AI: address review on PR #458

backend/app/controllers/tags_controller.rb

@@ -218,63 +218,16 @@ class TagsController < ApplicationController
     locale = resolve_locale!
 
     q = params[:q].to_s.strip.sub(/\Anot:/i, '')
-    prefix = "#{ ActiveRecord::Base.sanitize_sql_like(q) }%"
+    literal = ActiveRecord::Base.sanitize_sql_like(q)
+    nico = bool?(:nico, default: true)
+    present = bool?(:present, default: true)
 
-    with_nico = bool?(:nico, default: true)
-    present_only = bool?(:present, default: true)
-
-    alias_rows =
-        TagName
-        .where(language_code: locale.language_code, primary_flg: false)
-        .where('name LIKE ?', prefix)
-        .pluck(:tag_id, :name)
-
-    matched_alias_by_tag_id = { }
-    tag_ids = []
-    alias_rows.each do |tag_id, alias_name|
-      tag_ids << tag_id
-      matched_alias_by_tag_id[tag_id] ||= alias_name
+    rows = autocomplete_rows(locale:, pattern: "#{ literal }%", nico:, present:)
+    if rows.length < 20 && q.present?
+      suffix_rows = autocomplete_rows(locale:, pattern: "%#{ literal }", nico:, present:)
+      rows = (rows + suffix_rows).uniq { [_1['category'], _1['id']] }.first(20)
     end
 
-    base =
-        Tag
-        .joins(:tag_names)
-        .preload(:tag_names, :materials, :deerjikists, :tag_descriptions,
-                 parents: [:tag_names, :materials, :deerjikists, :tag_descriptions])
-        .where(tag_names: { language_code: locale.language_code, primary_flg: true },
-               deprecated_at: nil)
-    base = base.where('tags.post_count > 0') if present_only
-
-    canonical_hit = base.where('tag_names.name LIKE ?', prefix)
-
-    internal_tags = canonical_hit.or(base.where(id: tag_ids.uniq))
-
-    internal_rows =
-        internal_tags
-        .order(Arel.sql('tags.post_count DESC, tag_names.name'))
-        .limit(20)
-        .map { |tag|
-          TagRepr.base(tag, language_code: locale.language_code)
-                 .merge(matched_alias: matched_alias_by_tag_id[tag.id])
-        }
-
-    return render json: internal_rows unless with_nico
-
-    external_base = ExternalTag.all
-    external_base = external_base.where('post_count > 0') if present_only
-
-    external_rows =
-        external_base
-        .where("CONCAT(platform, ':', name) LIKE ? OR name LIKE ?", prefix, prefix)
-        .order(post_count: :desc, name: :asc)
-        .limit(20)
-        .map { external_tag_json(_1) }
-
-    rows =
-    (internal_rows + external_rows)
-        .sort_by { |row| [-row['post_count'], row['name'] || row[:name]] }
-        .first(20)
-
     render json: rows
   end
 
@@ -545,6 +498,59 @@ class TagsController < ApplicationController
 
   private
 
+  def autocomplete_rows locale:, pattern:, nico:, present:
+    alias_rows =
+        TagName
+        .where(language_code: locale.language_code, primary_flg: false)
+        .where('name LIKE ?', pattern)
+        .pluck(:tag_id, :name)
+
+    matched_alias_by_tag_id = { }
+    tag_ids = []
+    alias_rows.each do |tag_id, alias_name|
+      tag_ids << tag_id
+      matched_alias_by_tag_id[tag_id] ||= alias_name
+    end
+
+    base =
+        Tag
+        .joins(:tag_names)
+        .preload(:tag_names, :materials, :deerjikists, :tag_descriptions,
+                 parents: [:tag_names, :materials, :deerjikists, :tag_descriptions])
+        .where(tag_names: { language_code: locale.language_code, primary_flg: true },
+               deprecated_at: nil)
+    base = base.where('tags.post_count > 0') if present
+
+    canonical_hit = base.where('tag_names.name LIKE ?', pattern)
+
+    internal_tags = canonical_hit.or(base.where(id: tag_ids.uniq))
+
+    internal_rows =
+        internal_tags
+        .order(Arel.sql('tags.post_count DESC, tag_names.name'))
+        .limit(20)
+        .map { |tag|
+          TagRepr.base(tag, language_code: locale.language_code)
+                 .merge(matched_alias: matched_alias_by_tag_id[tag.id])
+        }
+
+    return internal_rows unless nico
+
+    external_base = ExternalTag.all
+    external_base = external_base.where('post_count > 0') if present
+
+    external_rows =
+        external_base
+        .where("CONCAT(platform, ':', name) LIKE ? OR name LIKE ?", pattern, pattern)
+        .order(post_count: :desc, name: :asc)
+        .limit(20)
+        .map { external_tag_json(_1) }
+
+    (internal_rows + external_rows)
+        .sort_by { |row| [-row['post_count'], row['name'] || row[:name]] }
+        .first(20)
+  end
+
   def material_filter_param default:
     value = params[:material_filter].to_s.presence
     return default unless ['present', 'missing', 'any'].include?(value)

backend/db/migrate/20261115000000_add_post_count_index_to_tags.rb

@@ -1,5 +0,0 @@
-class AddPostCountIndexToTags < ActiveRecord::Migration[8.0]
-  def change
-    add_index :tags, :post_count
-  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_11_15_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_10_15_010000) 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
@@ -630,7 +630,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_11_15_000000) do
     t.integer "post_count", default: 0, null: false
     t.integer "version_no", null: false
     t.index ["deprecated_at"], name: "index_tags_on_deprecated_at"
-    t.index ["post_count"], name: "index_tags_on_post_count"
     t.check_constraint "(`deprecated_at` is null) or (`category` <> _utf8mb4'nico')", name: "chk_tags_deprecated_at_not_nico"
     t.check_constraint "`version_no` > 0", name: "chk_tags_version_no_positive"
   end

backend/spec/models/tag_spec.rb

@@ -2,19 +2,6 @@ require 'rails_helper'
 
 RSpec.describe Tag, type: :model do
   include WikiRecords
-
-  describe 'post_count index' do
-    it 'has a non-unique index on post_count alone' do
-      indexes = described_class.connection.indexes(described_class.table_name)
-
-      expect(indexes).to include(
-          have_attributes(
-              name: 'index_tags_on_post_count',
-              columns: ['post_count'],
-              unique: false))
-    end
-  end
-
   describe '#has_description?' do
     let(:tag) { create(:tag) }
 

backend/spec/requests/tags_spec.rb

@@ -482,6 +482,7 @@ RSpec.describe 'Tags API', type: :request do
         create(:tag, category: :general, primary_name: name, post_count: 1)
         create(:external_tag, name:, post_count: 1)
       end
+      create(:external_tag, name: 'suffix_combined', post_count: 100)
 
       get '/tags/autocomplete', params: { q: 'combined' }
 
@@ -490,6 +491,39 @@ RSpec.describe 'Tags API', type: :request do
       expect(json.map { |row| row.fetch('name') }).to eq(expected.first(20))
     end
 
+    it 'appends primary, alias, and external suffix matches without duplicate resources' do
+      prefix = create(:tag, primary_name: 'tail', post_count: 1)
+      create(:tag_name, :alias, name: 'tail_alias', tag: prefix)
+      create(:tag_name, :alias, name: 'alias_tail', tag: prefix)
+      create(:tag, primary_name: 'primary_tail', post_count: 4)
+      alias_target = create(:tag, primary_name: 'alias_target', post_count: 3)
+      create(:tag_name, :alias, name: 'suffix_tail', tag: alias_target)
+      external = create(:external_tag, id: prefix.id, name: 'external_tail', post_count: 5)
+      create(:tag, primary_name: 'middle_tail_only', post_count: 100)
+      create(:external_tag, name: 'middle_tail_only', post_count: 100)
+
+      get '/tags/autocomplete', params: { q: 'tail' }
+
+      expect(response).to have_http_status(:ok)
+      expect(json.map { |row| row.fetch('name') }).to eq(
+          ['tail', 'nico:external_tail', 'primary_tail', 'alias_target'])
+      expect(json.first.fetch('matched_alias')).to eq('tail_alias')
+      expect(json.last.fetch('matched_alias')).to eq('suffix_tail')
+      expect(json[1]).to include('id' => external.id, 'category' => 'nico')
+    end
+
+    it 'fills only the remaining places with suffix matches' do
+      names = 19.times.map { |number| "capacity_#{ number.to_s.rjust(2, '0') }" }
+      names.each { create(:tag, primary_name: _1, post_count: 1) }
+      create(:tag, primary_name: 'first_capacity', post_count: 3)
+      create(:external_tag, name: 'second_capacity', post_count: 2)
+
+      get '/tags/autocomplete', params: { q: 'capacity' }
+
+      expect(response).to have_http_status(:ok)
+      expect(json.map { |row| row.fetch('name') }).to eq(names + ['first_capacity'])
+    end
+
     it 'excludes external tags but preserves internal alias matches when nico is false' do
       internal = create(:tag, category: :general, primary_name: 'switch_internal', post_count: 1)
       alias_target = create(:tag, category: :general, primary_name: 'alias_target', post_count: 1)
@@ -518,12 +552,20 @@ RSpec.describe 'Tags API', type: :request do
         create(:external_tag, name: literal, post_count: 1)
         create(:tag, category: :general, primary_name: 'literalXmatch', post_count: 2)
         create(:external_tag, name: 'literalXmatch', post_count: 2)
+        suffix = "suffix_literal#{ wildcard }"
+        create(:tag, primary_name: suffix, post_count: 1)
+        suffix_alias = create(:tag, primary_name: 'suffix_alias_target', post_count: 1)
+        create(:tag_name, :alias, name: "alias_#{ suffix }", tag: suffix_alias)
+        create(:external_tag, name: suffix, post_count: 1)
+        create(:tag, primary_name: 'suffix_literalX', post_count: 2)
+        create(:external_tag, name: 'suffix_literalX', post_count: 2)
 
         get '/tags/autocomplete', params: { q: "literal#{ wildcard }" }
 
         expect(json.map { |row| row.fetch('name') })
             .to contain_exactly(
-                literal, primary_tag_name_for(alias_target, 'ja').name, "nico:#{ literal }")
+                literal, primary_tag_name_for(alias_target, 'ja').name, "nico:#{ literal }",
+                suffix, 'suffix_alias_target', "nico:#{ suffix }")
       end
     end
 

frontend/src/components/layout/SidebarComponent.test.tsx

@@ -70,16 +70,6 @@ describe ('SidebarComponent', () => {
     vi.spyOn (HTMLElement.prototype, 'hasPointerCapture').mockReturnValue (true)
   })
 
-  it ('limits sidebar scrolling to desktop to avoid clipping mobile suggestions', () => {
-    renderSidebar ()
-
-    // jsdom has no layout; guard the responsive classes responsible for clipping.
-    const sidebar = screen.getByText ('Sidebar body')
-
-    expect (sidebar).not.toHaveClass ('overflow-y-auto')
-    expect (sidebar).toHaveClass ('md:overflow-y-auto')
-  })
-
   it ('uses maxWidth without applying the container main-width reserve twice', async () => {
     localStorage.setItem ('sidebar:test-sidebar:left:width', '700')
     const onWidthChange = vi.fn ()

frontend/src/components/layout/SidebarComponent.tsx

@@ -339,7 +339,7 @@ const SidebarComponent: FC<Props> = ({
 	  </style>
 	</Helmet>
 
-	<div className="h-full md:overflow-y-auto p-4 sidebar">
+	<div className="h-full overflow-y-auto p-4 sidebar">
 	  {children}
 	</div>
 

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

@@ -35,10 +35,6 @@ const renderPage = () =>
 describe ('TagDetailPage', () => {
   beforeEach (() => {
     vi.clearAllMocks ()
-    tagsApi.fetchTag.mockReset ()
-    api.apiPut.mockReset ()
-    api.isApiError.mockReset ()
-    toastApi.toast.mockReset ()
     api.isApiError.mockReturnValue (false)
   })
 
@@ -55,11 +51,8 @@ describe ('TagDetailPage', () => {
   })
 
   it ('submits edited tag fields', async () => {
-    const updatedTag = buildTag ({ id: 7, name: 'new', aliases: ['alias'] })
-    tagsApi.fetchTag
-	.mockResolvedValue (updatedTag)
-	.mockResolvedValueOnce (buildTag ({ id: 7, name: 'old' }))
-    api.apiPut.mockResolvedValueOnce (updatedTag)
+    tagsApi.fetchTag.mockResolvedValueOnce (buildTag ({ id: 7, name: 'old' }))
+    api.apiPut.mockResolvedValueOnce (buildTag ({ id: 7, name: 'new', aliases: ['alias'] }))
 
     renderPage ()