fix(redirect): keep localeRoutes aliases under autoDetectPath /

Preference gating must not skip getClientRedirect for unprefixed
paths — force defaultLocale instead so /product → /our-products works.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: s00d

packages/utils/src/auto-detect-path.ts

@@ -1,13 +1,14 @@
 /**
- * Whether preference-based locale redirects may run for an unprefixed path (#242).
+ * Whether cookie / Accept-Language preference may steer locale redirects (#242).
  *
  * Modes (`ModuleOptions.autoDetectPath`):
  * - `'/'` (default) — only `/`
  * - `'no_prefix'` — any path without a locale prefix
  * - `'*'` — every path (also enables aggressive prefixed-URL rewrites in the plugin)
  * - any other string — exact path match
  *
- * Prefixed strategy cleanup (e.g. `/en` → `/` under `prefix_except_default`) is not gated here.
+ * Does not gate strategy / `localeRoutes` canonicalization: when preference is denied on an
+ * unprefixed path, the plugin still runs `getClientRedirect` with the default locale.
  */
 export function shouldAttemptLocaleRedirect(path: string, options: { autoDetectPath?: string; hasLocalePrefix?: boolean } = {}): boolean {
   const mode = options.autoDetectPath ?? '/'

src/runtime/middleware/i18n-redirect.global.ts

@@ -43,9 +43,11 @@ export default defineNuxtRouteMiddleware((to, from) => {
   const hasLocalePrefix = Boolean(firstSegment && validLocales.includes(firstSegment))
   const allowPreferenceRedirect = shouldAttemptLocaleRedirect(path, { autoDetectPath, hasLocalePrefix })
 
-  // Preference redirects on unprefixed paths are gated by autoDetectPath.
-  // Prefixed strategy cleanup (e.g. /en → /) always runs.
-  if (!hasLocalePrefix && !allowPreferenceRedirect) return
+  // Cookie / Accept-Language preference is gated by autoDetectPath (#242).
+  // Unprefixed deep links still canonicalize with the default locale (localeRoutes aliases).
+  if (!hasLocalePrefix && !allowPreferenceRedirect) {
+    preferredLocale = defaultLocale
+  }
 
   if (autoDetectPath === '*' && !hasLocalePrefix) {
     preferredLocale = defaultLocale

src/runtime/plugins/06.redirect.ts

@@ -90,45 +90,48 @@ export default defineNuxtPlugin({
       if (i18nConfig.redirects !== false) {
         const allowPreferenceRedirect = shouldAttemptLocaleRedirect(path, { autoDetectPath, hasLocalePrefix })
 
-        // Preference redirects on unprefixed paths are gated by autoDetectPath.
-        // Prefixed strategy cleanup (e.g. /en → /) always runs.
-        if (hasLocalePrefix || allowPreferenceRedirect) {
-          const localeState = autoDetectPath !== '*' ? useState<string | null>('i18n-locale', () => null) : null
-          let preferredLocale = resolvePreferredLocale({
-            defaultLocale,
-            validLocales,
-            autoDetectLanguage: i18nConfig.autoDetectLanguage,
-            stateLocale: localeState?.value ?? null,
-            cookieLocale: cookieName ? getCookie(event, cookieName) : null,
-            acceptLanguageHeader: getHeader(event, 'accept-language'),
-            ignoreStateLocale: autoDetectPath === '*',
-          })
-
-          if (autoDetectPath === '*' && !hasLocalePrefix) {
-            preferredLocale = defaultLocale
-          }
+        const localeState = autoDetectPath !== '*' ? useState<string | null>('i18n-locale', () => null) : null
+        let preferredLocale = resolvePreferredLocale({
+          defaultLocale,
+          validLocales,
+          autoDetectLanguage: i18nConfig.autoDetectLanguage,
+          stateLocale: localeState?.value ?? null,
+          cookieLocale: cookieName ? getCookie(event, cookieName) : null,
+          acceptLanguageHeader: getHeader(event, 'accept-language'),
+          ignoreStateLocale: autoDetectPath === '*',
+        })
+
+        // Cookie / Accept-Language preference is gated by autoDetectPath (#242).
+        // Unprefixed deep links still run getClientRedirect with the default locale so
+        // custom localeRoutes aliases (e.g. /product → /our-products) keep working.
+        if (!hasLocalePrefix && !allowPreferenceRedirect) {
+          preferredLocale = defaultLocale
+        }
 
-          if (autoDetectPath === '*' && hasLocalePrefix && firstSegment !== preferredLocale) {
-            const rest = pathSegments.slice(1).join('/')
-            let targetPath: string
-            if (preferredLocale === defaultLocale && i18nConfig.strategy === 'prefix_except_default') {
-              targetPath = rest ? `/${rest}` : '/'
-            } else {
-              targetPath = rest ? `/${preferredLocale}/${rest}` : `/${preferredLocale}`
-            }
-            if (cookieName) {
-              const { watch: _w2, ...cookieOpts2 } = getLocaleCookieOptions()
-              setCookie(event, cookieName, preferredLocale, cookieOpts2)
-            }
-            if (DEBUG) console.error('[i18n-redirect] REDIRECT autoDetectPath *', { path, targetPath, preferredLocale })
-            return performRedirect(targetPath + (url.search || '') + (url.hash || ''))
-          }
+        if (autoDetectPath === '*' && !hasLocalePrefix) {
+          preferredLocale = defaultLocale
+        }
 
-          const redirectPath = i18nStrategy.getClientRedirect(path, preferredLocale)
-          if (redirectPath) {
-            if (DEBUG) console.error('[i18n-redirect] REDIRECT', { path, redirectPath, preferredLocale })
-            return performRedirect(redirectPath + (url.search || '') + (url.hash || ''))
+        if (autoDetectPath === '*' && hasLocalePrefix && firstSegment !== preferredLocale) {
+          const rest = pathSegments.slice(1).join('/')
+          let targetPath: string
+          if (preferredLocale === defaultLocale && i18nConfig.strategy === 'prefix_except_default') {
+            targetPath = rest ? `/${rest}` : '/'
+          } else {
+            targetPath = rest ? `/${preferredLocale}/${rest}` : `/${preferredLocale}`
           }
+          if (cookieName) {
+            const { watch: _w2, ...cookieOpts2 } = getLocaleCookieOptions()
+            setCookie(event, cookieName, preferredLocale, cookieOpts2)
+          }
+          if (DEBUG) console.error('[i18n-redirect] REDIRECT autoDetectPath *', { path, targetPath, preferredLocale })
+          return performRedirect(targetPath + (url.search || '') + (url.hash || ''))
+        }
+
+        const redirectPath = i18nStrategy.getClientRedirect(path, preferredLocale)
+        if (redirectPath) {
+          if (DEBUG) console.error('[i18n-redirect] REDIRECT', { path, redirectPath, preferredLocale })
+          return performRedirect(redirectPath + (url.search || '') + (url.hash || ''))
         }
       }
     }