ヘルプを Wiki から分離 (#424) (#430)

画面上でのテストは完了．
移行にす早さが求められるので，準備ができたらマージする．

Reviewed-on: #430
Co-authored-by: miteruzo <miteruzo@naver.com>

backend/spec/models/shared_tag_ids_spec.rb

@@ -0,0 +1,84 @@
+require 'rails_helper'
+
+RSpec.describe 'Shared Tag and ExternalTag IDs', type: :model do
+  include TagGroupRecords
+  let(:user) { create_member_user! }
+
+  def create_resource resource
+    if resource == :tag
+      Tag.find_or_create_by_tag_name!(Locale.nipponese, 'shared_id_new', category: :general)
+    else
+      ExternalTag.create!(platform: :nico, name: 'shared_id_new')
+    end
+  end
+
+  [:tag, :external_tag].each do |resource|
+    it "starts #{ resource } at 1 when both tables are empty" do
+      expect(Tag.count).to eq(0)
+      expect(ExternalTag.count).to eq(0)
+      expect(create_resource(resource).id).to eq(1)
+    end
+
+    it "allocates #{ resource } above the other table's maximum" do
+      create(:tag, id: resource == :tag ? 1 : 20)
+      create(:external_tag, id: resource == :external_tag ? 1 : 20)
+
+      expect(create_resource(resource).id).to eq(21)
+    end
+
+    it "uses the current maximum after deleting earlier #{ resource } records" do
+      tag = create(:tag, id: 100)
+      TagName.where(tag_id: tag.id).update_all(tag_id: nil)
+      tag.destroy!
+      create(:external_tag, id: 200).destroy!
+      expect(Tag.unscoped.count).to eq(0)
+      expect(ExternalTag.unscoped.count).to eq(0)
+      expect(create_resource(resource).id).to eq(1)
+    end
+
+    it "preserves legacy overlaps and gaps when creating #{ resource }" do
+      [1, 2, 5].each { create(:tag, id: _1) }
+      [1, 3, 8].each { create(:external_tag, id: _1) }
+      tags = Tag.order(:id).map(&:attributes)
+      external_tags = ExternalTag.order(:id).map(&:attributes)
+
+      record = create_resource(resource)
+
+      aggregate_failures do
+        expect(record.id).to eq(9)
+        expect(Tag.where(id: [1, 2, 5]).order(:id).map(&:attributes)).to eq(tags)
+        expect(ExternalTag.where(id: [1, 3, 8]).order(:id).map(&:attributes)).to eq(external_tags)
+        expect(Tag.exists?(id: 3)).to be(false)
+        expect(ExternalTag.exists?(id: 2)).to be(false)
+      end
+    end
+
+    it "ignores the description and group ID space when creating #{ resource }" do
+      tag = create(:tag, id: 1)
+      create(:external_tag, id: 2)
+      TagDescription.create!(id: 100, tag:, language_code: 'ja', body: '', version_no: 1)
+      seed_group(name: 'separate_space', id: 200)
+
+      expect(create_resource(resource).id).to eq(3)
+    end
+  end
+
+  it 'preserves overlapping IDs during updates without rewriting the other resource' do
+    tag = create(:tag, id: 5)
+    external = create(:external_tag, id: 5)
+    tag.update!(category: :meta)
+    external.update!(name: 'updated_external')
+
+    expect(tag.reload.id).to eq(5)
+    expect(external.reload.id).to eq(5)
+    expect(tag.category).to eq('meta')
+    expect(external.name).to eq('updated_external')
+    expect(Tag.count).to eq(1)
+    expect(ExternalTag.count).to eq(1)
+  end
+
+  it 'allocates distinct IDs for successive creations across both tables' do
+    records = [:tag, :external_tag].map { create_resource(_1) }
+    expect(records.map(&:id)).to eq([1, 2])
+  end
+end

backend/spec/models/tag_repr_spec.rb

@@ -0,0 +1,50 @@
+require 'rails_helper'
+
+RSpec.describe TagRepr do
+  let(:tag) { create(:tag) }
+
+  def description_for record
+    TagDescription.create!(tag: record, language_code: 'ja', body: '', version_no: 1)
+  end
+
+  it 'keeps has_wiki boolean for the selected language in base and inline' do
+    description_for(tag)
+    [:base, :inline].each do |method|
+      expect(described_class.public_send(method, tag).as_json.fetch('has_wiki')).to be(true)
+      expect(described_class.public_send(method, tag, language_code: 'en')
+          .as_json.fetch('has_wiki')).to be(false)
+    end
+  end
+
+  it 'uses the same language for a tag and its parents' do
+    parent = create(:tag)
+    description_for(tag)
+    description_for(parent)
+    TagImplication.create!(tag:, parent_tag: parent)
+    ['ja', 'en'].each do |language_code|
+      row = described_class.base(tag, language_code:).as_json
+      expected = language_code == 'ja'
+      expect(row.fetch('has_wiki')).to be(expected)
+      expect(row.fetch('parents').sole.fetch('has_wiki')).to be(expected)
+    end
+  end
+
+  it 'preloads existence checks for many tags and their parents without Wiki reads' do
+    parent = create(:tag)
+    description_for(parent)
+    records = Array.new(3) do
+      create(:tag).tap { TagImplication.create!(tag: _1, parent_tag: parent) }
+    end
+    description_for(records.first)
+    queries = []
+    subscriber = ->(*args) { queries << args.last.fetch(:sql) }
+    rows = nil
+    ActiveSupport::Notifications.subscribed(subscriber, 'sql.active_record') do
+      rows = described_class.many(records).as_json
+    end
+    expect(rows.map { _1.fetch('has_wiki') }).to eq([true, false, false])
+    expect(rows.map { _1.fetch('parents').sole.fetch('has_wiki') }).to eq([true] * 3)
+    expect(queries.grep(/\bSELECT\b.*\btag_descriptions\b/im).size).to be <= 2
+    expect(queries.grep(/\bwiki_(pages|revisions|versions)\b/i)).to be_empty
+  end
+end

backend/spec/models/tag_spec.rb

@@ -1,6 +1,47 @@
 require 'rails_helper'
 
 RSpec.describe Tag, type: :model do
+  describe '#has_description?' do
+    let(:tag) { create(:tag) }
+
+    it 'checks the requested language and treats an empty description as present' do
+      TagDescription.create!(tag:, language_code: 'ja', body: '', version_no: 1)
+      expect(tag.has_description?(language_code: 'ja')).to be(true)
+      expect(tag.has_description?(language_code: 'en')).to be(false)
+    end
+
+    it 'returns false without a description' do
+      expect(tag.has_description?(language_code: 'ja')).to be(false)
+    end
+
+    it 'does not use a Wiki page as evidence of a description' do
+      user = create_member_user!
+      Wiki::Commit.create_legacy_content!(tag_name: tag.tag_name('ja'), body: 'legacy',
+                                          created_by_user: user)
+      expect(tag.has_description?(language_code: 'ja')).to be(false)
+    end
+
+    it 'reuses preloaded descriptions without reading Wiki or querying again' do
+      TagDescription.create!(tag:, language_code: 'ja', body: '', version_no: 1)
+      loaded = Tag.includes(:tag_descriptions).find(tag.id)
+      queries = []
+      subscriber = ->(*args) { queries << args.last.fetch(:sql) }
+      ActiveSupport::Notifications.subscribed(subscriber, 'sql.active_record') do
+        expect(loaded.has_description?(language_code: 'ja')).to be(true)
+        expect(loaded.has_description?(language_code: 'en')).to be(false)
+      end
+      expect(queries).to be_empty
+    end
+
+    it 'keeps language selection generic without enabling another Language record' do
+      tag.association(:tag_descriptions).target = [
+          TagDescription.new(tag:, language_code: 'en', body: '', version_no: 1)]
+      tag.association(:tag_descriptions).loaded!
+      expect(tag.has_description?(language_code: 'en')).to be(true)
+      expect(tag.has_description?(language_code: 'ja')).to be(false)
+    end
+  end
+
   describe 'external tag separation' do
     ['nico:reserved', 'NiCo:reserved'].each do |name|
       it "rejects the reserved prefix #{ name } for internal tags" do