AI: address review on PR #460

backend/app/models/post_implication.rb

@@ -8,7 +8,6 @@ class PostImplication < ApplicationRecord
   validates :parent_post_id, presence: true
 
   validate :parent_post_mustnt_be_itself
-  validate :parent_post_mustnt_create_cycle
 
   private
 
@@ -17,24 +16,4 @@ class PostImplication < ApplicationRecord
       errors.add :parent_post_id, '親投稿に同じ投稿を設定することはできません．'
     end
   end
-
-  def parent_post_mustnt_create_cycle
-    return if post_id.blank? || parent_post_id.blank?
-    return if errors[:parent_post_id].present?
-
-    ancestor_ids = Set.new
-    frontier_ids = [parent_post_id]
-
-    until frontier_ids.empty?
-      if frontier_ids.include?(post_id)
-        errors.add :parent_post_id, :invalid
-        return
-      end
-
-      ancestor_ids.merge(frontier_ids)
-      frontier_ids = PostImplication.where(post_id: frontier_ids)
-          .distinct.pluck(:parent_post_id)
-          .reject { ancestor_ids.include?(_1) }
-    end
-  end
 end

backend/spec/models/post_implication_spec.rb

@@ -48,47 +48,4 @@ RSpec.describe PostImplication, type: :model do
     expect(duplicate).not_to be_valid
     expect(duplicate.errors[:post_id]).to be_present
   end
-
-  it 'rejects a parent that would create a two-post cycle' do
-    described_class.create!(post: post_record, parent_post:)
-
-    implication = described_class.new(
-        post: parent_post, parent_post: post_record)
-
-    expect(implication).not_to be_valid
-    expect(implication.errors.of_kind?(:parent_post_id, :invalid)).to be true
-  end
-
-  it 'rejects a parent that would create a three-post cycle' do
-    ancestor_post = create(:post)
-    described_class.create!(post: post_record, parent_post:)
-    described_class.create!(post: parent_post, parent_post: ancestor_post)
-
-    implication = described_class.new(
-        post: ancestor_post, parent_post: post_record)
-
-    expect(implication).not_to be_valid
-    expect(implication.errors.of_kind?(:parent_post_id, :invalid)).to be true
-  end
-
-  it 'allows a parent with an ancestor when no cycle would result' do
-    ancestor_post = create(:post)
-    described_class.create!(post: parent_post, parent_post: ancestor_post)
-
-    implication = described_class.new(post: post_record, parent_post:)
-
-    expect(implication).to be_valid
-  end
-
-  it 'terminates when existing ancestors already contain a cycle' do
-    ancestor_post = create(:post)
-    described_class.create!(post: parent_post, parent_post: ancestor_post)
-    legacy_implication = described_class.new(
-        post: ancestor_post, parent_post:)
-    legacy_implication.save!(validate: false)
-
-    implication = described_class.new(post: post_record, parent_post:)
-
-    expect(implication).to be_valid
-  end
 end

frontend/server.ssr.test.mjs

@@ -2,6 +2,7 @@ import assert from 'node:assert/strict'
 import { createServer } from 'node:http'
 import { spawn } from 'node:child_process'
 import { after, before, test } from 'node:test'
+import { JSDOM } from 'jsdom'
 import { createServer as createViteServer } from 'vite'
 
 import { render } from './dist/server/entry-server.js'
@@ -402,6 +403,26 @@ test ('every canonical screen route returns page HTML without JavaScript', async
   }
 })
 
+test ('SSR HTML head includes reciprocal hreflang links with query parameters', async () => {
+  for (const locale of ['ja', 'ain-Kana']) {
+    const response = await fetch (`${httpOrigin}/${locale}/posts?page=2&limit=50`)
+    assert.equal (response.status, 200)
+    const dom = new JSDOM (await response.text ())
+    try
+    {
+      const links = [...dom.window.document.head.querySelectorAll ('link[rel="alternate"]')]
+      assert.deepEqual (links.map (link => ({
+        locale: link.getAttribute ('hreflang'), href: link.getAttribute ('href') })), [
+        { locale: 'ja', href: `${origin}/ja/posts?page=2&limit=50` },
+        { locale: 'ain-Kana', href: `${origin}/ain-Kana/posts?page=2&limit=50` }])
+    }
+    finally
+    {
+      dom.window.close ()
+    }
+  }
+})
+
 test ('YouTube posts return HTTP 200 with the embed rendered by SSR', async t => {
   for (const locale of ['ja', 'ain-Kana']) {
     await t.test (locale, async () => {

frontend/src/entry-server.tsx

@@ -1,6 +1,6 @@
 import { QueryClient, QueryClientProvider, dehydrate, skipToken } from '@tanstack/react-query'
 import { PassThrough } from 'node:stream'
-import { renderToPipeableStream } from 'react-dom/server'
+import { renderToPipeableStream, renderToStaticMarkup } from 'react-dom/server'
 import { HelmetProvider } from 'react-helmet-async'
 import { I18nextProvider } from 'react-i18next'
 import { createStaticHandler, createStaticRouter,
@@ -9,7 +9,7 @@ import { createStaticHandler, createStaticRouter,
 import { AppFrame, appRoutes, resolvePageRoute } from '@/App'
 import { apiGet, isApiError } from '@/lib/api'
 import { createUII18n } from '@/lib/i18n'
-import { fetchLocales, isLocaleCode, legacyLocalePath } from '@/lib/locales'
+import { fetchLocales, isLocaleCode, legacyLocalePath, switchLocalePath } from '@/lib/locales'
 import { localesKeys, sessionKeys } from '@/lib/queryKeys'
 import { withRenderContext } from '@/lib/renderContext.server'
 
@@ -171,8 +171,26 @@ export const render = async (
 	}))
       }
       const helmet = helmetContext.helmet!
+      const alternates = status === 200 && known != null
+	  ? await Promise.all (locales.locales.map (entry => entry.code)
+	      .filter (isLocaleCode)
+	      .filter (code => known.route.handle?.locale == null
+		  || known.route.handle.locale === code)
+	      .map (async targetLocale => {
+		const location = { pathname: url.pathname, search: url.search, hash: '' }
+		const path = targetLocale === locale
+		    ? url.pathname + url.search
+		    : (known.route.handle?.switchLocale != null
+		       ? await known.route.handle.switchLocale ({
+			   location, params: known.params, locale, targetLocale })
+		       : switchLocalePath (location, targetLocale))
+		return <link key={targetLocale} rel="alternate" hrefLang={targetLocale}
+		    href={new URL (path, origin).href}/>
+	      }))
+	  : []
       const head = [helmet.title, helmet.meta, helmet.link, helmet.style]
 	  .map (entry => entry.toString ()).join ('')
+	  + renderToStaticMarkup (<>{alternates}</>)
       const dehydrated = dehydrate (client, { shouldDehydrateQuery: query =>
 	  query.state.status !== 'pending'
 	  && query.meta?.clientOnly !== true