fix: leave the i18n copies of a page in other locales out of the route report

With prefix_except_default (or prefix_and_default) @nuxtjs/i18n adds a copy
of every page per other locale (/pl/contact next to /contact). The route
report sent them as pages of their own, so the CMS registry got a second,
untranslated page for each. They are the page's translations: the report
now skips routes named with another locale's suffix (contact___pl).

README.md

@@ -40,7 +40,7 @@ The layer's only module is its own local one (`lib/seo-module.ts`); it pulls in
   definePageMeta({ seo: { breadcrumbs: false } })        // no visible breadcrumbs here
   ```
 
-- **Route report (v0.2.0, D-33).** At server start the layer posts its static routes (pages without parameters, without the noindex ones above, without `noindexRoutes`) to `POST <apiBase>/registry/routes` as `{"routes": [...]}` (at most 2000 paths) with `Authorization: Bearer <routeReportToken>`, once per process, after the start; a failure is tried once more after 60 s, a 404 (a backend without the registry) or a refused token is logged and not retried. Nothing is sent without a token, with `routeReport: false`, with the layer off or while prerendering. The route list is written at build time into the server template `#seo-routes`; no network call happens at build time.
+- **Route report (v0.2.0, D-33).** At server start the layer posts its static routes (pages without parameters, without the noindex ones above, without `noindexRoutes`, and with `@nuxtjs/i18n`'s `prefix_except_default` or `prefix_and_default` without the copies of a page in the other locales, such as `/pl/contact` next to `/contact`: the CMS knows those as the page's translations, which an editor gives the page in SEO › Pages) to `POST <apiBase>/registry/routes` as `{"routes": [...]}` (at most 2000 paths) with `Authorization: Bearer <routeReportToken>`, once per process, after the start; a failure is tried once more after 60 s, a 404 (a backend without the registry) or a refused token is logged and not retried. Nothing is sent without a token, with `routeReport: false`, with the layer off or while prerendering. The route list is written at build time into the server template `#seo-routes`; no network call happens at build time.
 - **Drift check (v0.2.0, D-20c).** At server start the layer compares the site answer's content-type URL patterns (`routes`), pagination form, parameter and segments and HTML sitemap paths with its build-time routes and the `pagination` and `htmlSitemap` options, and logs one `[vue-seo-layer] drift: …` warning per mismatch. A CMS pattern counts as served by a route of the same shape or a catch-all under a static prefix; a catch-all at the root does not. The check never blocks or fails the start, and a backend without a site answer is skipped.
 - **Breadcrumbs, pagination and the HTML sitemap (v0.2.0).** See Components.
 - **Visitor address.** The server calls forward the visitor's `X-Forwarded-For` plus the address of the peer that reached Nuxt, also on route-cached (`swr`) renders, so the plugin's per-IP throttles (`seo-resolve`, `seo-notfound`, 600 a minute) keep one bucket per visitor. List the Nuxt server's address in the backend's `http.trusted_proxies`.

lib/routes.ts

@@ -42,15 +42,35 @@ export function pageMetaRobots(meta: Record<string, unknown> | undefined | null)
 /** The layer's own HTML sitemap pages, which the CMS knows already. */
 const isLayerPage = (name: unknown) => typeof name === 'string' && name.startsWith('seo-sitemap-')
 
+/**
+ * The route-name suffixes of @nuxtjs/i18n's copies of a page in the locales
+ * other than the default one (`contact___pl` with the default separator):
+ * with prefix_except_default or prefix_and_default the CMS knows those
+ * addresses as the page's translations, not as pages of their own. Nothing
+ * without i18n, with no_prefix or without a default locale.
+ */
+export function localeCopySuffixes(i18n: unknown): string[] {
+  if (!i18n || typeof i18n !== 'object') return []
+  const o = i18n as { strategy?: unknown; defaultLocale?: unknown; locales?: unknown; routesNameSeparator?: unknown }
+  const strategy = typeof o.strategy === 'string' ? o.strategy : 'prefix_except_default'
+  const def = typeof o.defaultLocale === 'string' ? o.defaultLocale : ''
+  if (strategy === 'no_prefix' || def === '' || !Array.isArray(o.locales)) return []
+  const sep = typeof o.routesNameSeparator === 'string' && o.routesNameSeparator !== '' ? o.routesNameSeparator : '___'
+  const codes = o.locales.map((l) => (typeof l === 'string' ? l : l && typeof l === 'object' ? (l as { code?: unknown }).code : undefined))
+  return codes.filter((c): c is string => typeof c === 'string' && c !== '' && c !== def).map((c) => `${sep}${c}`)
+}
+
 /**
  * The paths without parameters that may be indexed, sorted: no page whose
  * meta keeps it out of the index (requiresAuth, a noindex seo.robots), none
- * under seo.noindexRoutes, none of the layer's HTML sitemap pages and no
- * client-only page.
+ * under seo.noindexRoutes, none of the layer's HTML sitemap pages, no
+ * client-only page and no i18n copy of a page in another locale (a route
+ * whose name ends in one of localeCopies, see localeCopySuffixes).
  */
-export function staticRoutes(pages: readonly RoutePage[], noindexRoutes: readonly string[]): string[] {
+export function staticRoutes(pages: readonly RoutePage[], noindexRoutes: readonly string[], localeCopies: readonly string[] = []): string[] {
   const out = new Set<string>()
   for (const page of flattenPages(pages) as Array<RoutePage & { fullPath: string }>) {
+    if (typeof page.name === 'string' && localeCopies.some((suffix) => page.name!.endsWith(suffix))) continue
     // A parent with children renders through one of them.
     if (Array.isArray(page.children) && page.children.some((c) => c.path === '')) continue
     const path = page.fullPath

lib/seo-module.ts

@@ -12,7 +12,7 @@ import { fileURLToPath } from 'node:url'
 import { addServerTemplate, defineNuxtModule, extendPages, useLogger } from 'nuxt/kit'
 import { findOffenders, guardMessage, noindexRule, type GuardPage } from './guard.ts'
 import { htmlSitemapOption, paginationOption, type SeoHtmlSitemapOption, type SeoPaginationOption } from './options.ts'
-import { routePatterns, routesTemplate, staticRoutes, type RoutePage } from './routes.ts'
+import { localeCopySuffixes, routePatterns, routesTemplate, staticRoutes, type RoutePage } from './routes.ts'
 
 export interface SeoModuleOptions {
   /**
@@ -182,7 +182,8 @@ export default defineNuxtModule<SeoModuleOptions>({
       filename: '#seo-routes',
       getContents: () => {
         const resolved = (pages ?? []) as RoutePage[]
-        return routesTemplate(staticRoutes(resolved, noindexRoutes), routePatterns(resolved))
+        const i18n = (nuxt.options as { i18n?: unknown }).i18n
+        return routesTemplate(staticRoutes(resolved, noindexRoutes, localeCopySuffixes(i18n)), routePatterns(resolved))
       },
     })
     nuxt.hook('nitro:build:before', (nitro) => {

tests/routes.test.ts

@@ -1,7 +1,7 @@
 import assert from 'node:assert/strict'
 import test from 'node:test'
 import { htmlSitemapOption, paginationOption } from '../lib/options.ts'
-import { pageMetaRobots, robotsNoindex, routePatterns, routesTemplate, staticRoutes } from '../lib/routes.ts'
+import { localeCopySuffixes, pageMetaRobots, robotsNoindex, routePatterns, routesTemplate, staticRoutes } from '../lib/routes.ts'
 import { DRIFT_PREFIX, driftWarnings, routeServes } from '../server/lib/drift.ts'
 import { ROUTE_REPORT_MAX_ROUTES, routeReportBody, routeReportOutcome } from '../server/lib/routeReport.ts'
 
@@ -124,3 +124,25 @@ test('routeServes normalises CMS patterns: {param} and :param alike, the query p
   assert.equal(routeServes(route, '/blog/{category}/{slug}'), false)
   assert.equal(routeServes({ pattern: '/docs/**', catchAll: true }, '/docs/{a}/{b}'), true)
 })
+
+test('localeCopySuffixes: the other locales of a prefixed strategy, none without one', () => {
+  const locales = [{ code: 'en' }, { code: 'pl' }, 'de']
+  assert.deepEqual(localeCopySuffixes({ strategy: 'prefix_except_default', defaultLocale: 'en', locales }), ['___pl', '___de'])
+  assert.deepEqual(localeCopySuffixes({ defaultLocale: 'en', locales, routesNameSeparator: '__' }), ['__pl', '__de'])
+  assert.deepEqual(localeCopySuffixes({ strategy: 'prefix_and_default', defaultLocale: 'pl', locales }), ['___en', '___de'])
+  assert.deepEqual(localeCopySuffixes({ strategy: 'no_prefix', defaultLocale: 'en', locales }), [])
+  assert.deepEqual(localeCopySuffixes({ strategy: 'prefix_except_default', locales }), [])
+  assert.deepEqual(localeCopySuffixes(undefined), [])
+})
+
+test('staticRoutes leaves out the i18n copies of a page in the other locales', () => {
+  const localized = [
+    { path: '/', name: 'index___en' },
+    { path: '/pl', name: 'index___pl' },
+    { path: '/contact', name: 'contact___en' },
+    { path: '/pl/contact', name: 'contact___pl' },
+    { path: '/pl/konto', name: 'konto___pl', meta: { requiresAuth: true } },
+  ]
+  assert.deepEqual(staticRoutes(localized, [], ['___pl']), ['/', '/contact'])
+  assert.deepEqual(staticRoutes(localized, []), ['/', '/contact', '/pl', '/pl/contact'])
+})