middleware.ts — astro Source File

Source Code

import type { SSRManifest, SSRManifestI18n } from '../core/app/types.js';
import { REROUTE_DIRECTIVE_HEADER, ROUTE_TYPE_HEADER } from '../core/constants.js';
import { isRequestServerIsland, requestIs404Or500 } from '../core/routing/match.js';
import type { MiddlewareHandler } from '../types/public/common.js';
import type { APIContext } from '../types/public/context.js';
import {
	type MiddlewarePayload,
	normalizeTheLocale,
	notFound,
	redirectToDefaultLocale,
	redirectToFallback,
	requestHasLocale,
} from './index.js';

export function createI18nMiddleware(
	i18n: SSRManifest['i18n'],
	base: SSRManifest['base'],
	trailingSlash: SSRManifest['trailingSlash'],
	format: SSRManifest['buildFormat'],
): MiddlewareHandler {
	if (!i18n) return (_, next) => next();
	const payload: MiddlewarePayload = {
		...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: APIContext, response: Response): Response | undefined => {
		const url = context.url;
		if (url.pathname === base + '/' || url.pathname === base) {
			return _redirectToDefaultLocale(context);
		}

		// Astro can't know where the default locale is supposed to be, so it returns a 404.
		else if (!_requestHasLocale(context)) {
			return _noFoundForNonLocaleRoute(context, response);
		}

		return undefined;
	};

	const prefixOtherLocales = (context: APIContext, response: Response): Response | undefined => {
		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);
// ... (107 more lines)