ -1,13 +1,9 @@
 import React from 'react'
 
-import type { FC } from 'react'
-
 type Props = { children: React.ReactNode }
 
 
-const SubsectionTitle: FC<Props> = ({ children }) => (
+export default ({ children }: Props) => (
     <h3 className="my-2">
       {children}
     </h3>)
-
-export default SubsectionTitle

frontend/src/components/common/TabGroup.test.tsx

@@ -1,23 +0,0 @@
-import { fireEvent, render, screen } from '@testing-library/react'
-import { describe, expect, it } from 'vitest'
-
-import TabGroup, { Tab } from '@/components/common/TabGroup'
-
-describe ('TabGroup', () => {
-  it ('uses the init tab and switches tabs when clicked', () => {
-    render (
-        <TabGroup>
-          <Tab name="A">Alpha</Tab>
-          <Tab name="B" init>Beta</Tab>
-        </TabGroup>,
-    )
-
-    expect (screen.queryByText ('Alpha')).not.toBeInTheDocument ()
-    expect (screen.getByText ('Beta')).toBeInTheDocument ()
-
-    fireEvent.click (screen.getByText ('A'))
-
-    expect (screen.getByText ('Alpha')).toBeInTheDocument ()
-    expect (screen.queryByText ('Beta')).not.toBeInTheDocument ()
-  })
-})

frontend/src/components/common/TabGroup.tsx

@@ -1,5 +1,3 @@
-import type { FC } from 'react'
-
 import React, { useState } from 'react'
 import { cn } from '@/lib/utils'
 
@@ -12,7 +10,7 @@ type Props = { children: React.ReactNode }
 export const Tab = ({ children }: TabProps) => <>{children}</>
 
 
-const TabGroup: FC<Props> = ({ children }) => {
+export default ({ children }: Props) => {
   const tabs = React.Children.toArray (children) as React.ReactElement<TabProps>[]
 
   const [current, setCurrent] = useState<number> (() => {
@@ -39,5 +37,3 @@ const TabGroup: FC<Props> = ({ children }) => {
 	</div>
       </div>)
 }
-
-export default TabGroup

frontend/src/components/common/TagInput.test.tsx

@@ -1,44 +0,0 @@
-import { fireEvent, render, screen, waitFor } from '@testing-library/react'
-import { beforeEach, describe, expect, it, vi } from 'vitest'
-
-import TagInput from '@/components/common/TagInput'
-import { buildTag } from '@/test/factories'
-
-const api = vi.hoisted (() => ({
-  apiGet: vi.fn (),
-}))
-
-vi.mock ('@/lib/api', () => api)
-
-describe ('TagInput', () => {
-  beforeEach (() => {
-    vi.clearAllMocks ()
-  })
-
-  it ('updates value and fetches autocomplete for the last token', async () => {
-    const setValue = vi.fn ()
-    api.apiGet.mockResolvedValueOnce ([buildTag ({ name: '虹夏', postCount: 2 })])
-
-    render (<TagInput value="ぼっち 虹" setValue={setValue}/>)
-
-    fireEvent.change (screen.getByRole ('textbox'), { target: { value: 'ぼっち 虹夏' } })
-
-    await waitFor (() => {
-      expect (api.apiGet).toHaveBeenCalledWith (
-          '/tags/autocomplete',
-          { params: { q: '虹夏' } },
-      )
-    })
-    expect (setValue).toHaveBeenCalledWith ('ぼっち 虹夏')
-  })
-
-  it ('does not fetch when the last token is blank', () => {
-    const setValue = vi.fn ()
-    render (<TagInput value="" setValue={setValue}/>)
-
-    fireEvent.change (screen.getByRole ('textbox'), { target: { value: ' ' } })
-
-    expect (api.apiGet).not.toHaveBeenCalled ()
-    expect (setValue).toHaveBeenCalledWith (' ')
-  })
-})