astro/dist/i18n/middleware.js

Astro is a modern site builder with web best practices, performance, and DX front-of-mind.

import { REROUTE_DIRECTIVE_HEADER, ROUTE_TYPE_HEADER } from "../core/constants.js";
import { isRequestServerIsland, requestIs404Or500 } from "../core/routing/match.js";
import {
  normalizeTheLocale,
  notFound,
  redirectToDefaultLocale,
  redirectToFallback,
  requestHasLocale
} from "./index.js";
function createI18nMiddleware(i18n, base, trailingSlash, format) {
  if (!i18n) return (_, next) => next();
  const payload = {
    ...i18n,
    trailingSlash,
    base,
    format,
    domains: {}
  };
  const _redirectToDefaultLocale = redirectToDefaultLocale(payload);
  const _noFoundForNonLocaleRoute = notFound(payload);
  const _requestHasLocale = requestHasLocale(payload.locales);
  const _redirectToFallback = redirectToFallback(payload);
  const prefixAlways = (context, response) => {
    const url = context.url;
    if (url.pathname === base + "/" || url.pathname === base) {
      return _redirectToDefaultLocale(context);
    } else if (!_requestHasLocale(context)) {
      return _noFoundForNonLocaleRoute(context, response);
    }
    return void 0;
  };
  const prefixOtherLocales = (context, response) => {
    let pathnameContainsDefaultLocale = false;
    const url = context.url;
    for (const segment of url.pathname.split("/")) {
      if (normalizeTheLocale(segment) === normalizeTheLocale(i18n.defaultLocale)) {
        pathnameContainsDefaultLocale = true;
        break;
      }
    }
    if (pathnameContainsDefaultLocale) {
      const newLocation = url.pathname.replace(`/${i18n.defaultLocale}`, "");
      response.headers.set("Location", newLocation);
      return _noFoundForNonLocaleRoute(context);
    }
    return void 0;
  };
  return async (context, next) => {
    const response = await next();
    const type = response.headers.get(ROUTE_TYPE_HEADER);
    const isReroute = response.headers.get(REROUTE_DIRECTIVE_HEADER);
    if (isReroute === "no" && typeof i18n.fallback === "undefined") {
      return response;
    }
    if (type !== "page" && type !== "fallback") {
      return response;
    }
    if (requestIs404Or500(context.request, base)) {
      return response;
    }
    if (isRequestServerIsland(context.request, base)) {
      return response;
    }
    const { currentLocale } = context;
    switch (i18n.strategy) {
      // NOTE: theoretically, we should never hit this code path
      case "manual": {
        return response;
      }
      case "domains-prefix-other-locales": {
        if (localeHasntDomain(i18n, currentLocale)) {
          const result = prefixOtherLocales(context, response);
          if (result) {
            return result;
          }
        }
        break;
      }
      case "pathname-prefix-other-locales": {
        const result = prefixOtherLocales(context, response);
        if (result) {
          return result;
        }
        break;
      }
      case "domains-prefix-always-no-redirect": {
        if (localeHasntDomain(i18n, currentLocale)) {
          const result = _noFoundForNonLocaleRoute(context, response);
          if (result) {
            return result;
          }
        }
        break;
      }
      case "pathname-prefix-always-no-redirect": {
        const result = _noFoundForNonLocaleRoute(context, response);
        if (result) {
          return result;
        }
        break;
      }
      case "pathname-prefix-always": {
        const result = prefixAlways(context, response);
        if (result) {
          return result;
        }
        break;
      }
      case "domains-prefix-always": {
        if (localeHasntDomain(i18n, currentLocale)) {
          const result = prefixAlways(context, response);
          if (result) {
            return result;
          }
        }
        break;
      }
    }
    return _redirectToFallback(context, response);
  };
}
function localeHasntDomain(i18n, currentLocale) {
  for (const domainLocale of Object.values(i18n.domainLookupTable)) {
    if (domainLocale === currentLocale) {
      return false;
    }
  }
  return true;
}
export {
  createI18nMiddleware
};