@starci/next-i18n

The next-intl stack of a StarCi Next.js front end, written once (FE-I18N-1) and generic over the app's locales. The app names its locales and keeps its message catalogs; the routing, the proxy, the navigation, the request config and the locale read of the [locale] layout come from here. No component, no class string, no lifecycle of its own (FE-PACKAGES-2).

| entry | export | what it is for | |---|---|---| | @starci/next-i18n | defineI18n(options) | the locales, the default, the time zone, the prefix mode and the cookie in one typed value: routing for next-intl, isLocale, localeOf, intlTagOf. Client-safe. | | @starci/next-i18n/proxy | createProxy(i18n, options?) | the proxy of src/proxy.ts: locale negotiation, except for the roots the app lists and files with an extension | | @starci/next-i18n/navigation | createI18nNavigation(i18n) | locale-aware Link, redirect, usePathname, useRouter, getPathname | | @starci/next-i18n/request | createRequestConfig(i18n, { app, loadMessages, readRouteLocale? }) | the default export of modules/i18n/request.ts that next-intl's plugin loads | | @starci/next-i18n/layout | createReadLocaleSegment(i18n) | the readLocaleSegment(params) a [locale] layout calls; an unknown locale is a 404 |

The proxy, the navigation and the server entries are separate subpaths because they run under different React export conditions: the proxy must never evaluate the navigation.

In an app

// modules/i18n/routing.ts: the one description of the languages
export const i18n = defineI18n({ locales: ["vi", "en"], defaultLocale: "vi", timeZone: "Asia/Ho_Chi_Minh" })

// src/proxy.ts
export const proxy = createProxy(i18n)

// modules/i18n/request.ts: the app only names its catalogs
export default createRequestConfig(i18n, { app: "web", loadMessages: (locale) => import(`./messages/${locale}.json`) })

// app/[locale]/layout.tsx
const { locale, messages, timeZone } = await createReadLocaleSegment(i18n)(props.params)

With experimental.rootParams the request config reads the locale from the route: readRouteLocale: () => locale() (from next/root-params).

Tests

npm test typechecks, lints and runs the node:test specs under 90% line coverage; the specs drive next-intl's real middleware and navigation in Node (src/next-esm.setup.ts resolves Next's bare subpaths the way a bundler does and is no part of the package).

next (>= 16) and next-intl (>= 4) are peers, the versions of the app's stack.