modified-next-i18next/dist/es/serverSideTranslations.js

A slightly modified version of next-i18next to allow for different folder structure.

import fs from 'fs';
import path from 'path';
import { createConfig } from './config/createConfig';
import createClient from './createClient';
const DEFAULT_CONFIG_PATH = './next-i18next.config.js';

const getFallbackLocales = fallbackLng => {
  if (typeof fallbackLng === 'string') {
    return [fallbackLng];
  }

  if (Array.isArray(fallbackLng)) {
    return fallbackLng;
  }

  if (typeof fallbackLng === 'object' && fallbackLng !== null) {
    return Object.values(fallbackLng).reduce((all, locales) => [...all, ...locales], []);
  }

  return [];
};

const flatNamespaces = namespacesByLocale => {
  const allNamespaces = [];

  for (const localNamespaces of namespacesByLocale) {
    allNamespaces.push(...localNamespaces);
  }

  return Array.from(new Set(allNamespaces));
};

export const serverSideTranslations = async (initialLocale, namespacesRequired = [], configOverride = null) => {
  if (typeof initialLocale !== 'string') {
    throw new Error('Initial locale argument was not passed into serverSideTranslations');
  }

  let userConfig = configOverride;

  if (fs.existsSync(path.resolve(DEFAULT_CONFIG_PATH))) {
    userConfig = await import(path.resolve(DEFAULT_CONFIG_PATH));
  }

  if (userConfig === null) {
    throw new Error('next-i18next was unable to find a user config');
  }

  const config = createConfig({ ...userConfig,
    lng: initialLocale
  });
  const {
    localeExtension,
    localePath,
    fallbackLng
  } = config;
  const {
    i18n,
    initPromise
  } = createClient({ ...config,
    lng: initialLocale
  });
  await initPromise;
  const initialI18nStore = {};
  config.locales.forEach(lng => {
    initialI18nStore[lng] = {};
  });
  getFallbackLocales(fallbackLng).forEach(lng => {
    initialI18nStore[lng] = {};
  });

  if (namespacesRequired.length === 0) {
    const getLocaleNamespaces = path => fs.readdirSync(path).map(file => file.replace(`.${localeExtension}`, ''));

    const namespacesByLocale = Object.keys(initialI18nStore).map(locale => getLocaleNamespaces(path.resolve(process.cwd(), `${localePath}/${locale}`)));
    namespacesRequired = flatNamespaces(namespacesByLocale);
  }

  namespacesRequired.forEach(ns => {
    for (const locale in initialI18nStore) {
      initialI18nStore[locale][ns] = (i18n.services.resourceStore.data[locale] || {})[ns] || {};
    }
  });
  return {
    _nextI18Next: {
      initialI18nStore,
      initialLocale,
      userConfig: config.serializeConfig ? userConfig : null
    }
  };
};