Wiki のバージョン管理 (#317) (#333)

#317

#317

#317

#317

#317

#317

Co-authored-by: miteruzo <miteruzo@naver.com>
Reviewed-on: #333

backend/spec/factories/wiki_pages.rb

@@ -3,5 +3,7 @@ FactoryBot.define do
     title { "TestPage" }
     association :created_user, factory: :user
     association :updated_user, factory: :user
+
+    body { ' ' }
   end
 end

backend/spec/models/tag_spec.rb

@@ -107,11 +107,13 @@ RSpec.describe Tag, type: :model do
     context 'when the source tag_name has a wiki_page' do
       let!(:source_post_tag) { PostTag.create!(post: post_record, tag: source_tag) }
       let!(:wiki_page) do
-        WikiPage.create!(
-          tag_name: source_tag_name,
-          created_user: create_admin_user!,
-          updated_user: create_admin_user!
-        )
+        admin = create_admin_user!
+
+        Wiki::Commit.create_content!(
+            tag_name: source_tag_name,
+            body: 'source wiki body',
+            created_by_user: admin,
+            message: 'init')
       end
 
       it 'rolls back the transaction' do

backend/spec/requests/tag_versions_spec.rb

@@ -214,5 +214,30 @@ RSpec.describe 'TagVersions API', type: :request do
       expect(versions.size).to eq(1)
       expect(versions.first['version_no']).to eq(2)
     end
+
+    it 'does not create tag versions by wiki updates when tag has no versions yet' do
+      wiki_tag_name = TagName.create!(name: 'tag_versions_from_wiki')
+      wiki_tag = Tag.create!(tag_name: wiki_tag_name, category: :general)
+
+      wiki_page =
+          Wiki::Commit.create_content!(
+              tag_name: wiki_tag_name,
+              body: 'before',
+              created_by_user: member,
+              message: 'init')
+
+      Wiki::Commit.content!(
+          page: wiki_page,
+          body: 'after',
+          created_user: member,
+          message: 'edit',
+          base_revision_id: wiki_page.current_revision.id)
+
+      get '/tags/versions', params: { id: wiki_tag.id }
+
+      expect(response).to have_http_status(:ok)
+      expect(json.fetch('versions')).to eq([])
+      expect(json.fetch('count')).to eq(0)
+    end
   end
 end

backend/spec/requests/tag_wiki_history_integrity_spec.rb

@@ -0,0 +1,160 @@
+require 'rails_helper'
+
+RSpec.describe 'Tag and wiki history integrity', type: :request do
+  let(:member_user) { create(:user, role: 'member') }
+
+  def stub_current_user user
+    allow_any_instance_of(ApplicationController).to receive(:current_user).and_return(user)
+  end
+
+  def create_tag! name:, category: :general
+    tag_name = TagName.create!(name:)
+    Tag.create!(tag_name:, category:)
+  end
+
+  def create_wiki_for_tag! tag:, body: 'wiki body', user: member_user
+    Wiki::Commit.create_content!(
+        tag_name: tag.tag_name,
+        body:,
+        created_by_user: user,
+        message: 'init')
+  end
+
+  before do
+    stub_current_user(member_user)
+  end
+
+  describe 'PATCH /tags/:id' do
+    it 'records wiki_version when tag name changes and tag has wiki' do
+      tag = create_tag!(name: 'patch_tag_wiki_before')
+      wiki_page = create_wiki_for_tag!(tag:, body: 'wiki body before')
+
+      expect {
+        patch "/tags/#{ tag.id }", params: {
+          name: 'patch_tag_wiki_after',
+        }
+      }
+          .to change(TagVersion, :count).by(2)
+          .and change(WikiVersion, :count).by(1)
+
+      expect(response).to have_http_status(:ok)
+
+      tag.reload
+      wiki_page.reload
+      version = wiki_page.wiki_versions.order(:version_no).last
+
+      expect(tag.name).to eq('patch_tag_wiki_after')
+      expect(wiki_page.title).to eq('patch_tag_wiki_after')
+
+      expect(version).to have_attributes(
+        event_type: 'update',
+        title: 'patch_tag_wiki_after',
+        body: 'wiki body before',
+        created_by_user_id: member_user.id
+      )
+    end
+
+    it 'does not record wiki_version when only category changes' do
+      tag = create_tag!(name: 'patch_tag_category_only')
+      wiki_page = create_wiki_for_tag!(tag:, body: 'wiki body before')
+
+      before_wiki_versions = wiki_page.wiki_versions.count
+
+      expect {
+        patch "/tags/#{ tag.id }", params: {
+          category: 'meme',
+        }
+      }
+          .to change(TagVersion, :count).by(2)
+
+      expect(response).to have_http_status(:ok)
+
+      tag.reload
+      wiki_page.reload
+
+      expect(tag.name).to eq('patch_tag_category_only')
+      expect(tag.category).to eq('meme')
+      expect(wiki_page.wiki_versions.count).to eq(before_wiki_versions)
+    end
+  end
+
+  describe 'PUT /tags/:id' do
+    it 'records wiki_version when tag name changes and tag has wiki' do
+      tag = create_tag!(name: 'put_tag_wiki_before')
+      wiki_page = create_wiki_for_tag!(tag:, body: 'wiki body before')
+
+      expect {
+        put "/tags/#{ tag.id }", params: {
+          name: 'put_tag_wiki_after',
+          category: 'general',
+          aliases: '',
+          parent_tags: '',
+        }
+      }
+          .to change(TagVersion, :count).by(2)
+          .and change(WikiVersion, :count).by(1)
+
+      expect(response).to have_http_status(:ok)
+
+      tag.reload
+      wiki_page.reload
+      version = wiki_page.wiki_versions.order(:version_no).last
+
+      expect(tag.name).to eq('put_tag_wiki_after')
+      expect(wiki_page.title).to eq('put_tag_wiki_after')
+
+      expect(version).to have_attributes(
+        event_type: 'update',
+        title: 'put_tag_wiki_after',
+        body: 'wiki body before',
+        created_by_user_id: member_user.id
+      )
+    end
+
+    it 'does not record wiki_version when only category changes' do
+      tag = create_tag!(name: 'put_tag_category_only')
+      wiki_page = create_wiki_for_tag!(tag:, body: 'wiki body before')
+
+      before_wiki_versions = wiki_page.wiki_versions.count
+
+      expect {
+        put "/tags/#{ tag.id }", params: {
+          name: 'put_tag_category_only',
+          category: 'meme',
+          aliases: '',
+          parent_tags: '',
+        }
+      }
+          .to change(TagVersion, :count).by(2)
+
+      expect(response).to have_http_status(:ok)
+
+      tag.reload
+      wiki_page.reload
+
+      expect(tag.name).to eq('put_tag_category_only')
+      expect(tag.category).to eq('meme')
+      expect(wiki_page.wiki_versions.count).to eq(before_wiki_versions)
+    end
+
+    it 'does not record wiki_version when only aliases change' do
+      tag = create_tag!(name: 'put_tag_alias_only')
+      wiki_page = create_wiki_for_tag!(tag:, body: 'wiki body before')
+
+      before_wiki_versions = wiki_page.wiki_versions.count
+
+      expect {
+        put "/tags/#{ tag.id }", params: {
+          name: 'put_tag_alias_only',
+          category: 'general',
+          aliases: 'put_tag_alias_only_alias',
+          parent_tags: '',
+        }
+      }
+          .to change(TagVersion, :count).by(2)
+
+      expect(response).to have_http_status(:ok)
+      expect(wiki_page.reload.wiki_versions.count).to eq(before_wiki_versions)
+    end
+  end
+end

backend/spec/requests/tags_spec.rb

@@ -471,6 +471,54 @@ RSpec.describe 'Tags API', type: :request do
         expect(response).to have_http_status(:unprocessable_entity)
         expect(nico_tag.reload.category).to eq('nico')
       end
+
+      it 'PATCH で tag の name を変更すると対応する wiki version を作成する' do
+        wiki_page =
+            Wiki::Commit.create_content!(
+                tag_name: tag.tag_name,
+                body: 'wiki body before',
+                created_by_user: member_user,
+                message: 'init')
+
+        expect {
+          patch "/tags/#{ tag.id }", params: {
+            name: 'patch_wiki_renamed_tag',
+          }
+        }
+            .to change(TagVersion, :count).by(2)
+            .and change(WikiVersion, :count).by(1)
+
+        expect(response).to have_http_status(:ok)
+
+        version = wiki_page.reload.wiki_versions.order(:version_no).last
+
+        expect(version).to have_attributes(
+          event_type: 'update',
+          title: 'patch_wiki_renamed_tag',
+          body: 'wiki body before',
+          created_by_user_id: member_user.id
+        )
+      end
+
+      it 'tag の category だけを変更しても wiki version は作成しない' do
+        wiki_page =
+            Wiki::Commit.create_content!(
+                tag_name: tag.tag_name,
+                body: 'wiki body before',
+                created_by_user: member_user,
+                message: 'init')
+
+        before_wiki_version_count = wiki_page.reload.wiki_versions.count
+
+        expect {
+          patch "/tags/#{ tag.id }", params: {
+            category: 'meme',
+          }
+        }.to change(TagVersion, :count).by(2)
+
+        expect(response).to have_http_status(:ok)
+        expect(wiki_page.reload.wiki_versions.count).to eq(before_wiki_version_count)
+      end
     end
   end
 
@@ -876,6 +924,136 @@ RSpec.describe 'Tags API', type: :request do
         expect(system_tag.reload.name).to eq(old_name)
         expect(system_tag.category).to eq(old_category)
       end
+
+      it 'wiki を持つ tag を更新すると wiki version も作成する' do
+        wiki_page =
+            Wiki::Commit.create_content!(
+                tag_name: tag.tag_name,
+                body: 'wiki body before',
+                created_by_user: member_user,
+                message: 'init')
+
+        Wiki::Commit.content!(
+          page: wiki_page,
+          body: 'wiki body before',
+          created_user: member_user,
+          message: 'init'
+        )
+
+        expect {
+          put "/tags/#{ tag.id }", params: {
+            name: 'put_wiki_version_tag',
+            category: 'meme',
+            aliases: 'unko',
+            parent_tags: '',
+          }
+        }
+            .to change(TagVersion, :count).by(2)
+            .and change(WikiVersion, :count).by(1)
+
+        expect(response).to have_http_status(:ok)
+
+        version = wiki_page.reload.wiki_versions.order(:version_no).last
+
+        expect(version).to have_attributes(
+          event_type: 'update',
+          title: 'put_wiki_version_tag',
+          body: 'wiki body before',
+          created_by_user_id: member_user.id
+        )
+      end
+
+      it '別名を他 tag から奪った場合、奪はれた側の tag version も作成する' do
+        pending '#329 で対応予定'
+
+        old_owner = Tag.create!(
+          tag_name: TagName.create!(name: 'put_alias_old_owner'),
+          category: :general
+        )
+        stolen_alias = TagName.create!(
+          name: 'put_stolen_alias',
+          canonical: old_owner.tag_name
+        )
+
+        expect(old_owner.tag_name.aliases.map(&:name)).to include('put_stolen_alias')
+
+        expect {
+          put "/tags/#{ tag.id }", params: {
+            name: 'spec_tag',
+            category: 'general',
+            aliases: 'unko put_stolen_alias',
+            parent_tags: '',
+          }
+        }
+            .to change { tag.reload.tag_versions.count }.by(2)
+            .and change { old_owner.reload.tag_versions.count }.by(2)
+
+        expect(response).to have_http_status(:ok)
+
+        expect(stolen_alias.reload.canonical).to eq(tag.tag_name)
+        expect(old_owner.reload.tag_name.aliases.map(&:name)).not_to include('put_stolen_alias')
+
+        old_owner_versions = old_owner.tag_versions.order(:version_no)
+
+        expect(old_owner_versions.first.event_type).to eq('create')
+        expect(old_owner_versions.first.aliases.split).to include('put_stolen_alias')
+
+        expect(old_owner_versions.second.event_type).to eq('update')
+        expect(old_owner_versions.second.aliases.split).not_to include('put_stolen_alias')
+      end
+
+      it 'parent_tags に指定すると循環する tag は 422 にする' do
+        pending '#332 で対応予定'
+
+        child = Tag.create!(
+          tag_name: TagName.create!(name: 'put_cycle_child'),
+          category: :general
+        )
+
+        TagImplication.create!(tag: child, parent_tag: tag)
+
+        put "/tags/#{ tag.id }", params: {
+          name: 'spec_tag',
+          category: 'general',
+          aliases: 'unko',
+          parent_tags: child.name,
+        }
+
+        expect(response).to have_http_status(:unprocessable_entity)
+
+        expect(TagImplication.where(tag:, parent_tag: child)).not_to exist
+      end
+
+      it 'tag の name を変更すると対応する wiki version を作成する' do
+        wiki_page =
+            Wiki::Commit.create_content!(
+                tag_name: tag.tag_name,
+                body: 'wiki body before',
+                created_by_user: member_user,
+                message: 'init')
+
+        expect {
+          put "/tags/#{ tag.id }", params: {
+            name: 'put_wiki_renamed_tag',
+            category: 'general',
+            aliases: 'unko',
+            parent_tags: '',
+          }
+        }
+            .to change(TagVersion, :count).by(2)
+            .and change(WikiVersion, :count).by(1)
+
+        expect(response).to have_http_status(:ok)
+
+        version = wiki_page.reload.wiki_versions.order(:version_no).last
+
+        expect(version).to have_attributes(
+          event_type: 'update',
+          title: 'put_wiki_renamed_tag',
+          body: 'wiki body before',
+          created_by_user_id: member_user.id
+        )
+      end
     end
   end
 end

backend/spec/requests/wiki_body_search_pending_spec.rb

@@ -0,0 +1,27 @@
+require 'rails_helper'
+
+RSpec.describe 'Wiki body search', type: :request do
+  let!(:user) { create_member_user! }
+
+  it 'searches wiki pages by body text' do
+    pending 'Wiki 本文検索実装時に有効化する'
+
+    Wiki::Commit.create_content!(
+        tag_name: TagName.create!(name: 'wiki_body_search_hit'),
+        body: 'unique body keyword for wiki search',
+        created_by_user: user,
+        message: 'init')
+
+    Wiki::Commit.create_content!(
+        tag_name: TagName.create!(name: 'wiki_body_search_miss'),
+        body: 'ordinary body',
+        created_by_user: user,
+        message: 'init')
+
+    get '/wiki/search', params: { body: 'unique body keyword' }
+
+    expect(response).to have_http_status(:ok)
+    expect(json.map { |page| page['title'] }).to include('wiki_body_search_hit')
+    expect(json.map { |page| page['title'] }).not_to include('wiki_body_search_miss')
+  end
+end

backend/spec/requests/wiki_conflict_spec.rb

@@ -0,0 +1,42 @@
+require 'rails_helper'
+
+RSpec.describe 'Wiki conflict handling', type: :request do
+  let!(:user) { create_member_user! }
+
+  def auth_headers user
+    { 'X-Transfer-Code' => user.inheritance_code }
+  end
+
+  it 'returns 409 when base_revision_id is stale' do
+    page =
+        Wiki::Commit.create_content!(
+            tag_name: TagName.create!(name: 'wiki_conflict_request'),
+            body: 'first',
+            created_by_user: user,
+            message: 'init')
+
+    stale_id = page.current_revision.id
+
+    Wiki::Commit.content!(
+        page:,
+        body: 'second',
+        created_user: user,
+        message: 'other edit',
+        base_revision_id: stale_id)
+
+    put "/wiki/#{ page.id }",
+        params: {
+          title: 'wiki_conflict_request',
+          body: 'third',
+          message: 'stale',
+          base_revision_id: stale_id,
+        },
+        headers: auth_headers(user)
+
+    expect(response).to have_http_status(:conflict)
+
+    page.reload
+    expect(page.body).to eq('second')
+    expect(page.current_revision.message).to eq('other edit')
+  end
+end

backend/spec/requests/wiki_history_integrity_spec.rb

@@ -0,0 +1,196 @@
+require 'cgi'
+require 'rails_helper'
+
+RSpec.describe 'Wiki history integrity', type: :request do
+  let!(:user) { create_member_user! }
+
+  def auth_headers user
+    { 'X-Transfer-Code' => user.inheritance_code }
+  end
+
+  def create_wiki_page title:, body: 'body', message: 'init', user: self.user
+    Wiki::Commit.create_content!(
+        tag_name: TagName.create!(name: title),
+        body:,
+        created_by_user: user,
+        message:)
+  end
+
+  describe 'POST /wiki' do
+    it 'creates wiki_page, wiki_revision, and wiki_version atomically' do
+      expect {
+        post '/wiki',
+             params: {
+               title: 'wiki_history_create_atomic',
+               body: "a\nb\nc",
+               message: 'initial commit',
+             },
+             headers: auth_headers(user)
+      }
+          .to change(WikiPage, :count).by(1)
+          .and change(WikiRevision, :count).by(1)
+          .and change(WikiVersion, :count).by(1)
+
+      expect(response).to have_http_status(:created)
+
+      page = WikiPage.find(json.fetch('id'))
+      revision = page.current_revision
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(page.title).to eq('wiki_history_create_atomic')
+      expect(page.body).to eq("a\nb\nc")
+
+      expect(revision).to be_content
+      expect(revision.message).to eq('initial commit')
+      expect(revision.lines_count).to eq(3)
+
+      expect(version).to have_attributes(
+        version_no: 1,
+        event_type: 'create',
+        title: 'wiki_history_create_atomic',
+        body: "a\nb\nc",
+        reason: 'initial commit',
+        created_by_user_id: user.id
+      )
+    end
+
+    it 'returns 422 and creates nothing when normalised body is blank' do
+      expect {
+        post '/wiki',
+             params: {
+               title: 'wiki_history_blank_body',
+               body: "\r\n\r\n",
+               message: 'blank',
+             },
+             headers: auth_headers(user)
+      }
+          .not_to change(WikiPage, :count)
+
+      expect(response).to have_http_status(:unprocessable_entity)
+      expect(WikiPage.joins(:tag_name).where(tag_names: { name: 'wiki_history_blank_body' })).not_to exist
+    end
+
+    it 'returns 422 and creates no partial page when title already exists' do
+      create_wiki_page(title: 'wiki_history_duplicate_title', body: 'first')
+
+      expect {
+        post '/wiki',
+             params: {
+               title: 'wiki_history_duplicate_title',
+               body: 'second',
+               message: 'duplicate',
+             },
+             headers: auth_headers(user)
+      }
+          .not_to change(WikiPage, :count)
+
+      expect(response).to have_http_status(:unprocessable_entity)
+      expect(WikiPage.joins(:tag_name).where(tag_names: { name: 'wiki_history_duplicate_title' }).count).to eq(1)
+    end
+  end
+
+  describe 'PUT /wiki/:id' do
+    it 'updates body and records wiki_revision and wiki_version' do
+      page = create_wiki_page(title: 'wiki_history_update_body', body: 'before')
+      current_id = page.current_revision.id
+
+      expect {
+        put "/wiki/#{ page.id }",
+            params: {
+              title: 'wiki_history_update_body',
+              body: 'after',
+              message: 'edit body',
+              base_revision_id: current_id,
+            },
+            headers: auth_headers(user)
+      }
+          .to change(WikiRevision, :count).by(1)
+          .and change(WikiVersion, :count).by(1)
+
+      expect(response).to have_http_status(:ok)
+
+      page.reload
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(page.title).to eq('wiki_history_update_body')
+      expect(page.body).to eq('after')
+
+      expect(version).to have_attributes(
+        event_type: 'update',
+        title: 'wiki_history_update_body',
+        body: 'after',
+        reason: 'edit body',
+        created_by_user_id: user.id
+      )
+    end
+
+    it 'renames title and records wiki_version with new title' do
+      page = create_wiki_page(title: 'wiki_history_rename_before', body: 'before')
+      current_id = page.current_revision.id
+
+      expect {
+        put "/wiki/#{ page.id }",
+            params: {
+              title: 'wiki_history_rename_after',
+              body: 'after',
+              message: 'rename',
+              base_revision_id: current_id,
+            },
+            headers: auth_headers(user)
+      }
+          .to change(WikiRevision, :count).by(1)
+          .and change(WikiVersion, :count).by(1)
+
+      expect(response).to have_http_status(:ok)
+
+      page.reload
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(page.title).to eq('wiki_history_rename_after')
+      expect(page.body).to eq('after')
+
+      expect(version).to have_attributes(
+        event_type: 'update',
+        title: 'wiki_history_rename_after',
+        body: 'after',
+        reason: 'rename',
+        created_by_user_id: user.id
+      )
+    end
+
+    it 'does not change title, body, revision, or version on stale base_revision_id' do
+      page = create_wiki_page(title: 'wiki_history_conflict_page', body: 'first')
+      stale_id = page.current_revision.id
+
+      Wiki::Commit.content!(
+          page:,
+          body: 'second',
+          created_user: user,
+          message: 'other edit',
+          base_revision_id: stale_id)
+
+      page.reload
+      current_title = page.title
+      current_body = page.body
+      revision_count = page.wiki_revisions.count
+      version_count = page.wiki_versions.count
+
+      put "/wiki/#{ page.id }",
+          params: {
+            title: 'wiki_history_conflict_renamed',
+            body: 'third',
+            message: 'stale edit',
+            base_revision_id: stale_id,
+          },
+          headers: auth_headers(user)
+
+      expect(response).to have_http_status(:conflict)
+
+      page.reload
+      expect(page.title).to eq(current_title)
+      expect(page.body).to eq(current_body)
+      expect(page.wiki_revisions.count).to eq(revision_count)
+      expect(page.wiki_versions.count).to eq(version_count)
+    end
+  end
+end

backend/spec/requests/wiki_restore_pending_spec.rb

@@ -0,0 +1,37 @@
+require 'rails_helper'
+
+RSpec.describe 'Wiki restore', type: :request do
+  let!(:user) { create_member_user! }
+
+  def auth_headers user
+    { 'X-Transfer-Code' => user.inheritance_code }
+  end
+
+  it 'restores wiki page to previous version' do
+    pending 'Wiki 版巻き戻し API 実装時に有効化する'
+
+    page =
+        Wiki::Commit.create_content!(
+            tag_name: TagName.create!(name: 'wiki_restore_page'),
+            body: 'v1',
+            created_by_user: user,
+            message: 'init')
+
+    v1 = page.wiki_versions.order(:version_no).last
+
+    Wiki::Commit.content!(
+        page:,
+        body: 'v2',
+        created_user: user,
+        message: 'edit',
+        base_revision_id: page.current_revision.id)
+
+    post "/wiki/#{ page.id }/restore",
+         params: { version_no: v1.version_no },
+         headers: auth_headers(user)
+
+    expect(response).to have_http_status(:ok)
+    expect(page.reload.body).to eq('v1')
+    expect(page.wiki_versions.order(:version_no).last.event_type).to eq('restore')
+  end
+end

backend/spec/requests/wiki_spec.rb

@@ -4,13 +4,19 @@ require 'securerandom'
 
 
 RSpec.describe 'Wiki API', type: :request do
+  def auth_headers(user)
+    { 'X-Transfer-Code' => user.inheritance_code }
+  end
+
   let!(:user) { create_member_user! }
 
   let!(:tn) { TagName.create!(name: 'spec_wiki_title') }
   let!(:page) do
-    WikiPage.create!(tag_name: tn, created_user: user, updated_user: user).tap do |p|
-      Wiki::Commit.content!(page: p, body: 'init', created_user: user, message: 'init')
-    end
+    Wiki::Commit.create_content!(
+        tag_name: tn,
+        body: 'init',
+        created_by_user: user,
+        message: 'init')
   end
 
   describe 'GET /wiki' do
@@ -37,11 +43,12 @@ RSpec.describe 'Wiki API', type: :request do
     context 'when wiki page exists' do
       it 'returns wiki page with title' do
         request
+
         expect(response).to have_http_status(:ok)
 
         expect(json).to include(
-            'id'        => page.id,
-            'title'     => 'spec_wiki_title')
+            'id' => page.id,
+            'title' => 'spec_wiki_title')
       end
     end
 
@@ -50,6 +57,7 @@ RSpec.describe 'Wiki API', type: :request do
 
       it 'returns 404' do
         request
+
         expect(response).to have_http_status(:not_found)
       end
     end
@@ -99,25 +107,34 @@ RSpec.describe 'Wiki API', type: :request do
         end
             .to change(WikiPage, :count).by(1)
             .and change(WikiRevision, :count).by(1)
+            .and change(WikiVersion, :count).by(1)
 
         expect(response).to have_http_status(:created)
 
         page_id = json.fetch('id')
         expect(json.fetch('title')).to eq('TestPage')
 
-        page = WikiPage.find(page_id)
-        rev = page.current_revision
+        created_page = WikiPage.find(page_id)
+        version = created_page.wiki_versions.order(:version_no).last
+
+        expect(version).to have_attributes(
+          version_no: 1,
+          event_type: 'create',
+          title: 'TestPage',
+          body: "a\nb\nc",
+          created_by_user_id: member.id
+        )
+
+        rev = created_page.current_revision
         expect(rev).to be_present
         expect(rev).to be_content
         expect(rev.message).to eq('init')
 
-        # body が復元できること
-        expect(page.body).to eq("a\nb\nc")
+        expect(created_page.body).to eq("a\nb\nc")
 
-        # 行数とリレーションの整合
         expect(rev.lines_count).to eq(3)
         expect(rev.wiki_revision_lines.order(:position).pluck(:position)).to eq([0, 1, 2])
-        expect(rev.wiki_lines.pluck(:body)).to match_array(%w[a b c])
+        expect(rev.wiki_lines.pluck(:body)).to match_array(['a', 'b', 'c'])
       end
 
       it 'reuses existing WikiLine rows by sha256' do
@@ -135,6 +152,41 @@ RSpec.describe 'Wiki API', type: :request do
         # "a" の WikiLine が増殖しない（1行のはず）
         expect(WikiLine.where(body: 'a').count).to eq(1)
       end
+
+      it 'deduplicates duplicated new lines before upsert' do
+        duplicated = 'duplicated_line_for_wiki_line_upsert_spec'
+
+        post endpoint,
+             params: { title: 'DuplicateNewLine', body: "#{ duplicated }\n#{ duplicated }" },
+             headers: auth_headers(member)
+
+        expect(response).to have_http_status(:created)
+
+        page = WikiPage.find(json.fetch('id'))
+        rev = page.current_revision
+
+        expect(rev.lines_count).to eq(2)
+        expect(WikiLine.where(body: duplicated).count).to eq(1)
+        expect(rev.wiki_revision_lines.count).to eq(2)
+        expect(rev.wiki_revision_lines.pluck(:wiki_line_id).uniq.size).to eq(1)
+      end
+
+      it 'normalises CRLF and strips trailing newlines' do
+        post endpoint,
+             params: { title: 'NormalisedBody', body: "a\r\nb\r\n\r\n", message: 'normalise' },
+             headers: auth_headers(member)
+
+        expect(response).to have_http_status(:created)
+
+        page = WikiPage.find(json.fetch('id'))
+        rev = page.current_revision
+        version = page.wiki_versions.order(:version_no).last
+
+        expect(page.body).to eq("a\nb")
+        expect(version.body).to eq("a\nb")
+        expect(rev.lines_count).to eq(2)
+        expect(rev.wiki_lines.order('wiki_revision_lines.position').map(&:body)).to eq(['a', 'b'])
+      end
     end
   end
 
@@ -146,17 +198,14 @@ RSpec.describe 'Wiki API', type: :request do
       { 'X-Transfer-Code' => user.inheritance_code }
     end
 
-    #let!(:page) { create(:wiki_page, title: 'TestPage') }
-    let!(:page) do
-      build(:wiki_page, title: 'TestPage').tap do |p|
-        puts p.errors.full_messages unless p.valid?
-        p.save!
-      end
-    end
+    let!(:test_tag_name) { TagName.create!(name: 'TestPage') }
 
-    before do
-      # 初期版を 1 つ作っておく（更新が“2版目”になるように）
-      Wiki::Commit.content!(page: page, body: "a\nb", created_user: member, message: 'init')
+    let!(:page) do
+      Wiki::Commit.create_content!(
+          tag_name: test_tag_name,
+          body: "a\nb",
+          created_by_user: member,
+          message: 'init')
     end
 
     context 'when not logged in' do
@@ -182,14 +231,6 @@ RSpec.describe 'Wiki API', type: :request do
             headers: auth_headers(member)
         expect(response).to have_http_status(:unprocessable_entity)
       end
-
-      it 'returns 422 when title mismatched (if you forbid rename here)' do
-        put "/wiki/#{page.id}",
-            params: { title: 'OtherTitle', body: 'x' },
-            headers: auth_headers(member)
-        # 君の controller 例だと title 変更は 422 にしてた
-        expect(response).to have_http_status(:unprocessable_entity)
-      end
     end
 
     context 'when success' do
@@ -200,7 +241,18 @@ RSpec.describe 'Wiki API', type: :request do
           put "/wiki/#{page.id}",
               params: { title: 'TestPage', body: "x\ny", message: 'edit', base_revision_id: current_id },
               headers: auth_headers(member)
-        end.to change(WikiRevision, :count).by(1)
+        end
+            .to change(WikiRevision, :count).by(1)
+            .and change(WikiVersion, :count).by(1)
+
+        version = page.wiki_versions.order(:version_no).last
+
+        expect(version).to have_attributes(
+          event_type: 'update',
+          title: 'TestPage',
+          body: "x\ny",
+          created_by_user_id: member.id
+        )
 
         expect(response).to have_http_status(:ok)
 
@@ -211,25 +263,60 @@ RSpec.describe 'Wiki API', type: :request do
         expect(page.body).to eq("x\ny")
         expect(rev.base_revision_id).to eq(current_id)
       end
+
+      it 'wiki body だけを変更しても tag version は作成しない' do
+        linked_tag_name = TagName.create!(name: 'wiki_body_only_tag')
+        linked_tag = Tag.create!(tag_name: linked_tag_name, category: :general)
+
+        TagVersionRecorder.record!(
+            tag: linked_tag,
+            event_type: :create,
+            created_by_user: member)
+
+        linked_page =
+            Wiki::Commit.create_content!(
+                tag_name: linked_tag_name,
+                body: 'before',
+                created_by_user: member,
+                message: 'init')
+
+        current_id = linked_page.current_revision.id
+        before_count = linked_tag.reload.tag_versions.count
+
+        expect {
+          put "/wiki/#{ linked_page.id }",
+              params: {
+                title: 'wiki_body_only_tag',
+                body: 'after',
+                message: 'edit',
+                base_revision_id: current_id,
+              },
+              headers: auth_headers(member)
+        }
+            .to change(WikiRevision, :count).by(1)
+            .and change(WikiVersion, :count).by(1)
+
+        expect(response).to have_http_status(:ok)
+        expect(linked_tag.reload.tag_versions.count).to eq(before_count)
+      end
     end
 
-    # TODO: コンフリクト未実装のため，実装したらコメント外す．
-    # context 'when conflict' do
-    #   it 'returns 409 when base_revision_id mismatches' do
-    #     # 先に別ユーザ（同じ member でもOK）が 1 回更新して先頭を進める
-    #     Wiki::Commit.content!(page: page, body: "zzz", created_user: member, message: 'other edit')
-    #     page.reload
+    context 'when conflict' do
+      it 'returns 409 when base_revision_id mismatches' do
+        # 先に別ユーザ（同じ member でもOK）が 1 回更新して先頭を進める
+        Wiki::Commit.content!(page: page, body: "zzz", created_user: member, message: 'other edit')
+        page.reload
 
-    #     stale_id = page.wiki_revisions.order(:id).first.id # わざと古い id
-    #     put "/wiki/#{page.id}",
-    #         params: { title: 'TestPage', body: 'x', base_revision_id: stale_id },
-    #         headers: auth_headers(member)
+        stale_id = page.wiki_revisions.order(:id).first.id # わざと古い id
+        put "/wiki/#{page.id}",
+            params: { title: 'TestPage', body: 'x', base_revision_id: stale_id },
+            headers: auth_headers(member)
 
-    #     expect(response).to have_http_status(:conflict)
-    #     json = JSON.parse(response.body)
-    #     expect(json['error']).to eq('conflict')
-    #   end
-    # end
+        expect(response).to have_http_status(:conflict)
+        json = JSON.parse(response.body)
+        expect(json['error']).to eq('conflict')
+      end
+    end
 
     context 'when page not found' do
       it 'returns 404' do
@@ -261,14 +348,17 @@ RSpec.describe 'Wiki API', type: :request do
 
   describe 'GET /wiki/search' do
     before do
-      # 追加で検索ヒット用
-      TagName.create!(name: 'spec_wiki_title_2')
-      WikiPage.create!(tag_name: TagName.find_by!(name: 'spec_wiki_title_2'),
-                       created_user: user, updated_user: user)
+      Wiki::Commit.create_content!(
+          tag_name: TagName.create!(name: 'spec_wiki_title_2'),
+          body: 'search body 2',
+          created_by_user: user,
+          message: 'init')
 
-      TagName.create!(name: 'unrelated_title')
-      WikiPage.create!(tag_name: TagName.find_by!(name: 'unrelated_title'),
-                       created_user: user, updated_user: user)
+      Wiki::Commit.create_content!(
+          tag_name: TagName.create!(name: 'unrelated_title'),
+          body: 'unrelated body',
+          created_by_user: user,
+          message: 'init')
     end
 
     it 'returns up to 20 pages filtered by title like' do
@@ -278,7 +368,9 @@ RSpec.describe 'Wiki API', type: :request do
       expect(json).to be_an(Array)
 
       titles = json.map { |p| p['title'] }
-      expect(titles).to include('spec_wiki_title', 'spec_wiki_title_2')
+
+      expect(titles).to include('spec_wiki_title')
+      expect(titles).to include('spec_wiki_title_2')
       expect(titles).not_to include('unrelated_title')
     end
 
@@ -329,7 +421,12 @@ RSpec.describe 'Wiki API', type: :request do
     it 'returns empty array when page has no revisions and filtered by id' do
       # 別ページを作って revision 無し
       tn2 = TagName.create!(name: 'spec_no_rev')
-      p2 = WikiPage.create!(tag_name: tn2, created_user: user, updated_user: user)
+      # 異常データ: revision 無し WikiPage を直接作る
+      p2 = WikiPage.create!(
+          tag_name: tn2,
+          body: 'init',
+          created_user: user,
+          updated_user: user)
 
       get "/wiki/changes?id=#{p2.id}"
       expect(response).to have_http_status(:ok)
@@ -398,29 +495,68 @@ RSpec.describe 'Wiki API', type: :request do
       expect(json['older_revision_id']).to eq(rev_a.id)
       expect(json['newer_revision_id']).to eq(page.current_revision.id)
     end
+  end
 
-    it 'returns 422 when "to" is redirect revision' do
-      # redirect revision を作る
-      tn2 = TagName.create!(name: 'redirect_target')
-      target = WikiPage.create!(tag_name: tn2, created_user: user, updated_user: user)
+  describe 'Wiki::Commit.redirect!' do
+    it 'raises because redirect revisions are deprecated' do
+      target_tag_name = TagName.create!(name: 'redirect_deprecated_target')
+      target =
+          Wiki::Commit.create_content!(
+              tag_name: target_tag_name,
+              body: 'target',
+              created_by_user: user,
+              message: 'init')
 
-      Wiki::Commit.redirect!(page: page, redirect_page: target, created_user: user, message: 'redir')
-      redirect_rev = page.current_revision
-      expect(redirect_rev).to be_redirect
-
-      get "/wiki/#{page.id}/diff?from=#{rev_a.id}&to=#{redirect_rev.id}"
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'returns 422 when "from" is redirect revision' do
-      tn2 = TagName.create!(name: 'redirect_target2')
-      target = WikiPage.create!(tag_name: tn2, created_user: user, updated_user: user)
-
-      Wiki::Commit.redirect!(page: page, redirect_page: target, created_user: user, message: 'redir2')
-      redirect_rev = page.current_revision
-
-      get "/wiki/#{page.id}/diff?from=#{redirect_rev.id}&to=#{rev_b.id}"
-      expect(response).to have_http_status(:unprocessable_entity)
+      expect {
+        Wiki::Commit.redirect!(
+          page: page,
+          redirect_page: target,
+          created_user: user,
+          message: 'redirect',
+          base_revision_id: page.current_revision.id
+        )
+      }.to raise_error(RuntimeError, '廃止しました．')
     end
   end
+
+  it 'wiki title を変更すると対応する tag の version を作成する' do
+    linked_tag_name = TagName.create!(name: 'wiki_linked_tag_for_version')
+    linked_tag = Tag.create!(tag_name: linked_tag_name, category: :general)
+
+    linked_page =
+        Wiki::Commit.create_content!(
+            tag_name: linked_tag_name,
+            body: 'before',
+            created_by_user: user,
+            message: 'init')
+
+    current_id = linked_page.current_revision.id
+
+    expect {
+      put "/wiki/#{ linked_page.id }",
+          params: {
+            title: 'wiki_linked_tag_for_version_renamed',
+            body: 'after',
+            message: 'rename',
+            base_revision_id: current_id,
+          },
+          headers: auth_headers(user)
+    }
+        .to change(WikiRevision, :count).by(1)
+        .and change(WikiVersion, :count).by(1)
+        .and change { linked_tag.reload.tag_versions.count }.by(2)
+
+    expect(response).to have_http_status(:ok)
+
+    linked_tag.reload
+    expect(linked_tag.name).to eq('wiki_linked_tag_for_version_renamed')
+
+    versions = linked_tag.tag_versions.order(:version_no)
+
+    expect(versions.first.event_type).to eq('create')
+    expect(versions.first.name).to eq('wiki_linked_tag_for_version')
+
+    expect(versions.second.event_type).to eq('update')
+    expect(versions.second.name).to eq('wiki_linked_tag_for_version_renamed')
+  end
 end

backend/spec/requests/wiki_title_collision_spec.rb

@@ -0,0 +1,62 @@
+require 'rails_helper'
+
+RSpec.describe 'Wiki title collision', type: :request do
+  let!(:user) { create_member_user! }
+
+  def auth_headers user
+    { 'X-Transfer-Code' => user.inheritance_code }
+  end
+
+  def create_wiki_page title:, body:
+    Wiki::Commit.create_content!(
+        tag_name: TagName.create!(name: title),
+        body:,
+        created_by_user: user,
+        message: 'init')
+  end
+
+  it 'returns 422 when renaming wiki title to existing title' do
+    source = create_wiki_page(title: 'wiki_collision_source', body: 'source body')
+    create_wiki_page(title: 'wiki_collision_target', body: 'target body')
+
+    source_revision_count = source.wiki_revisions.count
+    source_version_count = source.wiki_versions.count
+    old_title = source.title
+    old_body = source.body
+
+    put "/wiki/#{ source.id }",
+        params: {
+          title: 'wiki_collision_target',
+          body: 'new body',
+          message: 'rename collision',
+          base_revision_id: source.current_revision.id,
+        },
+        headers: auth_headers(user)
+
+    expect(response).to have_http_status(:unprocessable_entity)
+
+    source.reload
+
+    expect(source.title).to eq(old_title)
+    expect(source.body).to eq(old_body)
+    expect(source.wiki_revisions.count).to eq(source_revision_count)
+    expect(source.wiki_versions.count).to eq(source_version_count)
+  end
+
+  it 'returns 422 when creating wiki with existing title' do
+    create_wiki_page(title: 'wiki_collision_create', body: 'already exists')
+
+    expect {
+      post '/wiki',
+           params: {
+             title: 'wiki_collision_create',
+             body: 'new body',
+             message: 'duplicate create',
+           },
+           headers: auth_headers(user)
+    }
+        .not_to change(WikiPage, :count)
+
+    expect(response).to have_http_status(:unprocessable_entity)
+  end
+end

backend/spec/services/wiki/commit_integrity_spec.rb

@@ -0,0 +1,173 @@
+require 'digest'
+require 'rails_helper'
+
+RSpec.describe Wiki::Commit do
+  let(:user) { create_member_user! }
+
+  def create_page title:, body: 'initial body'
+    described_class.create_content!(
+        tag_name: TagName.create!(name: title),
+        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: TagName.create!(name: 'commit_integrity_create'),
+            body: "a\r\nb\r\n\r\n",
+            created_by_user: user,
+            message: 'init')
+      }
+          .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')
+    end
+
+    it 'rejects body that becomes blank after normalisation' do
+      tag_name = TagName.create!(name: 'commit_integrity_blank')
+
+      expect {
+        described_class.create_content!(
+            tag_name:,
+            body: "\r\n\r\n",
+            created_by_user: user,
+            message: 'blank')
+      }
+          .to raise_error(ActiveRecord::RecordInvalid)
+
+      expect(WikiPage.where(tag_name:)).not_to exist
+    end
+  end
+
+  describe '.content!' do
+    it 'updates page body, revision, and version' do
+      page = create_page(title: 'commit_integrity_update', body: 'before')
+      current_id = page.current_revision.id
+
+      expect {
+        described_class.content!(
+            page:,
+            body: 'after',
+            created_user: user,
+            message: 'edit',
+            base_revision_id: current_id)
+      }
+          .to change(WikiRevision, :count).by(1)
+          .and change(WikiVersion, :count).by(1)
+
+      page.reload
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(page.body).to eq('after')
+      expect(version.body).to eq('after')
+      expect(version.reason).to eq('edit')
+    end
+
+    it 'does not record tag_version on body-only wiki update' do
+      tag_name = TagName.create!(name: 'commit_integrity_linked_tag')
+      tag = Tag.create!(tag_name:, category: :general)
+
+      page =
+          described_class.create_content!(
+              tag_name:,
+              body: 'before',
+              created_by_user: user,
+              message: 'init')
+
+      TagVersionRecorder.record!(
+          tag:,
+          event_type: :create,
+          created_by_user: user)
+
+      before_count = tag.reload.tag_versions.count
+
+      described_class.content!(
+          page:,
+          body: 'after',
+          created_user: user,
+          message: 'edit',
+          base_revision_id: page.current_revision.id)
+
+      expect(tag.reload.tag_versions.count).to eq(before_count)
+    end
+
+    it 'raises conflict and leaves page, revision, and version unchanged' do
+      page = create_page(title: 'commit_integrity_conflict', body: 'first')
+      stale_id = page.current_revision.id
+
+      described_class.content!(
+          page:,
+          body: 'second',
+          created_user: user,
+          message: 'second',
+          base_revision_id: stale_id)
+
+      page.reload
+      before_body = page.body
+      before_revision_count = page.wiki_revisions.count
+      before_version_count = page.wiki_versions.count
+
+      expect {
+        described_class.content!(
+            page:,
+            body: 'third',
+            created_user: user,
+            message: 'stale',
+            base_revision_id: stale_id)
+      }
+          .to raise_error(Wiki::Commit::Conflict)
+
+      page.reload
+      expect(page.body).to eq(before_body)
+      expect(page.wiki_revisions.count).to eq(before_revision_count)
+      expect(page.wiki_versions.count).to eq(before_version_count)
+    end
+
+    it 'deduplicates duplicated missing wiki lines' do
+      page = create_page(title: 'commit_integrity_dedup', body: 'before')
+      duplicated = 'commit_integrity_duplicate_line'
+
+      described_class.content!(
+          page:,
+          body: "#{ duplicated }\n#{ duplicated }",
+          created_user: user,
+          message: 'dedup',
+          base_revision_id: page.current_revision.id)
+
+      revision = page.reload.current_revision
+
+      expect(WikiLine.where(body: duplicated).count).to eq(1)
+      expect(revision.wiki_revision_lines.count).to eq(2)
+      expect(revision.wiki_revision_lines.pluck(:wiki_line_id).uniq.size).to eq(1)
+    end
+  end
+
+  describe '.redirect!' do
+    it 'raises because redirect revisions are deprecated' do
+      page = create_page(title: 'commit_integrity_redirect_source', body: 'source')
+      target = create_page(title: 'commit_integrity_redirect_target', body: 'target')
+
+      expect {
+        described_class.redirect!(
+            page:,
+            redirect_page: target,
+            created_user: user,
+            message: 'redirect',
+            base_revision_id: page.current_revision.id)
+      }
+          .to raise_error(RuntimeError, '廃止しました．')
+    end
+  end
+end

backend/spec/services/wiki/commit_spec.rb

@@ -0,0 +1,150 @@
+require 'rails_helper'
+
+RSpec.describe Wiki::Commit do
+  let(:user) { create_member_user! }
+
+  def create_page(title: 'commit_spec_page', body: 'initial body')
+    tag_name = TagName.create!(name: title)
+
+    Wiki::Commit.create_content!(
+        tag_name:,
+        body:,
+        created_by_user: user,
+        message: 'init')
+  end
+
+  describe '.content!' do
+    it 'stores normalised body in wiki_pages and wiki_versions' do
+      page = create_page(title: 'commit_normalised_page')
+
+      described_class.content!(
+        page:,
+        body: "a\r\nb\r\n\r\n",
+        created_user: user,
+        message: 'init'
+      )
+
+      page.reload
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(page.body).to eq("a\nb")
+      expect(version.body).to eq("a\nb")
+      expect(page.current_revision.lines_count).to eq(2)
+    end
+
+    it 'deduplicates duplicated missing wiki lines before upsert' do
+      page = create_page(title: 'commit_duplicate_line_page')
+      duplicated = 'commit_duplicate_line'
+
+      described_class.content!(
+        page:,
+        body: "#{ duplicated }\n#{ duplicated }",
+        created_user: user,
+        message: 'init'
+      )
+
+      page.reload
+
+      expect(WikiLine.where(body: duplicated).count).to eq(1)
+      expect(page.current_revision.lines_count).to eq(2)
+      expect(page.current_revision.wiki_revision_lines.count).to eq(2)
+    end
+
+    it 'raises conflict when base_revision_id is stale' do
+      page = create_page(title: 'commit_conflict_page')
+
+      first = described_class.content!(
+        page:,
+        body: 'first',
+        created_user: user,
+        message: 'first'
+      )
+
+      described_class.content!(
+        page:,
+        body: 'second',
+        created_user: user,
+        message: 'second',
+        base_revision_id: first.id
+      )
+
+      expect {
+        described_class.content!(
+          page:,
+          body: 'third',
+          created_user: user,
+          message: 'third',
+          base_revision_id: first.id
+        )
+      }.to raise_error(Wiki::Commit::Conflict)
+    end
+
+    it 'does not record tag version when corresponding tag has no versions' do
+      tag_name = TagName.create!(name: 'commit_linked_tag_without_versions')
+      tag = Tag.create!(tag_name:, category: :general)
+
+      page =
+          described_class.create_content!(
+              tag_name:,
+              body: 'before',
+              created_by_user: user,
+              message: 'init')
+
+      expect(tag.reload.tag_versions.count).to eq(0)
+
+      current_revision_id = page.current_revision.id
+
+      expect {
+        described_class.content!(
+            page:,
+            body: 'after',
+            created_user: user,
+            message: 'edit',
+            base_revision_id: current_revision_id)
+      }.to change(WikiVersion, :count).by(1)
+
+      expect(tag.reload.tag_versions.count).to eq(0)
+    end
+
+    it 'does not record tag version when corresponding tag has no versions' do
+      tag_name = TagName.create!(name: 'commit_linked_tag_without_versions')
+      tag = Tag.create!(tag_name:, category: :general)
+
+      page =
+          described_class.create_content!(
+              tag_name:,
+              body: 'before',
+              created_by_user: user,
+              message: 'init')
+
+      current_revision_id = page.current_revision.id
+
+      expect {
+        described_class.content!(
+            page:,
+            body: 'after',
+            created_user: user,
+            message: 'edit',
+            base_revision_id: current_revision_id)
+      }.to change(WikiVersion, :count).by(1)
+
+      expect(tag.reload.tag_versions.count).to eq(0)
+    end
+  end
+
+  describe '.redirect!' do
+    it 'raises because redirect revisions are deprecated' do
+      page = create_page(title: 'commit_redirect_source')
+      target = create_page(title: 'commit_redirect_target')
+
+      expect {
+        described_class.redirect!(
+          page:,
+          redirect_page: target,
+          created_user: user,
+          message: 'redirect'
+        )
+      }.to raise_error(RuntimeError, '廃止しました．')
+    end
+  end
+end

backend/spec/services/wiki_version_recorder_spec.rb

@@ -0,0 +1,99 @@
+require 'rails_helper'
+
+RSpec.describe WikiVersionRecorder do
+  let(:user) { create_member_user! }
+
+  def create_page title:, body: 'body'
+    Wiki::Commit.create_content!(
+        tag_name: TagName.create!(name: title),
+        body:,
+        created_by_user: user,
+        message: 'init')
+  end
+
+  describe '.record!' do
+    it 'records title, body, reason, user, and version number' do
+      page = create_page(title: 'wiki_version_recorder_basic', body: 'body')
+
+      expect {
+        described_class.record!(
+            page:,
+            event_type: :update,
+            reason: 'manual reason',
+            created_by_user: user)
+      }
+          .to change { page.reload.wiki_versions.count }.by(1)
+
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(version).to have_attributes(
+        version_no: 2,
+        event_type: 'update',
+        title: 'wiki_version_recorder_basic',
+        body: 'body',
+        reason: 'manual reason',
+        created_by_user_id: user.id
+      )
+    end
+
+    it 'does not create duplicated update version for identical snapshot' do
+      page = create_page(title: 'wiki_version_recorder_duplicate', body: 'body')
+
+      described_class.record!(
+          page:,
+          event_type: :update,
+          reason: nil,
+          created_by_user: user)
+
+      before_count = page.reload.wiki_versions.count
+
+      described_class.record!(
+          page:,
+          event_type: :update,
+          reason: nil,
+          created_by_user: user)
+
+      expect(page.reload.wiki_versions.count).to eq(before_count)
+    end
+
+    it 'creates update version when title changes' do
+      page = create_page(title: 'wiki_version_recorder_title_before', body: 'body')
+      page.tag_name.update!(name: 'wiki_version_recorder_title_after')
+
+      expect {
+        described_class.record!(
+            page:,
+            event_type: :update,
+            reason: 'rename',
+            created_by_user: user)
+      }
+          .to change { page.reload.wiki_versions.count }.by(1)
+
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(version.title).to eq('wiki_version_recorder_title_after')
+      expect(version.body).to eq('body')
+      expect(version.reason).to eq('rename')
+    end
+
+    it 'creates update version when body changes' do
+      page = create_page(title: 'wiki_version_recorder_body', body: 'before')
+      page.update!(body: 'after')
+
+      expect {
+        described_class.record!(
+            page:,
+            event_type: :update,
+            reason: 'body',
+            created_by_user: user)
+      }
+          .to change { page.reload.wiki_versions.count }.by(1)
+
+      version = page.wiki_versions.order(:version_no).last
+
+      expect(version.title).to eq('wiki_version_recorder_body')
+      expect(version.body).to eq('after')
+      expect(version.reason).to eq('body')
+    end
+  end
+end