feat: support extending messages hook

TODO.md

@@ -33,7 +33,7 @@ This todo is based on [nuxt/i18n](https://i18n.nuxtjs.org/) docs.
 - [x] Different domains
 - [x] Locale fallback
 - [ ] Per-component translations
-- [ ] Extending messages hook
+- [x] Extending messages hook
 
 ## API Reference
 

docs/content/30.guide/13.extend-messages.md

@@ -3,11 +3,6 @@ title: Extending messages hook
 description: "Nuxt hook to extend app's messages"
 ---
 
-::alert{type="warning"}
-// TODO:
-🚧 This feature is not implemented yet.
-::
-
 If you're a **module author** and want that module to provide extra messages for your project, you can merge them into the normally loaded messages by using the `i18n:extend-messages` hook.
 
 To do this, in your module's setup file listen to the Nuxt hook and push your messages. `@nuxtjs/i18n` will do the rest.
@@ -16,24 +11,26 @@ This is particularly useful if your module use translated content and you want t
 
 Example:
 
-```js{}[my-module-exemple/setup.js]
-export default function () {
-  const { nuxt } = this
-
-  nuxt.hook('i18n:extend-messages', function (additionalMessages) {
-    additionalMessages.push({
-      en: {
-        'my-module-exemple': {
-          hello: 'Hello from external module'
-        }
-      },
-      fr: {
-        'my-module-exemple': {
-          hello: 'Bonjour depuis le module externe'
+```ts{}[my-module-exemple/module1.ts]
+import { defineNuxtModule } from '@nuxt/kit'
+
+export default defineNuxtModule({
+  async setup(options, nuxt) {
+    nuxt.hook('i18n:extend-messages', (additionalMessages, localeCodes) => {
+      additionalMessages.push({
+        en: {
+          'my-module-exemple': {
+            hello: 'Hello from external module'
+          }
+        },
+        fr: {
+          'my-module-exemple': {
+            hello: 'Bonjour depuis le module externe'
+          }
         }
-      }
+      })
     })
-  })
+  }
 }
 ```
 

docs/content/50.API/7.nuxt.md

@@ -20,7 +20,7 @@ If you set `i18n.vueI18n.legacy` option to `false` in your `@nuxtjs/i18n` config
 
 Example use:
 
-```js
+```ts
 export default defineNuxtPlugin(nuxtApp => {
   nuxtApp.$i18n.onBeforeLanguageSwitch = (oldLocale, newLocale, isInitialSetup, nuxtApp) => {
     console.log('onBeforeLanguageSwitch', oldLocale, newLocale, isInitialSetup)
@@ -35,3 +35,41 @@ export default defineNuxtPlugin(nuxtApp => {
 ### localeHead()
 
 See more info about those in [Extension of Vue](./vue) section.
+
+
+## Extension of NuxtHooks
+
+### `i18n:extend-messages` Hook
+
+- **Arguments**:
+  - additionalMessages (type: ` LocaleMessages<DefineLocaleMessage>[]`)
+  - localeCodes (type: `string[]`) - locale codes, which is resolved with `locales` option
+
+The `additionalMessages` array can be pushed locale messages paired with the locale.
+
+Example:
+
+```ts
+import { defineNuxtModule } from '@nuxt/kit'
+
+export default defineNuxtModule({
+  async setup(options, nuxt) {
+    nuxt.hook('i18n:extend-messages', (additionalMessages, localeCodes) => {
+      additionalMessages.push({
+        en: {
+          'my-module-exemple': {
+            hello: 'Hello from external module'
+          }
+        },
+        fr: {
+          'my-module-exemple': {
+            hello: 'Bonjour depuis le module externe'
+          }
+        }
+      })
+    })
+  }
+}
+```
+
+See also [Extending messages hook](../guide/extend-messages)

playground/module1.ts

@@ -0,0 +1,20 @@
+import { defineNuxtModule } from '@nuxt/kit'
+
+export default defineNuxtModule({
+  async setup(options, nuxt) {
+    // @ts-ignore
+    await nuxt.hook('i18n:extend-messages', (messages, localeCodes) => {
+      messages.push({
+        en: {
+          foo: 'Foo'
+        },
+        fr: {
+          foo: 'Foo FR'
+        },
+        ja: {
+          foo: 'Foo JA'
+        }
+      })
+    })
+  }
+})

playground/nuxt.config.ts

@@ -1,10 +1,11 @@
 import { defineNuxtConfig } from 'nuxt'
 // @ts-ignore
 import I18nModule from '../dist/module.mjs'
+import Module1 from './module1'
 
 // https://v3.nuxtjs.org/docs/directory-structure/nuxt.config
 export default defineNuxtConfig({
-  modules: [I18nModule],
+  modules: [Module1, I18nModule],
 
   vite: {
     build: {
@@ -45,10 +46,10 @@ export default defineNuxtConfig({
     // strategy: 'no_prefix',
     // strategy: 'prefix',
     // strategy: 'prefix_and_default',
-    parsePages: false,
+    // parsePages: false,
     pages: {
       about: {
-        ja: false
+        ja: '/about-ja'
       }
     },
     // differentDomains: true,

playground/pages/index.vue

@@ -14,6 +14,7 @@ definePageMeta({
 
 console.log('useBrowserLocale', useBrowserLocale())
 console.log('localeProperties', localeProperties)
+console.log('foo', t('foo'))
 
 function getLocaleName(code: string) {
   const locale = (locales.value as LocaleObject[]).find(i => i.code === code)

specs/extend_messages.spec.ts

@@ -0,0 +1,30 @@
+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: {
+      defaultLocale: 'en'
+    }
+  }
+})
+
+test('extend message hook', async () => {
+  const home = url('/')
+  const page = await createPage()
+  const messages: string[] = []
+  page.on('console', msg => messages.push(msg.text()))
+  await page.goto(home)
+
+  expect(await getText(page, '#extend-message')).toEqual('Hello from external module')
+
+  // click `fr` lang switch link
+  await page.locator('#lang-switcher-with-nuxt-link a').click()
+
+  expect(await getText(page, '#extend-message')).toEqual('Bonjour depuis le module externe')
+})

specs/fixtures/basic/module.ts

@@ -0,0 +1,21 @@
+import { defineNuxtModule } from '@nuxt/kit'
+
+export default defineNuxtModule({
+  async setup(options, nuxt) {
+    // @ts-ignore
+    await nuxt.hook('i18n:extend-messages', (messages, localeCodes) => {
+      messages.push({
+        en: {
+          'my-module-exemple': {
+            hello: 'Hello from external module'
+          }
+        },
+        fr: {
+          'my-module-exemple': {
+            hello: 'Bonjour depuis le module externe'
+          }
+        }
+      })
+    })
+  }
+})

specs/fixtures/basic/nuxt.config.ts

@@ -1,9 +1,10 @@
 import { defineNuxtConfig } from 'nuxt'
 import I18nModule from '../../..'
+import CustomModule from './module'
 
 // https://v3.nuxtjs.org/docs/directory-structure/nuxt.config
 export default defineNuxtConfig({
-  modules: [I18nModule],
+  modules: [CustomModule, I18nModule],
 
   i18n: {
     lazy: false,

specs/fixtures/basic/pages/index.vue

@@ -49,6 +49,9 @@ useHead({
       >:
       <code id="home-use-locale-head">{{ i18nHead }}</code>
     </section>
+    <section>
+      <code id="extend-message">{{ t('my-module-exemple.hello') }}</code>
+    </section>
     <NuxtLink id="link-about" exact :to="localePath('about')">{{ $t('about') }}</NuxtLink>
     <NuxtLink id="link-blog" :to="localePath('blog')">{{ $t('blog') }}</NuxtLink>
     <NuxtLink id="link-ignore-disable" :to="localePath('/ignore-routes/disable')"

src/bundler.ts

@@ -11,28 +11,29 @@ import type { NuxtI18nOptions } from './types'
 const debug = createDebug('@nuxtjs/i18n:bundler')
 
 export async function extendBundler(
-  options: Required<NuxtI18nOptions>,
   nuxt: Nuxt,
-  hasLocaleFiles: boolean,
-  langPath: string | null
+  options: {
+    nuxtOptions: Required<NuxtI18nOptions>
+    hasLocaleFiles: boolean
+    langPath: string | null
+  }
 ) {
+  const { nuxtOptions, hasLocaleFiles, langPath } = options
+
   // setup nitro
   if (nuxt.options.nitro.replace) {
-    nuxt.options.nitro.replace['__DEBUG__'] = options.debug
+    nuxt.options.nitro.replace['__DEBUG__'] = nuxtOptions.debug
   } else {
     nuxt.options.nitro.replace = {
-      __DEBUG__: options.debug
+      __DEBUG__: nuxtOptions.debug
     }
   }
   debug('nitro.replace', nuxt.options.nitro.replace)
 
   // extract macros from components
   const macroOptions: TransformMacroPluginOptions = {
     dev: nuxt.options.dev,
-    sourcemap: nuxt.options.sourcemap.server || nuxt.options.sourcemap.client,
-    macros: {
-      defineI18nRoute: 'i18n'
-    }
+    sourcemap: nuxt.options.sourcemap.server || nuxt.options.sourcemap.client
   }
 
   try {
@@ -58,7 +59,7 @@ export async function extendBundler(
           __VUE_I18N_FULL_INSTALL__: 'true',
           __VUE_I18N_LEGACY_API__: 'true',
           __INTLIFY_PROD_DEVTOOLS__: 'false',
-          __DEBUG__: JSON.stringify(options.debug)
+          __DEBUG__: JSON.stringify(nuxtOptions.debug)
         })
       )
     })
@@ -80,10 +81,10 @@ export async function extendBundler(
 
   extendViteConfig(config => {
     if (config.define) {
-      config.define['__DEBUG__'] = JSON.stringify(options.debug)
+      config.define['__DEBUG__'] = JSON.stringify(nuxtOptions.debug)
     } else {
       config.define = {
-        __DEBUG__: JSON.stringify(options.debug)
+        __DEBUG__: JSON.stringify(nuxtOptions.debug)
       }
     }
     debug('vite.config.define', config.define)

src/gen.ts

@@ -5,13 +5,15 @@ import { genImport, genSafeVariableName, genDynamicImport } from 'knitwork'
 
 import type { NuxtI18nOptions, NuxtI18nInternalOptions, LocaleInfo } from './types'
 import type { NuxtI18nOptionsDefault } from './constants'
+import type { AdditionalMessages } from './messages'
 
 export type LoaderOptions = {
   localeCodes?: string[]
   localeInfo?: LocaleInfo[]
   nuxtI18nOptions?: NuxtI18nOptions
   nuxtI18nOptionsDefault?: NuxtI18nOptionsDefault
   nuxtI18nInternalOptions?: NuxtI18nInternalOptions
+  additionalMessages?: AdditionalMessages
 }
 
 const debug = createDebug('@nuxtjs/i18n:gen')
@@ -93,6 +95,8 @@ export function generateLoaderOptions(
       }
       codes += `}\n`
       return codes
+    } else if (rootKey === 'additionalMessages') {
+      return `export const ${rootKey} = ${generaeteAdditionalMessages(rootValue, dev)}\n`
 	  } else {
 	    return `export const ${rootKey} = ${toCode(rootValue)}\n`
 	  }
@@ -122,6 +126,22 @@ function generateVueI18nOptions(options: Record<string, any>, dev: boolean): str
   return genCode
 }
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function generaeteAdditionalMessages(value: Record<string, any>, dev: boolean): string {
+  let genCode = 'Object({'
+  for (const [locale, messages] of Object.entries(value)) {
+    genCode += `${JSON.stringify(locale)}:[`
+    for (const [, p] of Object.entries(messages)) {
+      genCode += `() => Promise.resolve(${
+        generateJSON(JSON.stringify(p), { type: 'bare', env: dev ? 'development' : 'production' }).code
+      }),`
+    }
+    genCode += `],`
+  }
+  genCode += '})'
+  return genCode
+}
+
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export function stringifyObj(obj: Record<string, any>): string {
   return `Object({${Object.entries(obj)

src/messages.ts

@@ -0,0 +1,31 @@
+import createDebug from 'debug'
+
+import type { Nuxt } from '@nuxt/schema'
+import type { DefineLocaleMessage, Locale, LocaleMessages } from 'vue-i18n'
+
+const debug = createDebug('@nuxtjs/i18n:messages')
+
+export type AdditionalMessages = Record<Locale, DefineLocaleMessage[]>
+
+export async function extendMessages(nuxt: Nuxt, localeCodes: string[]): Promise<AdditionalMessages> {
+  const additionalMessages: LocaleMessages<DefineLocaleMessage>[] = []
+  await nuxt.callHook('i18n:extend-messages', additionalMessages, localeCodes)
+  debug('i18n:extend-messages additional messages', additionalMessages)
+
+  return normalizeAdditionalMessages(additionalMessages, localeCodes)
+}
+
+async function normalizeAdditionalMessages(additional: LocaleMessages<DefineLocaleMessage>[], localeCodes: string[]) {
+  const additionalMessages: AdditionalMessages = {}
+  for (const localeCode of localeCodes) {
+    additionalMessages[localeCode] = []
+  }
+
+  for (const [, messages] of Object.entries(additional)) {
+    for (const [locale, message] of Object.entries(messages)) {
+      additionalMessages[locale].push(message)
+    }
+  }
+
+  return additionalMessages
+}