多言語化の基盤作り (#55) (#421)

Reviewed-on: #421
Co-authored-by: miteruzo <miteruzo@naver.com>

backend/spec/models/language_spec.rb

@@ -0,0 +1,32 @@
+require 'rails_helper'
+
+RSpec.describe Language, type: :model do
+  it 'accepts Nipponese as the current supported language' do
+    expect(described_class.find('ja')).to be_valid
+    expect(described_class.where(deprecated_at: nil).pluck(:code)).to eq(['ja'])
+  end
+
+  it 'accepts English when multilingual support is enabled' do
+    pending '日本語以外の Language 有効化は別課題で実装する'
+    expect { described_class.create!(code: 'en', name: 'English') }
+        .to change(described_class, :count).by(1)
+  end
+
+  it 'rejects an unsupported language code' do
+    expect {
+      described_class.create!(code: 'xx', name: 'Unsupported')
+    }.to raise_error { |error|
+      expect(error).to be_a(ArgumentError).or be_a(ActiveRecord::RecordInvalid)
+    }
+  end
+
+  ['en', 'fr'].each do |code|
+    it "does not register #{ code } as a currently supported language" do
+      expect {
+        described_class.create!(code:, name: 'Unsupported')
+      }.to raise_error { |error|
+        expect(error).to be_a(ArgumentError).or be_a(ActiveRecord::RecordInvalid)
+      }
+    end
+  end
+end

backend/spec/models/locale_spec.rb

@@ -0,0 +1,129 @@
+require 'rails_helper'
+
+RSpec.describe Locale, type: :model do
+  include_context 'English locale'
+
+  def create_english_locale!
+    prepare_english_reference!
+    described_class.create!(code: 'en', language_code: 'en',
+                            script_code: 'Latn', region_code: 826,
+                            variants: '', name: 'English')
+  end
+
+  it 'keeps the active Nipponese locale consistent with its identity tuple' do
+    expect(described_class.where(deprecated_at: nil).pluck(:code)).to eq(['ja'])
+    expect(described_class.nipponese).to have_attributes(
+        code: 'ja', language_code: 'ja', script_code: 'Jpan',
+        region_code: 392, variants: '')
+  end
+
+  it 'rejects a duplicate locale identity tuple at the database boundary' do
+    expect {
+      described_class.insert_all!([{ code: 'ja-duplicate', language_code: 'ja',
+                                    script_code: 'Jpan', region_code: 392,
+                                    variants: '', name: '日本語',
+                                    created_at: Time.current }])
+    }.to raise_error(ActiveRecord::RecordNotUnique)
+  end
+
+  it 'generates a primary name for every existing tag using the name generator' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    first = create(:tag, primary_name: 'first_existing_tag')
+    second = create(:tag, primary_name: 'second_existing_tag')
+    allow(TagName).to receive(:generate_name).and_call_original
+    allow(TagName).to receive(:generate_name)
+        .with(kind_of(described_class), first, primary_tag_name_for(first, 'ja'))
+        .and_return('name_from_generator')
+
+    locale = create_english_locale!
+
+    expect(TagName).to have_received(:generate_name)
+        .with(locale, first, primary_tag_name_for(first, 'ja'))
+    expect(TagName).to have_received(:generate_name)
+        .with(locale, second, primary_tag_name_for(second, 'ja'))
+    expect(first.tag_names.find_by!(language_code: 'en', primary_flg: true))
+        .to have_attributes(name: 'name_from_generator', tag_id: first.id,
+                            language_code: 'en', script_code: 'Latn',
+                            primary_flg: true, auto_generated: true)
+    expect(second.tag_names.find_by!(language_code: 'en', primary_flg: true))
+        .to have_attributes(tag_id: second.id, language_code: 'en',
+                            script_code: 'Latn', primary_flg: true,
+                            auto_generated: true)
+    expect(TagName.where(language_code: 'en', primary_flg: true,
+                         tag_id: [first.id, second.id]).count).to eq(2)
+  end
+
+  it 'does not duplicate an existing primary name in the new language' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    prepare_english_reference!
+    tag = create(:tag, primary_name: 'already_named')
+    existing = create(:tag_name, name: 'existing_english', tag:,
+                                 language_code: 'en', script_code: 'Latn')
+
+    create_english_locale!
+
+    expect(TagName.where(tag_id: tag.id, language_code: 'en', primary_flg: true))
+        .to contain_exactly(existing)
+    expect(existing.reload).to have_attributes(
+        tag_id: tag.id, language_code: 'en', script_code: 'Latn',
+        primary_flg: true, auto_generated: false)
+  end
+
+  it 'creates a primary name when the language has only an alias' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    prepare_english_reference!
+    tag = create(:tag, primary_name: 'alias_only_tag')
+    alias_name = create(:tag_name, :alias, name: 'alias_en',
+                                          tag:,
+                                          language_code: 'en', script_code: 'Latn')
+
+    create_english_locale!
+
+    expect(alias_name.reload).to have_attributes(
+        tag_id: tag.id,
+        language_code: 'en', script_code: 'Latn', primary_flg: false)
+    generated = TagName.find_by!(tag_id: tag.id, language_code: 'en', primary_flg: true)
+    expect(generated).to have_attributes(tag_id: tag.id, language_code: 'en',
+                                         script_code: 'Latn', primary_flg: true,
+                                         auto_generated: true)
+    expect(TagName.where(tag_id: tag.id, language_code: 'en', primary_flg: true).count).to eq(1)
+  end
+
+  it 'rolls back the locale and all generated names when backfill fails' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    prepare_english_reference!
+    first = create(:tag, primary_name: 'atomic_first')
+    second = create(:tag, primary_name: 'atomic_second')
+    allow(TagName).to receive(:generate_name).and_call_original
+    allow(TagName).to receive(:generate_name)
+        .with(kind_of(described_class), second, primary_tag_name_for(second, 'ja'))
+        .and_raise('backfill failed')
+
+    expect { create_english_locale! }.to raise_error('backfill failed')
+
+    expect(described_class.exists?(code: 'en')).to be(false)
+    expect(TagName.where(language_code: 'en', tag_id: [first.id, second.id])).to be_empty
+  end
+
+  it 'accepts a stable locale code outside the historical enum values' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    prepare_english_reference!
+
+    locale = described_class.create!(
+        code: 'en-x-rspec', language_code: 'en',
+        script_code: 'Latn', region_code: 826,
+        variants: 'x-rspec', name: 'English')
+
+    expect(locale.reload).to have_attributes(
+        code: 'en-x-rspec', language_code: 'en', script_code: 'Latn',
+        region_code: 826, variants: 'x-rspec')
+  end
+
+  it 'registers the future British English locale tuple' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+
+    expect(locale).to have_attributes(code: 'en', language_code: 'en',
+                                    script_code: 'Latn', region_code: 826,
+                                    variants: '')
+  end
+end

backend/spec/models/material_export_item_spec.rb

@@ -2,7 +2,7 @@ require 'rails_helper'
 
 RSpec.describe MaterialExportItem, type: :model do
   let(:user) { create(:user, :member) }
-  let(:tag) { Tag.create!(tag_name: TagName.create!(name: 'export_item'), category: :material) }
+  let(:tag) { create(:tag, primary_name: 'export_item', category: :material) }
   let(:material) do
     Material.create!(tag:, url: 'https://example.com/material',
                      created_by_user: user, updated_by_user: user)

backend/spec/models/post_spec.rb

@@ -18,7 +18,7 @@ RSpec.describe Post, type: :model do
       expect(post.snapshot_tags_json).to eq([
           { 'tag_id' => tag.id,
             'version_no' => tag.version_no,
-            'name' => tag.name,
+            'name' => primary_tag_name_for(tag, 'ja').name,
             'category' => tag.category,
             'sections' => [{ 'begin_ms' => 2000, 'end_ms' => nil }] },
           { 'external_tag_id' => external.id }])

backend/spec/models/post_version_spec.rb

@@ -1,8 +1,8 @@
 require 'rails_helper'
 
 RSpec.describe PostVersion, type: :model do
-  let!(:tag_name) { TagName.create!(name: 'post_version_spec_tag') }
-  let!(:tag) { Tag.create!(tag_name: tag_name, category: :general) }
+  let!(:tag_name) { create(:tag_name, name: 'post_version_spec_tag') }
+  let!(:tag) { create(:tag, primary_tag_name: tag_name, category: :general) }
 
   let!(:post_record) do
     Post.create!(title: 'spec post', url: 'https://example.com/post-version-spec').tap do |post|

backend/spec/models/script_spec.rb

@@ -0,0 +1,35 @@
+require 'rails_helper'
+
+RSpec.describe Script, type: :model do
+  include_context 'English locale'
+
+  it 'selects locales by script code, not language code' do
+    expect(described_class.find('Jpan').locales).to contain_exactly(Locale.nipponese)
+  end
+
+  it 'accepts supported script codes and rejects unsupported ones' do
+    expect(described_class.find('Jpan')).to be_valid
+    expect(described_class.where(deprecated_at: nil).pluck(:code)).to eq(['Jpan'])
+    expect {
+      described_class.create!(code: 'Zzzz', name: 'Unsupported')
+    }.to raise_error { |error|
+      expect(error).to be_a(ArgumentError).or be_a(ActiveRecord::RecordInvalid)
+    }
+  end
+
+  it 'does not register Latin as a currently supported script' do
+    expect {
+      described_class.create!(code: 'Latn', name: 'Latin')
+    }.to raise_error { |error|
+      expect(error).to be_a(ArgumentError).or be_a(ActiveRecord::RecordInvalid)
+    }
+  end
+
+  it 'selects Latin locales when multilingual support is enabled' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    locale
+
+    expect(described_class.find('Latn').locales).to contain_exactly(locale)
+    expect(described_class.find('Jpan').locales).not_to include(locale)
+  end
+end

backend/spec/models/tag_implication_spec.rb

@@ -2,8 +2,8 @@ require 'rails_helper'
 
 RSpec.describe TagImplication, type: :model do
   it 'rejects a parent tag that would create a cycle' do
-    child = create(:tag, name: 'tag_implication_cycle_child')
-    parent = create(:tag, name: 'tag_implication_cycle_parent')
+    child = create(:tag, primary_name: 'tag_implication_cycle_child')
+    parent = create(:tag, primary_name: 'tag_implication_cycle_parent')
 
     described_class.create!(tag: child, parent_tag: parent)
 
@@ -17,9 +17,9 @@ RSpec.describe TagImplication, type: :model do
   end
 
   it 'terminates even when existing data already contains a cycle' do
-    child = create(:tag, name: 'tag_implication_existing_cycle_child')
-    parent = create(:tag, name: 'tag_implication_existing_cycle_parent')
-    ancestor = create(:tag, name: 'tag_implication_existing_cycle_ancestor')
+    child = create(:tag, primary_name: 'tag_implication_existing_cycle_child')
+    parent = create(:tag, primary_name: 'tag_implication_existing_cycle_parent')
+    ancestor = create(:tag, primary_name: 'tag_implication_existing_cycle_ancestor')
 
     described_class.create!(tag: parent, parent_tag: ancestor)
     described_class.insert_all!(

backend/spec/models/tag_name_sanitisation_rule_spec.rb

@@ -31,12 +31,48 @@ RSpec.describe TagNameSanitisationRule, type: :model do
 
   describe '.apply!' do
     before do
-      described_class.create!(priority: 10, source_pattern: '_', replacement: '')
+      described_class.create!(priority: 10, source_pattern: 'foo_', replacement: 'foo')
+    end
+
+    context 'when only another language has the sanitised name' do
+      include_context 'English locale'
+
+      it 'keeps both names when sanitisation produces a cross-language match' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        nipponese = create(:tag_name, name: 'foobar')
+        english = create(:tag_name, name: 'temporary',
+                                   language_code: 'en', script_code: 'Latn')
+        english.update_columns(name: 'foo_bar')
+
+        expect { described_class.apply! }.not_to change(TagName, :count)
+
+        expect(english.reload).to have_attributes(name: 'foobar', language_code: 'en')
+        expect(nipponese.reload).to have_attributes(name: 'foobar', language_code: 'ja')
+      end
+
+      it 'renames without merging tags or deleting either language identity' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        nipponese = create(:tag, primary_name: 'foobar')
+        english_name = create(:tag_name, name: 'temporary',
+                                        language_code: 'en', script_code: 'Latn')
+        english = create(:tag, primary_tag_name: english_name)
+        english_name.update_columns(name: 'foo_bar')
+
+        described_class.apply!
+
+        expect(english_name.reload).to have_attributes(
+            name: 'foobar', language_code: 'en', tag_id: english.id)
+        expect(primary_tag_name_for(nipponese.reload, 'ja')).to have_attributes(
+            name: 'foobar', language_code: 'ja', tag_id: nipponese.id)
+        expect(primary_tag_name_for(english.reload, 'en')).to eq(english_name)
+      end
     end
 
     context 'when no conflicting tag_name exists' do
       let!(:tag_name) do
-        TagName.create!(name: 'tmp').tap do |tn|
+        create(:tag_name, name: 'tmp').tap do |tn|
           tn.update_columns(name: 'foo_bar', updated_at: Time.current)
         end
       end
@@ -47,10 +83,10 @@ RSpec.describe TagNameSanitisationRule, type: :model do
       end
     end
 
-    context 'when a conflicting canonical tag_name exists' do
-      let!(:existing) { TagName.create!(name: 'foobar') }
+    context 'when a conflicting primary tag name exists' do
+      let!(:existing) { create(:tag_name, name: 'foobar') }
       let!(:source) do
-        TagName.create!(name: 'tmp').tap do |tn|
+        create(:tag_name, name: 'tmp').tap do |tn|
           tn.update_columns(name: 'foo_bar', updated_at: Time.current)
         end
       end
@@ -63,48 +99,56 @@ RSpec.describe TagNameSanitisationRule, type: :model do
     end
 
     context 'when the source tag_name has a tag and the existing one has no tag' do
-      let!(:existing) { TagName.create!(name: 'foobar') }
-      let!(:source_tag) { create(:tag, name: 'tmp', category: :general) }
-      let!(:source_tag_name_id) { source_tag.tag_name_id }
+      let!(:existing) { create(:tag_name, name: 'foobar') }
+      let!(:source_tag) { create(:tag, primary_name: 'tmp', category: :general) }
+      let!(:source_tag_name_id) { primary_tag_name_for(source_tag, 'ja').id }
 
       before do
-        source_tag.tag_name.update_columns(name: 'foo_bar', updated_at: Time.current)
+        primary_tag_name_for(source_tag, 'ja').update_columns(
+            name: 'foo_bar', updated_at: Time.current)
       end
 
       it 'moves the tag to the existing tag_name' do
         described_class.apply!
-        expected_tag_name_id = existing.canonical_id || existing.id
-        expect(source_tag.reload.tag_name_id).to eq(expected_tag_name_id)
+        expect(existing.reload).to have_attributes(
+            tag_id: source_tag.id, language_code: 'ja', primary_flg: true)
+        expect(primary_tag_name_for(source_tag, 'ja')).to eq(existing)
+        expect(primary_tag_name_for(source_tag.reload, 'ja')).to eq(existing)
         expect(TagName.unscoped.exists?(source_tag_name_id)).to be(false)
       end
     end
 
     context 'when the sanitised name is an alias of an existing tag' do
       let!(:existing_tag) { create(:tag) }
+      let!(:existing_primary) { primary_tag_name_for(existing_tag, 'ja') }
       let!(:alias_name) do
-        TagName.create!(name: 'foobar', canonical: existing_tag.tag_name)
+        create(:tag_name, :alias, name: 'foobar', tag: existing_tag)
       end
       let!(:source) do
-        TagName.create!(name: 'tmp').tap do |tn|
+        create(:tag_name, name: 'tmp').tap do |tn|
           tn.update_columns(name: 'foo_bar', updated_at: Time.current)
         end
       end
 
-      it 'deletes only the source and preserves the alias and its canonical tag' do
+      it 'deletes only the source and preserves the alias and its owning tag' do
         described_class.apply!
 
         expect(TagName.unscoped.exists?(source.id)).to be(false)
-        expect(alias_name.reload.canonical).to eq(existing_tag.tag_name)
+        expect(alias_name.reload).to have_attributes(
+            tag_id: existing_tag.id, language_code: 'ja', primary_flg: false)
+        expect(TagName.find_by!(tag_id: existing_tag.id,
+                                language_code: 'ja', primary_flg: true))
+            .to eq(existing_primary)
         expect(Tag.find(existing_tag.id)).to eq(existing_tag)
       end
     end
 
     context 'when both source and existing tag_names have tags' do
-      let!(:existing_tn) { TagName.create!(name: 'foobar') }
-      let!(:existing_tag) { Tag.create!(tag_name: existing_tn, category: :general) }
+      let!(:existing_tn) { create(:tag_name, name: 'foobar') }
+      let!(:existing_tag) { create(:tag, primary_tag_name: existing_tn, category: :general) }
 
-      let!(:source_tn) { TagName.create!(name: 'tmp') }
-      let!(:source_tag) { Tag.create!(tag_name: source_tn, category: :general) }
+      let!(:source_tn) { create(:tag_name, name: 'tmp') }
+      let!(:source_tag) { create(:tag, primary_tag_name: source_tn, category: :general) }
       let!(:source_tag_name_id) { source_tn.id }
 
       before do
@@ -120,7 +164,7 @@ RSpec.describe TagNameSanitisationRule, type: :model do
         expect(Tag.unscoped.exists?(source_tag.id)).to be(false)
         expect(TagName.unscoped.exists?(source_tag_name_id)).to be(false)
         expect(post.reload.tags).to contain_exactly(existing_tag)
-        expect(existing_tag.reload.name).to eq('foobar')
+        expect(primary_tag_name_for(existing_tag.reload, 'ja').name).to eq('foobar')
       end
     end
   end

backend/spec/models/tag_name_spec.rb

@@ -0,0 +1,171 @@
+require 'rails_helper'
+
+RSpec.describe TagName, type: :model do
+  include_context 'English locale'
+
+  it 'allows the same name in different languages' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    locale
+    create(:tag_name, name: 'shared_name')
+    english = build(:tag_name, name: 'shared_name',
+                              language_code: 'en', script_code: 'Latn')
+
+    expect(english).to be_valid
+    expect { english.save! }.to change(described_class, :count).by(1)
+  end
+
+  it 'rejects a duplicate name within the same language' do
+    create(:tag_name, name: 'shared_name')
+    duplicate = build(:tag_name, name: 'shared_name')
+
+    expect(duplicate).to be_invalid
+    expect(duplicate.errors.of_kind?(:name, :taken)).to be(true)
+  end
+
+  it 'creates Nipponese factory names without requiring a tag' do
+    name = create(:tag_name)
+
+    expect(name.reload).to have_attributes(
+        language_code: 'ja', script_code: 'Jpan', primary_flg: true,
+        auto_generated: false, tag_id: nil)
+  end
+
+  it 'defaults ordinary persisted human names to confirmed provenance' do
+    name = described_class.create!(name: 'ordinary_human_name', language_code: 'ja',
+                                   script_code: 'Jpan', primary_flg: true)
+
+    expect(name.reload.auto_generated).to be(false)
+  end
+
+  it 'persists both sides of the representative tag factory association' do
+    name = create(:tag_name)
+    tag = create(:tag, primary_tag_name: name)
+
+    expect(name.reload).to have_attributes(
+        tag_id: tag.id, language_code: 'ja', script_code: 'Jpan', primary_flg: true)
+    expect(name.tag).to eq(tag)
+    expect(described_class.find_by!(tag_id: tag.id, language_code: 'ja', primary_flg: true))
+        .to eq(name)
+    expect(tag.reload.tag_name_id).to eq(name.id)
+  end
+
+  it 'creates a complete ordinary tag factory under the active Nipponese language' do
+    tag = create(:tag, primary_name: 'factory_multilingual')
+
+    Locale.where(deprecated_at: nil).distinct.pluck(:language_code).each do |language_code|
+      expect(TagName.where(tag:, language_code:, primary_flg: true).count).to eq(1)
+    end
+    expect(TagName.where(tag:, language_code: 'ja', primary_flg: true))
+        .to contain_exactly(have_attributes(auto_generated: false))
+  end
+
+  it 'completes an ordinary tag factory under future active languages' do
+    pending '日本語以外の Locale 有効化は別課題で実装する'
+    locale
+    tag = create(:tag, primary_name: 'future_factory')
+
+    expect(TagName.where(tag:, language_code: 'en', primary_flg: true))
+        .to contain_exactly(have_attributes(auto_generated: true))
+  end
+
+  it 'builds a primary name without persisting the tag or its name' do
+    tag = nil
+
+    expect {
+      tag = build(:tag, primary_name: 'built_primary')
+    }.to change(Tag, :count).by(0).and change(described_class, :count).by(0)
+
+    expect(tag).to be_new_record
+    expect(tag.tag_names.target).to contain_exactly(have_attributes(
+        name: 'built_primary', language_code: 'ja', script_code: 'Jpan',
+        primary_flg: true))
+  end
+
+  it 'persists an alias owned by the same tag as its primary name' do
+    primary_name = create(:tag_name)
+    tag = create(:tag, primary_tag_name: primary_name)
+    alias_name = create(:tag_name, :alias, name: 'valid_alias', tag:)
+
+    expect(alias_name.reload).to have_attributes(
+        tag_id: tag.id,
+        primary_flg: false, language_code: 'ja')
+    primary = described_class.find_by!(tag_id: alias_name.tag_id,
+                                       language_code: alias_name.language_code,
+                                       primary_flg: true)
+    expect(primary).to eq(primary_name)
+  end
+
+  describe '.canonicalise' do
+    it 'leaves detached aliases unchanged' do
+      create(:tag_name, :alias, name: 'detached_alias')
+
+      expect(described_class.canonicalise(Locale.nipponese, ['detached_alias']))
+          .to eq(['detached_alias'])
+    end
+
+    it 'does not resolve a detached alias through another detached primary' do
+      create(:tag_name, :alias, name: 'detached_alias')
+      create(:tag_name, name: 'unrelated_detached_primary')
+
+      expect(described_class.canonicalise(Locale.nipponese, ['detached_alias']))
+          .to eq(['detached_alias'])
+    end
+
+    it 'resolves the primary name of the alias language on the same tag' do
+      pending '日本語以外の Locale 有効化は別課題で実装する'
+      locale
+      tag = create(:tag, primary_name: '日本語正本')
+      english_primary = primary_tag_name_for(tag, 'en')
+      english_primary.update!(name: 'english_primary', auto_generated: false)
+      english_alias = create(:tag_name, :alias, tag:, name: 'english_alias',
+                                                 language_code: 'en', script_code: 'Latn')
+      representative_id = tag.tag_name_id
+
+      primary = described_class.find_by!(tag_id: english_alias.tag_id,
+                                         language_code: english_alias.language_code,
+                                         primary_flg: true)
+
+      expect(primary).to eq(english_primary)
+      expect(described_class.canonicalise(locale, [english_alias.name]))
+          .to eq([english_primary.name])
+      expect(tag.reload.tag_name_id).to eq(representative_id)
+    end
+
+    it 'resolves only aliases in the requested language' do
+      pending '日本語以外の Locale 有効化は別課題で実装する'
+      locale
+      nipponese = create(:tag, primary_name: 'nipponese_canonical')
+      english_name = create(:tag_name, name: 'english_canonical',
+                                      language_code: 'en', script_code: 'Latn')
+      english = create(:tag, primary_tag_name: english_name)
+      nipponese_alias = create(:tag_name, :alias, name: 'shared_alias',
+                                                  tag: nipponese)
+      english_alias = create(:tag_name, :alias, name: 'shared_alias',
+                                                tag: english,
+                                                language_code: 'en', script_code: 'Latn')
+
+      expect(nipponese_alias.reload).to have_attributes(
+          tag_id: nipponese.id,
+          primary_flg: false, language_code: 'ja')
+      expect(english_alias.reload).to have_attributes(
+          tag_id: english.id,
+          primary_flg: false, language_code: 'en')
+      expect(described_class.canonicalise(locale, ['shared_alias']))
+          .to eq(['english_canonical'])
+      expect(described_class.canonicalise(Locale.nipponese, ['shared_alias']))
+          .to eq(['nipponese_canonical'])
+    end
+  end
+
+  it 'rejects the generated-name prefix in human input' do
+    human_name = build(:tag_name, name: 'Tag_#999', auto_generated: false)
+
+    expect(human_name).to be_invalid
+  end
+
+  it 'allows the generated-name prefix for system-created names' do
+    generated_name = build(:tag_name, name: 'Tag_#1000', auto_generated: true)
+
+    expect { generated_name.save! }.to change(described_class, :count).by(1)
+  end
+end

backend/spec/models/tag_spec.rb

@@ -4,12 +4,12 @@ RSpec.describe Tag, type: :model do
   describe 'external tag separation' do
     ['nico:reserved', 'NiCo:reserved'].each do |name|
       it "rejects the reserved prefix #{ name } for internal tags" do
-        tag = build(:tag, name:)
+        tag = build(:tag, primary_name: name)
 
         expect(tag).to be_invalid
         expect(tag.errors[:name]).to be_present
         expect {
-          described_class.normalise_tags!([name])
+          described_class.normalise_tags!(Locale.nipponese, [name])
         }.to raise_error(Tag::NicoTagNormalisationError)
       end
     end
@@ -25,128 +25,161 @@ RSpec.describe Tag, type: :model do
   end
 
   describe '.normalise_tags!' do
+    include_context 'English locale'
+
+    it 'canonicalises aliases in the supplied language only' do
+      pending '日本語以外の Locale 有効化は別課題で実装する'
+      prepare_english_reference!
+      nipponese = create(:tag, primary_name: 'nipponese_canonical')
+      english_name = create(:tag_name, name: 'english_canonical',
+                                      language_code: 'en', script_code: 'Latn')
+      english = create(:tag, primary_tag_name: english_name)
+      primary_tag_name_for(english, 'ja').update!(
+          name: 'english_in_nipponese', auto_generated: false)
+      english_locale = locale
+      nipponese_alias = create(:tag_name, :alias, name: 'shared_alias',
+                                                  tag: nipponese)
+      english_alias = create(:tag_name, :alias, name: 'shared_alias',
+                                                tag: english,
+                                                language_code: 'en', script_code: 'Latn')
+
+      expect(nipponese_alias.reload).to have_attributes(
+          tag_id: nipponese.id,
+          primary_flg: false, language_code: 'ja')
+      expect(english_alias.reload).to have_attributes(
+          tag_id: english.id,
+          primary_flg: false, language_code: 'en')
+      expect(described_class.normalise_tags!(
+          english_locale, ['shared_alias'],
+          with_tagme: false, with_no_deerjikist: false)).to eq([english])
+      expect(described_class.normalise_tags!(
+          Locale.nipponese, ['shared_alias'],
+          with_tagme: false, with_no_deerjikist: false)).to eq([nipponese])
+    end
+
     it 'rejects deprecated tags when deny_deprecated is enabled' do
-      tag_name = TagName.create!(name: 'normalise deprecated tag')
-      deprecated_tag = Tag.create!(
-        tag_name:,
-        category: :general,
-        deprecated_at: 1.day.from_now
-      )
+      tag_name = create(:tag_name, name: 'normalise deprecated tag')
+      deprecated_tag = create(:tag,
+          primary_tag_name: tag_name,
+          category: :general,
+          deprecated_at: 1.day.from_now)
 
       expect {
-        described_class.normalise_tags!(
-          [deprecated_tag.name],
-          deny_deprecated: true
-        )
+        described_class.normalise_tags!(Locale.nipponese,
+            [primary_tag_name_for(deprecated_tag, 'ja').name],
+            deny_deprecated: true)
       }.to raise_error(Tag::DeprecatedTagNormalisationError) { |error|
-        expect(error.tag_names).to eq([deprecated_tag.name])
+        expect(error.tag_names).to eq([primary_tag_name_for(deprecated_tag, 'ja').name])
       }
     end
 
     it 'rejects invalid section literals instead of treating them as zero' do
       expect {
-        described_class.normalise_tags!(
-          ['normalise_invalid_section[1:aa-2:00]'],
-          with_sections: true
-        )
+        described_class.normalise_tags!(Locale.nipponese,
+            ['normalise_invalid_section[1:aa-2:00]'],
+            with_sections: true)
       }.to raise_error(Tag::SectionLiteralParseError)
     end
 
     it 'parses open-ended section literals' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[1:00-]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[1:00-]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections).fetch(tag.id)).to eq([[60_000, nil]])
     end
 
     it 'parses omitted begin as zero' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[-1:00]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[-1:00]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections).fetch(tag.id)).to eq([[0, 60_000]])
     end
 
     it 'treats fully open section literals as plain tags' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[-]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[-]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections)[tag.id]).to be_nil
     end
 
     it 'treats [0:00-] as a plain tag' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[0:00-]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[0:00-]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections)[tag.id]).to be_nil
     end
 
     it 'expands zero-width sections to one millisecond' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[1:00-1:00]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[1:00-1:00]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections).fetch(tag.id)).to eq([[60_000, 60_001]])
     end
 
     it 'swaps reversed section boundaries' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[2:00-1:00]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[2:00-1:00]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections).fetch(tag.id)).to eq([[60_000, 120_000]])
     end
 
     it 'merges open-ended sections over later bounded sections' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[1:00-][2:00-3:00]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[1:00-][2:00-3:00]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections).fetch(tag.id)).to eq([[60_000, nil]])
     end
 
     it 'merges adjacent bounded and open-ended sections' do
-      result = described_class.normalise_tags!(
-        ['伊地知ニジカ[1:00-3:00][3:00-]'],
-        with_sections: true
-      )
+      result = described_class.normalise_tags!(Locale.nipponese,
+          ['伊地知ニジカ[1:00-3:00][3:00-]'],
+          with_sections: true)
 
-      tag = result.fetch(:tags).find { _1.name == '伊地知ニジカ' }
+      tag = result.fetch(:tags).find do |candidate|
+        primary_tag_name_for(candidate, 'ja').name == '伊地知ニジカ'
+      end
       expect(result.fetch(:sections).fetch(tag.id)).to eq([[60_000, nil]])
     end
   end
 
   describe '.expand_parent_tags' do
     it 'expands through multiple deprecated parents to an active ancestor' do
-      child = create(:tag, name: 'expand_child')
-      deprecated_parent = create(
-        :tag,
-        name: 'expand_deprecated_parent',
-        deprecated_at: Time.current
-      )
-      deprecated_grandparent = create(
-        :tag,
-        name: 'expand_deprecated_grandparent',
-        deprecated_at: Time.current
-      )
-      active_ancestor = create(:tag, name: 'expand_active_ancestor')
+      child = create(:tag, primary_name: 'expand_child')
+      deprecated_parent = create(:tag,
+          primary_name: 'expand_deprecated_parent',
+          deprecated_at: Time.current)
+      deprecated_grandparent = create(:tag,
+          primary_name: 'expand_deprecated_grandparent',
+          deprecated_at: Time.current)
+      active_ancestor = create(:tag, primary_name: 'expand_active_ancestor')
       TagImplication.create!(tag: child, parent_tag: deprecated_parent)
       TagImplication.create!(tag: deprecated_parent, parent_tag: deprecated_grandparent)
       TagImplication.create!(tag: deprecated_grandparent, parent_tag: active_ancestor)
@@ -163,8 +196,8 @@ RSpec.describe Tag, type: :model do
     end
 
     it 'terminates when implications contain a cycle' do
-      first = create(:tag, name: 'expand_cycle_first')
-      second = create(:tag, name: 'expand_cycle_second')
+      first = create(:tag, primary_name: 'expand_cycle_first')
+      second = create(:tag, primary_name: 'expand_cycle_second')
       TagImplication.create!(tag: first, parent_tag: second)
       now = Time.current
       TagImplication.insert_all!(
@@ -183,55 +216,268 @@ RSpec.describe Tag, type: :model do
   end
 
   describe '.find_or_create_by_tag_name!' do
+    context 'with an explicit locale' do
+      include_context 'English locale'
+
+      it 'creates the representative name with locale attributes and ownership' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        tag = described_class.find_or_create_by_tag_name!(
+            locale, 'english_name', category: :character)
+
+        expect(primary_tag_name_for(tag, 'en')).to have_attributes(
+            language_code: 'en', script_code: 'Latn',
+            primary_flg: true, tag_id: tag.id)
+        expect(tag.category).to eq('character')
+      end
+
+      it 'uses the English primary as the source for a generated Nipponese name' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        allow(TagName).to receive(:generate_name).and_return('generated_nipponese')
+
+        tag = described_class.find_or_create_by_tag_name!(
+            locale, 'english_origin', category: :general)
+
+        expect(TagName.where(tag:, language_code: 'en', primary_flg: true))
+            .to contain_exactly(have_attributes(
+                name: 'english_origin', auto_generated: false))
+        expect(TagName.where(tag:, language_code: 'ja', primary_flg: true))
+            .to contain_exactly(have_attributes(
+                name: 'generated_nipponese', auto_generated: true))
+        source_tag_name = TagName.find_by!(tag:, language_code: 'en', primary_flg: true)
+        expect(TagName).to have_received(:generate_name)
+            .with(Locale.nipponese, tag, source_tag_name)
+      end
+
+      it 'gives a new tag one primary name for every active language' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        tag = described_class.find_or_create_by_tag_name!(
+            Locale.nipponese, 'new_multilingual_tag', category: :general)
+
+        expect(TagName.where(tag:, language_code: 'ja', primary_flg: true).count).to eq(1)
+        expect(TagName.where(tag:, language_code: 'en', primary_flg: true).count).to eq(1)
+      end
+
+      it 'creates one primary per language when multiple locales use English' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        described_class.find_or_create_by_tag_name!(
+            locale, 'before_second_english_locale', category: :general)
+        Locale.create!(code: 'en-x-rspec', language_code: 'en',
+                       script_code: 'Latn', region_code: 826,
+                       variants: 'x-rspec', name: 'English')
+
+        tag = described_class.find_or_create_by_tag_name!(
+            locale, 'one_english_primary', category: :general)
+
+        expect(TagName.where(tag:, language_code: 'en', primary_flg: true).count).to eq(1)
+        expect(TagName.where(tag:, language_code: 'ja', primary_flg: true).count).to eq(1)
+      end
+
+      it 'rolls back a new tag and requested name if name generation fails' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        original_tag_count = described_class.count
+        allow(TagName).to receive(:generate_name).and_raise('generation failed')
+
+        expect {
+          described_class.find_or_create_by_tag_name!(
+              locale, 'atomic_english_name', category: :general)
+        }.to raise_error('generation failed')
+
+        expect(described_class.count).to eq(original_tag_count)
+        expect(TagName.where(language_code: 'en', name: 'atomic_english_name')).to be_empty
+        expect(described_class.joins(:tag_names)
+            .where(tag_names: { name: 'atomic_english_name' })).to be_empty
+      end
+
+      it 'keeps a detached requested name detached if generation fails' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        detached = create(:tag_name, :alias, name: 'atomic_detached',
+                                           language_code: 'en', script_code: 'Latn')
+        original_tag_count = described_class.count
+        allow(TagName).to receive(:generate_name).and_raise('generation failed')
+
+        expect {
+          described_class.find_or_create_by_tag_name!(
+              locale, detached.name, category: :general)
+        }.to raise_error('generation failed')
+
+        expect(described_class.count).to eq(original_tag_count)
+        expect(detached.reload).to have_attributes(tag_id: nil, primary_flg: false)
+      end
+
+      it 'promotes a detached alias into the requested primary name' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        detached = create(:tag_name, :alias, name: 'detached_english',
+                                           language_code: 'en', script_code: 'Latn')
+
+        tag = described_class.find_or_create_by_tag_name!(
+            locale, detached.name, category: :general)
+
+        expect(detached.reload).to have_attributes(
+            tag_id: tag.id, primary_flg: true, canonical_id: nil,
+            auto_generated: false)
+        expect(TagName.where(tag:, language_code: 'en', primary_flg: true))
+            .to contain_exactly(detached)
+      end
+
+      it 'creates separate tag identities for the same name in different languages' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        nipponese = described_class.find_or_create_by_tag_name!(
+            Locale.nipponese, 'same_name', category: :general)
+        english = described_class.find_or_create_by_tag_name!(
+            locale, 'same_name', category: :character)
+
+        expect(english).not_to eq(nipponese)
+        expect(primary_tag_name_for(english, 'en')).to have_attributes(
+            name: 'same_name', tag_id: english.id, language_code: 'en', primary_flg: true)
+        expect(primary_tag_name_for(nipponese, 'ja')).to have_attributes(
+            name: 'same_name', tag_id: nipponese.id, language_code: 'ja', primary_flg: true)
+        expect(described_class.find_or_create_by_tag_name!(
+            locale, 'same_name', category: :general)).to eq(english)
+        expect(described_class.find_or_create_by_tag_name!(
+            Locale.nipponese, 'same_name', category: :general)).to eq(nipponese)
+      end
+
+      it 'preserves the V1 representative when looking up another primary language' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        tag = create(:tag, primary_name: '日本語代表名')
+        representative_id = tag.tag_name_id
+        english = primary_tag_name_for(tag, 'en')
+        english.update!(name: 'english_primary', auto_generated: false)
+
+        found = described_class.find_or_create_by_tag_name!(
+            locale, english.name, category: :general)
+
+        expect(found).to eq(tag)
+        expect(tag.reload.tag_name_id).to eq(representative_id)
+        expect(english.reload.tag_id).to eq(tag.id)
+      end
+
+      it 'normalises names using the supplied locale' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        tags = described_class.normalise_tags!(
+            locale, ['character:normalised_english'],
+            with_tagme: false, with_no_deerjikist: false)
+
+        expect(tags.length).to eq(1)
+        expect(primary_tag_name_for(tags.first, 'en')).to have_attributes(
+            name: 'normalised_english', language_code: 'en', script_code: 'Latn',
+            primary_flg: true, tag_id: tags.first.id)
+      end
+    end
+
     it 'creates a tag and name with the requested category after stripping whitespace' do
       tag = nil
 
       expect {
-        tag = described_class.find_or_create_by_tag_name!(
+        tag = described_class.find_or_create_by_tag_name!(Locale.nipponese,
             '  lookup_new  ', category: :character)
       }.to change(Tag, :count).by(1).and change(TagName, :count).by(1)
 
-      expect(tag.name).to eq('lookup_new')
+      expect(primary_tag_name_for(tag, 'ja').name).to eq('lookup_new')
       expect(tag.category).to eq('character')
+      expect(TagName.where(tag:, language_code: 'ja', primary_flg: true).count).to eq(1)
+      expect(primary_tag_name_for(tag, 'ja').auto_generated).to be(false)
     end
 
-    it 'reuses the canonical tag for an alias without changing its category' do
+    it 'promotes a detached Nipponese alias into a human-confirmed primary' do
+      detached = create(:tag_name, :alias, name: 'detached_nipponese')
+
+      tag = described_class.find_or_create_by_tag_name!(
+          Locale.nipponese, detached.name, category: :general)
+
+      expect(detached.reload).to have_attributes(
+          tag_id: tag.id, primary_flg: true, canonical_id: nil,
+          auto_generated: false)
+      expect(TagName.where(tag:, language_code: 'ja', primary_flg: true))
+          .to contain_exactly(detached)
+    end
+
+    it 'reuses the owning tag for an alias without changing its category' do
       tag = create(:tag, category: :character)
-      alias_name = TagName.create!(name: 'lookup_alias', canonical: tag.tag_name)
+      representative_id = tag.tag_name_id
+      alias_name = create(:tag_name, :alias, name: 'lookup_alias', tag:)
+      expect(alias_name.reload).to have_attributes(
+          tag_id: tag.id,
+          primary_flg: false, language_code: 'ja')
       found = nil
 
       expect {
-        found = described_class.find_or_create_by_tag_name!(
+        found = described_class.find_or_create_by_tag_name!(Locale.nipponese,
             alias_name.name, category: :general)
       }.to change(Tag, :count).by(0).and change(TagName, :count).by(0)
 
       expect(found).to eq(tag)
       expect(found.category).to eq('character')
+      expect(tag.reload.tag_name_id).to eq(representative_id)
     end
 
-    it 'creates a tag for an existing canonical name reached through an alias' do
-      canonical = create(:tag_name)
-      alias_name = TagName.create!(name: 'lookup_alias', canonical:)
-      tag = nil
+    it 'reuses the owning tag through another alias' do
+      tag = create(:tag)
+      primary = primary_tag_name_for(tag, 'ja')
+      alias_name = create(:tag_name, :alias, name: 'lookup_alias', tag:)
+      other_alias = create(:tag_name, :alias, name: 'lookup_other_alias', tag:)
+
+      expect([alias_name.reload, other_alias.reload]).to all(have_attributes(
+          tag_id: tag.id,
+          primary_flg: false, language_code: 'ja'))
 
       expect {
-        tag = described_class.find_or_create_by_tag_name!(
+        found = described_class.find_or_create_by_tag_name!(Locale.nipponese,
             alias_name.name, category: :general)
-      }.to change(Tag, :count).by(1).and change(TagName, :count).by(0)
+        expect(found).to eq(tag)
+      }.to change(Tag, :count).by(0).and change(TagName, :count).by(0)
 
-      expect(tag.tag_name).to eq(canonical)
+      expect(primary_tag_name_for(tag.reload, 'ja')).to eq(primary)
     end
   end
 
   describe '.merge_tags!' do
     let!(:target_tag) { create(:tag, category: :general) }
     let!(:source_tag) { create(:tag, category: :general) }
-    let!(:source_tag_name) { source_tag.tag_name }
+    let!(:source_tag_name) { primary_tag_name_for(source_tag, 'ja') }
 
     let!(:post_record) do
       Post.create!(url: 'https://example.com/posts/1', title: 'test post')
     end
 
+    context 'with names in multiple languages' do
+      include_context 'English locale'
+
+      it 'keeps the target primary and moves source names as aliases' do
+        pending '日本語以外の Locale 有効化は別課題で実装する'
+        locale
+        english_primary = primary_tag_name_for(target_tag, 'en')
+        source_primary = primary_tag_name_for(source_tag, 'en')
+        source_alias = create(:tag_name, :alias, tag: source_tag,
+            name: 'source_english_alias', language_code: 'en', script_code: 'Latn')
+
+        expect([english_primary, source_primary]).to all(have_attributes(
+            primary_flg: true, auto_generated: true))
+
+        described_class.merge_tags!(target_tag, [source_tag])
+
+        expect(primary_tag_name_for(target_tag.reload, 'en')).to eq(english_primary)
+        expect(TagName.where(tag: target_tag, language_code: 'en', primary_flg: true))
+            .to contain_exactly(english_primary)
+        expect([source_primary.reload, source_alias.reload]).to all(have_attributes(
+            tag_id: target_tag.id, language_code: 'en', primary_flg: false))
+        expect(TagName.where(tag: target_tag, language_code: 'ja', primary_flg: true))
+            .to contain_exactly(primary_tag_name_for(target_tag, 'ja'))
+        expect(source_tag_name.reload).to have_attributes(
+            tag_id: target_tag.id, language_code: 'ja', primary_flg: false)
+      end
+    end
+
     context 'when merging a simple source tag' do
       let!(:source_post_tag) { PostTag.create!(post: post_record, tag: source_tag) }
 
@@ -243,7 +489,8 @@ RSpec.describe Tag, type: :model do
         expect(PostTag.exists?(post: post_record, tag: source_tag)).to be(false)
         expect(target_link).to be_present
         expect(Tag.unscoped.exists?(source_tag.id)).to be(false)
-        expect(source_tag_name.reload.canonical_id).to eq(target_tag.tag_name_id)
+        expect(source_tag_name.reload).to have_attributes(
+            tag_id: target_tag.id, language_code: 'ja', primary_flg: false)
         expect(target_tag.reload.post_count).to eq(1)
       end
     end
@@ -269,15 +516,16 @@ RSpec.describe Tag, type: :model do
         expect(target_post_tag.reload.sections).to contain_exactly(target_section)
 
         expect(Tag.unscoped.exists?(source_tag.id)).to be(false)
-        expect(source_tag_name.reload.canonical_id).to eq(target_tag.tag_name_id)
+        expect(source_tag_name.reload).to have_attributes(
+            tag_id: target_tag.id, language_code: 'ja', primary_flg: false)
         expect(target_tag.reload.post_count).to eq(1)
       end
     end
 
     it 'keeps source history and records the new target alias after deleting the source' do
       user = create_member_user!
-      source_name = source_tag.name
-      source_alias = TagName.create!(name: 'merge_alias', canonical: source_tag_name)
+      source_name = primary_tag_name_for(source_tag, 'ja').name
+      source_alias = create(:tag_name, :alias, name: 'merge_alias', tag: source_tag)
       TagVersioning.ensure_snapshot!(source_tag, created_by_user: user)
       original_version = source_tag.tag_versions.first
 
@@ -287,13 +535,17 @@ RSpec.describe Tag, type: :model do
       expect(versions.pluck(:version_no, :event_type))
           .to eq([[1, 'create'], [2, 'discard']])
       expect(versions.first).to eq(original_version)
-      expect(versions.last).to have_attributes(
-          name: source_name, aliases: source_alias.name, created_by_user: user)
+      expect(versions.last.created_by_user).to eq(user)
+      expect(versions.last.names.fetch('ja')).to eq(
+          'name' => source_name, 'script_code' => 'Jpan',
+          'auto_generated' => false,
+          'aliases' => [{ 'name' => source_alias.name, 'script_code' => 'Jpan' }])
       expect(Tag.unscoped.exists?(source_tag.id)).to be(false)
 
       target_versions = target_tag.tag_versions.order(:version_no)
       expect(target_versions.pluck(:event_type)).to eq(['create', 'update'])
-      expect(target_versions.last.aliases.split).to eq([source_name])
+      target_aliases = target_versions.last.names.fetch('ja').fetch('aliases').pluck('name')
+      expect(target_aliases).to contain_exactly('merge_alias', source_name)
     end
 
     it 'deletes source relationships while preserving unrelated relationships' do
@@ -347,7 +599,8 @@ RSpec.describe Tag, type: :model do
         expect(Tag.unscoped.exists?(source_tag.id)).to be(false)
         expect(PostTag.exists?(post: post_record, tag: source_tag)).to be(false)
         expect(target_link).to be_present
-        expect(source_tag_name.reload.canonical_id).to eq(target_tag.tag_name_id)
+        expect(source_tag_name.reload).to have_attributes(
+            tag_id: target_tag.id, language_code: 'ja', primary_flg: false)
         expect(target_tag.reload.post_count).to eq(1)
       end
     end
@@ -378,7 +631,8 @@ RSpec.describe Tag, type: :model do
         expect(target_link).to be_present
 
         expect(Tag.unscoped.exists?(source_tag.id)).to be(false)
-        expect(source_tag_name.reload.canonical_id).to eq(target_tag.tag_name_id)
+        expect(source_tag_name.reload).to have_attributes(
+            tag_id: target_tag.id, language_code: 'ja', primary_flg: false)
         expect(target_tag.reload.post_count).to eq(1)
       end
     end
@@ -397,7 +651,7 @@ RSpec.describe Tag, type: :model do
 
       it 'rolls back earlier deletions, links, and history when a later source has a wiki' do
         earlier_source = create(:tag)
-        earlier_name = earlier_source.tag_name
+        earlier_name = primary_tag_name_for(earlier_source, 'ja')
         source_section = create(:post_tag_section, post: post_record,
                                                    tag: source_tag,
                                                    begin_ms: 1000, end_ms: 2000)
@@ -407,7 +661,8 @@ RSpec.describe Tag, type: :model do
         }.to raise_error(ActiveRecord::RecordInvalid)
 
         expect(Tag.unscoped.exists?(earlier_source.id)).to be(true)
-        expect(earlier_name.reload.canonical_id).to be_nil
+        expect(earlier_name.reload).to have_attributes(
+            tag_id: earlier_source.id, language_code: 'ja', primary_flg: true)
         expect(TagVersion.where(tag_id: [earlier_source.id, source_tag.id, target_tag.id]))
             .to be_empty
         expect(Tag.unscoped.exists?(source_tag.id)).to be(true)
@@ -416,7 +671,8 @@ RSpec.describe Tag, type: :model do
         expect(source_post_tag.sections).to contain_exactly(source_section)
         expect(PostTag.find_by(post: post_record, tag: target_tag)).to be_nil
         expect(source_tag.reload.post_count).to eq(1)
-        expect(source_tag_name.reload.canonical_id).to be_nil
+        expect(source_tag_name.reload).to have_attributes(
+            tag_id: source_tag.id, language_code: 'ja', primary_flg: true)
         expect(target_tag.reload.post_count).to eq(0)
       end
     end

backend/spec/models/version_record_spec.rb

@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 RSpec.describe VersionRecord, type: :model do
-  let!(:tag) { create(:tag, name: 'version_record_tag') }
+  let!(:tag) { create(:tag, primary_name: 'version_record_tag') }
   let!(:nico_tag) { create(:external_tag, name: 'version_record_tag') }
 
   it 'makes TagVersion read only after create' do
@@ -9,13 +9,14 @@ RSpec.describe VersionRecord, type: :model do
       tag: tag,
       version_no: 1,
       event_type: 'create',
-      name: tag.name,
+      name: primary_tag_name_for(tag, 'ja').name,
       category: tag.category,
       aliases: '',
+      names: { ja: { name: primary_tag_name_for(tag, 'ja').name,
+                     script_code: 'Jpan', auto_generated: false, aliases: [] } },
       parent_tag_ids: '',
       created_at: Time.current,
-      created_by_user: nil
-    )
+      created_by_user: nil)
 
     expect {
       version.update!(name: 'changed')
@@ -27,13 +28,14 @@ RSpec.describe VersionRecord, type: :model do
       tag: tag,
       version_no: 1,
       event_type: 'create',
-      name: tag.name,
+      name: primary_tag_name_for(tag, 'ja').name,
       category: tag.category,
       aliases: '',
+      names: { ja: { name: primary_tag_name_for(tag, 'ja').name,
+                     script_code: 'Jpan', auto_generated: false, aliases: [] } },
       parent_tag_ids: '',
       created_at: Time.current,
-      created_by_user: nil
-    )
+      created_by_user: nil)
 
     expect {
       version.destroy!