未翻訳ブログページのSEO信号を整理

astro.config.mjs

@@ -4,6 +4,44 @@ import sitemap from '@astrojs/sitemap'
 import rehypeExternalLinks from 'rehype-external-links'
 import rehypeOptimizeImages from './src/utils/rehype-optimize-images'
 import rehypeInjectAds from './src/utils/rehype-inject-ads'
+import { existsSync, readdirSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+
+const defaultLocale = 'ja'
+const locales = ['ja', 'en', 'zh-cn', 'es', 'pt', 'fr', 'ko', 'de', 'ru']
+const translatedBlogSlugsByLocale = Object.fromEntries(
+  locales
+    .filter((locale) => locale !== defaultLocale)
+    .map((locale) => {
+      const dir = fileURLToPath(
+        new URL(`./src/content/blog/${locale}/`, import.meta.url),
+      )
+      return [
+        locale,
+        new Set(
+          existsSync(dir)
+            ? readdirSync(dir)
+                .filter((file) => file.endsWith('.md'))
+                .map((file) => file.replace(/\.md$/, ''))
+            : [],
+        ),
+      ]
+    }),
+)
+
+function isMissingLocalizedBlogPost(page) {
+  const { pathname } = new URL(page)
+  const parts = pathname.split('/').filter(Boolean)
+  const [locale, section, slug] = parts
+  return (
+    locale &&
+    locale !== defaultLocale &&
+    translatedBlogSlugsByLocale[locale] &&
+    section === 'blog' &&
+    parts.length === 3 &&
+    !translatedBlogSlugsByLocale[locale].has(decodeURIComponent(slug))
+  )
+}
 
 export default defineConfig({
   site: 'https://acecore.net',
@@ -33,6 +71,7 @@ export default defineConfig({
       lastmod: new Date(),
       filter(page) {
         return (
+          !isMissingLocalizedBlogPost(page) &&
           !page.includes('/blog/tags/') &&
           !page.includes('/blog/archive/') &&
           !page.includes('/blog/authors/') &&

public/_redirects

@@ -52,6 +52,38 @@
 /de/blog/business-system-implementation-tips/ https://systems.acecore.net/guide/ 301
 /ru/blog/business-system-implementation-tips https://systems.acecore.net/guide/ 301
 /ru/blog/business-system-implementation-tips/ https://systems.acecore.net/guide/ 301
+/en/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/en/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/zh-cn/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/zh-cn/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/es/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/es/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/pt/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/pt/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/fr/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/fr/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/ko/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/ko/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/de/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/de/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/ru/blog/homepage-production-cost-guide https://acecore.net/blog/homepage-production-cost-guide/ 301
+/ru/blog/homepage-production-cost-guide/ https://acecore.net/blog/homepage-production-cost-guide/ 301
+/en/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/en/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
+/zh-cn/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/zh-cn/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
+/es/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/es/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
+/pt/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/pt/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
+/fr/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/fr/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
+/ko/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/ko/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
+/de/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/de/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
+/ru/blog/service-cta-contact-prefill https://acecore.net/blog/service-cta-contact-prefill/ 301
+/ru/blog/service-cta-contact-prefill/ https://acecore.net/blog/service-cta-contact-prefill/ 301
 /blog/tags/システム開発 https://systems.acecore.net/guide/ 301
 /blog/tags/システム開発/ https://systems.acecore.net/guide/ 301
 /en/blog/tags/システム開発 https://systems.acecore.net/guide/ 301

src/layouts/BaseLayout.astro

@@ -25,6 +25,8 @@ interface Props {
   locale?: Locale
   breadcrumbItems?: { name: string; item?: string }[]
   languageSwitcherPath?: string
+  canonicalPath?: string
+  alternateUrls?: { locale: Locale; url: string }[]
 }
 
 const locale = Astro.props.locale ?? getLocaleFromUrl(Astro.url)
@@ -44,12 +46,14 @@ const {
   preloadImage,
   breadcrumbItems,
   languageSwitcherPath,
+  canonicalPath,
+  alternateUrls,
 } = Astro.props
 
 const isHome = title === t(locale, 'nav.home')
 const gaFallbackDelay = isHome ? 12000 : 4000
 const pageTitle = isHome ? t(locale, 'meta.siteTitle') : `${title} | Acecore`
-const canonicalURL = new URL(Astro.url.pathname, Astro.site)
+const canonicalURL = new URL(canonicalPath ?? Astro.url.pathname, Astro.site)
 const ogImage = image || new URL('/uploads/og-default.png', Astro.site).href
 const isMonetizedPage =
   Astro.url.pathname === '/blog/' || Astro.url.pathname.startsWith('/blog/')
@@ -146,7 +150,8 @@ const breadcrumbLd =
       }
     : null)
 
-const alternateUrls = getAlternateUrls(Astro.url.pathname, siteOrigin)
+const alternateUrlEntries =
+  alternateUrls ?? getAlternateUrls(Astro.url.pathname, siteOrigin)
 
 import { ClientRouter } from 'astro:transitions'
 import Header from '../components/Header.astro'
@@ -220,14 +225,14 @@ import { SITE } from '../data/site'
       href={locale === defaultLocale ? '/rss.xml' : `/${locale}/rss.xml`}
     />
     {
-      alternateUrls.map(({ locale: l, url }) => (
+      alternateUrlEntries.map(({ locale: l, url }) => (
         <link rel="alternate" hreflang={htmlLangMap[l]} href={url} />
       ))
     }
     <link
       rel="alternate"
       hreflang="x-default"
-      href={alternateUrls.find((a) => a.locale === defaultLocale)?.url}
+      href={alternateUrlEntries.find((a) => a.locale === defaultLocale)?.url}
     />
     <link rel="preconnect" href={SITE.url} />
     {

src/pages/[locale]/blog/[...slug].astro

@@ -5,16 +5,22 @@ import { locales, defaultLocale, type Locale } from '../../../i18n'
 import { isBasePost } from '../../../utils/blog-i18n'
 
 export async function getStaticPaths() {
-  const allPosts = (await getCollection('blog'))
+  const allRawPosts = await getCollection('blog')
+  const allPosts = allRawPosts
     .filter(isBasePost)
     .sort((a, b) => b.data.date.getTime() - a.data.date.getTime())
+  const translatedPostIds = new Set(
+    allRawPosts.filter((post) => !isBasePost(post)).map((post) => post.id),
+  )
   return locales
     .filter((l) => l !== defaultLocale)
     .flatMap((locale) =>
-      allPosts.map((post) => ({
-        params: { locale, slug: post.id },
-        props: { post, allPosts },
-      })),
+      allPosts
+        .filter((post) => translatedPostIds.has(`${locale}/${post.id}`))
+        .map((post) => ({
+          params: { locale, slug: post.id },
+          props: { post, allPosts },
+        })),
     )
 }
 

src/views/BlogPostPage.astro

@@ -33,6 +33,7 @@ import {
   getDateParts,
   defaultLocale,
   htmlLangMap,
+  locales,
   type Locale,
 } from '../i18n'
 import { getCollection } from 'astro:content'
@@ -64,6 +65,21 @@ const authors = await getAllAuthors()
 const tagsData = await getAllTags()
 const post = localizePost(basePost, allRawPosts, locale)
 const baseSlug = basePost.id
+const isFallbackLocalePost = locale !== defaultLocale && post.id === basePost.id
+const canonicalPostPath = isFallbackLocalePost
+  ? `/blog/${baseSlug}/`
+  : u(`/blog/${baseSlug}/`)
+const canonicalPostUrl = new URL(canonicalPostPath, Astro.site).href
+const alternateUrls = locales
+  .filter(
+    (l) =>
+      l === defaultLocale ||
+      allRawPosts.some((candidate) => candidate.id === `${l}/${baseSlug}`),
+  )
+  .map((l) => ({
+    locale: l,
+    url: new URL(getLocalizedUrl(`/blog/${baseSlug}/`, l), Astro.site).href,
+  }))
 
 const { Content, headings } = await render(post)
 const tocHeadings = headings.filter((h) => h.depth >= 2 && h.depth <= 3)
@@ -145,7 +161,7 @@ const blogPostingLd = {
   },
   mainEntityOfPage: {
     '@type': 'WebPage',
-    '@id': `https://acecore.net/blog/${baseSlug}/`,
+    '@id': canonicalPostUrl,
   },
   inLanguage: htmlLangMap[locale],
 }
@@ -229,9 +245,12 @@ const ctaHeading = isDefaultLocale
   jsonLd={jsonLdData}
   publishedTime={post.data.date}
   modifiedTime={post.data.lastUpdated}
+  robots={isFallbackLocalePost ? 'noindex, follow' : 'index, follow'}
   tags={post.data.tags}
   author={author?.name}
   locale={locale}
+  canonicalPath={canonicalPostPath}
+  alternateUrls={alternateUrls}
   preloadImage={postImage
     ? {
         src: optimizeImage(postImage),
@@ -397,7 +416,7 @@ const ctaHeading = isDefaultLocale
 
         <div class="my-10 border-t border-slate-200 py-6">
           <ShareButtons
-            url={`https://acecore.net/blog/${baseSlug}/`}
+            url={canonicalPostUrl}
             title={post.data.title}
             locale={locale}
           />