fix: alwaysRedirect does not work with redirectOn 'all' and 'no prefix' (#1884)

* fix always redirect

* fix

---------

Co-authored-by: khaled.borghol <khaled.borghol@abyatonline.com>

Author: borghol

specs/browser_language_detection/always_redirect/prefix_and_default_all.spec.ts

@@ -0,0 +1,37 @@
+import { test, expect } from 'vitest'
+import { fileURLToPath } from 'node:url'
+import { setup, url, createPage } from '@nuxt/test-utils'
+import { getText } from '../../helper'
+
+await setup({
+  rootDir: fileURLToPath(new URL(`../../fixtures/basic`, import.meta.url)),
+  browser: true,
+  // overrides
+  nuxtConfig: {
+    i18n: {
+      strategy: 'prefix_and_default',
+      detectBrowserLanguage: {
+        alwaysRedirect: true,
+        redirectOn: 'all'
+      }
+    }
+  }
+})
+
+test('alwaysRedirect: all', async () => {
+  const blog = url('/blog/article')
+  const page = await createPage(undefined, { locale: 'en' }) // set browser locale
+  await page.goto(blog)
+
+  // detect locale from navigator language
+  expect(await getText(page, '#lang-switcher-current-locale code')).toEqual('en')
+
+  // click `fr` lang switch link
+  await page.locator('#set-locale-link-fr').click()
+  expect(await getText(page, '#lang-switcher-current-locale code')).toEqual('fr')
+
+  // go to `en` home page
+  await page.goto(blog)
+  expect(page.url().endsWith('/fr/blog/article'))
+  expect(await getText(page, '#lang-switcher-current-locale code')).toEqual('fr')
+})

specs/browser_language_detection/always_redirect/prefix_and_default_no_prefix.spec.ts

@@ -0,0 +1,41 @@
+import { test, expect } from 'vitest'
+import { fileURLToPath } from 'node:url'
+import { setup, url, createPage } from '@nuxt/test-utils'
+import { getText } from '../../helper'
+
+await setup({
+  rootDir: fileURLToPath(new URL(`../../fixtures/fallback`, import.meta.url)),
+  browser: true,
+  // overrides
+  nuxtConfig: {
+    i18n: {
+      strategy: 'prefix_and_default',
+      detectBrowserLanguage: {
+        alwaysRedirect: true,
+        redirectOn: 'no prefix'
+      }
+    }
+  }
+})
+
+test('alwaysRedirect: no prefix', async () => {
+  const blog = url('/about')
+  const page = await createPage(undefined, { locale: 'en' }) // set browser locale
+  await page.goto(blog)
+
+  // detect locale from navigator language
+  expect(await getText(page, '#lang-switcher-current-locale code')).toEqual('en')
+
+  // click `fr` lang switch link
+  await page.locator('#set-locale-link-fr').click()
+  expect(await getText(page, '#lang-switcher-current-locale code')).toEqual('fr')
+
+  // go to `en` home page
+  await page.goto(url('/ja/about'))
+  expect(page.url().endsWith('/ja/about'))
+  expect(await getText(page, '#lang-switcher-current-locale code')).toEqual('ja')
+
+  await page.goto(url('/about'))
+  expect(page.url().endsWith('/ja/about'))
+  expect(await getText(page, '#lang-switcher-current-locale code')).toEqual('ja')
+})

src/runtime/internal.ts

@@ -406,8 +406,11 @@ export function detectBrowserLanguage<Context extends NuxtApp = NuxtApp>(
       if (finalLocale !== vueI18nLocale /* && path !== '/'*/) {
         __DEBUG__ && console.log('detectBrowserLanguage: finalLocale !== vueI18nLocale', finalLocale)
         return { locale: finalLocale, stat: true, from: localeFrom }
-      } else {
-        if (alwaysRedirect && path === '/') {
+      } else if (alwaysRedirect) {
+        const redirectOnRoot = path === '/'
+        const redirectOnAll = redirectOn === 'all'
+        const redirectOnNoPrefix = redirectOn === 'no prefix' && !path.match(getLocalesRegex(localeCodes as string[]))
+        if (redirectOnRoot || redirectOnAll || redirectOnNoPrefix) {
           return { locale: finalLocale, stat: true, from: localeFrom }
         }
       }