#351

Reviewed-on: #350

backend/app/controllers/posts_controller.rb

@@ -95,7 +95,8 @@ class PostsController < ApplicationController
   end
 
   def random
-    post = filtered_posts.preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+    post = filtered_posts
+           .preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
            .order('RAND()')
            .first
     return head :not_found unless post
@@ -108,7 +109,7 @@ class PostsController < ApplicationController
     return head :not_found unless post
 
     render json: PostRepr.base(post, current_user)
-                         .merge(tags: build_tag_tree_for(post.tags),
+                         .merge(tags: build_tag_tree_for(post),
                                 related: PostRepr.many(post.related(limit: 20)))
   end
 
@@ -132,11 +133,11 @@ class PostsController < ApplicationController
     ApplicationRecord.transaction do
       post.save!
 
-      tags = Tag.normalise_tags!(tag_names)
+      Tag.normalise_tags!(tag_names, with_sections: true) => { tags:, sections: }
       TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
 
       tags = Tag.expand_parent_tags(tags)
-      sync_post_tags!(post, tags)
+      sync_post_tags!(post, tags, sections)
 
       sync_parent_posts!(post, parent_post_ids)
 
@@ -235,7 +236,7 @@ class PostsController < ApplicationController
 
     post.reload
     json = PostRepr.base(post, current_user)
-    json['tags'] = build_tag_tree_for(post.tags)
+    json['tags'] = build_tag_tree_for(post)
     render json:, status: :ok
   rescue Tag::NicoTagNormalisationError
     head :bad_request
@@ -337,7 +338,7 @@ class PostsController < ApplicationController
   def tagged_post_ids_for(name) =
       Post.joins(tags: :tag_name).where(tag_names: { name: }).select(:id)
 
-  def sync_post_tags! post, desired_tags
+  def sync_post_tags! post, desired_tags, sections
     desired_tags.each do |t|
       t.save! if t.new_record?
     end
@@ -356,13 +357,20 @@ class PostsController < ApplicationController
       end
     end
 
+    PostTagSection.where(post_id: post.id).destroy_all
+    sections.each do |tag_id, ranges|
+      ranges.each do |begin_ms, end_ms|
+        PostTagSection.create!(post_id: post.id, tag_id:, begin_ms:, end_ms:)
+      end
+    end
+
     PostTag.where(post_id: post.id, tag_id: to_remove.to_a).kept.find_each do |pt|
       pt.discard_by!(current_user)
     end
   end
 
-  def build_tag_tree_for tags
-    tags = tags.to_a
+  def build_tag_tree_for post
+    tags = post.tags.to_a
     tag_ids = tags.map(&:id)
 
     implications = TagImplication.where(parent_tag_id: tag_ids, tag_id: tag_ids)
@@ -384,8 +392,11 @@ class PostsController < ApplicationController
       tag = tags_by_id[tag_id]
       return nil unless tag
 
+      sections = PostTagSection.where(post_id: post.id, tag_id:)
+                 .as_json(only: [:begin_ms, :end_ms])
+
       if path.include?(tag_id)
-        return TagRepr.base(tag).merge(children: [])
+        return TagRepr.base(tag).merge(children: [], sections:)
       end
 
       if memo.key?(tag_id)
@@ -397,7 +408,7 @@ class PostsController < ApplicationController
 
       children = child_ids.filter_map { |cid| build_node.(cid, new_path) }
 
-      memo[tag_id] = TagRepr.base(tag).merge(children:)
+      memo[tag_id] = TagRepr.base(tag).merge(children:, sections:)
     end
 
     root_ids.filter_map { |id| build_node.call(id, []) }
@@ -408,7 +419,7 @@ class PostsController < ApplicationController
 
     params[:parent_post_ids].to_s.split.map { |token|
       id = Integer(token, exception: false)
-      raise ArgumentError, "親投稿 Id. が不正です: #{ token }" if id.nil? || id <= 0
+      raise ArgumentError, "親投稿 Id. が不正です: #{ token }" if !(id) || id <= 0
 
       id
     }.uniq
@@ -470,7 +481,21 @@ class PostsController < ApplicationController
   end
 
   def editable_tag_names_from_post post
-    post.tags.not_nico.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+    post
+        .post_tags
+        .kept
+        .joins(tag: :tag_name)
+        .merge(Tag.not_nico)
+        .includes(:sections, tag: :tag_name)
+        .order('tag_names.name')
+        .map do |post_tag|
+      name = post_tag.tag.tag_name.name
+      sections = post_tag.sections.sort_by(&:begin_ms)
+
+      next name if sections.empty?
+
+      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
+    end
   end
 
   def post_incoming_snapshot title:, original_created_from:, original_created_before:,
@@ -502,9 +527,16 @@ class PostsController < ApplicationController
   end
 
   def incoming_tag_names_for_snapshot raw_tag_names
-    tags = Tag.normalise_tags!(raw_tag_names, with_tagme: false)
+    Tag.normalise_tags!(raw_tag_names, with_tagme: false, with_sections: true) =>
+        { tags:, sections: }
 
-    Tag.expand_parent_tags(tags).map(&:name).uniq.sort
+    Tag.expand_parent_tags(tags).uniq(&:id).map { |tag|
+      "#{ tag.name }#{ sections[tag.id].to_a.map { section_literal(_1) }.join }"
+    }.sort
+  end
+
+  def section_literal section
+    "[#{ Post.ms_to_time(section[0]) }-#{ Post.ms_to_time(section[1]) }]"
   end
 
   def post_conflict_json post:, base_version_no:, base_snapshot:,
@@ -591,7 +623,8 @@ class PostsController < ApplicationController
                  original_created_from: snapshot[:original_created_from],
                  original_created_before: snapshot[:original_created_before])
 
-    editable_tags = Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false)
+    Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false, with_sections: true) =>
+        { tags: editable_tags, sections: }
     TagVersioning.record_tag_snapshots!(editable_tags, created_by_user: current_user)
 
     readonly_tags = post.tags.nico.to_a
@@ -599,7 +632,7 @@ class PostsController < ApplicationController
     tags = readonly_tags + editable_tags
     tags = Tag.expand_parent_tags(tags)
 
-    sync_post_tags!(post, tags)
+    sync_post_tags!(post, tags, sections)
     sync_parent_posts!(post, snapshot[:parent_post_ids])
 
     PostVersionRecorder.record!(post:, event_type: :update, created_by_user: current_user)

backend/app/models/post.rb

@@ -56,7 +56,38 @@ class Post < ApplicationRecord
     super(options).merge(thumbnail: nil)
   end
 
-  def snapshot_tag_names = tags.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
+  def snapshot_tag_names
+    post_tags
+        .kept
+        .joins(tag: :tag_name)
+        .includes(:sections, tag: :tag_name)
+        .order('tag_names.name')
+        .map do |post_tag|
+      name = post_tag.tag.tag_name.name
+      sections = post_tag.sections.sort_by(&:begin_ms)
+
+      next name if sections.empty?
+
+      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
+    end
+  end
+
+  def self.section_literal section
+    "[#{ Post.ms_to_time(section.begin_ms) }-#{ Post.ms_to_time(section.end_ms) }]"
+  end
+
+  def self.ms_to_time ms
+    total_s = ms / 1_000
+    s = total_s % 60
+    min = (total_s / 60) % 60
+    h = total_s / 3_600
+
+    if h.positive?
+      '%d:%02d:%02d' % [h, min, s]
+    else
+      '%d:%02d' % [min, s]
+    end
+  end
 
   def snapshot_parent_post_ids = parents.order(:id).pluck(:id)
 

backend/app/models/post_tag.rb

@@ -10,6 +10,12 @@ class PostTag < ApplicationRecord
   belongs_to :created_user, class_name: 'User', optional: true
   belongs_to :deleted_user, class_name: 'User', optional: true
 
+  has_many :sections, -> { order(:begin_ms) }, class_name: 'PostTagSection',
+                                               foreign_key: [:post_id, :tag_id],
+                                               primary_key: [:post_id, :tag_id],
+                                               dependent: :delete_all,
+                                               inverse_of: :post_tag
+
   validates :post_id, presence: true
   validates :tag_id, presence: true
   validates :post_id, uniqueness: {

backend/app/models/post_tag_section.rb

@@ -0,0 +1,20 @@
+class PostTagSection < ApplicationRecord
+  self.primary_key = :post_id, :tag_id, :begin_ms
+
+  belongs_to :post
+  belongs_to :tag
+
+  belongs_to :post_tag, -> { kept }, foreign_key: [:post_id, :tag_id],
+                                     primary_key: [:post_id, :tag_id],
+                                     inverse_of: :sections,
+                                     optional: true
+
+  validates :post_id, presence: true
+  validates :tag_id, presence: true
+
+  validates :begin_ms, presence: true,
+                       numericality: { only_integer: true, greater_than_or_equal_to: 0 }
+
+  validates :end_ms, presence: true,
+                     numericality: { only_integer: true, greater_than: :begin_ms }
+end

backend/app/models/tag.rb

@@ -92,22 +92,50 @@ class Tag < ApplicationRecord
 
   def self.normalise_tags! tag_names, with_tagme: true,
                                       with_no_deerjikist: true,
-                                      deny_nico: true
+                                      deny_nico: true,
+                                      with_sections: false
     if deny_nico && tag_names.any? { |n| n.downcase.start_with?('nico:') }
       raise NicoTagNormalisationError
     end
 
+    sections = { }
     tags = tag_names.map do |name|
       pf, cat = CATEGORY_PREFIXES.find { |p, _| name.downcase.start_with?(p) } || ['', nil]
-      name = TagName.canonicalise(name.sub(/\A#{ pf }/i, '')).first
+
+      name = name.sub(/\A#{ pf }/i, '')
+
+      sections_by_tag = []
+      while n = name.sub!(/^(\S*?)\[([0-9:.]*?)-([0-9:.]*?)\](\S*?)$/, '\1\4 \2 \3')
+        name, *section_raw = n.split
+
+        begin_ms, end_ms = section_raw.map { time_to_ms(_1) }
+        next if begin_ms == end_ms
+
+        begin_ms, end_ms = end_ms, begin_ms if begin_ms > end_ms
+
+        sections_by_tag << [begin_ms, end_ms]
+      end
+
+      name = TagName.canonicalise(name).first
+
       find_or_create_by_tag_name!(name, category: (cat || :general)).tap do |tag|
         tag.update!(category: cat) if cat && tag.category != cat
+        next if sections_by_tag.empty?
+
+        sections[tag.id] ||= []
+        sections[tag.id].concat(sections_by_tag)
       end
     end
 
     tags << Tag.tagme if with_tagme && tags.size < 10 && tags.none?(Tag.tagme)
     tags << Tag.no_deerjikist if with_no_deerjikist && tags.all? { |t| !(t.deerjikist?) }
-    tags.uniq(&:id)
+    tags.uniq!(&:id)
+
+    if with_sections
+      { tags:, sections: }
+    else
+      tags
+    end
   end
 
   def self.expand_parent_tags tags
@@ -228,4 +256,23 @@ class Tag < ApplicationRecord
       errors.add :category, 'ニジラーと紐づいてゐるタグはニジラー・カテゴリである必要があります．'
     end
   end
+
+  def self.time_to_ms str
+    parts = str.split(':')
+
+    s_part = parts.pop
+    s, ms = s_part.split('.')
+
+    total_s = s.to_i
+
+    if parts.length >= 1
+      total_s += parts.pop.to_i * 60
+    end
+
+    if parts.length >= 1
+      total_s += parts.pop.to_i * 3_600
+    end
+
+    total_s * 1_000 + ms.to_s.ljust(3, '0')[0, 3].to_i
+  end
 end

backend/db/migrate/20260518235300_create_post_tag_sections.rb

@@ -0,0 +1,19 @@
+class CreatePostTagSections < ActiveRecord::Migration[8.0]
+  def change
+    create_table :post_tag_sections, primary_key: [:post_id, :tag_id, :begin_ms] do |t|
+      t.references :post, null: false, foreign_key: true, index: false
+      t.references :tag, null: false, foreign_key: true, index: false
+      t.integer :begin_ms, null: false
+      t.integer :end_ms, null: false
+      t.timestamps
+
+      t.index [:post_id, :begin_ms], name: 'idx_post_tag_sections_post_id_begin_ms'
+
+      t.check_constraint 'begin_ms >= 0',
+                         name: 'chk_post_tag_sections_begin_ms_natural'
+
+      t.check_constraint 'begin_ms < end_ms',
+                         name: 'chk_post_tag_sections_end_ms_after_begin_ms'
+    end
+  end
+end

backend/db/migrate/20260519013100_add_video_ms_to_posts.rb

@@ -0,0 +1,9 @@
+class AddVideoMsToPosts < ActiveRecord::Migration[8.0]
+  def change
+    add_column :posts, :video_ms, :integer
+    add_index :posts, [:video_ms, :id], name: 'idx_posts_video_ms_id'
+
+    add_check_constraint :posts, 'video_ms IS NULL OR video_ms > 0',
+                         name: 'chk_posts_video_ms_positive'
+  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_05_07_213300) do
+ActiveRecord::Schema[8.0].define(version: 2026_05_19_013100) 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
@@ -137,6 +137,19 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
     t.index ["target_post_id"], name: "index_post_similarities_on_target_post_id"
   end
 
+  create_table "post_tag_sections", primary_key: ["post_id", "tag_id", "begin_ms"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
+    t.bigint "post_id", null: false
+    t.bigint "tag_id", null: false
+    t.integer "begin_ms", null: false
+    t.integer "end_ms", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["post_id", "begin_ms"], name: "idx_post_tag_sections_post_id_begin_ms"
+    t.index ["tag_id"], name: "fk_rails_8be3847903"
+    t.check_constraint "`begin_ms` < `end_ms`", name: "chk_post_tag_sections_end_ms_after_begin_ms"
+    t.check_constraint "`begin_ms` >= 0", name: "chk_post_tag_sections_begin_ms_natural"
+  end
+
   create_table "post_tags", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.bigint "tag_id", null: false
@@ -187,8 +200,11 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
     t.datetime "original_created_before"
     t.datetime "updated_at", null: false
     t.integer "version_no", null: false
+    t.integer "video_ms"
     t.index ["uploaded_user_id"], name: "index_posts_on_uploaded_user_id"
     t.index ["url"], name: "index_posts_on_url", unique: true
+    t.index ["video_ms", "id"], name: "idx_posts_video_ms_id"
+    t.check_constraint "(`video_ms` is null) or (`video_ms` > 0)", name: "chk_posts_video_ms_positive"
     t.check_constraint "`version_no` > 0", name: "chk_posts_version_no_positive"
   end
 
@@ -290,6 +306,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["expires_at"], name: "index_theatre_watching_users_on_expires_at"
+    t.index ["theatre_id", "expires_at"], name: "idx_on_theatre_id_skip_expires_at_4c8de1dd42"
     t.index ["theatre_id", "expires_at"], name: "index_theatre_watching_users_on_theatre_id_and_expires_at"
     t.index ["theatre_id"], name: "index_theatre_watching_users_on_theatre_id"
     t.index ["user_id"], name: "index_theatre_watching_users_on_user_id"
@@ -446,6 +463,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) do
   add_foreign_key "post_implications", "posts", column: "parent_post_id"
   add_foreign_key "post_similarities", "posts"
   add_foreign_key "post_similarities", "posts", column: "target_post_id"
+  add_foreign_key "post_tag_sections", "posts"
+  add_foreign_key "post_tag_sections", "tags"
   add_foreign_key "post_tags", "posts"
   add_foreign_key "post_tags", "tags"
   add_foreign_key "post_tags", "users", column: "created_user_id"

backend/spec/factories/post_tag_sections.rb

@@ -0,0 +1,8 @@
+FactoryBot.define do
+  factory :post_tag_section do
+    association :post
+    association :tag
+    begin_ms { 1_000 }
+    end_ms { 2_000 }
+  end
+end

backend/spec/factories/post_tags.rb

@@ -0,0 +1,6 @@
+FactoryBot.define do
+  factory :post_tag do
+    association :post
+    association :tag
+  end
+end

backend/spec/factories/posts.rb

@@ -0,0 +1,8 @@
+FactoryBot.define do
+  factory :post do
+    sequence(:url) { |n| "https://example.com/factory-post-#{ n }" }
+    title { 'factory post' }
+    thumbnail_base { nil }
+    uploaded_user { nil }
+  end
+end

backend/spec/models/post_tag_spec.rb

@@ -0,0 +1,29 @@
+RSpec.describe PostTag, type: :model do
+  describe '#sections' do
+    it 'loads sections by post_id and tag_id' do
+      post_tag = create(:post_tag)
+      section = create(:post_tag_section,
+                       post: post_tag.post,
+                       tag: post_tag.tag,
+                       begin_ms: 1000,
+                       end_ms: 2000)
+
+      expect(post_tag.sections).to contain_exactly(section)
+    end
+
+    it 'does not load sections for another tag on the same post' do
+      post = create(:post)
+      tag = create(:tag)
+      other_tag = create(:tag)
+
+      post_tag = create(:post_tag, post:, tag:)
+      create(:post_tag_section,
+             post:,
+             tag: other_tag,
+             begin_ms: 1000,
+             end_ms: 2000)
+
+      expect(post_tag.sections).to be_empty
+    end
+  end
+end

docs/commands.md

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

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'] },
+  { ignores: ['dist', 'tailwind.config.js'] },
   {
     extends: [js.configs.recommended, ...tseslint.configs.recommended],
     files: ['**/*.{ts,tsx}'],

frontend/package.json

@@ -8,6 +8,8 @@
     "build": "tsc -b && vite build",
     "postbuild": "node scripts/generate-sitemap.js",
     "lint": "eslint .",
+    "test": "vitest",
+    "test:run": "vitest run",
     "preview": "vite preview"
   },
   "dependencies": {
@@ -45,6 +47,10 @@
   "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",
@@ -58,11 +64,13 @@
     "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

@@ -93,7 +93,7 @@ const PostDetailRoute = ({ user }: { user: User | null }) => {
 }
 
 
-export default (() => {
+const App: FC = () => {
   const [user, setUser] = useState<User | null> (null)
   const [status, setStatus] = useState (200)
 
@@ -156,4 +156,6 @@ export default (() => {
 	  </DialogueProvider>
 	</BrowserRouter>
       </>)
-}) satisfies FC
+}
+
+export default App

frontend/src/components/DraggableDroppableTagRow.tsx

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

frontend/src/components/ErrorScreen.test.tsx

@@ -0,0 +1,32 @@
+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 }
 
 
-export default (({ status }: Props) => {
+const ErrorScreen: FC<Props> = ({ status }) => {
   const [message, rightMsg, leftMsg]: [string, string, string] = (() => {
     switch (status)
     {
@@ -58,4 +58,6 @@ export default (({ status }: Props) => {
 	  <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 = (
     }))
 
 
-export default (() => {
+const MaterialSidebar: FC = () => {
   const [tags, setTags] = useState<TagWithDepth[]> ([])
   const [openTags, setOpenTags] = useState<Record<number, boolean>> ({ })
   const [tagFetchedFlags, setTagFetchedFlags] = useState<Record<number, boolean>> ({ })
@@ -94,4 +94,6 @@ export default (() => {
 	  {renderTags (tags)}
 	</ul>
       </SidebarComponent>)
-}) satisfies FC
+}
+
+export default MaterialSidebar

frontend/src/components/MenuSeparator.tsx

@@ -1,9 +1,11 @@
 import type { FC } from 'react'
 
 
-export default (() => (
+const MenuSeparator: FC = () => (
     <>
       <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/PostEditForm.test.tsx

@@ -0,0 +1,69 @@
+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

@@ -6,25 +6,30 @@ import Label from '@/components/common/Label'
 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 { msToTime } from '@/lib/utils'
 
 import type { FC, FormEvent } from 'react'
 
-import type { Post, Tag } from '@/types'
+import type { Post, TagWithSections } from '@/types'
 
 
-const tagsToStr = (tags: Tag[]): string => {
-  const result: Tag[] = []
+const tagsToStr = (tags: TagWithSections[]): string => {
+  const result: Omit<TagWithSections, 'children'>[] = []
 
-  const walk = (tag: Tag) => {
+  const walk = (tag: TagWithSections) => {
     const { children, ...rest } = tag
     result.push (rest)
-    children?.forEach (walk)
+    children.forEach (walk)
   }
 
   tags.filter (t => t.category !== 'nico').forEach (walk)
 
-  return [...(new Set (result.map (t => t.name)))].join (' ')
+  return [...(new Set (result.map (t =>
+      `${ t.name }${ t.sections
+		     .map (s => `[${ msToTime (s.beginMs) }-${ msToTime (s.endMs) }]`)
+		     .join ('') }`)))].join (' ')
 }
 
 
@@ -32,7 +37,7 @@ type Props = { post:    Post
 	       onSave:  (newPost: Post) => void }
 
 
-export default (({ post, onSave }: Props) => {
+const PostEditForm: FC<Props> = ({ post, onSave }) => {
   const [disabled, setDisabled] = useState (false)
   const [originalCreatedBefore, setOriginalCreatedBefore] =
       useState<string | null> (post.originalCreatedBefore)
@@ -62,7 +67,7 @@ export default (({ post, onSave }: Props) => {
     }
     catch (e)
     {
-      const response = (e as any)?.response
+      const response = isApiError<{ mergeable?: boolean }> (e) ? e.response : undefined
 
       if (response?.status !== 409)
 	{
@@ -164,4 +169,6 @@ export default (({ post, onSave }: Props) => {
 	  更新
 	</Button>
       </form>)
-}) satisfies FC<Props>
+}
+
+export default PostEditForm

frontend/src/components/PostEmbed.test.tsx

@@ -0,0 +1,63 @@
+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 (),
+}))
+
+vi.mock ('@/components/dialogues/DialogueProvider', () => ({
+  useDialogue: () => dialogue,
+}))
+
+vi.mock ('@/components/NicoViewer', () => ({
+  default: ({ id }: { id: string }) => <div>Nico:{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 ('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

@@ -16,8 +16,9 @@ type Props = {
     onMetadataChange?:  (meta: NiconicoMetadata) => void }
 
 
-export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
+const PostEmbed: FC<Props> = ({ ref, post, onLoadComplete, onMetadataChange }) => {
   const dialogue = useDialogue ()
+  const [framed, setFramed] = useState (false)
 
   const url = new URL (post.url)
 
@@ -44,7 +45,7 @@ export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
   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
@@ -72,8 +73,6 @@ export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
     }
   }
 
-  const [framed, setFramed] = useState (false)
-
   return (
       <>
 	{framed
@@ -101,4 +100,6 @@ export default (({ ref, post, onLoadComplete, onMetadataChange }: Props) => {
 	      </a>
 	    </div>)}
       </>)
-}) satisfies FC<Props>
+}
+
+export default PostEmbed

frontend/src/components/PostFormTagsArea.test.tsx

@@ -0,0 +1,34 @@
+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

@@ -36,7 +36,7 @@ type Props = Omit<ComponentPropsWithoutRef<'textarea'>, 'value' | 'onChange' | '
     setTags:  (tags: string) => void }
 
 
-export default (({ tags, setTags, ...rest }: Props) => {
+const PostFormTagsArea: FC<Props> = ({ tags, setTags, ...rest }) => {
   const ref = useRef<HTMLTextAreaElement> (null)
 
   const [bounds, setBounds] = useState<{ start: number; end: number }> ({ start: 0, end: 0 })
@@ -97,4 +97,6 @@ export default (({ tags, setTags, ...rest }: Props) => {
 		activeIndex={-1}
 		onSelect={handleTagSelect}/>)}
       </div>)
-}) satisfies FC<Props>
+}
+
+export default PostFormTagsArea

frontend/src/components/PostList.test.tsx

@@ -0,0 +1,44 @@
+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 }
 
 
-export default (({ posts, onClick }: Props) => {
+const PostList: FC<Props> = ({ posts, onClick }) => {
   const location = useLocation ()
 
   const setForLocationKey = useSharedTransitionStore (s => s.setForLocationKey)
@@ -70,4 +70,6 @@ export default (({ posts, onClick }: Props) => {
 	      </PrefetchLink>)
 	})}
       </div>)
-}) satisfies FC<Props>
+}
+
+export default PostList

frontend/src/components/PostOriginalCreatedTimeField.test.tsx

@@ -0,0 +1,63 @@
+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

@@ -12,11 +12,11 @@ type Props = {
     setOriginalCreatedBefore: (x: string | null) => void }
 
 
-export default (({ disabled,
+const PostOriginalCreatedTimeField: FC<Props> = ({ disabled,
 		   originalCreatedFrom,
 		   setOriginalCreatedFrom,
 		   originalCreatedBefore,
-		   setOriginalCreatedBefore }: Props) => (
+		   setOriginalCreatedBefore }) => (
     <div>
       <Label>オリジナルの作成日時</Label>
       <div className="my-1 flex">
@@ -71,4 +71,6 @@ export default (({ disabled,
 	  </Button>
 	</div>
       </div>
-    </div>)) satisfies FC<Props>
+    </div>)
+
+export default PostOriginalCreatedTimeField

frontend/src/components/RouteBlockerOverlay.test.tsx

@@ -0,0 +1,30 @@
+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 }) }))
 
 
-export default (() => {
+const RouteBlockerOverlay: FC = () => {
   const active = useOverlayStore (s => s.active)
 
   useEffect (() => {
@@ -43,4 +43,6 @@ export default (() => {
 	  </div>
 	</div>
       </div>)
-}) satisfies FC
+}
+
+export default RouteBlockerOverlay

frontend/src/components/SortHeader.test.tsx

@@ -0,0 +1,39 @@
+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

@@ -26,13 +26,13 @@ import { dateString, originalCreatedAtString } from '@/lib/utils'
 import type { DragEndEvent } from '@dnd-kit/core'
 import type { FC, MutableRefObject, ReactNode } from 'react'
 
-import type { Category, Post, Tag } from '@/types'
+import type { Category, Post, TagWithSections } from '@/types'
 
-type TagByCategory = { [key in Category]: Tag[] }
+type TagByCategory = { [key in Category]: TagWithSections[] }
 
 
 const renderTagTree = (
-    tag:              Tag,
+    tag:              TagWithSections,
     nestLevel:        number,
     path:             string,
     suppressClickRef: MutableRefObject<boolean>,
@@ -63,7 +63,7 @@ const renderTagTree = (
 
 
 const isDescendant = (
-    root:     Tag,
+    root:     TagWithSections,
     targetId: number,
 ): boolean => {
   if (!(root.children))
@@ -84,8 +84,8 @@ const isDescendant = (
 const findTag = (
     byCat:  TagByCategory,
     id:     number,
-): Tag | undefined => {
-  const walk = (nodes: Tag[]): Tag | undefined => {
+): TagWithSections | undefined => {
+  const walk = (nodes: TagWithSections[]): TagWithSections | undefined => {
     for (const t of nodes)
       {
 	if (t.id === id)
@@ -151,7 +151,7 @@ const DropSlot = ({ cat }: { cat: Category }) => {
 type Props = { post: Post; sp?: boolean }
 
 
-export default (({ post, sp }: Props) => {
+const TagDetailSidebar: FC<Props> = ({ post, sp }) => {
   sp = Boolean (sp)
 
   const qc = useQueryClient ()
@@ -167,7 +167,7 @@ export default (({ post, sp }: Props) => {
       }
 
     for (const cat of Object.keys (tagsTmp) as (keyof typeof tagsTmp)[])
-      tagsTmp[cat].sort ((tagA: Tag, tagB: Tag) => tagA.name < tagB.name ? -1 : 1)
+      tagsTmp[cat].sort ((tagA: TagWithSections, tagB: TagWithSections) => tagA.name < tagB.name ? -1 : 1)
 
     return tagsTmp
   }, [post])
@@ -376,4 +376,6 @@ export default (({ post, sp }: Props) => {
 	  </DragOverlay>
 	</DndContext>
       </SidebarComponent>)
-}) satisfies FC<Props>
+}
+
+export default TagDetailSidebar

frontend/src/components/TagLink.test.tsx

@@ -0,0 +1,45 @@
+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
 
 
-export default (({ tag,
+const TagLink: FC<Props> = ({ 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 }`)
@@ -126,4 +126,6 @@ export default (({ tag,
 	{withCount && (
 	    <span className="ml-1">{tag.postCount}</span>)}
       </>)
-}) satisfies FC<Props>
+}
+
+export default TagLink

frontend/src/components/TagSearch.tsx

@@ -12,7 +12,7 @@ import type { ChangeEvent, FC, KeyboardEvent } from 'react'
 import type { Tag } from '@/types'
 
 
-export default (() => {
+const TagSearch: FC = () => {
   const location = useLocation ()
   const navigate = useNavigate ()
 
@@ -115,4 +115,6 @@ export default (() => {
 		      activeIndex={activeIndex}
 		      onSelect={handleTagSelect}/>
       </div>)
-}) satisfies FC
+}
+
+export default TagSearch

frontend/src/components/TagSearchBox.test.tsx

@@ -0,0 +1,30 @@
+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 }
 
 
-export default (({ suggestions, activeIndex, onSelect }: Props) => {
+const TagSearchBox: FC<Props> = ({ suggestions, activeIndex, onSelect }) => {
   if (suggestions.length === 0)
     return
 
@@ -26,4 +26,6 @@ export default (({ suggestions, activeIndex, onSelect }: Props) => {
 	      <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 }
 
 
-export default (({ posts, onClick }: Props) => {
+const TagSidebar: FC<Props> = ({ posts, onClick }) => {
   const navigate = useNavigate ()
 
   const [tagsVsbl, setTagsVsbl] = useState (false)
@@ -126,4 +126,6 @@ export default (({ posts, onClick }: Props) => {
 	  {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)
@@ -80,7 +80,7 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 }
 
 
-export default (({ user }: Props) => {
+const TopNav: FC<Props> = ({ user }) => {
   const location = useLocation ()
 
   const dirRef = useRef<(-1) | 1> (1)
@@ -159,12 +159,12 @@ export default (({ user }: Props) => {
   useEffect (() => {
     const unsubscribe = WikiIdBus.subscribe (setWikiId)
     return () => unsubscribe ()
-  }, [activeIdx])
+  }, [])
 
   useEffect (() => {
     setMenuOpen (false)
     setOpenItemIdx (activeIdx)
-  }, [location])
+  }, [activeIdx, location])
 
   return (
       <>
@@ -433,4 +433,6 @@ export default (({ user }: Props) => {
 	      </motion.div>)}
 	</AnimatePresence>
       </>)
-}) satisfies FC<Props>
+}
+
+export default TopNav

frontend/src/components/TopNavUser.test.tsx

@@ -0,0 +1,29 @@
+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 }
 
 
-export default (({ user, sp }: Props) => {
+const TopNavUser: FC<Props> = ({ user, sp }) => {
   if (!(user))
     return
 
@@ -28,4 +28,6 @@ export default (({ user, sp }: Props) => {
 	  {user.name || '名もなきニジラー'}
 	</PrefetchLink>
       </>)
-}) satisfies FC<Props>
+}
+
+export default TopNavUser

frontend/src/components/TwitterEmbed.test.tsx

@@ -0,0 +1,19 @@
+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 }
 
 
-export default (({ userId, statusId }: Props) => {
+const TwitterEmbed: FC<Props> = ({ userId, statusId }) => {
   const now = (new Date).toLocaleDateString ()
 
   return (
@@ -18,4 +18,6 @@ export default (({ userId, statusId }: Props) => {
 	</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
 
 
-export default (({ title, body }: Props) => {
+const WikiBody: FC<Props> = ({ title, body }) => {
   const { data } = useQuery ({
       enabled: Boolean (body),
       queryKey: wikiKeys.index ({ }),
@@ -39,4 +39,6 @@ export default (({ title, body }: Props) => {
       <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

@@ -0,0 +1,27 @@
+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

@@ -25,7 +25,7 @@ type Props = Omit<ComponentPropsWithoutRef<'input'>, 'onChange'> & {
     onBlur?:    (ev: FocusEvent<HTMLInputElement>) => void }
 
 
-export default (({ value, onChange, className, onBlur, ...rest }: Props) => {
+const DateTimeField: FC<Props> = ({ value, onChange, className, onBlur, ...rest }) => {
   const [local, setLocal] = useState ('')
 
   useEffect (() => {
@@ -44,4 +44,6 @@ export default (({ value, onChange, className, onBlur, ...rest }: Props) => {
 	    onChange?.(v ? (new Date (v)).toISOString () : null)
 	  }}
 	  onBlur={onBlur}/>)
-}) satisfies FC<Props>
+}
+
+export default DateTimeField

frontend/src/components/common/Form.tsx

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

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

@@ -0,0 +1,26 @@
+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

@@ -1,12 +1,14 @@
 import React from 'react'
 
+import type { FC } from 'react'
+
 type Props = { children:  React.ReactNode
                checkBox?: { label:    string
                             checked:  boolean
                             onChange: (event: React.ChangeEvent<HTMLInputElement>) => void } }
 
 
-export default ({ children, checkBox }: Props) => {
+const Label: FC<Props> = ({ children, checkBox }) => {
   if (!(checkBox))
     {
       return (
@@ -26,3 +28,5 @@ export default ({ children, checkBox }: Props) => {
         </label>
       </div>)
 }
+
+export default Label

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

@@ -0,0 +1,15 @@
+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

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

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

@@ -0,0 +1,38 @@
+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 = (
 }
 
 
-export default (({ page, totalPages, siblingCount = 3 }) => {
+const Pagination: FC<Props> = ({ page, totalPages, siblingCount = 3 }) => {
   const location = useLocation ()
 
   const buildTo = (p: number) => {
@@ -124,4 +124,6 @@ export default (({ page, totalPages, siblingCount = 3 }) => {
 	      </>)}
 	</div>
       </nav>)
-}) satisfies FC<Props>
+}
+
+export default Pagination

frontend/src/components/common/SectionTitle.tsx

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

frontend/src/components/common/SubsectionTitle.tsx

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

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

@@ -0,0 +1,23 @@
+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

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

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

@@ -0,0 +1,44 @@
+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 (' ')
+  })
+})

frontend/src/components/common/TagInput.tsx

@@ -12,7 +12,7 @@ type Props = {
     value:      string
     setValue:   (value: string) => void }
 
-export default (({ value, setValue }: Props) => {
+const TagInput: FC<Props> = ({ value, setValue }) => {
   const [activeIndex, setActiveIndex] = useState (-1)
   const [suggestions, setSuggestions] = useState<Tag[]> ([])
   const [suggestionsVsbl, setSuggestionsVsbl] = useState (false)
@@ -62,9 +62,12 @@ export default (({ value, setValue }: Props) => {
     case 'Enter':
       if (activeIndex < 0)
 	break
+      {
 	ev.preventDefault ()
 	const selected = suggestions[activeIndex]
-      selected && handleTagSelect (selected)
+	if (selected)
+	  handleTagSelect (selected)
+      }
       break
 
     case 'Escape':
@@ -94,4 +97,6 @@ export default (({ value, setValue }: Props) => {
 	    activeIndex={activeIndex}
 	    onSelect={handleTagSelect}/>
       </div>)
-}) satisfies FC<Props>
+}
+
+export default TagInput

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

@@ -0,0 +1,37 @@
+import { createRef } from 'react'
+import { render, screen } from '@testing-library/react'
+import { describe, expect, it } from 'vitest'
+
+import Form from '@/components/common/Form'
+import SectionTitle from '@/components/common/SectionTitle'
+import SubsectionTitle from '@/components/common/SubsectionTitle'
+import TextArea from '@/components/common/TextArea'
+
+describe ('common typography and form components', () => {
+  it ('renders Form children inside the standard container', () => {
+    render (<Form><span>Content</span></Form>)
+
+    expect (screen.getByText ('Content')).toBeInTheDocument ()
+  })
+
+  it ('renders SectionTitle as an h2', () => {
+    render (<SectionTitle>Section</SectionTitle>)
+
+    expect (screen.getByRole ('heading', { level: 2, name: 'Section' })).toBeInTheDocument ()
+  })
+
+  it ('renders SubsectionTitle as an h3', () => {
+    render (<SubsectionTitle>Subsection</SubsectionTitle>)
+
+    expect (screen.getByRole ('heading', { level: 3, name: 'Subsection' })).toBeInTheDocument ()
+  })
+
+  it ('forwards refs and props to TextArea', () => {
+    const ref = createRef<HTMLTextAreaElement> ()
+
+    render (<TextArea ref={ref} aria-label="Body" defaultValue="text"/>)
+
+    expect (ref.current).toBe (screen.getByLabelText ('Body'))
+    expect (screen.getByLabelText ('Body')).toHaveValue ('text')
+  })
+})

frontend/src/components/dialogues/DialogueProvider.tsx

@@ -57,7 +57,7 @@ let nextDialogueId = 1
 type Props = { children: ReactNode }
 
 
-export default (({ children }: Props) => {
+const DialogueProvider: FC<Props> = ({ children }) => {
   const [queue, setQueue] = useState<DialogueRequest[]> ([])
 
   const push = useCallback ((request: Omit<DialogueRequest, 'id'>) => {
@@ -174,7 +174,7 @@ export default (({ children }: Props) => {
 	      </DialogContent>)}
 	</Dialog>
       </DialogueContext.Provider>)
-}) satisfies FC<Props>
+}
 
 
 export const useDialogue = () => {
@@ -185,3 +185,5 @@ export const useDialogue = () => {
 
   return dialogue
 }
+
+export default DialogueProvider

frontend/src/components/layout/MainArea.tsx

@@ -9,10 +9,12 @@ type Props = {
     className?: string }
 
 
-export default (({ children, className }: Props) => (
+const MainArea: FC<Props> = ({ children, className }) => (
     <motion.main
 	transition={{ layout: { duration: .2, ease: 'easeOut' } }}
 	className={cn ('flex-1 overflow-y-auto p-4', className)}
 	layout="position">
       {children}
-    </motion.main>)) satisfies FC<Props>
+    </motion.main>)
+
+export default MainArea

frontend/src/components/layout/SidebarComponent.tsx

@@ -6,7 +6,7 @@ import type { FC, ReactNode } from 'react'
 type Props = { children: ReactNode }
 
 
-export default (({ children }: Props) => (
+const SidebarComponent: FC<Props> = ({ children }) => (
     <motion.div
 	layout="position"
 	transition={{ layout: { duration: .2, ease: 'easeOut' } }}
@@ -27,4 +27,6 @@ export default (({ children }: Props) => (
       </Helmet>
 
       {children}
-    </motion.div>)) satisfies FC<Props>
+    </motion.div>)
+
+export default SidebarComponent

frontend/src/components/ui/use-toast.tsx

@@ -18,13 +18,6 @@ type ToasterToast = ToastProps & {
   action?: ToastActionElement
 }
 
-const actionTypes = {
-  ADD_TOAST: "ADD_TOAST",
-  UPDATE_TOAST: "UPDATE_TOAST",
-  DISMISS_TOAST: "DISMISS_TOAST",
-  REMOVE_TOAST: "REMOVE_TOAST",
-} as const
-
 let count = 0
 
 function genId() {
@@ -32,23 +25,21 @@ function genId() {
   return count.toString()
 }
 
-type ActionType = typeof actionTypes
-
 type Action =
   | {
-      type: ActionType["ADD_TOAST"]
+      type: "ADD_TOAST"
       toast: ToasterToast
     }
   | {
-      type: ActionType["UPDATE_TOAST"]
+      type: "UPDATE_TOAST"
       toast: Partial<ToasterToast>
     }
   | {
-      type: ActionType["DISMISS_TOAST"]
+      type: "DISMISS_TOAST"
       toastId?: ToasterToast["id"]
     }
   | {
-      type: ActionType["REMOVE_TOAST"]
+      type: "REMOVE_TOAST"
       toastId?: ToasterToast["id"]
     }
 

frontend/src/components/users/InheritDialogue.tsx

@@ -1,3 +1,5 @@
+import type { FC } from 'react'
+
 import { useState } from 'react'
 
 import { useDialogue } from '@/components/dialogues/DialogueProvider'
@@ -18,7 +20,7 @@ type Props = { visible:         boolean
 	       setUser:         (user: User) => void }
 
 
-export default ({ visible, onVisibleChange, setUser }: Props) => {
+const InheritDialogue: FC<Props> = ({ visible, onVisibleChange, setUser }) => {
   const dialogue = useDialogue ()
 
   const [inputCode, setInputCode] = useState ('')
@@ -68,3 +70,5 @@ export default ({ visible, onVisibleChange, setUser }: Props) => {
 	</DialogContent>
       </Dialog>)
 }
+
+export default InheritDialogue

frontend/src/components/users/UserCodeDialogue.tsx

@@ -1,3 +1,5 @@
+import type { FC } from 'react'
+
 import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import { Button } from '@/components/ui/button'
 import { Dialog,
@@ -17,7 +19,7 @@ type Props = { visible:         boolean
 	       setUser:         React.Dispatch<React.SetStateAction<User | null>> }
 
 
-export default ({ visible, onVisibleChange, user, setUser }: Props) => {
+const UserCodeDialogue: FC<Props> = ({ visible, onVisibleChange, user, setUser }) => {
   const dialogue = useDialogue ()
 
   const handleChange = async () => {
@@ -69,3 +71,5 @@ export default ({ visible, onVisibleChange, user, setUser }: Props) => {
 	</DialogContent>
       </Dialog>)
 }
+
+export default UserCodeDialogue

frontend/src/lib/api.test.ts

@@ -0,0 +1,96 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const mocks = vi.hoisted (() => {
+  const client = {
+    delete: vi.fn (),
+    get:    vi.fn (),
+    patch:  vi.fn (),
+    post:   vi.fn (),
+    put:    vi.fn (),
+  }
+
+  return {
+    client,
+    isAxiosError: vi.fn (),
+  }
+})
+
+vi.mock ('axios', () => ({
+  default: {
+    create:       vi.fn (() => mocks.client),
+    isAxiosError: mocks.isAxiosError,
+  },
+}))
+
+vi.mock ('@/config', () => ({
+  API_BASE_URL: '/api',
+}))
+
+describe ('api helpers', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    localStorage.clear ()
+  })
+
+  it ('adds the transfer code header and camelizes get responses', async () => {
+    localStorage.setItem ('user_code', 'abc123')
+    mocks.client.get.mockResolvedValueOnce ({
+      data: { post_id: 1, nested_value: { created_at: 'now' } },
+    })
+
+    const { apiGet } = await import ('@/lib/api')
+    const data = await apiGet<{ postId: number; nestedValue: { createdAt: string } }> (
+        '/posts/1',
+        { headers: { 'X-Extra': '1' }, params: { page: 2 } },
+    )
+
+    expect (mocks.client.get).toHaveBeenCalledWith (
+        '/posts/1',
+        {
+          headers: { 'X-Transfer-Code': 'abc123', 'X-Extra': '1' },
+          params:  { page: 2 },
+        },
+    )
+    expect (data).toEqual ({ postId: 1, nestedValue: { createdAt: 'now' } })
+  })
+
+  it ('passes an empty body for post-like requests when body is omitted', async () => {
+    mocks.client.patch.mockResolvedValueOnce ({ data: { ok_value: true } })
+
+    const { apiPatch } = await import ('@/lib/api')
+    const data = await apiPatch<{ okValue: boolean }> ('/posts/1')
+
+    expect (mocks.client.patch).toHaveBeenCalledWith (
+        '/posts/1',
+        {},
+        { headers: { 'X-Transfer-Code': '' } },
+    )
+    expect (data.okValue).toBe (true)
+  })
+
+  it ('does not camelize blob responses', async () => {
+    const blob = new Blob (['csv'])
+    mocks.client.get.mockResolvedValueOnce ({ data: blob })
+
+    const { apiGet } = await import ('@/lib/api')
+    const data = await apiGet<Blob> ('/exports', { responseType: 'blob' })
+
+    expect (data).toBe (blob)
+  })
+
+  it ('delegates deletes and exposes axios error detection', async () => {
+    const err = new Error ('bad')
+    mocks.client.delete.mockResolvedValueOnce ({})
+    mocks.isAxiosError.mockReturnValueOnce (true)
+
+    const { apiDelete, isApiError } = await import ('@/lib/api')
+    await apiDelete ('/posts/1')
+
+    expect (mocks.client.delete).toHaveBeenCalledWith (
+        '/posts/1',
+        { headers: { 'X-Transfer-Code': '' } },
+    )
+    expect (isApiError (err)).toBe (true)
+    expect (mocks.isAxiosError).toHaveBeenCalledWith (err)
+  })
+})

frontend/src/lib/api.ts

@@ -28,7 +28,7 @@ const apiP = async <T> (
   const res = await client[method] (path, body ?? { }, withUserCode (opt))
   if (opt?.responseType === 'blob')
     return res.data as T
-  return toCamel (res.data as any, { deep: true }) as T
+  return toCamel (res.data as Record<string, unknown>, { deep: true }) as T
 }
 
 
@@ -39,7 +39,7 @@ export const apiGet = async <T> (
   const res = await client.get (path, withUserCode (opt))
   if (opt?.responseType === 'blob')
     return res.data as T
-  return toCamel (res.data as any, { deep: true }) as T
+  return toCamel (res.data as Record<string, unknown>, { deep: true }) as T
 }
 
 
@@ -72,4 +72,5 @@ export const apiDelete = async (
 }
 
 
-export const isApiError = (err: unknown): err is AxiosError => axios.isAxiosError (err)
+export const isApiError = <T = unknown> (err: unknown): err is AxiosError<T> =>
+    axios.isAxiosError (err)

frontend/src/lib/posts.test.ts

@@ -0,0 +1,117 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { fetchPostChanges, fetchPosts, toggleViewedFlg, updatePost } from '@/lib/posts'
+
+import type { FetchPostsParams } from '@/types'
+
+const api = vi.hoisted (() => ({
+  apiDelete: vi.fn (),
+  apiGet:    vi.fn (),
+  apiPost:   vi.fn (),
+  apiPut:    vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+const baseParams: FetchPostsParams = {
+  url:                 '',
+  title:               '',
+  tags:                '',
+  match:               'all',
+  originalCreatedFrom: '',
+  originalCreatedTo:   '',
+  createdFrom:         '',
+  createdTo:           '',
+  updatedFrom:         '',
+  updatedTo:           '',
+  page:                1,
+  limit:               20,
+  order:               'updated_at:desc',
+}
+
+describe ('posts API functions', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('maps post search parameters to backend snake_case names', async () => {
+    api.apiGet.mockResolvedValueOnce ({ posts: [], count: 0 })
+
+    await fetchPosts ({
+      ...baseParams,
+      title:               'title',
+      tags:                'a b',
+      originalCreatedFrom: '2026-01-01',
+      updatedTo:           '2026-02-01',
+    })
+
+    expect (api.apiGet).toHaveBeenCalledWith (
+        '/posts',
+        {
+          params: {
+            title:                 'title',
+            tags:                  'a b',
+            match:                 'all',
+            original_created_from: '2026-01-01',
+            updated_to:            '2026-02-01',
+            page:                  1,
+            limit:                 20,
+            order:                 'updated_at:desc',
+          },
+        },
+    )
+  })
+
+  it ('updates posts with version and merge controls', async () => {
+    api.apiPut.mockResolvedValueOnce ({ id: 5 })
+
+    await updatePost (
+        {
+          id:                    5,
+          title:                 'new title',
+          tags:                  'tag',
+          parentPostIds:         '1 2',
+          originalCreatedFrom:   null,
+          originalCreatedBefore: '2026-01-02T00:00:00Z',
+        },
+        { baseVersionNo: 7, force: true, merge: false },
+    )
+
+    expect (api.apiPut).toHaveBeenCalledWith (
+        '/posts/5',
+        {
+          title:                   'new title',
+          tags:                    'tag',
+          parent_post_ids:         '1 2',
+          original_created_from:   null,
+          original_created_before: '2026-01-02T00:00:00Z',
+        },
+        {
+          params: {
+            base_version_no: '7',
+            force:           '1',
+            merge:           '0',
+          },
+        },
+    )
+  })
+
+  it ('uses the viewed endpoint method matching the requested state', async () => {
+    await toggleViewedFlg ('9', true)
+    await toggleViewedFlg ('9', false)
+
+    expect (api.apiPost).toHaveBeenCalledWith ('/posts/9/viewed')
+    expect (api.apiDelete).toHaveBeenCalledWith ('/posts/9/viewed')
+  })
+
+  it ('keeps optional post history filters out when blank', async () => {
+    api.apiGet.mockResolvedValueOnce ({ versions: [], count: 0 })
+
+    await fetchPostChanges ({ page: 2, limit: 50 })
+
+    expect (api.apiGet).toHaveBeenCalledWith (
+        '/posts/versions',
+        { params: { page: 2, limit: 50 } },
+    )
+  })
+})

frontend/src/lib/prefetchers.test.ts

@@ -0,0 +1,112 @@
+import { QueryClient } from '@tanstack/react-query'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { prefetchForURL } from '@/lib/prefetchers'
+
+const postsApi = vi.hoisted (() => ({
+  fetchPost:        vi.fn (),
+  fetchPostChanges: vi.fn (),
+  fetchPosts:       vi.fn (),
+}))
+
+const tagsApi = vi.hoisted (() => ({
+  fetchTag:        vi.fn (),
+  fetchTagByName:  vi.fn (),
+  fetchTagChanges: vi.fn (),
+  fetchTags:       vi.fn (),
+}))
+
+const wikiApi = vi.hoisted (() => ({
+  fetchWikiPage:        vi.fn (),
+  fetchWikiPageByTitle: vi.fn (),
+  fetchWikiPages:       vi.fn (),
+}))
+
+vi.mock ('@/lib/posts', () => postsApi)
+vi.mock ('@/lib/tags', () => tagsApi)
+vi.mock ('@/lib/wiki', () => wikiApi)
+
+const qc = () => new QueryClient ({
+  defaultOptions: { queries: { retry: false } },
+})
+
+describe ('prefetchForURL', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    postsApi.fetchPosts.mockResolvedValue ({ posts: [], count: 0 })
+    postsApi.fetchPost.mockResolvedValue ({ id: 1 })
+    postsApi.fetchPostChanges.mockResolvedValue ({ versions: [], count: 0 })
+    tagsApi.fetchTags.mockResolvedValue ({ tags: [], count: 0 })
+    tagsApi.fetchTag.mockResolvedValue ({ id: 1 })
+    tagsApi.fetchTagByName.mockResolvedValue (null)
+    tagsApi.fetchTagChanges.mockResolvedValue ({ versions: [], count: 0 })
+    wikiApi.fetchWikiPages.mockResolvedValue ([])
+    wikiApi.fetchWikiPage.mockResolvedValue ({ id: 1 })
+    wikiApi.fetchWikiPageByTitle.mockResolvedValue (null)
+  })
+
+  it ('prefetches post indexes from query parameters', async () => {
+    await prefetchForURL (
+        qc (),
+        'http://localhost/posts?tags=a+b&match=any&page=2&limit=5&order=title%3Aasc',
+    )
+
+    expect (postsApi.fetchPosts).toHaveBeenCalledWith (
+        expect.objectContaining ({
+          tags:  'a b',
+          match: 'any',
+          page:  2,
+          limit: 5,
+          order: 'title:asc',
+        }),
+    )
+  })
+
+  it ('prefetches post detail pages', async () => {
+    await prefetchForURL (qc (), 'http://localhost/posts/12')
+
+    expect (postsApi.fetchPost).toHaveBeenCalledWith ('12')
+  })
+
+  it ('prefetches tag indexes from query parameters', async () => {
+    await prefetchForURL (
+        qc (),
+        'http://localhost/tags?post=9&name=x&category=general&page=4&post_count_lte=10',
+    )
+
+    expect (tagsApi.fetchTags).toHaveBeenCalledWith (
+        expect.objectContaining ({
+          post:         9,
+          name:         'x',
+          category:     'general',
+          page:         4,
+          postCountLTE: 10,
+        }),
+    )
+  })
+
+  it ('prefetches wiki show pages and related tag/post data', async () => {
+    wikiApi.fetchWikiPageByTitle.mockResolvedValueOnce ({
+      id:    3,
+      title: 'Actual',
+      body:  'body',
+    })
+
+    await prefetchForURL (qc (), 'http://localhost/wiki/Alias')
+
+    expect (wikiApi.fetchWikiPageByTitle).toHaveBeenCalledWith ('Alias', { version: undefined })
+    expect (wikiApi.fetchWikiPage).toHaveBeenCalledWith ('3', {})
+    expect (tagsApi.fetchTagByName).toHaveBeenCalledWith ('Actual')
+    expect (postsApi.fetchPosts).toHaveBeenCalledWith (
+        expect.objectContaining ({ tags: 'Actual', limit: 8 }),
+    )
+  })
+
+  it ('ignores routes without a prefetcher', async () => {
+    await prefetchForURL (qc (), 'http://localhost/unknown')
+
+    expect (postsApi.fetchPosts).not.toHaveBeenCalled ()
+    expect (tagsApi.fetchTags).not.toHaveBeenCalled ()
+    expect (wikiApi.fetchWikiPages).not.toHaveBeenCalled ()
+  })
+})

frontend/src/lib/queryKeys.test.ts

@@ -0,0 +1,14 @@
+import { describe, expect, it } from 'vitest'
+
+import { postsKeys, tagsKeys, wikiKeys } from '@/lib/queryKeys'
+
+describe ('query keys', () => {
+  it ('uses stable namespaces for posts, tags, and wiki', () => {
+    expect (postsKeys.show ('3')).toEqual (['posts', '3'])
+    expect (postsKeys.related ('3')).toEqual (['related', '3'])
+    expect (tagsKeys.deerjikists ('7')).toEqual (['tags', 'deerjikists', '7'])
+    expect (wikiKeys.show ('Title', { version: '2' })).toEqual (
+        ['wiki', 'Title', { version: '2' }],
+    )
+  })
+})

frontend/src/lib/remark-wiki-autolink.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, it } from 'vitest'
+
+import remarkWikiAutolink from '@/lib/remark-wiki-autolink'
+
+import type { Root } from 'mdast'
+
+describe ('remarkWikiAutolink', () => {
+  it ('links matching wiki page names and prefers longer matches', () => {
+    const tree: Root = {
+      type:     'root',
+      children: [{
+        type:     'paragraph',
+        children: [{ type: 'text', value: '虹夏 and 虹' }],
+      }],
+    }
+
+    remarkWikiAutolink (['虹', '虹夏']) (tree)
+
+    expect (tree.children[0]).toMatchObject ({
+      type:     'paragraph',
+      children: [
+        {
+          type:     'link',
+          url:      '/wiki/%E8%99%B9%E5%A4%8F',
+          children: [{ type: 'text', value: '虹夏' }],
+        },
+        { type: 'text', value: ' and ' },
+        {
+          type:     'link',
+          url:      '/wiki/%E8%99%B9',
+          children: [{ type: 'text', value: '虹' }],
+        },
+      ],
+    })
+  })
+
+  it ('does not link text inside existing links or code', () => {
+    const tree: Root = {
+      type:     'root',
+      children: [
+        {
+          type:     'paragraph',
+          children: [{
+            type:     'link',
+            url:      '/existing',
+            children: [{ type: 'text', value: '虹' }],
+          }],
+        },
+        {
+          type:  'code',
+          value: '虹',
+        },
+      ],
+    }
+
+    remarkWikiAutolink (['虹']) (tree)
+
+    expect (tree.children[0]).toMatchObject ({
+      type:     'paragraph',
+      children: [{
+        type:     'link',
+        url:      '/existing',
+        children: [{ type: 'text', value: '虹' }],
+      }],
+    })
+    expect (tree.children[1]).toMatchObject ({ type: 'code', value: '虹' })
+  })
+})

frontend/src/lib/remark-wiki-autolink.ts

@@ -38,7 +38,7 @@ export default (pageNames: string[], basePath = '/wiki'): ((tree: Root) => void)
 	      let last = 0
 	      const parts: RootContent[] = []
 
-	      while (m = re.exec (value))
+	      while ((m = re.exec (value)) !== null)
 		{
 		  const start = m.index
 		  const end = start + m[0].length
@@ -70,7 +70,7 @@ export default (pageNames: string[], basePath = '/wiki'): ((tree: Root) => void)
 	    }
 	}
 
-      const maybeChidren = (node as any).children
+      const maybeChidren = 'children' in node ? node.children : undefined
       if (Array.isArray (maybeChidren))
 	{
 	  const parent = node as Parent

frontend/src/lib/tags.test.ts

@@ -0,0 +1,67 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { fetchTag, fetchTagByName, fetchTags } from '@/lib/tags'
+
+import type { FetchTagsParams } from '@/types'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+const baseParams: FetchTagsParams = {
+  post:         null,
+  name:         '',
+  category:     null,
+  postCountGTE: 0,
+  postCountLTE: null,
+  createdFrom:  '',
+  createdTo:    '',
+  updatedFrom:  '',
+  updatedTo:    '',
+  page:         1,
+  limit:        30,
+  order:        'updated_at:desc',
+}
+
+describe ('tags API functions', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('maps tag filters to backend parameters', async () => {
+    api.apiGet.mockResolvedValueOnce ({ tags: [], count: 0 })
+
+    await fetchTags ({
+      ...baseParams,
+      name:         '虹',
+      category:     'character',
+      postCountGTE: 10,
+      postCountLTE: 20,
+    })
+
+    expect (api.apiGet).toHaveBeenCalledWith (
+        '/tags',
+        {
+          params: {
+            name:           '虹',
+            category:       'character',
+            post_count_gte: 10,
+            post_count_lte: 20,
+            page:           1,
+            limit:          30,
+            order:          'updated_at:desc',
+          },
+        },
+    )
+  })
+
+  it ('returns null when tag fetches fail', async () => {
+    api.apiGet.mockRejectedValueOnce (new Error ('missing'))
+    api.apiGet.mockRejectedValueOnce (new Error ('missing'))
+
+    await expect (fetchTag ('1')).resolves.toBeNull ()
+    await expect (fetchTagByName ('unknown')).resolves.toBeNull ()
+  })
+})

frontend/src/lib/utils.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from 'vitest'
+
+import { cn, originalCreatedAtString, toDate } from '@/lib/utils'
+
+describe ('utils', () => {
+  it ('converts strings to dates and leaves date instances intact', () => {
+    const date = new Date ('2026-01-02T03:04:05Z')
+
+    expect (toDate ('2026-01-02T03:04:05Z')).toBeInstanceOf (Date)
+    expect (toDate (date)).toBe (date)
+  })
+
+  it ('merges conditional Tailwind classes', () => {
+    const hidden = false
+
+    expect (cn ('p-2', hidden && 'hidden', 'p-4')).toBe ('p-4')
+  })
+
+  it ('renders unknown original creation time ranges', () => {
+    expect (originalCreatedAtString (null, null)).toBe ('年月日不詳')
+    expect (
+        originalCreatedAtString (
+            '2026-01-01T00:00:00+09:00',
+            '2026-01-02T00:00:00+09:00',
+        ),
+    ).toContain ('時刻不詳')
+  })
+})

frontend/src/lib/utils.ts

@@ -71,3 +71,15 @@ export const originalCreatedAtString = (
 	       .join (' '))
   return rtn === '〜' ? '年月日不詳' : rtn
 }
+
+
+export const msToTime = (ms: number): string => {
+  const totalS = Math.trunc (ms / 1_000)
+  const s = String (totalS % 60)
+  const min = String (Math.trunc (totalS / 60) % 60)
+  const h = Math.trunc (totalS / 3_600)
+
+  return (h > 0
+	  ? `${ h }:${ min.padStart (2, '0') }:${ s.padStart (2, '0') }`
+	  : `${ min }:${ s.padStart (2, '0') }`)
+}

frontend/src/lib/wiki.test.ts

@@ -0,0 +1,48 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { fetchWikiPage, fetchWikiPageByTitle, fetchWikiPages } from '@/lib/wiki'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+describe ('wiki API functions', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+  })
+
+  it ('fetches wiki index and show pages with expected parameters', async () => {
+    api.apiGet.mockResolvedValueOnce ([])
+    api.apiGet.mockResolvedValueOnce ({ id: 1 })
+
+    await fetchWikiPages ({ title: '虹' })
+    await fetchWikiPage ('1', { version: '3' })
+
+    expect (api.apiGet).toHaveBeenNthCalledWith (
+        1,
+        '/wiki',
+        { params: { title: '虹' } },
+    )
+    expect (api.apiGet).toHaveBeenNthCalledWith (
+        2,
+        '/wiki/1',
+        { params: { version: '3' } },
+    )
+  })
+
+  it ('encodes title path segments and returns null on misses', async () => {
+    api.apiGet.mockResolvedValueOnce ({ id: 2 })
+    api.apiGet.mockRejectedValueOnce (new Error ('missing'))
+
+    await fetchWikiPageByTitle ('a/b c', { version: undefined })
+    await expect (fetchWikiPageByTitle ('missing', {})).resolves.toBeNull ()
+
+    expect (api.apiGet).toHaveBeenNthCalledWith (
+        1,
+        '/wiki/title/a%2Fb%20c',
+        { params: { version: undefined } },
+    )
+  })
+})

frontend/src/pages/Forbidden.tsx

@@ -1,4 +1,8 @@
+import type { FC } from 'react'
+
 import ErrorScreen from '@/components/ErrorScreen'
 
 
-export default () => <ErrorScreen status={403}/>
+const Forbidden: FC = () => <ErrorScreen status={403}/>
+
+export default Forbidden

frontend/src/pages/MorePage.tsx

@@ -11,7 +11,7 @@ import type { FC } from 'react'
 import type { User } from '@/types'
 
 
-export default (() => {
+const MorePage: FC = () => {
   const menu = menuOutline (
       { tag: null, wikiId: null, user: { } as User, pathName: location.pathname })
 
@@ -43,4 +43,6 @@ export default (() => {
 		  </section>))}
 	    </div>))}
       </MainArea>)
-}) satisfies FC
+}
+
+export default MorePage

frontend/src/pages/NotFound.tsx

@@ -1,4 +1,8 @@
+import type { FC } from 'react'
+
 import ErrorScreen from '@/components/ErrorScreen'
 
 
-export default () => <ErrorScreen status={404}/>
+const NotFound: FC = () => <ErrorScreen status={404}/>
+
+export default NotFound

frontend/src/pages/ServiceUnavailable.tsx

@@ -1,4 +1,8 @@
+import type { FC } from 'react'
+
 import ErrorScreen from '@/components/ErrorScreen'
 
 
-export default () => <ErrorScreen status={503}/>
+const ServiceUnavailable: FC = () => <ErrorScreen status={503}/>
+
+export default ServiceUnavailable

frontend/src/pages/deerjikists/DeerjikistDetailPage.tsx

@@ -1,5 +1,6 @@
 import { useQuery, useQueryClient } from '@tanstack/react-query'
-import { useEffect, useState } from 'react'
+import { useEffect, useMemo, useState } from 'react'
+import { Helmet } from 'react-helmet-async'
 import { useParams } from 'react-router-dom'
 
 import TagLink from '@/components/TagLink'
@@ -18,7 +19,7 @@ import type { FC, FormEvent } from 'react'
 import type { Deerjikist, Platform } from '@/types'
 
 
-export default (() => {
+const DeerjikistDetailPage: FC = () => {
   const { id } = useParams ()
   const tagId = String (id ?? '')
   const tagKey = tagsKeys.deerjikists (tagId)
@@ -26,7 +27,7 @@ export default (() => {
   const { data: qData, isLoading: loading } =
       useQuery ({ queryKey: tagKey, queryFn: () => fetchDeerjikistsByTag (tagId) })
   const tag = qData?.tag
-  const deerjikists = qData?.deerjikists ?? []
+  const deerjikists = useMemo (() => qData?.deerjikists ?? [], [qData])
 
   const [data, setData] =
       useState<(Omit<Deerjikist, 'platform'> & { platform: Platform | null })[]> ([])
@@ -69,6 +70,11 @@ export default (() => {
 
   return (
       <MainArea>
+	<Helmet>
+	  <meta name="robots" content="noindex"/>
+	  {tag && <title>{tag.name} | ニジラー情報</title>}
+	</Helmet>
+
 	{(loading || !(tag)) ? 'Loading...' : (
 	    <div className="max-w-xl">
 	      <PageTitle>
@@ -152,4 +158,6 @@ export default (() => {
 	    </div>
 	)}
       </MainArea>)
-}) satisfies FC
+}
+
+export default DeerjikistDetailPage

frontend/src/pages/materials/MaterialBasePage.test.tsx

@@ -0,0 +1,26 @@
+import { screen } from '@testing-library/react'
+import { Route, Routes } from 'react-router-dom'
+import { describe, expect, it, vi } from 'vitest'
+
+import MaterialBasePage from '@/pages/materials/MaterialBasePage'
+import { renderWithProviders } from '@/test/render'
+
+vi.mock ('@/components/MaterialSidebar', () => ({
+  default: () => <aside>Material sidebar</aside>,
+}))
+
+describe ('MaterialBasePage', () => {
+  it ('renders the material sidebar and nested route outlet', () => {
+    renderWithProviders (
+        <Routes>
+          <Route path="/materials" element={<MaterialBasePage/>}>
+            <Route index element={<div>Outlet content</div>}/>
+          </Route>
+        </Routes>,
+        { route: '/materials' },
+    )
+
+    expect (screen.getByText ('Material sidebar')).toBeInTheDocument ()
+    expect (screen.getByText ('Outlet content')).toBeInTheDocument ()
+  })
+})

frontend/src/pages/materials/MaterialBasePage.tsx

@@ -5,8 +5,10 @@ import MaterialSidebar from '@/components/MaterialSidebar'
 import type { FC } from 'react'
 
 
-export default (() => (
+const MaterialBasePage: FC = () => (
     <div className="md:flex md:flex-1 overflow-y-auto md:overflow-y-hidden">
       <MaterialSidebar/>
       <Outlet/>
-    </div>)) satisfies FC
+    </div>)
+
+export default MaterialBasePage

frontend/src/pages/materials/MaterialDetailPage.test.tsx

@@ -0,0 +1,86 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { Route, Routes } from 'react-router-dom'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import MaterialDetailPage from '@/pages/materials/MaterialDetailPage'
+import { buildMaterial, buildTag } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+  apiPut: vi.fn (),
+}))
+
+const wikiApi = vi.hoisted (() => ({
+  fetchWikiPages: vi.fn (),
+}))
+
+const toastApi = vi.hoisted (() => ({
+  toast: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+vi.mock ('@/lib/wiki', () => wikiApi)
+vi.mock ('@/components/ui/use-toast', () => toastApi)
+
+const renderPage = () =>
+  renderWithProviders (
+      <Routes>
+        <Route path="/materials/:id" element={<MaterialDetailPage/>}/>
+      </Routes>,
+      { route: '/materials/8' },
+  )
+
+describe ('MaterialDetailPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    api.apiGet.mockResolvedValue ([])
+    wikiApi.fetchWikiPages.mockResolvedValue ([])
+    vi.stubGlobal ('fetch', vi.fn (async () => ({
+      blob: async () => new Blob (['image'], { type: 'image/png' }),
+    })))
+  })
+
+  it ('loads and displays material detail', async () => {
+    api.apiGet.mockResolvedValueOnce (
+        buildMaterial ({
+          id:          8,
+          tag:         buildTag ({ name: '素材タグ' }),
+          file:        'image.png',
+          contentType: 'image/png',
+        }),
+    )
+
+    renderPage ()
+
+    await waitFor (() => {
+      expect (api.apiGet).toHaveBeenCalledWith ('/materials/8')
+    })
+    expect (await screen.findByAltText ('素材タグ')).toHaveAttribute ('src', 'image.png')
+  })
+
+  it ('submits edited material fields', async () => {
+    api.apiGet.mockResolvedValueOnce (
+        buildMaterial ({ id: 8, tag: buildTag ({ name: 'old' }), url: '' }),
+    )
+    api.apiPut.mockResolvedValueOnce (
+        buildMaterial ({ id: 8, tag: buildTag ({ name: 'new' }) }),
+    )
+
+    renderPage ()
+
+    fireEvent.click (await screen.findByText ('編輯'))
+    const textboxes = screen.getAllByRole ('textbox')
+    fireEvent.change (textboxes[0], { target: { value: 'new' } })
+    fireEvent.change (textboxes[1], { target: { value: 'https://example.com/ref' } })
+    fireEvent.click (screen.getByRole ('button', { name: '更新' }))
+
+    await waitFor (() => {
+      expect (api.apiPut).toHaveBeenCalledWith ('/materials/8', expect.any (FormData))
+    })
+    const formData = api.apiPut.mock.calls[0]?.[1] as FormData
+    expect (formData.get ('tag')).toBe ('new')
+    expect (formData.get ('url')).toBe ('https://example.com/ref')
+    expect (toastApi.toast).toHaveBeenCalledWith ({ title: '更新成功!' })
+  })
+})

frontend/src/pages/materials/MaterialDetailPage.tsx

@@ -21,7 +21,7 @@ import type { Material, Tag } from '@/types'
 type MaterialWithTag = Material & { tag: Tag }
 
 
-export default (() => {
+const MaterialDetailPage: FC = () => {
   const { id } = useParams ()
 
   const [file, setFile] = useState<File | null> (null)
@@ -179,4 +179,6 @@ export default (() => {
 	      </TabGroup>
 	    </>))}
       </MainArea>)
-}) satisfies FC
+}
+
+export default MaterialDetailPage

frontend/src/pages/materials/MaterialListPage.test.tsx

@@ -0,0 +1,62 @@
+import { screen, waitFor } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import MaterialListPage from '@/pages/materials/MaterialListPage'
+import { buildMaterial, buildTag } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const api = vi.hoisted (() => ({
+  apiGet: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+describe ('MaterialListPage', () => {
+  it ('shows the empty selection guide without a tag query', () => {
+    renderWithProviders (<MaterialListPage/>, { route: '/materials' })
+
+    expect (screen.getByText ('左のリストから照会したいタグを選択してください。')).toBeInTheDocument ()
+    expect (screen.getByRole ('link', { name: '素材を新規追加する' })).toHaveAttribute (
+        'href',
+        '/materials/new',
+    )
+  })
+
+  it ('loads materials for a tag query', async () => {
+    const tag = {
+      ...buildTag ({
+        id:       4,
+        name:     '素材タグ',
+        category: 'material',
+      }),
+      material: buildMaterial ({ id: 8, contentType: 'image/png', file: 'image.png' }),
+      children: [],
+    }
+    api.apiGet.mockResolvedValueOnce (tag)
+
+    renderWithProviders (<MaterialListPage/>, { route: '/materials?tag=%E7%B4%A0%E6%9D%90' })
+
+    await waitFor (() => {
+      expect (api.apiGet).toHaveBeenCalledWith (
+          '/tags/name/%E7%B4%A0%E6%9D%90/materials',
+      )
+    })
+    expect (await screen.findByRole ('link', { name: '素材タグ' })).toBeInTheDocument ()
+    expect (screen.getByRole ('link', { name: '' })).toHaveAttribute ('href', '/materials/8')
+  })
+
+  it ('offers adding a missing non-meme material', async () => {
+    api.apiGet.mockResolvedValueOnce ({
+      ...buildTag ({ name: '未登録', category: 'material' }),
+      material: null,
+      children: [],
+    })
+
+    renderWithProviders (<MaterialListPage/>, { route: '/materials?tag=x' })
+
+    expect (await screen.findByRole ('link', { name: '追加' })).toHaveAttribute (
+        'href',
+        '/materials/new?tag=%E6%9C%AA%E7%99%BB%E9%8C%B2',
+    )
+  })
+})

frontend/src/pages/materials/MaterialListPage.tsx

@@ -41,7 +41,7 @@ const MaterialCard = ({ tag }: { tag: TagWithMaterial }) => {
 }
 
 
-export default (() => {
+const MaterialListPage: FC = () => {
   const [loading, setLoading] = useState (false)
   const [tag, setTag] = useState<TagWithMaterial | null> (null)
 
@@ -69,7 +69,7 @@ export default (() => {
 	setLoading (false)
       }
     }) ()
-  }, [location.search])
+  }, [location.search, tagQuery])
 
   return (
       <MainArea>
@@ -163,4 +163,6 @@ export default (() => {
 		  </ul>
 		</>))}
       </MainArea>)
-}) satisfies FC
+}
+
+export default MaterialListPage

frontend/src/pages/materials/MaterialNewPage.test.tsx

@@ -0,0 +1,38 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import MaterialNewPage from '@/pages/materials/MaterialNewPage'
+import { renderWithProviders } from '@/test/render'
+
+const api = vi.hoisted (() => ({
+  apiPost: vi.fn (),
+}))
+
+const toastApi = vi.hoisted (() => ({
+  toast: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+vi.mock ('@/components/ui/use-toast', () => toastApi)
+
+describe ('MaterialNewPage', () => {
+  it ('initializes tag from query and submits form data', async () => {
+    api.apiPost.mockResolvedValueOnce ({})
+
+    renderWithProviders (<MaterialNewPage/>, { route: '/materials/new?tag=%E8%99%B9%E5%A4%8F' })
+
+    expect (screen.getAllByRole ('textbox')[0]).toHaveValue ('虹夏')
+    fireEvent.change (screen.getAllByRole ('textbox')[1], {
+      target: { value: 'https://example.com/ref' },
+    })
+    fireEvent.click (screen.getByRole ('button', { name: '追加' }))
+
+    await waitFor (() => {
+      expect (api.apiPost).toHaveBeenCalledWith ('/materials', expect.any (FormData))
+    })
+    const formData = api.apiPost.mock.calls[0]?.[1] as FormData
+    expect (formData.get ('tag')).toBe ('虹夏')
+    expect (formData.get ('url')).toBe ('https://example.com/ref')
+    expect (toastApi.toast).toHaveBeenCalledWith ({ title: '送信成功!' })
+  })
+})

frontend/src/pages/materials/MaterialNewPage.tsx

@@ -15,7 +15,7 @@ import { apiPost } from '@/lib/api'
 import type { FC } from 'react'
 
 
-export default (() => {
+const MaterialNewPage: FC = () => {
   const location = useLocation ()
   const query = new URLSearchParams (location.search)
   const tagQuery = query.get ('tag') ?? ''
@@ -121,4 +121,6 @@ export default (() => {
 	  </Button>
 	</Form>
       </MainArea>)
-}) satisfies FC
+}
+
+export default MaterialNewPage

frontend/src/pages/materials/MaterialSearchPage.tsx

@@ -10,7 +10,7 @@ import { SITE_TITLE } from '@/config'
 import type { FC, FormEvent } from 'react'
 
 
-export default (() => {
+const MaterialSearchPage: FC = () => {
   const [tagName, setTagName] = useState ('')
   const [parentTagName, setParentTagName] = useState ('')
 
@@ -46,4 +46,6 @@ export default (() => {
 	  </form>
 	</div>
       </MainArea>)
-}) satisfies FC
+}
+
+export default MaterialSearchPage

frontend/src/pages/posts/PostDetailPage.test.tsx

@@ -0,0 +1,109 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { Route, Routes } from 'react-router-dom'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import PostDetailPage from '@/pages/posts/PostDetailPage'
+import { buildPost, buildUser } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+import type { ReactNode } from 'react'
+
+const postsApi = vi.hoisted (() => ({
+  fetchPost:       vi.fn (),
+  toggleViewedFlg: vi.fn (),
+}))
+
+const api = vi.hoisted (() => ({
+  isApiError: vi.fn (() => false),
+}))
+
+vi.mock ('@/lib/posts', () => postsApi)
+vi.mock ('@/lib/api', () => api)
+vi.mock ('@/components/PostEmbed', () => ({
+  default: ({ post }: { post: { url: string } }) => <div>Embed:{post.url}</div>,
+}))
+vi.mock ('@/components/TagDetailSidebar', () => ({
+  default: () => <aside>Tag sidebar</aside>,
+}))
+vi.mock ('@/components/PostEditForm', () => ({
+  default: () => <div>Post edit form</div>,
+}))
+vi.mock ('framer-motion', () => ({
+  motion: {
+    div: ({ children }: { children?: ReactNode }) => <div>{children}</div>,
+    main: ({ children }: { children?: ReactNode }) => <main>{children}</main>,
+  },
+}))
+
+const renderPage = (user = buildUser ({ role: 'member' })) =>
+  renderWithProviders (
+      <Routes>
+        <Route path="/posts/:id" element={<PostDetailPage user={user}/>}/>
+      </Routes>,
+      { route: '/posts/9' },
+  )
+
+describe ('PostDetailPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    postsApi.toggleViewedFlg.mockResolvedValue (undefined)
+  })
+
+  it ('loads and displays a post detail', async () => {
+    postsApi.fetchPost.mockResolvedValue (
+        buildPost ({
+          id:            9,
+          url:           'https://example.com/9',
+          related:       [],
+          thumbnail:     null,
+          thumbnailBase: null,
+        }),
+    )
+
+    renderPage ()
+
+    await waitFor (() => {
+      expect (postsApi.fetchPost).toHaveBeenCalledWith ('9')
+    })
+    expect (await screen.findByText ('Embed:https://example.com/9')).toBeInTheDocument ()
+    expect (screen.getByRole ('button', { name: '未閲覧' })).toBeInTheDocument ()
+    expect (screen.getByText ('まだないよ（笑）')).toBeInTheDocument ()
+  })
+
+  it ('toggles viewed state through the mutation', async () => {
+    postsApi.fetchPost.mockResolvedValue (
+        buildPost ({ id: 9, viewed: false, thumbnail: null, thumbnailBase: null }),
+    )
+
+    renderPage ()
+
+    fireEvent.click (await screen.findByRole ('button', { name: '未閲覧' }))
+
+    await waitFor (() => {
+      expect (postsApi.toggleViewedFlg).toHaveBeenCalledWith ('9', true)
+    })
+  })
+
+  it ('shows the edit tab for members', async () => {
+    postsApi.fetchPost.mockResolvedValue (
+        buildPost ({ id: 9, thumbnail: null, thumbnailBase: null }),
+    )
+
+    renderPage (buildUser ({ role: 'member' }))
+
+    fireEvent.click (await screen.findByText ('編輯'))
+
+    expect (screen.getByText ('Post edit form')).toBeInTheDocument ()
+  })
+
+  it ('hides the edit tab for guests', async () => {
+    postsApi.fetchPost.mockResolvedValue (
+        buildPost ({ id: 9, thumbnail: null, thumbnailBase: null }),
+    )
+
+    renderPage (buildUser ({ role: 'guest' }))
+
+    expect (await screen.findByText ('関聯')).toBeInTheDocument ()
+    expect (screen.queryByText ('編輯')).not.toBeInTheDocument ()
+  })
+})

frontend/src/pages/posts/PostDetailPage.tsx

@@ -13,6 +13,7 @@ import MainArea from '@/components/layout/MainArea'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
+import { isApiError } from '@/lib/api'
 import { fetchPost, toggleViewedFlg } from '@/lib/posts'
 import { postsKeys, tagsKeys } from '@/lib/queryKeys'
 import { cn } from '@/lib/utils'
@@ -26,7 +27,7 @@ import type { NiconicoViewerHandle, Post, User } from '@/types'
 type Props = { user: User | null }
 
 
-export default (({ user }: Props) => {
+const PostDetailPage: FC<Props> = ({ user }) => {
   const { id } = useParams ()
   const postId = String (id ?? '')
   const postKey = postsKeys.show (postId)
@@ -43,17 +44,15 @@ export default (({ user }: Props) => {
   const [status, setStatus] = useState (200)
 
   const changeViewedFlg = useMutation ({
-      mutationFn: async () => {
-	const cur = qc.getQueryData<any> (postKey)
-	const next = !(cur?.viewed)
+      mutationFn: async (next: boolean) => {
 	await toggleViewedFlg (postId, next)
 	return next
       },
-      onMutate: async () => {
+      onMutate: async (next: boolean) => {
 	await qc.cancelQueries ({ queryKey: postKey })
-	const prev = qc.getQueryData<any> (postKey)
+	const prev = qc.getQueryData<Post> (postKey)
 	qc.setQueryData (postKey,
-			 (cur: any) => cur ? { ...cur, viewed: !(cur.viewed) } : cur)
+			 (cur: Post | undefined) => cur ? { ...cur, viewed: next } : cur)
 	return { prev }
       },
       onError: (...[, , ctx]) => {
@@ -69,7 +68,7 @@ export default (({ user }: Props) => {
     if (!(errorFlg))
       return
 
-    const code = (error as any)?.response.status ?? (error as any)?.status
+    const code = isApiError (error) ? error.response?.status : undefined
     if (code)
       setStatus (code)
   }, [errorFlg, error])
@@ -154,7 +153,7 @@ export default (({ user }: Props) => {
 		    ref={embedRef}
 		    post={post}
 		    onLoadComplete={() => embedRef.current?.play ()}/>
-		<Button onClick={() => changeViewedFlg.mutate ()}
+		<Button onClick={() => changeViewedFlg.mutate (!(post.viewed))}
 			disabled={changeViewedFlg.isPending}
 			className={cn ('text-white', viewedClass)}>
 		  {post.viewed ? '閲覧済' : '未閲覧'}
@@ -171,7 +170,7 @@ export default (({ user }: Props) => {
 			    post={post}
 			 onSave={newPost => {
 			      qc.setQueryData (postsKeys.show (postId),
-					       (prev: any) => newPost ?? prev)
+					       (prev: Post | undefined) => newPost ?? prev)
 			      qc.invalidateQueries ({ queryKey: postsKeys.root })
 			      qc.invalidateQueries ({ queryKey: tagsKeys.root })
 			    }}/>
@@ -185,4 +184,6 @@ export default (({ user }: Props) => {
 	  {post && <TagDetailSidebar post={post} sp/>}
 	</div>
       </div>)
-}) satisfies FC<Props>
+}
+
+export default PostDetailPage

frontend/src/pages/posts/PostHistoryPage.tsx

@@ -35,7 +35,7 @@ const renderDiff = (diff: { current: string | null; prev: string | null }) => (
     </>)
 
 
-export default (() => {
+const PostHistoryPage: FC = () => {
   const dialogue = useDialogue ()
 
   const location = useLocation ()
@@ -48,11 +48,11 @@ export default (() => {
   // 投稿列の結合で使用
   let rowsCnt: number
 
-  const { data: tag } =
-      tagId
-      ? useQuery ({ queryKey: tagsKeys.show (tagId),
-		    queryFn: () => fetchTag (tagId) })
-      : { data: null }
+  const tagQueryId = tagId ?? ''
+  const { data: tag } = useQuery ({
+      enabled:  Boolean (tagId),
+      queryKey: tagsKeys.show (tagQueryId),
+      queryFn:  () => fetchTag (tagQueryId) })
 
   const { data, isLoading: loading } = useQuery ({
       queryKey: postsKeys.changes ({ ...(id && { post: id }),
@@ -290,4 +290,6 @@ export default (() => {
 	      <Pagination page={page} totalPages={totalPages}/>
 	    </>)}
       </MainArea>)
-}) satisfies FC
+}
+
+export default PostHistoryPage

frontend/src/pages/posts/PostListPage.test.tsx

@@ -0,0 +1,74 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+
+import PostListPage from '@/pages/posts/PostListPage'
+import { buildPost, buildTag, buildWikiPage } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const postsApi = vi.hoisted (() => ({
+  fetchPosts: vi.fn (),
+}))
+
+const wikiApi = vi.hoisted (() => ({
+  fetchWikiPageByTitle: vi.fn (),
+  fetchWikiPages:       vi.fn (),
+}))
+
+vi.mock ('@/lib/posts', () => postsApi)
+vi.mock ('@/lib/wiki', () => wikiApi)
+
+describe ('PostListPage', () => {
+  it ('loads posts from the current query and renders the plaza tab', async () => {
+    const tag = buildTag ({ name: '虹夏' })
+    postsApi.fetchPosts.mockResolvedValueOnce ({
+      posts: [buildPost ({ id: 5, title: '投稿5', tags: [tag] })],
+      count: 1,
+    })
+    wikiApi.fetchWikiPageByTitle.mockResolvedValueOnce (buildWikiPage ({ title: '虹夏' }))
+    wikiApi.fetchWikiPages.mockResolvedValueOnce ([buildWikiPage ({ title: '虹夏' })])
+
+    renderWithProviders (<PostListPage/>, { route: '/posts?tags=%E8%99%B9%E5%A4%8F&page=2' })
+
+    await waitFor (() => {
+      expect (postsApi.fetchPosts).toHaveBeenCalledWith (
+          expect.objectContaining ({
+            tags:  '虹夏',
+            match: 'all',
+            page:  2,
+            limit: 20,
+          }),
+      )
+    })
+    expect (await screen.findByRole ('link', { name: '投稿5' })).toHaveAttribute (
+        'href',
+        '/posts/5',
+    )
+    expect (screen.getByText ('広場')).toBeInTheDocument ()
+  })
+
+  it ('shows the empty state when loading finishes without posts', async () => {
+    postsApi.fetchPosts.mockResolvedValueOnce ({ posts: [], count: 0 })
+
+    renderWithProviders (<PostListPage/>, { route: '/posts' })
+
+    expect (await screen.findByText ('広場には何もありませんよ．')).toBeInTheDocument ()
+  })
+
+  it ('renders the wiki tab for single-tag pages', async () => {
+    postsApi.fetchPosts.mockResolvedValueOnce ({ posts: [], count: 0 })
+    wikiApi.fetchWikiPageByTitle.mockResolvedValueOnce (
+        buildWikiPage ({ title: '虹夏', body: 'Wiki body' }),
+    )
+    wikiApi.fetchWikiPages.mockResolvedValueOnce ([buildWikiPage ({ title: '虹夏' })])
+
+    renderWithProviders (<PostListPage/>, { route: '/posts?tags=%E8%99%B9%E5%A4%8F' })
+
+    fireEvent.click (await screen.findByText ('Wiki'))
+
+    expect (await screen.findByText ('Wiki body')).toBeInTheDocument ()
+    expect (screen.getByRole ('link', { name: 'Wiki を見る' })).toHaveAttribute (
+        'href',
+        '/wiki/%E8%99%B9%E5%A4%8F',
+    )
+  })
+})

frontend/src/pages/posts/PostListPage.tsx

@@ -1,5 +1,5 @@
 import { useQuery } from '@tanstack/react-query'
-import { useLayoutEffect, useRef, useState } from 'react'
+import { useLayoutEffect, useMemo, useRef, useState } from 'react'
 import { Helmet } from 'react-helmet-async'
 import { useLocation } from 'react-router-dom'
 
@@ -20,7 +20,7 @@ import type { FC } from 'react'
 import type { WikiPage } from '@/types'
 
 
-export default (() => {
+const PostListPage: FC = () => {
   const containerRef = useRef<HTMLDivElement | null> (null)
 
   const [wikiPage, setWikiPage] = useState<WikiPage | null> (null)
@@ -30,7 +30,7 @@ export default (() => {
   const tagsQuery = query.get ('tags') ?? ''
   const anyFlg = query.get ('match') === 'any'
   const match = anyFlg ? 'any' : 'all'
-  const tags = tagsQuery.split (' ').filter (e => e !== '')
+  const tags = useMemo (() => tagsQuery.split (' ').filter (e => e !== ''), [tagsQuery])
   const tagsKey = tags.join (' ')
   const page = Number (query.get ('page') ?? 1)
   const limit = Number (query.get ('limit') ?? 20)
@@ -66,7 +66,7 @@ export default (() => {
 	;
       }
     }) ()
-  }, [location.search])
+  }, [location.search, tags])
 
   return (
       <div
@@ -76,7 +76,7 @@ export default (() => {
 	  <title>
 	    {tags.length
 	     ? `${ tags.join (anyFlg ? ' or ' : ' and ') } | ${ SITE_TITLE }`
-	     : `${ SITE_TITLE }　〜 ぼざろクリーチャーシリーズ綜合リンク集サイト`}
+	     : `${ SITE_TITLE }\u3000〜 ぼざろクリーチャーシリーズ綜合リンク集サイト`}
 	  </title>
 	</Helmet>
 
@@ -112,4 +112,6 @@ export default (() => {
 	  </TabGroup>
 	</MainArea>
       </div>)
-}) satisfies FC
+}
+
+export default PostListPage