#90

backend/Gemfile

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

backend/Gemfile.lock

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

backend/app/controllers/nico_tags_controller.rb

@@ -1,26 +1,69 @@
 class NicoTagsController < ApplicationController
   def index
-    limit = (params[:limit] || 20).to_i
+    name = params[:name].presence
-    cursor = params[:cursor].presence
+    linked_tag = params[:linked_tag].presence
+    link_status = params[:link_status].presence
+    order = params[:order].to_s.split(':', 2).map(&:strip)
+    order[0] = 'updated_at' unless order[0].in?(['name', 'created_at', 'updated_at'])
+    unless order[1].in?(['asc', 'desc'])
+      order[1] = order[0] == 'name' ? 'asc' : 'desc'
+    end
+    page = (params[:page].presence || 1).to_i
+    limit = (params[:limit].presence || 20).to_i
+
+    page = 1 if page < 1
+    limit = 1 if limit < 1
+
+    post_tag_max_sql =
+        PostTag
+        .select('tag_id, MAX(created_at) AS max_created_at')
+        .group('tag_id')
+        .to_sql
 
     q = Tag.nico_tags
+           .joins(:tag_name)
+           .joins("LEFT JOIN (#{ post_tag_max_sql }) post_tag_max " \
+                  'ON post_tag_max.tag_id = tags.id')
            .includes(:tag_name, tag_name: :wiki_page, linked_tags: { tag_name: :wiki_page })
-           .order(updated_at: :desc)
+    q = q.where('tag_names.name LIKE ?', "%#{ name }%") if name
-    q = q.where('tags.updated_at < ?', Time.iso8601(cursor)) if cursor
+    if linked_tag
-
+      linked_tag_ids =
-    tags = q.limit(limit + 1).to_a
+        Tag
-
+        .joins(:tag_name)
-    next_cursor = nil
+        .where('tag_names.name LIKE ?', "%#{ linked_tag }%")
-    if tags.size > limit
+        .pluck(:id)
-      next_cursor = tags.last.updated_at.iso8601(6)
+      linked_nico_tag_ids = NicoTagRelation.where(tag_id: linked_tag_ids).pluck(:nico_tag_id)
-      tags = tags.first(limit)
+      q = q.where(id: linked_nico_tag_ids)
+    end
+    if link_status.in?(['linked', 'unlinked'])
+      exists_sql =
+          'EXISTS (SELECT 1 FROM nico_tag_relations ' \
+          'WHERE nico_tag_relations.nico_tag_id = tags.id)'
+      q = link_status == 'linked' ? q.where(exists_sql) : q.where("NOT #{ exists_sql }")
     end
 
+    count = q.count
+    sort_sql =
+        case order[0]
+        when 'name'
+          'tag_names.name'
+        when 'updated_at'
+          'post_tag_max.max_created_at'
+        else
+          "tags.#{ order[0] }"
+        end
+    tags = q.reselect('tags.*',
+                      Arel.sql('post_tag_max.max_created_at AS recent_post_tag_created_at'))
+            .order(Arel.sql("#{ sort_sql } #{ order[1] }, tags.id #{ order[1] }"))
+            .limit(limit)
+            .offset((page - 1) * limit)
+            .to_a
+
     render json: { tags: tags.map { |tag|
-      TagRepr.base(tag).merge(linked_tags: tag.linked_tags.map { |lt|
+      TagRepr.base(tag).merge(
-        TagRepr.base(lt)
+          recent_post_tag_created_at: tag.recent_post_tag_created_at,
-      })
+          linked_tags: tag.linked_tags.map { |lt| TagRepr.base(lt) })
-    }, next_cursor: }
+    }, count: }
   end
 
   def update
@@ -33,13 +76,15 @@ class NicoTagsController < ApplicationController
     return render_bad_request('ニコニコ・タグを指定してください．') unless tag.nico?
 
     linked_tag_names = params[:tags].to_s.split
-    linked_tags = Tag.normalise_tags!(linked_tag_names, with_tagme: false,
+    linked_tags = nil
-                                                        with_no_deerjikist: false)
-    if linked_tags.any? { |t| t.nico? }
-      return render_unprocessable_entity('ニコニコ・タグ同士は連携できません．', field: :tags)
-    end
 
     ApplicationRecord.transaction do
+      linked_tags = Tag.normalise_tags!(linked_tag_names, with_tagme: false,
+                                                          with_no_deerjikist: false)
+      if linked_tags.any? { |t| t.nico? }
+        raise Tag::NicoTagNormalisationError
+      end
+
       TagVersioning.record_tag_snapshots!(linked_tags, created_by_user: current_user)
 
       tag.linked_tags = linked_tags
@@ -49,5 +94,21 @@ class NicoTagsController < ApplicationController
     end
 
     render json: tag.linked_tags.map { |t| TagRepr.base(t) }, status: :ok
+  rescue Tag::NicoTagNormalisationError
+    render_validation_error fields: { tags: ['ニコニコ・タグ同士は連携できません．'] }
+  rescue ActiveRecord::RecordInvalid => e
+    render_nico_tag_form_record_invalid e.record
+  end
+
+  private
+
+  def render_nico_tag_form_record_invalid record
+    if record.is_a?(TagName) || record.is_a?(Tag)
+      render_validation_error fields: { tags: record.errors.full_messages.map { |message|
+        "タグ名 “#{ record.name }”: #{ message }"
+      } }
+    else
+      render_validation_error record
+    end
   end
 end

backend/app/controllers/posts_controller.rb

@@ -453,7 +453,7 @@ class PostsController < ApplicationController
 
     if missing_ids.present?
       post.errors.add :parent_post_ids,
-                      "存在しない親投稿 ID があります: #{ missing_ids.join(' ') }"
+                      "存在しない親投稿 Id. があります: #{ missing_ids.join(' ') }"
       raise ActiveRecord::RecordInvalid, post
     end
 

backend/spec/requests/error_responses_spec.rb

@@ -2,20 +2,18 @@ require 'rails_helper'
 
 RSpec.describe 'error responses', type: :request do
   describe 'manual input errors' do
-    it 'returns a stable errors array for bad requests' do
+    it 'returns a stable payload for bad requests' do
-      user = create(:user)
+      get '/tags/name/%20/deerjikists'
-      sign_in_as(user)
-
-      put "/users/#{ user.id }", params: { name: '   ' }
 
       expect(response).to have_http_status(:bad_request)
-      expect(json.fetch('errors')).to contain_exactly(
+      expect(json).to include(
-          include('code' => 'bad_request',
+          'type' => 'bad_request',
-                  'field' => 'name',
+          'message' => be_present,
-                  'message' => be_present))
+          'errors' => {},
+          'base_errors' => [be_present])
     end
 
-    it 'returns a stable errors array for unprocessable requests' do
+    it 'returns a stable field-error payload for unprocessable requests' do
       member = create(:user, :member)
       tag = create(:tag, :general, name: 'error_response_tag')
       sign_in_as(member)
@@ -23,25 +21,27 @@ RSpec.describe 'error responses', type: :request do
       patch "/tags/#{ tag.id }", params: { category: 'nico' }
 
       expect(response).to have_http_status(:unprocessable_entity)
-      expect(json.fetch('errors')).to contain_exactly(
+      expect(json).to include(
-          include('code' => 'invalid',
+          'type' => 'validation_error',
-                  'field' => 'category',
+          'message' => '入力内容を確認してください．',
-                  'message' => be_present))
+          'base_errors' => [])
+      expect(json.fetch('errors')).to include(
+          'category' => ['ニコタグは変更できません．'])
     end
   end
 
   describe 'model validation errors' do
-    it 'returns field, code, and message for model errors' do
+    it 'returns field messages for model errors' do
       user = create(:user)
       sign_in_as(user)
 
       put "/users/#{ user.id }", params: { name: 'a' * 256 }
 
       expect(response).to have_http_status(:unprocessable_entity)
-      expect(json.fetch('errors')).to include(
+      expect(json).to include(
-          include('code' => 'too_long',
+          'type' => 'validation_error',
-                  'field' => 'name',
+          'message' => '入力内容を確認してください．')
-                  'message' => be_present))
+      expect(json.fetch('errors').fetch('name')).to include(be_present)
     end
   end
 end

backend/spec/requests/materials_spec.rb

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

backend/spec/requests/nico_tags_spec.rb

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

backend/spec/requests/posts_spec.rb

@@ -704,7 +704,7 @@ RSpec.describe 'Posts API', type: :request do
             category: :nico)
       end
 
-      it 'return 400' do
+      it 'returns 422 with tag field errors' do
         sign_in_as(member)
 
         post '/posts', params: post_write_params(
@@ -714,7 +714,13 @@ RSpec.describe 'Posts API', type: :request do
           thumbnail: dummy_upload
         )
 
-        expect(response).to have_http_status(:bad_request), response.body
+        expect(response).to have_http_status(:unprocessable_entity), response.body
+        expect(json).to include(
+            'type' => 'validation_error',
+            'message' => '入力内容を確認してください．',
+            'base_errors' => [])
+        expect(json.fetch('errors')).to include(
+            'tags' => ['ニコニコ・タグは直接指定できません．'])
       end
     end
 
@@ -931,7 +937,7 @@ RSpec.describe 'Posts API', type: :request do
             category: :nico)
       end
 
-      it 'return 400' do
+      it 'returns 422 with tag field errors' do
         sign_in_as(member)
 
         put "/posts/#{post_record.id}", params: post_update_params(
@@ -939,7 +945,13 @@ RSpec.describe 'Posts API', type: :request do
             title: 'updated title',
             tags: 'nico:nico_tag')
 
-        expect(response).to have_http_status(:bad_request), response.body
+        expect(response).to have_http_status(:unprocessable_entity), response.body
+        expect(json).to include(
+            'type' => 'validation_error',
+            'message' => '入力内容を確認してください．',
+            'base_errors' => [])
+        expect(json.fetch('errors')).to include(
+            'tags' => ['ニコニコ・タグは直接指定できません．'])
       end
     end
 

backend/spec/requests/tags_deerjikists_spec.rb

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

backend/spec/requests/users_spec.rb

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

frontend/src/App.tsx

@@ -62,6 +62,7 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	  <Route path="/tags/:id" element={<TagDetailPage/>}/>
 	  <Route path="/tags/:id/deerjikists" element={<DeerjikistDetailPage/>}/>
 	  <Route path="/tags/nico" element={<NicoTagListPage user={user}/>}/>
+	  <Route path="/nico/tags" element={<NicoTagListPage user={user}/>}/>
 	  <Route path="/tags/changes" element={<TagHistoryPage/>}/>
 	  <Route path="/theatres/:id" element={<TheatreDetailPage/>}/>
 	  <Route path="/materials" element={<MaterialBasePage/>}>
@@ -158,4 +159,4 @@ const App: FC = () => {
       </>)
 }
 
-export default App
+export default App

frontend/src/lib/apiErrors.test.ts

@@ -0,0 +1,79 @@
+import { describe, expect, it, vi } from 'vitest'
+
+const api = vi.hoisted (() => ({
+  isApiError: vi.fn (),
+}))
+
+vi.mock ('@/lib/api', () => api)
+
+describe ('extractValidationError', () => {
+  it ('extracts field and base errors from 422 validation responses', async () => {
+    api.isApiError.mockReturnValueOnce (true)
+
+    const { extractValidationError } = await import ('@/lib/apiErrors')
+    const validationError = extractValidationError<'name'> ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          message:     '入力内容を確認してください．',
+          errors:      { name: ['名前は必須です．'] },
+          base_errors: ['全体エラー'],
+        },
+      },
+    })
+
+    expect (validationError).toEqual ({
+      message:     '入力内容を確認してください．',
+      fieldErrors: { name: ['名前は必須です．'] },
+      baseErrors:  ['全体エラー'],
+    })
+  })
+
+  it ('preserves dotted field keys for indexed form rows', async () => {
+    api.isApiError.mockReturnValueOnce (true)
+
+    const { extractValidationError } = await import ('@/lib/apiErrors')
+    const validationError = extractValidationError<'deerjikists.0.platform'> ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          errors:      { 'deerjikists.0.platform': ['プラットフォームを入力してください．'] },
+          base_errors: [],
+        },
+      },
+    })
+
+    expect (validationError?.fieldErrors).toEqual ({
+      'deerjikists0Platform': ['プラットフォームを入力してください．'],
+    })
+  })
+
+  it ('does not treat 400 bad requests as form validation errors', async () => {
+    api.isApiError.mockReturnValueOnce (true)
+
+    const { extractValidationError } = await import ('@/lib/apiErrors')
+    const validationError = extractValidationError ({
+      response: {
+        status: 400,
+        data:   {
+          type:        'bad_request',
+          message:     'リクエストが不正です．',
+          errors:      {},
+          base_errors: ['リクエストが不正です．'],
+        },
+      },
+    })
+
+    expect (validationError).toBeNull ()
+  })
+
+  it ('ignores non-api errors', async () => {
+    api.isApiError.mockReturnValueOnce (false)
+
+    const { extractValidationError } = await import ('@/lib/apiErrors')
+
+    expect (extractValidationError (new Error ('network'))).toBeNull ()
+  })
+})

frontend/src/lib/apiErrors.ts

@@ -19,8 +19,13 @@ export const extractValidationError = <T extends string = string> (err: unknown)
   if (!(isApiError (err)) || err.response?.status !== 422)
     return null
 
-  const data = toCamel ((err.response.data ?? { }) as Record<string, unknown>,
+  const rawData = toCamel ((err.response.data ?? { }) as Record<string, unknown>,
-			{ deep: true }) as RawValidationError
+			   { deep: true }) as RawValidationError
+  const data: RawValidationError = {
+      type:       rawData.type as string | undefined,
+      message:    rawData.message as string | undefined,
+      errors:     rawData.errors as Record<string, string[]> | undefined,
+      baseErrors: rawData.baseErrors as string[] | undefined }
 
   if (data.type !== 'validation_error' && !(data.errors))
     return null

frontend/src/lib/prefetchers.test.ts

@@ -10,6 +10,7 @@ const postsApi = vi.hoisted (() => ({
 }))
 
 const tagsApi = vi.hoisted (() => ({
+  fetchNicoTags:   vi.fn (),
   fetchTag:        vi.fn (),
   fetchTagByName:  vi.fn (),
   fetchTagChanges: vi.fn (),
@@ -37,6 +38,7 @@ describe ('prefetchForURL', () => {
     postsApi.fetchPost.mockResolvedValue ({ id: 1 })
     postsApi.fetchPostChanges.mockResolvedValue ({ versions: [], count: 0 })
     tagsApi.fetchTags.mockResolvedValue ({ tags: [], count: 0 })
+    tagsApi.fetchNicoTags.mockResolvedValue ({ tags: [], count: 0 })
     tagsApi.fetchTag.mockResolvedValue ({ id: 1 })
     tagsApi.fetchTagByName.mockResolvedValue (null)
     tagsApi.fetchTagChanges.mockResolvedValue ({ versions: [], count: 0 })
@@ -85,6 +87,32 @@ describe ('prefetchForURL', () => {
     )
   })
 
+  it ('prefetches nico tag indexes and their alias from query parameters', async () => {
+    await prefetchForURL (
+        qc (),
+        'http://localhost/tags/nico?name=source&linked_tag=destination'
+	    + '&link_status=linked&page=3&limit=10',
+    )
+    await prefetchForURL (qc (), 'http://localhost/nico/tags?page=2')
+
+    expect (tagsApi.fetchNicoTags).toHaveBeenNthCalledWith (1, {
+      name:       'source',
+      linkedTag:  'destination',
+      linkStatus: 'linked',
+      page:       3,
+      limit:      10,
+      order:      'updated_at:desc',
+    })
+    expect (tagsApi.fetchNicoTags).toHaveBeenNthCalledWith (2, {
+      name:       '',
+      linkedTag:  '',
+      linkStatus: 'all',
+      page:       2,
+      limit:      20,
+      order:      'updated_at:desc',
+    })
+  })
+
   it ('prefetches wiki show pages and related tag/post data', async () => {
     wikiApi.fetchWikiPageByTitle.mockResolvedValueOnce ({
       id:    3,

frontend/src/lib/prefetchers.ts

@@ -3,7 +3,7 @@ import { match } from 'path-to-regexp'
 
 import { fetchPost, fetchPosts, fetchPostChanges } from '@/lib/posts'
 import { postsKeys, tagsKeys, wikiKeys } from '@/lib/queryKeys'
-import { fetchTagByName, fetchTag, fetchTagChanges, fetchTags } from '@/lib/tags'
+import { fetchNicoTags, fetchTagByName, fetchTag, fetchTagChanges, fetchTags } from '@/lib/tags'
 import { fetchWikiPage,
 	 fetchWikiPageByTitle,
 	 fetchWikiPages } from '@/lib/wiki'
@@ -170,6 +170,24 @@ const prefetchTagsIndex: Prefetcher = async (qc, url) => {
 }
 
 
+const prefetchNicoTagsIndex: Prefetcher = async (qc, url) => {
+  const keys = {
+      name:       url.searchParams.get ('name') ?? '',
+      linkedTag:  url.searchParams.get ('linked_tag') ?? '',
+      linkStatus: (url.searchParams.get ('link_status') || 'all') as
+		  'all' | 'linked' | 'unlinked',
+      page:       Number (url.searchParams.get ('page') || 1),
+      limit:      Number (url.searchParams.get ('limit') || 20),
+      order:      (url.searchParams.get ('order') || 'updated_at:desc') as
+		  'name:asc' | 'name:desc' | 'created_at:asc' | 'created_at:desc'
+		  | 'updated_at:asc' | 'updated_at:desc' }
+
+  await qc.prefetchQuery ({
+      queryKey: tagsKeys.nicoIndex (keys),
+      queryFn:  () => fetchNicoTags (keys) })
+}
+
+
 const prefetchTagShow: Prefetcher = async (qc, url) => {
   const m = mTag (url.pathname)
   if (!(m))
@@ -206,6 +224,8 @@ export const routePrefetchers: { test: (u: URL) => boolean; run: Prefetcher }[]
 		  && Boolean (mWiki (u.pathname))),
       run: prefetchWikiPageShow },
     { test: u => u.pathname === '/tags', run: prefetchTagsIndex },
+    { test: u => ['/tags/nico', '/nico/tags'].includes (u.pathname),
+      run: prefetchNicoTagsIndex },
     { test: u => (!(['/tags/nico', '/tags/changes'].includes (u.pathname))
 		  && Boolean (mTag (u.pathname))),
       run: prefetchTagShow },

frontend/src/lib/queryKeys.ts

@@ -1,4 +1,4 @@
-import type { FetchPostsParams, FetchTagsParams } from '@/types'
+import type { FetchNicoTagsParams, FetchPostsParams, FetchTagsParams } from '@/types'
 
 export const postsKeys = {
     root:     ['posts'] as const,
@@ -11,6 +11,8 @@ export const postsKeys = {
 export const tagsKeys = {
     root:         ['tags'] as const,
     index:        (p: FetchTagsParams) => ['tags', 'index', p] as const,
+    nicoRoot:     ['tags', 'nico'] as const,
+    nicoIndex:    (p: FetchNicoTagsParams) => ['tags', 'nico', 'index', p] as const,
     show:         (name: string) => ['tags', name] as const,
     changes:      (p: { id?: string; page: number; limit: number }) =>
 		      ['tags', 'changes', p] as const,

frontend/src/lib/tags.ts

@@ -1,6 +1,11 @@
 import { apiGet } from '@/lib/api'
 
-import type { Deerjikist, FetchTagsParams, Tag, TagVersion } from '@/types'
+import type { Deerjikist,
+	      FetchNicoTagsParams,
+	      FetchTagsParams,
+	      NicoTag,
+	      Tag,
+	      TagVersion } from '@/types'
 
 
 export const fetchTags = async (
@@ -23,6 +28,19 @@ export const fetchTags = async (
 	...(order && { order }) } })
 
 
+export const fetchNicoTags = async (
+    { name, linkedTag, linkStatus, page, limit, order }: FetchNicoTagsParams,
+): Promise<{ tags:  NicoTag[]
+	     count: number }> =>
+    await apiGet ('/tags/nico', { params: {
+	page,
+	limit,
+	name,
+	linked_tag:  linkedTag,
+	link_status: linkStatus === 'all' ? '' : linkStatus,
+	order } })
+
+
 export const fetchTag = async (id: string): Promise<Tag | null> => {
   try
   {

frontend/src/pages/deerjikists/DeerjikistDetailPage.test.tsx

@@ -0,0 +1,72 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { Route, Routes } from 'react-router-dom'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import DeerjikistDetailPage from '@/pages/deerjikists/DeerjikistDetailPage'
+import { buildTag } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+const tagsApi = vi.hoisted (() => ({
+  fetchDeerjikistsByTag: vi.fn (),
+}))
+
+const api = vi.hoisted (() => ({
+  apiPut:     vi.fn (),
+  isApiError: vi.fn (),
+}))
+
+const toastApi = vi.hoisted (() => ({
+  toast: vi.fn (),
+}))
+
+vi.mock ('@/lib/tags', () => tagsApi)
+vi.mock ('@/lib/api', () => api)
+vi.mock ('@/components/ui/use-toast', () => toastApi)
+
+const renderPage = () =>
+  renderWithProviders (
+      <Routes>
+        <Route path="/tags/:id/deerjikists" element={<DeerjikistDetailPage/>}/>
+      </Routes>,
+      { route: '/tags/7/deerjikists' },
+  )
+
+describe ('DeerjikistDetailPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    api.isApiError.mockReturnValue (false)
+  })
+
+  it ('shows indexed validation errors returned for deerjikist rows', async () => {
+    tagsApi.fetchDeerjikistsByTag.mockResolvedValueOnce ({
+      tag:         buildTag ({ id: 7, name: 'deerjika', category: 'deerjikist' }),
+      deerjikists: [{ platform: null, code: 'abc' }],
+    })
+    api.isApiError.mockReturnValue (true)
+    api.apiPut.mockRejectedValueOnce ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          message:     '入力内容を確認してください．',
+          errors:      { 'deerjikists.0.platform': ['プラットフォームを入力してください．'] },
+          base_errors: [],
+        },
+      },
+    })
+
+    renderPage ()
+
+    await screen.findByDisplayValue ('abc')
+    fireEvent.submit (screen.getByRole ('button', { name: '更新' }).closest ('form')!)
+
+    await waitFor (() => {
+      expect (api.apiPut).toHaveBeenCalledWith (
+          '/tags/7/deerjikists',
+          [{ platform: null, code: 'abc' }],
+      )
+    })
+    expect (await screen.findByText ('プラットフォームを入力してください．')).toBeInTheDocument ()
+    expect (screen.getByRole ('combobox')).toHaveAttribute ('aria-invalid', 'true')
+  })
+})

frontend/src/pages/deerjikists/DeerjikistDetailPage.tsx

@@ -20,7 +20,7 @@ import type { FC, FormEvent } from 'react'
 import type { Deerjikist, Platform } from '@/types'
 
 type DeerjikistFormField =
-    'deerjikists' | `deerjikists.${ number }.platform` | `deerjikists.${ number }.code`
+    'deerjikists' | `deerjikists${ number }Platform` | `deerjikists${ number }Code`
 
 
 const DeerjikistDetailPage: FC = () => {
@@ -105,45 +105,45 @@ const DeerjikistDetailPage: FC = () => {
 		      {/* プラットフォーム */}
 		      <FormField
 			  label="プラットフォーム"
-			  messages={fieldErrors[`deerjikists.${ i }.platform`]}>
+			  messages={fieldErrors[`deerjikists${ i }Platform`]}>
 			{({ describedBy, invalid }) => (
-			<select
+			    <select
-			    disabled={disabled}
+				disabled={disabled}
-			    value={datum.platform ?? ''}
+				value={datum.platform ?? ''}
-			    aria-describedby={describedBy}
+				aria-describedby={describedBy}
-			    aria-invalid={invalid}
+				aria-invalid={invalid}
-			    className={inputClass (invalid)}
+				className={inputClass (invalid)}
-			    onChange={e => setData (prev => {
+				onChange={e => setData (prev => {
-			      const rtn = [...prev]
+				  const rtn = [...prev]
-			      rtn[i] = { ...rtn[i],
+				  rtn[i] = { ...rtn[i],
-					 platform: (e.target.value || null) as Platform | null }
+					     platform: (e.target.value || null) as Platform | null }
-			      return rtn
+				  return rtn
-			    })}>
+				})}>
-			  <option value="">&nbsp;</option>
+			      <option value="">&nbsp;</option>
-			  {PLATFORMS.map (p => (
+			      {PLATFORMS.map (p => (
-			      <option key={p} value={p}>
+				  <option key={p} value={p}>
-				{PLATFORM_NAMES[p]}
+				    {PLATFORM_NAMES[p]}
-			      </option>))}
+				  </option>))}
-			</select>)}
+			    </select>)}
 		      </FormField>
 
 		      {/* コード */}
 		      <FormField
 			  label="コード"
-			  messages={fieldErrors[`deerjikists.${ i }.code`]}>
+			  messages={fieldErrors[`deerjikists${ i }Code`]}>
 			{({ describedBy, invalid }) => (
-			<input
+			    <input
-			    type="text"
+				type="text"
-			    disabled={disabled}
+				disabled={disabled}
-			    value={datum.code}
+				value={datum.code}
-			    aria-describedby={describedBy}
+				aria-describedby={describedBy}
-			    aria-invalid={invalid}
+				aria-invalid={invalid}
-			    className={inputClass (invalid)}
+				className={inputClass (invalid)}
-			    onChange={e => setData (prev => {
+				onChange={e => setData (prev => {
-			      const rtn = [...prev]
+				  const rtn = [...prev]
-			      rtn[i] = { ...rtn[i], code: e.target.value }
+				  rtn[i] = { ...rtn[i], code: e.target.value }
-			      return rtn
+				  return rtn
-			    })}/>)}
+				})}/>)}
 		      </FormField>
 		    </fieldset>
 		))}

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

@@ -1,11 +1,13 @@
 import { fireEvent, screen, waitFor } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import MaterialNewPage from '@/pages/materials/MaterialNewPage'
 import { renderWithProviders } from '@/test/render'
 
 const api = vi.hoisted (() => ({
-  apiPost: vi.fn (),
+  apiGet:     vi.fn (),
+  apiPost:    vi.fn (),
+  isApiError: vi.fn (),
 }))
 
 const toastApi = vi.hoisted (() => ({
@@ -16,6 +18,12 @@ vi.mock ('@/lib/api', () => api)
 vi.mock ('@/components/ui/use-toast', () => toastApi)
 
 describe ('MaterialNewPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    api.apiGet.mockResolvedValue ([])
+    api.isApiError.mockReturnValue (false)
+  })
+
   it ('initializes tag from query and submits form data', async () => {
     api.apiPost.mockResolvedValueOnce ({})
 
@@ -35,4 +43,30 @@ describe ('MaterialNewPage', () => {
     expect (formData.get ('url')).toBe ('https://example.com/ref')
     expect (toastApi.toast).toHaveBeenCalledWith ({ title: '送信成功!' })
   })
+
+  it ('shows validation errors for file and url fields', async () => {
+    api.isApiError.mockReturnValue (true)
+    api.apiPost.mockRejectedValueOnce ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          message:     '入力内容を確認してください．',
+          errors:      {
+            file: ['ファイルまたは URL は必須です．'],
+            url:  ['ファイルまたは URL は必須です．'],
+          },
+          base_errors: [],
+        },
+      },
+    })
+
+    renderWithProviders (<MaterialNewPage/>)
+
+    fireEvent.change (screen.getAllByRole ('textbox')[0], { target: { value: '虹夏' } })
+    fireEvent.click (screen.getByRole ('button', { name: '追加' }))
+
+    expect (await screen.findAllByText ('ファイルまたは URL は必須です．')).toHaveLength (2)
+    expect (screen.getAllByRole ('textbox')[1]).toHaveAttribute ('aria-invalid', 'true')
+  })
 })

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

@@ -1,13 +1,14 @@
 import { fireEvent, screen, waitFor } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import PostNewPage from '@/pages/posts/PostNewPage'
 import { buildUser } from '@/test/factories'
 import { renderWithProviders } from '@/test/render'
 
 const api = vi.hoisted (() => ({
-  apiGet:  vi.fn (),
+  apiGet:     vi.fn (),
-  apiPost: vi.fn (),
+  apiPost:    vi.fn (),
+  isApiError: vi.fn (),
 }))
 
 const toastApi = vi.hoisted (() => ({
@@ -18,6 +19,11 @@ vi.mock ('@/lib/api', () => api)
 vi.mock ('@/components/ui/use-toast', () => toastApi)
 
 describe ('PostNewPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    api.isApiError.mockReturnValue (false)
+  })
+
   it ('blocks guests', () => {
     renderWithProviders (<PostNewPage user={buildUser ({ role: 'guest' })}/>)
 
@@ -55,4 +61,36 @@ describe ('PostNewPage', () => {
     expect (formData.get ('tags')).toBe ('tag1 tag2')
     expect (toastApi.toast).toHaveBeenCalledWith ({ title: '投稿成功!' })
   })
+
+  it ('shows 422 validation errors for post fields', async () => {
+    api.apiGet.mockResolvedValue ([])
+    api.isApiError.mockReturnValue (true)
+    api.apiPost.mockRejectedValueOnce ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          message:     '入力内容を確認してください．',
+          errors:      { tags: ['ニコニコ・タグは直接指定できません．'] },
+          base_errors: ['投稿内容を確認してください．'],
+        },
+      },
+    })
+
+    renderWithProviders (<PostNewPage user={buildUser ({ role: 'member' })}/>)
+
+    const checkboxes = screen.getAllByRole ('checkbox', { name: '自動' })
+    fireEvent.click (checkboxes[0])
+    fireEvent.click (checkboxes[1])
+
+    const textboxes = screen.getAllByRole ('textbox')
+    fireEvent.change (textboxes[0], { target: { value: 'https://example.com/post' } })
+    fireEvent.change (textboxes[1], { target: { value: '投稿タイトル' } })
+    fireEvent.change (textboxes[3], { target: { value: 'nico:nico_tag' } })
+    fireEvent.click (screen.getByRole ('button', { name: '追加' }))
+
+    expect (await screen.findByText ('投稿内容を確認してください．')).toBeInTheDocument ()
+    expect (screen.getByText ('ニコニコ・タグは直接指定できません．')).toBeInTheDocument ()
+    expect (screen.getAllByRole ('textbox')[3]).toHaveAttribute ('aria-invalid', 'true')
+  })
 })

frontend/src/pages/tags/NicoTagListPage.test.tsx

@@ -0,0 +1,273 @@
+import { fireEvent, screen, waitFor } from '@testing-library/react'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import NicoTagListPage from '@/pages/tags/NicoTagListPage'
+import { dateString } from '@/lib/utils'
+import { buildTag, buildUser } from '@/test/factories'
+import { renderWithProviders } from '@/test/render'
+
+import type { NicoTag } from '@/types'
+
+const api = vi.hoisted (() => ({
+  apiGet:     vi.fn (),
+  apiPut:     vi.fn (),
+  isApiError: vi.fn (),
+}))
+
+const toastApi = vi.hoisted (() => ({
+  toast: vi.fn (),
+}))
+
+const dialogue = vi.hoisted (() => ({
+  confirm: vi.fn (),
+}))
+
+const scrollIntoView = vi.fn ()
+
+vi.mock ('@/lib/api', () => api)
+vi.mock ('@/components/ui/use-toast', () => toastApi)
+vi.mock ('@/components/dialogues/DialogueProvider', () => ({
+  useDialogue: () => dialogue,
+}))
+
+const buildNicoTag = (values: Partial<NicoTag> = {}): NicoTag => ({
+    ...buildTag (),
+    ...values,
+    category:               'nico',
+    linkedTags:             values.linkedTags ?? [],
+    recentPostTagCreatedAt: values.recentPostTagCreatedAt ?? null,
+})
+
+const renderPage = (route = '/tags/nico') =>
+  renderWithProviders (
+      <NicoTagListPage user={buildUser ({ role: 'member' })}/>,
+      { route },
+  )
+
+describe ('NicoTagListPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    api.isApiError.mockReturnValue (false)
+    dialogue.confirm.mockResolvedValue (true)
+    Element.prototype.scrollIntoView = scrollIntoView
+    scrollIntoView.mockClear ()
+  })
+
+  it ('loads a filtered page from URL search parameters', async () => {
+    api.apiGet.mockResolvedValue ({
+      tags:  [buildNicoTag ({
+        id:                     1,
+        name:                   'nico:linked',
+        createdAt:              '2024-01-02T03:04:05Z',
+        recentPostTagCreatedAt: '2025-01-02T03:04:05Z',
+        updatedAt:              '2026-01-02T03:04:05Z',
+      })],
+      count: 21,
+    })
+
+    renderPage (
+        '/tags/nico?name=linked&linked_tag=destination&link_status=linked'
+	+ '&page=2&order=name:asc',
+    )
+
+    await waitFor (() => {
+      expect (api.apiGet).toHaveBeenCalledWith (
+          '/tags/nico',
+          { params: {
+            page:        2,
+            limit:       20,
+            name:        'linked',
+            linked_tag:  'destination',
+            link_status: 'linked',
+            order:       'name:asc',
+          } },
+      )
+    })
+    expect (await screen.findByText ('21 件')).toBeInTheDocument ()
+    expect (screen.getByLabelText ('前のページ')).toBeInTheDocument ()
+    expect (screen.queryByText ('なし')).not.toBeInTheDocument ()
+    expect (screen.getByText (dateString ('2025-01-02T03:04:05Z'))).toBeInTheDocument ()
+    expect (screen.queryByText (dateString ('2026-01-02T03:04:05Z'))).not.toBeInTheDocument ()
+    expect (screen.getByRole ('link', { name: 'ニコニコタグ ▲' })).toHaveAttribute (
+        'href',
+        expect.stringContaining ('order=name%3Adesc'),
+    )
+    expect (screen.getByRole ('link', { name: '最初に記載された日時' })).toHaveAttribute (
+        'href',
+        expect.stringContaining ('order=created_at%3Adesc'),
+    )
+    expect (screen.getByRole ('link', { name: '最近記載された日時' })).toHaveAttribute (
+        'href',
+        expect.stringContaining ('order=updated_at%3Adesc'),
+    )
+
+    fireEvent.mouseEnter (screen.getByLabelText ('前のページ'))
+    await waitFor (() => {
+      expect (api.apiGet).toHaveBeenLastCalledWith (
+          '/tags/nico',
+          { params: {
+            page:        1,
+            limit:       20,
+            name:        'linked',
+            linked_tag:  'destination',
+            link_status: 'linked',
+            order:       'name:asc',
+          } },
+      )
+    })
+  })
+
+  it ('scrolls to the table when moving between pages', async () => {
+    api.apiGet.mockResolvedValue ({
+      tags:  [buildNicoTag ({ id: 1, name: 'nico:linked' })],
+      count: 21,
+    })
+
+    renderPage ()
+
+    fireEvent.click (await screen.findByLabelText ('次のページ'))
+
+    await waitFor (() => {
+      expect (scrollIntoView).toHaveBeenCalledWith ({ behavior: 'smooth' })
+    })
+  })
+
+  it ('navigates with submitted search conditions', async () => {
+    api.apiGet.mockResolvedValue ({ tags: [], count: 0 })
+    renderPage ()
+
+    fireEvent.change (screen.getByLabelText ('ニコニコタグ'), {
+      target: { value: 'source' },
+    })
+    fireEvent.change (screen.getByLabelText ('連携タグ'), {
+      target: { value: 'destination' },
+    })
+    fireEvent.change (screen.getByLabelText ('連携状態'), {
+      target: { value: 'unlinked' },
+    })
+    fireEvent.submit (screen.getByRole ('button', { name: '検索' }).closest ('form')!)
+
+    await waitFor (() => {
+      expect (api.apiGet).toHaveBeenLastCalledWith (
+          '/tags/nico',
+          { params: expect.objectContaining ({
+            page:        1,
+            name:        'source',
+            linked_tag:  'destination',
+            link_status: 'unlinked',
+          }) },
+      )
+    })
+  })
+
+  it ('updates links from a tag card', async () => {
+    api.apiGet
+      .mockResolvedValueOnce ({
+        tags:  [buildNicoTag ({ id: 7, name: 'nico:source' })],
+        count: 1,
+      })
+      .mockResolvedValueOnce ({
+        tags: [
+          buildNicoTag ({
+            id:         7,
+            name:       'nico:source',
+            linkedTags: [buildTag ({ id: 8, name: '連携先' })],
+          }),
+        ],
+        count: 1,
+      })
+    api.apiPut.mockResolvedValueOnce ([buildTag ({ id: 8, name: '連携先' })])
+
+    renderPage ()
+
+    fireEvent.click (await screen.findByRole ('button', { name: '編集' }))
+    fireEvent.change (screen.getByLabelText ('連携する広場タグ'), {
+      target: { value: '連携先' },
+    })
+    fireEvent.click (screen.getByRole ('button', { name: '保存' }))
+
+    await waitFor (() => {
+      expect (api.apiPut).toHaveBeenCalledWith (
+          '/tags/nico/7',
+          expect.any (FormData),
+          { headers: { 'Content-Type': 'multipart/form-data' } },
+      )
+    })
+    expect (await screen.findByText ('1 件')).toBeInTheDocument ()
+  })
+
+  it ('asks before discarding changes when editing another tag', async () => {
+    api.apiGet.mockResolvedValueOnce ({
+      tags: [
+        buildNicoTag ({ id: 1, name: 'nico:first' }),
+        buildNicoTag ({ id: 2, name: 'nico:second' }),
+      ],
+      count: 2,
+    })
+
+    renderPage ()
+    dialogue.confirm.mockResolvedValueOnce (false)
+
+    const editButtons = await screen.findAllByRole ('button', { name: '編集' })
+    fireEvent.click (editButtons[0])
+    fireEvent.change (screen.getByLabelText ('連携する広場タグ'), {
+      target: { value: '入力中' },
+    })
+    fireEvent.click (screen.getAllByRole ('button', { name: '編集' })[0])
+
+    await waitFor (() => {
+      expect (dialogue.confirm).toHaveBeenCalledWith ({
+        title:       '編集中の内容を破棄しますか?',
+        confirmText: '破棄',
+        variant:     'danger',
+      })
+    })
+    expect (screen.getAllByLabelText ('連携する広場タグ')).toHaveLength (1)
+    expect (screen.getByLabelText ('連携する広場タグ')).toHaveValue ('入力中')
+  })
+
+  it ('switches editing rows without confirmation when unchanged', async () => {
+    api.apiGet.mockResolvedValueOnce ({
+      tags: [
+        buildNicoTag ({ id: 1, name: 'nico:first' }),
+        buildNicoTag ({ id: 2, name: 'nico:second' }),
+      ],
+      count: 2,
+    })
+
+    renderPage ()
+
+    const editButtons = await screen.findAllByRole ('button', { name: '編集' })
+    fireEvent.click (editButtons[0])
+    fireEvent.click (screen.getAllByRole ('button', { name: '編集' })[0])
+
+    expect (dialogue.confirm).not.toHaveBeenCalled ()
+    expect (screen.getAllByLabelText ('連携する広場タグ')).toHaveLength (1)
+  })
+
+  it ('shows tags field validation errors inside the edited card', async () => {
+    api.apiGet.mockResolvedValueOnce ({
+      tags:  [buildNicoTag ({ id: 7, name: 'nico:source' })],
+      count: 1,
+    })
+    api.isApiError.mockReturnValue (true)
+    api.apiPut.mockRejectedValueOnce ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          errors:      { tags: ['タグ名を確認してください．'] },
+          base_errors: [],
+        },
+      },
+    })
+
+    renderPage ()
+
+    fireEvent.click (await screen.findByRole ('button', { name: '編集' }))
+    fireEvent.click (screen.getByRole ('button', { name: '保存' }))
+
+    expect (await screen.findByText ('タグ名を確認してください．')).toBeInTheDocument ()
+    expect (screen.getByLabelText ('連携する広場タグ')).toHaveAttribute ('aria-invalid', 'true')
+  })
+})

frontend/src/pages/tags/NicoTagListPage.tsx

@@ -1,120 +1,179 @@
-import type { FC } from 'react'
+import { useQuery, useQueryClient } from '@tanstack/react-query'
-
+import { Check, LoaderCircle, Pencil, X } from 'lucide-react'
-import { useCallback, useEffect, useRef, useState } from 'react'
+import { useEffect, useMemo, useState } from 'react'
 import { Helmet } from 'react-helmet-async'
+import { useLocation, useNavigate } from 'react-router-dom'
 
 import TagLink from '@/components/TagLink'
+import SortHeader from '@/components/SortHeader'
 import FieldError from '@/components/common/FieldError'
+import FormField from '@/components/common/FormField'
 import PageTitle from '@/components/common/PageTitle'
+import Pagination from '@/components/common/Pagination'
 import TextArea from '@/components/common/TextArea'
+import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import MainArea from '@/components/layout/MainArea'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
-import { apiGet, apiPut } from '@/lib/api'
+import { apiPut } from '@/lib/api'
 import { extractValidationError } from '@/lib/apiErrors'
+import { tagsKeys } from '@/lib/queryKeys'
+import { fetchNicoTags } from '@/lib/tags'
+import { cn, dateString, inputClass } from '@/lib/utils'
 import { canEditContent } from '@/lib/users'
 
-import type { NicoTag, Tag, User } from '@/types'
+import type { FC, FormEvent } from 'react'
 
+import type { FetchNicoTagsOrder, FetchNicoTagsOrderField, NicoTag, Tag, User } from '@/types'
+
+type LinkStatus = 'all' | 'linked' | 'unlinked'
 type Props = { user: User | null }
 
 
-const NicoTagListPage: FC<Props> = ({ user }) => {
+const setIf = (qs: URLSearchParams, key: string, value: string) => {
-  const [cursor, setCursor] = useState ('')
+  const trimmed = value.trim ()
-  const [editing, setEditing] = useState<{ [key: number]: boolean }> ({ })
+  if (trimmed)
-  const [errorsByTagId, setErrorsByTagId] = useState<Record<number, string[]>> ({ })
+    qs.set (key, trimmed)
-  const [loading, setLoading] = useState (false)
+}
-  const [nicoTags, setNicoTags] = useState<NicoTag[]> ([])
-  const [rawTags, setRawTags] = useState<{ [key: number]: string }> ({ })
 
-  const loaderRef = useRef<HTMLDivElement | null> (null)
+
+const NicoTagListPage: FC<Props> = ({ user }) => {
+  const dialogue = useDialogue ()
+  const location = useLocation ()
+  const navigate = useNavigate ()
+  const queryClient = useQueryClient ()
+  const query = useMemo (() => new URLSearchParams (location.search), [location.search])
+
+  const page = Number (query.get ('page') ?? 1)
+  const limit = Number (query.get ('limit') ?? 20)
+  const qName = query.get ('name') ?? ''
+  const qLinkedTag = query.get ('linked_tag') ?? ''
+  const qLinkStatus = (query.get ('link_status') || 'all') as LinkStatus
+  const order = (query.get ('order') || 'updated_at:desc') as FetchNicoTagsOrder
+
+  const [editingId, setEditingId] = useState<number | null> (null)
+  const [errorsByTagId, setErrorsByTagId] = useState<Record<number, string[]>> ({ })
+  const [linkStatus, setLinkStatus] = useState<LinkStatus> ('all')
+  const [linkedTag, setLinkedTag] = useState ('')
+  const [name, setName] = useState ('')
+  const [rawTags, setRawTags] = useState<Record<number, string>> ({ })
+  const [savingId, setSavingId] = useState<number | null> (null)
+
+  const keys = {
+      name: qName, linkedTag: qLinkedTag, linkStatus: qLinkStatus, page, limit, order }
+  const { data, isError, isLoading: loading } = useQuery ({
+      queryKey: tagsKeys.nicoIndex (keys),
+      queryFn:  () => fetchNicoTags (keys) })
+  const nicoTags = data?.tags ?? []
+  const count = data?.count ?? 0
 
   const editable = canEditContent (user)
+  const totalPages = Math.ceil (count / limit)
 
-  const applyLoadedTags = useCallback ((data: { tags: NicoTag[]; nextCursor: string },
+  const handleSearch = (e: FormEvent) => {
-					withCursor: boolean) => {
+    e.preventDefault ()
-    setNicoTags (tags => [...(withCursor ? tags : []), ...data.tags])
-    setCursor (data.nextCursor)
 
-    const newEditing = Object.fromEntries (data.tags.map (t => [t.id, false]))
+    const qs = new URLSearchParams ()
-    setEditing (editing => ({ ...editing, ...newEditing }))
+    setIf (qs, 'name', name)
-
+    setIf (qs, 'linked_tag', linkedTag)
-    const newRawTags = Object.fromEntries (
+    if (linkStatus !== 'all')
-	data.tags.map (t => [t.id, t.linkedTags.map (lt => lt.name).join (' ')]))
+      qs.set ('link_status', linkStatus)
-    setRawTags (rawTags => ({ ...rawTags, ...newRawTags }))
+    qs.set ('page', '1')
-  }, [])
+    qs.set ('limit', String (limit))
-
+    qs.set ('order', order)
-  const loadInitial = useCallback (async () => {
+    navigate (`${ location.pathname }?${ qs.toString () }`)
-    setLoading (true)
-
-    const data = await apiGet<{ tags: NicoTag[]; nextCursor: string }> ('/tags/nico')
-    applyLoadedTags (data, false)
-
-    setLoading (false)
-  }, [applyLoadedTags])
-
-  const loadMore = useCallback (async () => {
-    setLoading (true)
-
-    const data = await apiGet<{ tags: NicoTag[]; nextCursor: string }> (
-	'/tags/nico', { params: { cursor } })
-    applyLoadedTags (data, true)
-
-    setLoading (false)
-  }, [applyLoadedTags, cursor])
-
-  const handleEdit = async (id: number) => {
-    if (editing[id])
-      {
-	const formData = new FormData
-	formData.append ('tags', rawTags[id])
-
-	try
-	{
-	  const data = await apiPut<Tag[]> (`/tags/nico/${ id }`, formData,
-				      { headers: { 'Content-Type': 'multipart/form-data' } })
-	  setNicoTags (nicoTags => {
-	    nicoTags.find (t => t.id === id)!.linkedTags = data
-	    return [...nicoTags]
-	  })
-	  setRawTags (rawTags => ({ ...rawTags, [id]: data.map (t => t.name).join (' ') }))
-	  setErrorsByTagId (errors => ({ ...errors, [id]: [] }))
-
-	  toast ({ title: '更新しました．' })
-	}
-	catch (e)
-	{
-	  const validationError = extractValidationError<'tags'> (e)
-	  setErrorsByTagId (errors => ({ ...errors,
-					 [id]: validationError?.fieldErrors.tags ?? [] }))
-	  toast ({ title: '更新失敗', description: '入力内容を確認してください．' })
-	  return
-	}
-      }
-
-    setEditing (editing => ({ ...editing, [id]: !(editing[id]) }))
   }
 
-  useEffect(() => {
+  const defaultDirection = {
-    const observer = new IntersectionObserver (entries => {
+      name:       'asc',
-      if (entries[0].isIntersecting && !(loading) && cursor)
+      created_at: 'desc',
-	loadMore ()
+      updated_at: 'desc',
-    }, { threshold: 1 })
+  } as const
 
-    const target = loaderRef.current
+  const beginEdit = async (tag: NicoTag) => {
-    if (target)
+    const editingTag = nicoTags.find (tag => tag.id === editingId)
-      observer.observe (target)
+    const editingValue = editingTag?.linkedTags.map (tag => tag.name).join (' ') ?? ''
+    const editingChanged = editingId != null && rawTags[editingId] !== editingValue
 
-    return () => {
+    if (editingId != null && editingId !== tag.id && editingChanged
-      if (target)
+	&& !(await dialogue.confirm ({
-	observer.unobserve (target)
+	  title:       '編集中の内容を破棄しますか?',
+	  confirmText: '破棄',
+	  variant:     'danger',
+	})))
+      return
+
+    setEditingId (tag.id)
+    setRawTags (rawTags => ({
+	...rawTags,
+	[tag.id]: tag.linkedTags.map (linkedTag => linkedTag.name).join (' '),
+    }))
+    setErrorsByTagId (errors => ({ ...errors, [tag.id]: [] }))
+  }
+
+  const cancelEdit = (tag: NicoTag) => {
+    setEditingId (null)
+    setRawTags (rawTags => ({
+	...rawTags,
+	[tag.id]: tag.linkedTags.map (linkedTag => linkedTag.name).join (' '),
+    }))
+    setErrorsByTagId (errors => ({ ...errors, [tag.id]: [] }))
+  }
+
+  const saveLinks = async (id: number) => {
+    const formData = new FormData
+    formData.append ('tags', rawTags[id] ?? '')
+    setSavingId (id)
+
+    try
+    {
+      await apiPut<Tag[]> (`/tags/nico/${ id }`, formData,
+			   { headers: { 'Content-Type': 'multipart/form-data' } })
+      setErrorsByTagId (errors => ({ ...errors, [id]: [] }))
+      setEditingId (null)
+      await queryClient.invalidateQueries ({ queryKey: tagsKeys.nicoRoot })
+      toast ({ description: '連携を更新しました．' })
     }
-  }, [cursor, loadMore, loading])
+    catch (e)
+    {
+      const validationError = extractValidationError<'tags'> (e)
+      setErrorsByTagId (errors => ({
+	  ...errors,
+	  [id]: validationError?.fieldErrors.tags
+	      ?? validationError?.baseErrors
+	      ?? ['更新できませんでした．'],
+      }))
+      toast ({ title: '更新失敗', description: '入力内容を確認してください．' })
+    }
+    finally
+    {
+      setSavingId (null)
+    }
+  }
 
   useEffect (() => {
-    setNicoTags ([])
+    setName (qName)
-    loadInitial ()
+    setLinkedTag (qLinkedTag)
-  }, [loadInitial])
+    setLinkStatus (qLinkStatus)
+    setEditingId (null)
+
+    document.querySelector ('table')?.scrollIntoView ({ behavior: 'smooth' })
+  }, [location.search, qLinkedTag, qLinkStatus, qName])
+
+  useEffect (() => {
+    if (!(data))
+      return
+
+    setRawTags (Object.fromEntries (data.tags.map (tag => [
+      tag.id,
+      tag.linkedTags.map (linkedTag => linkedTag.name).join (' '),
+    ])))
+  }, [data])
+
+  useEffect (() => {
+    if (isError)
+      toast ({ title: '読込失敗', description: 'ニコニコ連携を読み込めませんでした．' })
+  }, [isError])
 
   return (
       <MainArea>
@@ -124,66 +183,201 @@ const NicoTagListPage: FC<Props> = ({ user }) => {
 
 	<div className="max-w-xl">
 	  <PageTitle>ニコニコ連携</PageTitle>
+	  <p className="mb-4 text-sm text-gray-600 dark:text-gray-300">
+	    ニコニコタグを広場のタグへ結び付けます．
+	  </p>
+
+	  <form onSubmit={handleSearch} className="space-y-2">
+	    <FormField label="ニコニコタグ">
+	      {({ invalid }) => (
+		  <input
+		      type="text"
+		      aria-label="ニコニコタグ"
+		      value={name}
+		      onChange={e => setName (e.target.value)}
+		      className={inputClass (invalid)}/>)}
+	    </FormField>
+
+	    <FormField label="連携タグ">
+	      {({ invalid }) => (
+		  <input
+		      type="text"
+		      aria-label="連携タグ"
+		      value={linkedTag}
+		      onChange={e => setLinkedTag (e.target.value)}
+		      className={inputClass (invalid)}/>)}
+	    </FormField>
+
+	    <FormField label="連携状態">
+	      {({ invalid }) => (
+		  <select
+		      aria-label="連携状態"
+		      value={linkStatus}
+		      onChange={e => setLinkStatus (e.target.value as LinkStatus)}
+		      className={inputClass (invalid)}>
+		    <option value="all">すべて</option>
+		    <option value="linked">連携済み</option>
+		    <option value="unlinked">未連携</option>
+		  </select>)}
+	    </FormField>
+
+	    <div className="py-3">
+	      <button
+		  type="submit"
+		  className="rounded bg-blue-500 px-4 py-2 text-white">
+		検索
+	      </button>
+	    </div>
+	  </form>
 	</div>
 
-	<div className="mt-4">
+	{loading
-	  {nicoTags.length > 0 && (
+	 ? 'Loading...'
-	      <table className="table-auto w-full border-collapse mb-4">
+	 : (
-		<thead className="border-b-2 border-black dark:border-white">
+	    <div className="mt-6">
-		  <tr>
+	      <div className="mb-3 flex items-baseline justify-between gap-4">
-		    <th className="p-2 text-left">ニコニコタグ</th>
+		<h2 className="text-lg font-bold">検索結果</h2>
-		    <th className="p-2 text-left">連携タグ</th>
+		<span className="text-sm text-gray-500 dark:text-gray-400">{count} 件</span>
-		    {editable && <th></th>}
+	      </div>
-		  </tr>
+
-		</thead>
+	      {nicoTags.length > 0
-		<tbody>
+	       ? (
-		  {nicoTags.map ((tag, i) => (
+		  <div className="overflow-x-auto">
-		      <tr key={i} className="even:bg-gray-100 dark:even:bg-gray-700">
+		    <table className="w-full min-w-[800px] table-fixed border-collapse">
-			<td className="p-2">
+		      <colgroup>
-			  <TagLink tag={tag} withWiki={false} withCount={false}/>
+			<col className="w-64"/>
-			</td>
+			<col className="w-[48rem]"/>
-			<td className="p-2">
+			<col className="w-56"/>
-			  {editing[tag.id]
+			<col className="w-56"/>
-			   ? (
+			{editable && <col className="w-24"/>}
-			      <>
+		      </colgroup>
-				<TextArea
+		      <thead className="border-b-2 border-black dark:border-white">
-				    value={rawTags[tag.id]}
+			<tr>
-				    invalid={(errorsByTagId[tag.id] ?? []).length > 0}
+			  <th className="p-2 text-left whitespace-nowrap">
-				    onChange={ev => {
+			    <SortHeader<FetchNicoTagsOrderField>
-				      setRawTags (rawTags => ({
+				by="name"
-					  ...rawTags,
+				label="ニコニコタグ"
-					  [tag.id]: ev.target.value }))
+				currentOrder={order}
-				    }}/>
+				defaultDirection={defaultDirection}/>
-				<FieldError messages={errorsByTagId[tag.id]}/>
+			  </th>
-			      </>)
+			  <th className="p-2 text-left">連携タグ</th>
-			   : tag.linkedTags.map((lt, j) => (
+			  <th className="p-2 text-left whitespace-nowrap">
-			      <span key={j} className="mr-2">
+			    <SortHeader<FetchNicoTagsOrderField>
-				<TagLink tag={lt}
+				by="created_at"
-					 linkFlg={false}
+				label="最初に記載された日時"
-					 withCount={false}/>
+				currentOrder={order}
-			      </span>))}
+				defaultDirection={defaultDirection}/>
-			</td>
+			  </th>
-			{editable && (
+			  <th className="p-2 text-left whitespace-nowrap">
-			    <td className="p-2">
+			    <SortHeader<FetchNicoTagsOrderField>
-			      <a href="#" onClick={ev => {
+				by="updated_at"
-				ev.preventDefault ()
+				label="最近記載された日時"
-				handleEdit (tag.id)
+				currentOrder={order}
-			      }}>
+				defaultDirection={defaultDirection}/>
-			        {editing[tag.id]
+			  </th>
-				 ? (
+			  {editable && <th className="p-2"></th>}
-				    <span className="text-red-600 hover:text-red-400
+			</tr>
-						     dark:text-red-300 dark:hover:text-red-100">
+		      </thead>
-				      更新
+		      <tbody>
-				    </span>)
+			{nicoTags.map (tag => {
-				 : <span>編輯</span>}
+			  const isEditing = editingId === tag.id
-			      </a>
+
-			    </td>)}
+			  return [
-		      </tr>))}
+			    <tr
-		</tbody>
+				key={tag.id}
-	      </table>)}
+				className={cn (
-	  {loading && 'Loading...'}
+				    'border-b border-gray-200 dark:border-gray-700',
-	  <div ref={loaderRef} className="h-12"></div>
+				    isEditing
-	</div>
+				    ? 'bg-rose-50 dark:bg-rose-950/30'
+				    : 'even:bg-gray-100 dark:even:bg-gray-800')}>
+			      <td className="p-2 align-top font-semibold">
+				<TagLink tag={tag} withWiki={false} withCount={false}/>
+			      </td>
+			      <td className="p-2 align-top">
+				{tag.linkedTags.map ((linkedTag, i) => (
+				    <span key={linkedTag.id}>
+				      {i > 0 && ' '}
+				      <TagLink
+					  tag={linkedTag}
+					  linkFlg={false}
+					  withCount={false}/>
+				    </span>))}
+			      </td>
+			      <td className="p-2 align-top whitespace-nowrap">
+				{dateString (tag.createdAt)}
+			      </td>
+			      <td className="p-2 align-top whitespace-nowrap">
+				{tag.recentPostTagCreatedAt && dateString (tag.recentPostTagCreatedAt)}
+			      </td>
+			      {editable && (
+				  <td className="p-2 text-right align-top">
+				    {!(isEditing) && (
+					<button
+					    type="button"
+					    onClick={() => beginEdit (tag)}
+					    className="inline-flex items-center gap-1 text-sm text-blue-700
+						       hover:underline dark:text-blue-300">
+					  <Pencil className="size-3.5"/>
+					  編集
+					</button>)}
+				  </td>)}
+			    </tr>,
+			    isEditing && (
+				<tr key={`${ tag.id }-edit`}
+				    className="border-b border-rose-200 bg-rose-50 dark:border-rose-900
+					       dark:bg-rose-950/30">
+				  <td colSpan={editable ? 5 : 4} className="p-3">
+				    <div className="space-y-2">
+				      <label htmlFor={`nico-links-${ tag.id }`}
+					     className="block text-sm font-semibold">
+					連携する広場タグ
+				      </label>
+				      <TextArea
+					  id={`nico-links-${ tag.id }`}
+					  value={rawTags[tag.id] ?? ''}
+					  invalid={(errorsByTagId[tag.id] ?? []).length > 0}
+					  className="min-h-24 resize-y"
+					  placeholder="タグ名を空白または改行で区切って入力"
+					  onChange={e => setRawTags (rawTags => ({
+					      ...rawTags,
+					      [tag.id]: e.target.value,
+					  }))}/>
+				      <FieldError messages={errorsByTagId[tag.id]}/>
+				      <div className="flex justify-end gap-2">
+					<button
+					    type="button"
+					    disabled={savingId === tag.id}
+					    onClick={() => cancelEdit (tag)}
+					    className="inline-flex items-center gap-1 rounded border
+						       border-gray-300 px-3 py-1.5 text-sm
+						       disabled:opacity-50 dark:border-gray-700">
+					  <X className="size-3.5"/>
+					  取消
+					</button>
+					<button
+					    type="button"
+					    disabled={savingId === tag.id}
+					    onClick={() => saveLinks (tag.id)}
+					    className="inline-flex items-center gap-1 rounded bg-rose-700
+						       px-3 py-1.5 text-sm text-white disabled:opacity-50">
+					  {savingId === tag.id
+					   ? <LoaderCircle className="size-3.5 animate-spin"/>
+					   : <Check className="size-3.5"/>}
+					  保存
+					</button>
+				      </div>
+				    </div>
+				  </td>
+				</tr>),
+			  ]
+			})}
+		      </tbody>
+		    </table>
+		  </div>)
+	       : <p>結果ないよ（笑）</p>}
+
+	      <Pagination page={page} totalPages={totalPages}/>
+	    </div>)}
       </MainArea>)
 }
 

frontend/src/pages/tags/TagDetailPage.test.tsx

@@ -1,6 +1,6 @@
 import { fireEvent, screen, waitFor } from '@testing-library/react'
 import { Route, Routes } from 'react-router-dom'
-import { describe, expect, it, vi } from 'vitest'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import TagDetailPage from '@/pages/tags/TagDetailPage'
 import { buildTag } from '@/test/factories'
@@ -11,7 +11,8 @@ const tagsApi = vi.hoisted (() => ({
 }))
 
 const api = vi.hoisted (() => ({
-  apiPut: vi.fn (),
+  apiPut:     vi.fn (),
+  isApiError: vi.fn (),
 }))
 
 const toastApi = vi.hoisted (() => ({
@@ -28,9 +29,14 @@ const renderPage = () =>
         <Route path="/tags/:id" element={<TagDetailPage/>}/>
       </Routes>,
       { route: '/tags/7' },
-  )
+)
 
 describe ('TagDetailPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    api.isApiError.mockReturnValue (false)
+  })
+
   it ('loads and displays an editable tag', async () => {
     tagsApi.fetchTag.mockResolvedValueOnce (
         buildTag ({ id: 7, name: '虹夏', category: 'character', aliases: ['drums'] }),
@@ -68,4 +74,28 @@ describe ('TagDetailPage', () => {
 
     expect (await screen.findByRole ('button', { name: '更新' })).toBeDisabled ()
   })
+
+  it ('shows validation errors returned for tag fields', async () => {
+    tagsApi.fetchTag.mockResolvedValueOnce (buildTag ({ id: 7, name: 'old' }))
+    api.isApiError.mockReturnValue (true)
+    api.apiPut.mockRejectedValueOnce ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          message:     '入力内容を確認してください．',
+          errors:      { category: ['ニコタグは変更できません．'] },
+          base_errors: [],
+        },
+      },
+    })
+
+    renderPage ()
+
+    await screen.findByDisplayValue ('old')
+    fireEvent.submit (screen.getByRole ('button', { name: '更新' }).closest ('form')!)
+
+    expect (await screen.findByText ('ニコタグは変更できません．')).toBeInTheDocument ()
+    expect (screen.getByRole ('combobox')).toHaveAttribute ('aria-invalid', 'true')
+  })
 })

frontend/src/pages/users/SettingPage.test.tsx

@@ -1,12 +1,13 @@
 import { fireEvent, screen, waitFor } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import SettingPage from '@/pages/users/SettingPage'
 import { buildUser } from '@/test/factories'
 import { renderWithProviders } from '@/test/render'
 
 const api = vi.hoisted (() => ({
-  apiPut: vi.fn (),
+  apiPut:     vi.fn (),
+  isApiError: vi.fn (),
 }))
 
 const toastApi = vi.hoisted (() => ({
@@ -23,6 +24,11 @@ vi.mock ('@/components/users/InheritDialogue', () => ({
 }))
 
 describe ('SettingPage', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    api.isApiError.mockReturnValue (false)
+  })
+
   it ('shows loading when user is absent', () => {
     renderWithProviders (<SettingPage user={null} setUser={vi.fn ()}/>)
 
@@ -51,4 +57,28 @@ describe ('SettingPage', () => {
     expect (setUser).toHaveBeenCalled ()
     expect (toastApi.toast).toHaveBeenCalledWith ({ title: '設定を更新しました．' })
   })
+
+  it ('shows validation errors returned for the name field', async () => {
+    const user = buildUser ({ id: 11, name: 'old' })
+    api.isApiError.mockReturnValue (true)
+    api.apiPut.mockRejectedValueOnce ({
+      response: {
+        status: 422,
+        data:   {
+          type:        'validation_error',
+          message:     '入力内容を確認してください．',
+          errors:      { name: ['名前は必須です．'] },
+          base_errors: [],
+        },
+      },
+    })
+
+    renderWithProviders (<SettingPage user={user} setUser={vi.fn ()}/>)
+
+    fireEvent.change (screen.getByRole ('textbox'), { target: { value: '' } })
+    fireEvent.click (screen.getByRole ('button', { name: '更新' }))
+
+    expect (await screen.findByText ('名前は必須です．')).toBeInTheDocument ()
+    expect (screen.getByRole ('textbox')).toHaveAttribute ('aria-invalid', 'true')
+  })
 })

frontend/src/types.ts

@@ -52,6 +52,18 @@ export type FetchTagsParams = {
     limit:        number
     order:        FetchTagsOrder }
 
+export type FetchNicoTagsParams = {
+    name:       string
+    linkedTag:  string
+    linkStatus: 'all' | 'linked' | 'unlinked'
+    page:       number
+    limit:      number
+    order:      FetchNicoTagsOrder }
+
+export type FetchNicoTagsOrder = `${ FetchNicoTagsOrderField }:${ 'asc' | 'desc' }`
+
+export type FetchNicoTagsOrderField = 'name' | 'created_at' | 'updated_at'
+
 export type Material = {
     id:             number
     tag:            Tag
@@ -83,8 +95,9 @@ export type MenuVisibleItem = {
     subMenu:  SubMenuItem[] }
 
 export type NicoTag = Tag & {
-    category:   'nico'
+    category:               'nico'
-    linkedTags: Tag[] }
+    linkedTags:             Tag[]
+    recentPostTagCreatedAt: string | null }
 
 export type NiconicoMetadata = {
     currentTime:            number