sendou.ink/app/modules/i18n/loader.server.ts

import type { EntryContext } from "@remix-run/server-runtime";
import { createInstance } from "i18next";
import Backend from "i18next-fs-backend";
import { resolve } from "node:path";
import { initReactI18next } from "react-i18next";
import { config } from "./config";
import i18next from "./i18next.server";
import type { i18n as i18nType } from "i18next";

export async function i18Instance(request: Request, context: EntryContext) {
  const instance = createInstance() as i18nType;

  const lng = await i18next.getLocale(request);
  const ns = i18next.getRouteNamespaces(context);

  await instance
    .use(initReactI18next)
    .use(Backend)
    .init({
      ...config,
      lng,
      ns,
      backend: {
        loadPath: resolve("./public/locales/{{lng}}/{{ns}}.json"),
      },
    });

  return instance;
}