feat: Support multiple languages on one or more domains while having …

…different domains (nuxt-modules#2705)

* support multiple languages on one or more domains

* add debug log

* fix after rebase

* update docs

docs/content/docs/2.guide/9.different-domains.md

@@ -113,3 +113,60 @@ NUXT_PUBLIC_I18N_LOCALES_FR_DOMAIN=fr.example.test
 NUXT_PUBLIC_I18N_LOCALES_UK_DOMAIN=uk.staging.example.test
 NUXT_PUBLIC_I18N_LOCALES_FR_DOMAIN=fr.staging.example.test
 ```
+
+## Using different domains for only some of the languages
+
+If one or more of the domains need to host multiple languages, the default language of each domain needs to have `domainDefault: true` so there is a per domain fallback locale.
+The option `differentDomains` still need to be set to `true` though.
+
+```js {}[nuxt.config.js]
+export default defineNuxtConfig({
+  // ...
+  i18n: {
+    locales: [
+      {
+        code: 'en',
+        domain: 'mydomain.com',
+        domainDefault: true
+      },
+      {
+        code: 'pl',
+        domain: 'mydomain.com'
+      },
+      {
+        code: 'ua',
+        domain: 'mydomain.com'
+      },
+      {
+        code: 'es',
+        domain: 'es.mydomain.com',
+        domainDefault: true
+      },
+      {
+        code: 'fr',
+        domain: 'fr.mydomain.com',
+        domainDefault: true
+      }
+    ],
+    strategy: 'prefix',
+    differentDomains: true
+    // Or enable the option in production only
+    // differentDomains: (process.env.NODE_ENV === 'production')
+  },
+  // ...
+})
+```
+
+Given above configuration with the `prefix` strategy, following requests will be:
+- https://mydomain.com -> https://mydomain.com/en (en language)
+- https://mydomain.com/pl -> https://mydomain.com/pl (pl language)
+- https://mydomain.com/ua -> https://mydomain.com/ua (ua language)
+- https://es.mydomain.com -> https://es.mydomain.com/es (es language)
+- https://fr.mydomain.com -> https://fr.mydomain.com/fr (fr language)
+
+The same requests when using the `prefix_except_default` strategy, will be:
+- https://mydomain.com -> https://mydomain.com (en language)
+- https://mydomain.com/pl -> https://mydomain.com/pl (pl language)
+- https://mydomain.com/ua -> https://mydomain.com/ua (ua language)
+- https://es.mydomain.com -> https://es.mydomain.com (es language)
+- https://fr.mydomain.com -> https://fr.mydomain.com (fr language)

docs/content/docs/3.options/2.routing.md

@@ -44,6 +44,7 @@ When using an object form, the properties can be:
 - `files` - The name of the file in which multiple locale messages are defined. Will be resolved relative to `langDir` path when loading locale messages from file.
 - `dir` - The dir property specifies the direction of the elements and content, value could be `'rtl'`, `'ltr'` or `'auto'`.
 - `domain` (required when using [`differentDomains`](/docs/options/domain#differentdomains)) - the domain name you'd like to use for that locale (including the port if used). This property can also be set using [`runtimeConfig`](/docs/options/runtime-config).
+- `domainDefault` (required when using [`differentDomains`](/docs/options/domain#differentdomains) while one or more of the domains having multiple locales) - set `domainDefault` to `true` for each locale that should act as a default locale for the particular domain.
 - `...` - any custom property set on the object will be exposed at runtime. This can be used, for example, to define the language name for the purpose of using it in a language selector on the page.
 
 You can access all the properties of the current locale through the `localeProperties` property. When using an array of codes, it will only include the `code` property.

specs/different_domains.spec.ts

@@ -41,6 +41,7 @@ await setup({
         }
       ],
       differentDomains: true,
+      strategy: 'no_prefix',
       detectBrowserLanguage: {
         useCookie: true
       }

specs/different_domains_multi_locales_prefix.spec.ts

@@ -0,0 +1,86 @@
+import { test, expect, describe } from 'vitest'
+import { fileURLToPath } from 'node:url'
+import { setup, $fetch, undiciRequest } from './utils'
+import { getDom } from './helper'
+
+await setup({
+  rootDir: fileURLToPath(new URL(`./fixtures/different_domains`, import.meta.url)),
+  // overrides
+  nuxtConfig: {
+    i18n: {
+      locales: [
+        {
+          code: 'en',
+          iso: 'en',
+          name: 'English',
+          domain: 'nuxt-app.localhost',
+          domainDefault: true
+        },
+        {
+          code: 'no',
+          iso: 'no-NO',
+          name: 'Norwegian',
+          domain: 'nuxt-app.localhost'
+        },
+        {
+          code: 'fr',
+          iso: 'fr-FR',
+          name: 'Français',
+          domain: 'fr.nuxt-app.localhost'
+        }
+      ],
+      differentDomains: true,
+      strategy: 'prefix',
+      detectBrowserLanguage: {
+        useCookie: true
+      }
+    }
+  }
+})
+
+describe('detection locale with host on server', () => {
+  test.each([
+    ['en', 'nuxt-app.localhost', 'Homepage'],
+    ['fr', 'fr.nuxt-app.localhost', 'Accueil']
+  ])('%s host', async (locale, host, header) => {
+    const res = await undiciRequest('/' + locale, {
+      headers: {
+        Host: host
+      }
+    })
+    const dom = getDom(await res.body.text())
+
+    expect(dom.querySelector('#lang-switcher-current-locale code').textContent).toEqual(locale)
+    expect(dom.querySelector('#home-header').textContent).toEqual(header)
+  })
+})
+
+test('detection locale with x-forwarded-host on server', async () => {
+  const html = await $fetch('/fr', {
+    headers: {
+      'X-Forwarded-Host': 'fr.nuxt-app.localhost'
+    }
+  })
+  const dom = getDom(html)
+
+  expect(dom.querySelector('#lang-switcher-current-locale code').textContent).toEqual('fr')
+  expect(dom.querySelector('#home-header').textContent).toEqual('Accueil')
+})
+
+test('pass `<NuxtLink> to props', async () => {
+  const res = await undiciRequest('/fr', {
+    headers: {
+      Host: 'fr.nuxt-app.localhost'
+    }
+  })
+  const dom = getDom(await res.body.text())
+  expect(dom.querySelector('#switch-locale-path-usages .switch-to-en a').getAttribute('href')).toEqual(
+    `http://nuxt-app.localhost/en`
+  )
+  expect(dom.querySelector('#switch-locale-path-usages .switch-to-no a').getAttribute('href')).toEqual(
+    `http://nuxt-app.localhost/no`
+  )
+  expect(dom.querySelector('#switch-locale-path-usages .switch-to-fr a').getAttribute('href')).toEqual(
+    `http://fr.nuxt-app.localhost/fr`
+  )
+})

specs/different_domains_multi_locales_prefix_except_default.spec.ts

@@ -0,0 +1,95 @@
+import { test, expect, describe } from 'vitest'
+import { fileURLToPath } from 'node:url'
+import { setup, $fetch, undiciRequest } from './utils'
+import { getDom } from './helper'
+
+await setup({
+  rootDir: fileURLToPath(new URL(`./fixtures/different_domains`, import.meta.url)),
+  // overrides
+  nuxtConfig: {
+    i18n: {
+      locales: [
+        {
+          code: 'en',
+          iso: 'en',
+          name: 'English',
+          domain: 'nuxt-app.localhost',
+          domainDefault: true
+        },
+        {
+          code: 'no',
+          iso: 'no-NO',
+          name: 'Norwegian',
+          domain: 'nuxt-app.localhost'
+        },
+        {
+          code: 'fr',
+          iso: 'fr-FR',
+          name: 'Français',
+          domain: 'fr.nuxt-app.localhost',
+          domainDefault: true
+        },
+        {
+          code: 'ja',
+          iso: 'jp-JA',
+          name: 'Japan',
+          domain: 'ja.nuxt-app.localhost',
+          domainDefault: true
+        }
+      ],
+      differentDomains: true,
+      strategy: 'prefix_except_default',
+      detectBrowserLanguage: {
+        useCookie: true
+      }
+    }
+  }
+})
+
+describe('detection locale with host on server', () => {
+  test.each([
+    ['/', 'en', 'nuxt-app.localhost', 'Homepage'],
+    ['/no', 'no', 'nuxt-app.localhost', 'Hjemmeside'],
+    ['/', 'fr', 'fr.nuxt-app.localhost', 'Accueil']
+  ])('%s host', async (path, locale, host, header) => {
+    const res = await undiciRequest(path, {
+      headers: {
+        Host: host
+      }
+    })
+    const dom = getDom(await res.body.text())
+
+    expect(dom.querySelector('#lang-switcher-current-locale code').textContent).toEqual(locale)
+    expect(dom.querySelector('#home-header').textContent).toEqual(header)
+  })
+})
+
+test('detection locale with x-forwarded-host on server', async () => {
+  const html = await $fetch('/', {
+    headers: {
+      'X-Forwarded-Host': 'fr.nuxt-app.localhost'
+    }
+  })
+  const dom = getDom(html)
+
+  expect(dom.querySelector('#lang-switcher-current-locale code').textContent).toEqual('fr')
+  expect(dom.querySelector('#home-header').textContent).toEqual('Accueil')
+})
+
+test('pass `<NuxtLink> to props', async () => {
+  const res = await undiciRequest('/', {
+    headers: {
+      Host: 'fr.nuxt-app.localhost'
+    }
+  })
+  const dom = getDom(await res.body.text())
+  expect(dom.querySelector('#switch-locale-path-usages .switch-to-en a').getAttribute('href')).toEqual(
+    `http://nuxt-app.localhost`
+  )
+  expect(dom.querySelector('#switch-locale-path-usages .switch-to-no a').getAttribute('href')).toEqual(
+    `http://nuxt-app.localhost/no`
+  )
+  expect(dom.querySelector('#switch-locale-path-usages .switch-to-fr a').getAttribute('href')).toEqual(
+    `http://fr.nuxt-app.localhost`
+  )
+})

specs/fixtures/different_domains/i18n.config.ts

@@ -27,6 +27,19 @@ export default {
           article: 'This is blog article page'
         }
       }
+    },
+    no: {
+      welcome: 'Velkommen',
+      home: 'Hjemmeside',
+      profile: 'Profil',
+      about: 'Om oss',
+      posts: 'Artikkeler',
+      dynamic: 'Dynamic',
+      pages: {
+        blog: {
+          article: 'Dette er bloggartikkelsiden'
+        }
+      }
     }
   },
   fallbackLocale: 'en'

specs/fixtures/different_domains/nuxt.config.ts

@@ -14,6 +14,12 @@ export default defineNuxtConfig({
         name: 'English',
         domain: 'en.nuxt-app.localhost'
       },
+      {
+        code: 'no',
+        iso: 'no-NO',
+        name: 'Norwegian',
+        domain: 'no.nuxt-app.localhost'
+      },
       {
         code: 'fr',
         iso: 'fr-FR',

src/module.ts

@@ -114,13 +114,6 @@ export default defineNuxtModule<NuxtI18nOptions>({
       )
     }
 
-    if (options.strategy === 'no_prefix' && options.differentDomains) {
-      logger.warn(
-        '`differentDomains` option and `no_prefix` strategy are not compatible. ' +
-          'Change strategy or disable `differentDomains` option.'
-      )
-    }
-
     if (options.dynamicRouteParams) {
       logger.warn(
         'The `dynamicRouteParams` options is deprecated and will be removed in `v9`, use the `useSetI18nParams` composable instead.'

src/routing.ts

@@ -1,4 +1,5 @@
 import { getNormalizedLocales } from './utils'
+import { isObject } from '@intlify/shared'
 
 import type { Locale } from 'vue-i18n'
 import type { NuxtPage } from '@nuxt/schema'
@@ -25,13 +26,12 @@ export function prefixLocalizedRoute(
   options: LocalizeRoutesParams,
   extra = false
 ): boolean {
-  const isDefaultLocale = localizeOptions.locale === (options.defaultLocale ?? '')
+  const isDefaultLocale = localizeOptions.locale === (localizeOptions.defaultLocale ?? '')
   const isChildWithRelativePath = localizeOptions.parent != null && !localizeOptions.path.startsWith('/')
 
   // no need to add prefix if child's path is relative
   return (
     !extra &&
-    !options.differentDomains &&
     !isChildWithRelativePath &&
     // skip default locale if strategy is 'prefix_except_default'
     !(isDefaultLocale && options.strategy === 'prefix_except_default')
@@ -86,6 +86,14 @@ export function localizeRoutes(routes: NuxtPage[], options: LocalizeRoutesParams
     return routes
   }
 
+  let defaultLocales = [options.defaultLocale ?? '']
+  if (options.differentDomains) {
+    const domainDefaults = options.locales
+      .filter(locale => (isObject(locale) ? locale.domainDefault : false))
+      .map(locale => (isObject(locale) ? locale.code : locale))
+    defaultLocales = defaultLocales.concat(domainDefaults)
+  }
+
   function localizeRoute(
     route: NuxtPage,
     { locales = [], parent, parentLocalized, extra = false }: LocalizeRouteParams
@@ -112,7 +120,7 @@ export function localizeRoutes(routes: NuxtPage[], options: LocalizeRoutesParams
     const localizedRoutes: (LocalizedRoute | NuxtPage)[] = []
     for (const locale of componentOptions.locales) {
       const localized: LocalizedRoute = { ...route, locale, parent }
-      const isDefaultLocale = locale === options.defaultLocale
+      const isDefaultLocale = defaultLocales.includes(locale)
       const addDefaultTree = isDefaultLocale && options.strategy === 'prefix_and_default' && parent == null && !extra
 
       // localize route again for strategy `prefix_and_default`
@@ -131,7 +139,11 @@ export function localizeRoutes(routes: NuxtPage[], options: LocalizeRoutesParams
       // use custom path if found
       localized.path = componentOptions.paths?.[locale] ?? localized.path
 
-      const localePrefixable = prefixLocalizedRoute(localized, options, extra)
+      const localePrefixable = prefixLocalizedRoute(
+        { defaultLocale: isDefaultLocale ? locale : options.defaultLocale, ...localized },
+        options,
+        extra
+      )
       if (localePrefixable) {
         localized.path = join('/', locale, localized.path)