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/services/wiki/commit_integrity_spec.rb

@@ -2,41 +2,42 @@ require 'digest'
 require 'rails_helper'
 
 RSpec.describe Wiki::Commit do
+  include WikiRecords
   let(:user) { create_member_user! }
 
   def create_page title:, body: 'initial body'
-    described_class.create_content!(
-        tag_name: create(:tag_name, name: title),
+    seed_wiki_page(
+        tag_name: create(:tag, primary_name: title).tag_name('ja'),
         body:,
         created_by_user: user,
         message: 'init')
   end
 
   describe '.create_content!' do
-    it 'creates page, revision, and version with normalised body' do
-      expect {
-        described_class.create_content!(
-            tag_name: create(:tag_name, name: 'commit_integrity_create'),
-            body: "a\r\nb\r\n\r\n",
-            created_by_user: user,
-            message: 'init')
-      }
-          .to change(WikiPage, :count).by(1)
+    it 'rejects standalone Help creation without adding page or history' do
+      name = create(:tag_name, name: 'Help:frozen_service')
+      counts = [WikiPage.count, WikiRevision.count, WikiVersion.count]
+      expect do
+        described_class.create_content!(tag_name: name, body: 'initial', created_by_user: user)
+      end.to raise_error(ActiveRecord::RecordInvalid)
+      expect([WikiPage.count, WikiRevision.count, WikiVersion.count]).to eq(counts)
+    end
+
+    it 'keeps the internal compatibility writer available' do
+      name = create(:tag_name, name: 'タググループ:compatibility_service')
+      page = nil
+      expect do
+        page = described_class.create_legacy_content!(
+            tag_name: name, body: 'initial', created_by_user: user)
+      end.to change(WikiPage, :count).by(1)
           .and change(WikiRevision, :count).by(1)
           .and change(WikiVersion, :count).by(1)
-
-      page = WikiPage.joins(:tag_name).find_by!(tag_names: { name: 'commit_integrity_create' })
-      revision = page.current_revision
-      version = page.wiki_versions.order(:version_no).last
-
-      expect(page.body).to eq("a\nb")
-      expect(revision.lines_count).to eq(2)
-      expect(version.body).to eq("a\nb")
-      expect(version.reason).to eq('init')
+      expect(page.current_revision.body).to eq('initial')
+      expect(page.wiki_versions.sole.body).to eq('initial')
     end
 
     it 'rejects body that becomes blank after normalisation' do
-      tag_name = create(:tag_name, name: 'commit_integrity_blank')
+      tag_name = create(:tag, primary_name: 'commit_integrity_blank').tag_name('ja')
 
       expect {
         described_class.create_content!(
@@ -52,6 +53,17 @@ RSpec.describe Wiki::Commit do
   end
 
   describe '.content!' do
+    it 'rejects standalone Help updates without modifying histories' do
+      page = seed_wiki_page(tag_name: create(:tag_name, name: 'Help:standalone'),
+                            body: 'before', created_by_user: user)
+      counts = [WikiRevision.count, WikiVersion.count]
+      expect do
+        described_class.content!(page:, body: 'after', created_user: user)
+      end.to raise_error(ActiveRecord::RecordInvalid)
+      expect(page.reload.body).to eq('before')
+      expect([WikiRevision.count, WikiVersion.count]).to eq(counts)
+    end
+
     it 'updates page body, revision, and version' do
       page = create_page(title: 'commit_integrity_update', body: 'before')
       current_id = page.current_revision.id
@@ -80,7 +92,7 @@ RSpec.describe Wiki::Commit do
       tag = create(:tag, primary_tag_name: tag_name, category: :general)
 
       page =
-          described_class.create_content!(
+          seed_wiki_page(
               tag_name:,
               body: 'before',
               created_by_user: user,