feat(i18n): disable redirect to default language

.changeset/cyan-grapes-suffer.md

@@ -0,0 +1,24 @@
+---
+"astro": minor
+---
+
+
+Adds a new `i18n.routing` config option `redirectToDefaultLocale` to disable automatic redirects of the root URL (`/`) to the default locale when `prefixDefaultLocale: true` is set.
+
+In projects where every route, including the default locale, is prefixed with `/[locale]/` path, this property allows you to control whether or not `src/pages/index.astro` should automatically redirect your site visitors from `/` to `/[defaultLocale]`.
+
+You can now opt out of this automatic redirection by setting `redirectToDefaultLocale: false`:
+
+```js
+// astro.config.mjs
+export default defineConfig({
+  i18n:{
+    defaultLocale: "en",
+    locales: ["en", "fr"],
+    routing: {
+      prefixDefaultLocale: true,
+      redirectToDefaultLocale: false
+    }
+  }
+})
+```

packages/astro/src/@types/astro.ts

@@ -1493,6 +1493,35 @@ export interface AstroUserConfig {
 			 */
 			prefixDefaultLocale: boolean;
 
+			/**
+			 * @docs
+			 * @name i18n.routing.redirectToDefaultLocale
+			 * @kind h4
+			 * @type {boolean}
+			 * @default `true`
+			 * @version 4.2.0
+			 * @description
+			 *
+			 * Configures whether or not the home URL (`/`) generated by `src/pages/index.astro`
+			 * will redirect to `/[defaultLocale]` when `prefixDefaultLocale: true` is set.
+			 * 
+			 * Set `redirectToDefaultLocale: false` to disable this automatic redirection at the root of your site:
+			 * ```js
+			 * // astro.config.mjs
+			 * export default defineConfig({
+			 *   i18n:{
+			 *     defaultLocale: "en",
+			 * 		locales: ["en", "fr"],
+			 *     routing: {
+			 *       prefixDefaultLocale: true,
+			 *       redirectToDefaultLocale: false
+			 *     }
+			 *   }
+			 * })
+			 *```
+			 * */
+			redirectToDefaultLocale: boolean;
+
 			/**
 			 * @name i18n.routing.strategy
 			 * @type {"pathname"}

packages/astro/src/core/app/types.ts

@@ -7,6 +7,7 @@ import type {
 	SSRResult,
 } from '../../@types/astro.js';
 import type { SinglePageBuiltModule } from '../build/types.js';
+import type { RoutingStrategies } from '../config/schema.js';
 
 export type ComponentPath = string;
 
@@ -56,7 +57,7 @@ export type SSRManifest = {
 
 export type SSRManifestI18n = {
 	fallback?: Record<string, string>;
-	routing?: 'prefix-always' | 'prefix-other-locales';
+	routing?: RoutingStrategies;
 	locales: Locales;
 	defaultLocale: string;
 };

packages/astro/src/core/config/schema.ts

@@ -64,7 +64,10 @@ const ASTRO_CONFIG_DEFAULTS = {
 	},
 } satisfies AstroUserConfig & { server: { open: boolean } };
 
-type RoutingStrategies = 'prefix-always' | 'prefix-other-locales';
+export type RoutingStrategies =
+	| 'pathname-prefix-always'
+	| 'pathname-prefix-other-locales'
+	| 'pathname-prefix-always-no-redirect';
 
 export const AstroConfigSchema = z.object({
 	root: z
@@ -329,17 +332,31 @@ export const AstroConfigSchema = z.object({
 				routing: z
 					.object({
 						prefixDefaultLocale: z.boolean().default(false),
+						redirectToDefaultLocale: z.boolean().default(true),
 						strategy: z.enum(['pathname']).default('pathname'),
 					})
 					.default({})
+					.refine(
+						({ prefixDefaultLocale, redirectToDefaultLocale }) => {
+							return !(prefixDefaultLocale === false && redirectToDefaultLocale === false);
+						},
+						{
+							message:
+								'The option `i18n.redirectToDefaultLocale` is only useful when the `i18n.prefixDefaultLocale` is set to `true`. Remove the option `i18n.redirectToDefaultLocale`, or change its value to `true`.',
+						}
+					)
 					.transform((routing) => {
 						let strategy: RoutingStrategies;
 						switch (routing.strategy) {
 							case 'pathname': {
 								if (routing.prefixDefaultLocale === true) {
-									strategy = 'prefix-always';
+									if (routing.redirectToDefaultLocale) {
+										strategy = 'pathname-prefix-always';
+									} else {
+										strategy = 'pathname-prefix-always-no-redirect';
+									}
 								} else {
-									strategy = 'prefix-other-locales';
+									strategy = 'pathname-prefix-other-locales';
 								}
 							}
 						}

packages/astro/src/core/endpoint/index.ts

@@ -16,6 +16,7 @@ import {
 	computePreferredLocaleList,
 } from '../render/context.js';
 import { type Environment, type RenderContext } from '../render/index.js';
+import type { RoutingStrategies } from '../config/schema.js';
 
 const clientAddressSymbol = Symbol.for('astro.clientAddress');
 const clientLocalsSymbol = Symbol.for('astro.locals');
@@ -27,7 +28,7 @@ type CreateAPIContext = {
 	props: Record<string, any>;
 	adapterName?: string;
 	locales: Locales | undefined;
-	routingStrategy: 'prefix-always' | 'prefix-other-locales' | undefined;
+	routingStrategy: RoutingStrategies | undefined;
 	defaultLocale: string | undefined;
 };
 

packages/astro/src/core/render/context.ts

@@ -11,6 +11,7 @@ import { normalizeTheLocale, toCodes } from '../../i18n/index.js';
 import { AstroError, AstroErrorData } from '../errors/index.js';
 import type { Environment } from './environment.js';
 import { getParamsAndProps } from './params-and-props.js';
+import type { RoutingStrategies } from '../config/schema.js';
 
 const clientLocalsSymbol = Symbol.for('astro.locals');
 
@@ -31,7 +32,7 @@ export interface RenderContext {
 	locals?: object;
 	locales: Locales | undefined;
 	defaultLocale: string | undefined;
-	routing: 'prefix-always' | 'prefix-other-locales' | undefined;
+	routing: RoutingStrategies | undefined;
 }
 
 export type CreateRenderContextArgs = Partial<
@@ -239,7 +240,7 @@ export function computePreferredLocaleList(request: Request, locales: Locales):
 export function computeCurrentLocale(
 	request: Request,
 	locales: Locales,
-	routingStrategy: 'prefix-always' | 'prefix-other-locales' | undefined,
+	routingStrategy: RoutingStrategies | undefined,
 	defaultLocale: string | undefined
 ): undefined | string {
 	const requestUrl = new URL(request.url);
@@ -256,7 +257,7 @@ export function computeCurrentLocale(
 			}
 		}
 	}
-	if (routingStrategy === 'prefix-other-locales') {
+	if (routingStrategy === 'pathname-prefix-other-locales') {
 		return defaultLocale;
 	}
 	return undefined;

packages/astro/src/core/render/result.ts

@@ -18,6 +18,7 @@ import {
 	computePreferredLocale,
 	computePreferredLocaleList,
 } from './context.js';
+import type { RoutingStrategies } from '../config/schema.js';
 
 const clientAddressSymbol = Symbol.for('astro.clientAddress');
 const responseSentSymbol = Symbol.for('astro.responseSent');
@@ -53,7 +54,7 @@ export interface CreateResultArgs {
 	cookies?: AstroCookies;
 	locales: Locales | undefined;
 	defaultLocale: string | undefined;
-	routingStrategy: 'prefix-always' | 'prefix-other-locales' | undefined;
+	routingStrategy: RoutingStrategies | undefined;
 }
 
 function getFunctionExpression(slot: any) {

packages/astro/src/core/routing/manifest/create.ts

@@ -516,7 +516,7 @@ export function createRouteManifest(
 	const i18n = settings.config.i18n;
 	if (i18n) {
 		// First we check if the user doesn't have an index page.
-		if (i18n.routing === 'prefix-always') {
+		if (i18n.routing === 'pathname-prefix-always') {
 			let index = routes.find((route) => route.route === '/');
 			if (!index) {
 				let relativePath = path.relative(
@@ -583,7 +583,7 @@ export function createRouteManifest(
 
 		// Work done, now we start creating "fallback" routes based on the configuration
 
-		if (i18n.routing === 'prefix-always') {
+		if (i18n.routing === 'pathname-prefix-always') {
 			// we attempt to retrieve the index page of the default locale
 			const defaultLocaleRoutes = routesByLocale.get(i18n.defaultLocale);
 			if (defaultLocaleRoutes) {
@@ -656,7 +656,7 @@ export function createRouteManifest(
 							let route: string;
 							if (
 								fallbackToLocale === i18n.defaultLocale &&
-								i18n.routing === 'prefix-other-locales'
+								i18n.routing === 'pathname-prefix-other-locales'
 							) {
 								if (fallbackToRoute.pathname) {
 									pathname = `/${fallbackFromLocale}${fallbackToRoute.pathname}`;

packages/astro/src/i18n/index.ts

@@ -3,14 +3,15 @@ import type { AstroConfig, Locales } from '../@types/astro.js';
 import { shouldAppendForwardSlash } from '../core/build/util.js';
 import { MissingLocale } from '../core/errors/errors-data.js';
 import { AstroError } from '../core/errors/index.js';
+import type { RoutingStrategies } from '../core/config/schema.js';
 
 type GetLocaleRelativeUrl = GetLocaleOptions & {
 	locale: string;
 	base: string;
 	locales: Locales;
 	trailingSlash: AstroConfig['trailingSlash'];
 	format: AstroConfig['build']['format'];
-	routing?: 'prefix-always' | 'prefix-other-locales';
+	routing?: RoutingStrategies;
 	defaultLocale: string;
 };
 
@@ -45,7 +46,7 @@ export function getLocaleRelativeUrl({
 	path,
 	prependWith,
 	normalizeLocale = true,
-	routing = 'prefix-other-locales',
+	routing = 'pathname-prefix-other-locales',
 	defaultLocale,
 }: GetLocaleRelativeUrl) {
 	const codeToUse = peekCodePathToUse(_locales, locale);
@@ -57,7 +58,7 @@ export function getLocaleRelativeUrl({
 	}
 	const pathsToJoin = [base, prependWith];
 	const normalizedLocale = normalizeLocale ? normalizeTheLocale(codeToUse) : codeToUse;
-	if (routing === 'prefix-always') {
+	if (routing === 'pathname-prefix-always') {
 		pathsToJoin.push(normalizedLocale);
 	} else if (locale !== defaultLocale) {
 		pathsToJoin.push(normalizedLocale);
@@ -88,7 +89,7 @@ type GetLocalesBaseUrl = GetLocaleOptions & {
 	locales: Locales;
 	trailingSlash: AstroConfig['trailingSlash'];
 	format: AstroConfig['build']['format'];
-	routing?: 'prefix-always' | 'prefix-other-locales';
+	routing?: RoutingStrategies;
 	defaultLocale: string;
 };
 
@@ -100,15 +101,15 @@ export function getLocaleRelativeUrlList({
 	path,
 	prependWith,
 	normalizeLocale = false,
-	routing = 'prefix-other-locales',
+	routing = 'pathname-prefix-other-locales',
 	defaultLocale,
 }: GetLocalesBaseUrl) {
 	const locales = toPaths(_locales);
 	return locales.map((locale) => {
 		const pathsToJoin = [base, prependWith];
 		const normalizedLocale = normalizeLocale ? normalizeTheLocale(locale) : locale;
 
-		if (routing === 'prefix-always') {
+		if (routing === 'pathname-prefix-always') {
 			pathsToJoin.push(normalizedLocale);
 		} else if (locale !== defaultLocale) {
 			pathsToJoin.push(normalizedLocale);

packages/astro/src/i18n/middleware.ts

@@ -2,6 +2,7 @@ import { appendForwardSlash, joinPaths } from '@astrojs/internal-helpers/path';
 import type { Locales, MiddlewareHandler, RouteData, SSRManifest } from '../@types/astro.js';
 import type { PipelineHookFunction } from '../core/pipeline.js';
 import { getPathByLocale, normalizeTheLocale } from './index.js';
+import { shouldAppendForwardSlash } from '../core/build/util.js';
 
 const routeDataSymbol = Symbol.for('astro.routeData');
 
@@ -54,30 +55,52 @@ export function createI18nMiddleware(
 
 		if (response instanceof Response) {
 			const pathnameContainsDefaultLocale = url.pathname.includes(`/${defaultLocale}`);
-			if (i18n.routing === 'prefix-other-locales' && pathnameContainsDefaultLocale) {
-				const newLocation = url.pathname.replace(`/${defaultLocale}`, '');
-				response.headers.set('Location', newLocation);
-				return new Response(null, {
-					status: 404,
-					headers: response.headers,
-				});
-			} else if (i18n.routing === 'prefix-always') {
-				if (url.pathname === base + '/' || url.pathname === base) {
-					if (trailingSlash === 'always') {
-						return context.redirect(`${appendForwardSlash(joinPaths(base, i18n.defaultLocale))}`);
-					} else {
-						return context.redirect(`${joinPaths(base, i18n.defaultLocale)}`);
+			switch (i18n.routing) {
+				case 'pathname-prefix-other-locales': {
+					if (pathnameContainsDefaultLocale) {
+						const newLocation = url.pathname.replace(`/${defaultLocale}`, '');
+						response.headers.set('Location', newLocation);
+						return new Response(null, {
+							status: 404,
+							headers: response.headers,
+						});
+					}
+					break;
+				}
+
+				case 'pathname-prefix-always-no-redirect': {
+					// We return a 404 if:
+					// - the current path isn't a root. e.g. / or /<base>
+					// - the URL doesn't contain a locale
+					const isRoot = url.pathname === base + '/' || url.pathname === base;
+					if (!(isRoot || pathnameHasLocale(url.pathname, i18n.locales))) {
+						return new Response(null, {
+							status: 404,
+							headers: response.headers,
+						});
 					}
+					break;
 				}
 
-				// Astro can't know where the default locale is supposed to be, so it returns a 404 with no content.
-				else if (!pathnameHasLocale(url.pathname, i18n.locales)) {
-					return new Response(null, {
-						status: 404,
-						headers: response.headers,
-					});
+				case 'pathname-prefix-always': {
+					if (url.pathname === base + '/' || url.pathname === base) {
+						if (trailingSlash === 'always') {
+							return context.redirect(`${appendForwardSlash(joinPaths(base, i18n.defaultLocale))}`);
+						} else {
+							return context.redirect(`${joinPaths(base, i18n.defaultLocale)}`);
+						}
+					}
+
+					// Astro can't know where the default locale is supposed to be, so it returns a 404 with no content.
+					else if (!pathnameHasLocale(url.pathname, i18n.locales)) {
+						return new Response(null, {
+							status: 404,
+							headers: response.headers,
+						});
+					}
 				}
 			}
+
 			if (response.status >= 300 && fallback) {
 				const fallbackKeys = i18n.fallback ? Object.keys(i18n.fallback) : [];
 
@@ -103,7 +126,7 @@ export function createI18nMiddleware(
 					let newPathname: string;
 					// If a locale falls back to the default locale, we want to **remove** the locale because
 					// the default locale doesn't have a prefix
-					if (pathFallbackLocale === defaultLocale && routing === 'prefix-other-locales') {
+					if (pathFallbackLocale === defaultLocale && routing === 'pathname-prefix-other-locales') {
 						newPathname = url.pathname.replace(`/${urlLocale}`, ``);
 					} else {
 						newPathname = url.pathname.replace(`/${urlLocale}`, `/${pathFallbackLocale}`);

packages/astro/test/fixtures/i18n-routing-prefix-always/src/pages/index.astro

@@ -0,0 +1,8 @@
+<html>
+<head>
+	<title>Astro</title>
+</head>
+<body>
+I am index
+</body>
+</html>