fix(i18n): move transformation outside the user schema (#10169)

* fix(i18n): move transformation outside the user schema

* fix condition

* cleanup

* ops

* fix regression

15 files changed, 224 insertions, 191 deletions

diff --git a/packages/astro/src/core/app/index.ts b/packages/astro/src/core/app/index.ts
index 094ac97b5..74bd4ecbb 100644
--- a/packages/astro/src/core/app/index.ts
+++ b/packages/astro/src/core/app/index.ts
@@ -166,9 +166,9 @@ export class App {
 
 		if (
 			this.#manifest.i18n &&
-			(this.#manifest.i18n.routing === 'domains-prefix-always' ||
-				this.#manifest.i18n.routing === 'domains-prefix-other-locales' ||
-				this.#manifest.i18n.routing === 'domains-prefix-always-no-redirect')
+			(this.#manifest.i18n.strategy === 'domains-prefix-always' ||
+				this.#manifest.i18n.strategy === 'domains-prefix-other-locales' ||
+				this.#manifest.i18n.strategy === 'domains-prefix-always-no-redirect')
 		) {
 			// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-Host
 			let host = request.headers.get('X-Forwarded-Host');
diff --git a/packages/astro/src/core/app/types.ts b/packages/astro/src/core/app/types.ts
index 17b7c0872..740165710 100644
--- a/packages/astro/src/core/app/types.ts
+++ b/packages/astro/src/core/app/types.ts
@@ -8,7 +8,7 @@ import type {
 	SSRResult,
 } from '../../@types/astro.js';
 import type { SinglePageBuiltModule } from '../build/types.js';
-import type { RoutingStrategies } from '../config/schema.js';
+import type { RoutingStrategies } from '../../i18n/utils.js';
 
 export type ComponentPath = string;
 
@@ -60,7 +60,7 @@ export type SSRManifest = {
 
 export type SSRManifestI18n = {
 	fallback?: Record<string, string>;
-	routing: RoutingStrategies;
+	strategy: RoutingStrategies;
 	locales: Locales;
 	defaultLocale: string;
 	domainLookupTable: Record<string, string>;
diff --git a/packages/astro/src/core/build/generate.ts b/packages/astro/src/core/build/generate.ts
index 29a32a88b..e27f71fcc 100644
--- a/packages/astro/src/core/build/generate.ts
+++ b/packages/astro/src/core/build/generate.ts
@@ -60,6 +60,7 @@ import type {
 import { getTimeStat, shouldAppendForwardSlash } from './util.js';
 import { NoPrerenderedRoutesWithDomains } from '../errors/errors-data.js';
 import { RenderContext } from '../render-context.js';
+import { toRoutingStrategy } from '../../i18n/utils.js';
 
 function createEntryURL(filePath: string, outFolder: URL) {
 	return new URL('./' + filePath + `?time=${Date.now()}`, outFolder);
@@ -582,7 +583,7 @@ function createBuildManifest(
 	if (settings.config.i18n) {
 		i18nManifest = {
 			fallback: settings.config.i18n.fallback,
-			routing: settings.config.i18n.routing,
+			strategy: toRoutingStrategy(settings.config.i18n),
 			defaultLocale: settings.config.i18n.defaultLocale,
 			locales: settings.config.i18n.locales,
 			domainLookupTable: {},
diff --git a/packages/astro/src/core/build/plugins/plugin-manifest.ts b/packages/astro/src/core/build/plugins/plugin-manifest.ts
index 8b97651db..35c3632d0 100644
--- a/packages/astro/src/core/build/plugins/plugin-manifest.ts
+++ b/packages/astro/src/core/build/plugins/plugin-manifest.ts
@@ -17,6 +17,7 @@ import { cssOrder, mergeInlineCss, type BuildInternals } from '../internal.js';
 import type { AstroBuildPlugin } from '../plugin.js';
 import type { StaticBuildOptions } from '../types.js';
 import { normalizeTheLocale } from '../../../i18n/index.js';
+import { toRoutingStrategy } from '../../../i18n/utils.js';
 
 const manifestReplace = '@@ASTRO_MANIFEST_REPLACE@@';
 const replaceExp = new RegExp(`['"]${manifestReplace}['"]`, 'g');
@@ -235,14 +236,7 @@ function buildManifest(
 	 * logic meant for i18n domain support, where we fill the lookup table
 	 */
 	const i18n = settings.config.i18n;
-	if (
-		settings.config.experimental.i18nDomains &&
-		i18n &&
-		i18n.domains &&
-		(i18n.routing === 'domains-prefix-always' ||
-			i18n.routing === 'domains-prefix-other-locales' ||
-			i18n.routing === 'domains-prefix-always-no-redirect')
-	) {
+	if (settings.config.experimental.i18nDomains && i18n && i18n.domains) {
 		for (const [locale, domainValue] of Object.entries(i18n.domains)) {
 			domainLookupTable[domainValue] = normalizeTheLocale(locale);
 		}
@@ -257,7 +251,7 @@ function buildManifest(
 	if (settings.config.i18n) {
 		i18nManifest = {
 			fallback: settings.config.i18n.fallback,
-			routing: settings.config.i18n.routing,
+			strategy: toRoutingStrategy(settings.config.i18n),
 			locales: settings.config.i18n.locales,
 			defaultLocale: settings.config.i18n.defaultLocale,
 			domainLookupTable,
diff --git a/packages/astro/src/core/config/schema.ts b/packages/astro/src/core/config/schema.ts
index e840f93a9..f62e322c5 100644
--- a/packages/astro/src/core/config/schema.ts
+++ b/packages/astro/src/core/config/schema.ts
@@ -66,14 +66,6 @@ const ASTRO_CONFIG_DEFAULTS = {
 	},
 } satisfies AstroUserConfig & { server: { open: boolean } };
 
-export type RoutingStrategies =
-	| 'pathname-prefix-always'
-	| 'pathname-prefix-other-locales'
-	| 'pathname-prefix-always-no-redirect'
-	| 'domains-prefix-always'
-	| 'domains-prefix-other-locales'
-	| 'domains-prefix-always-no-redirect';
-
 export const AstroConfigSchema = z.object({
 	root: z
 		.string()
@@ -363,37 +355,6 @@ export const AstroConfigSchema = z.object({
 					),
 			})
 			.optional()
-			.transform((i18n) => {
-				if (i18n) {
-					let { routing, domains } = i18n;
-					let strategy: RoutingStrategies;
-					const hasDomains = domains ? Object.keys(domains).length > 0 : false;
-					if (!hasDomains) {
-						if (routing.prefixDefaultLocale === true) {
-							if (routing.redirectToDefaultLocale) {
-								strategy = 'pathname-prefix-always';
-							} else {
-								strategy = 'pathname-prefix-always-no-redirect';
-							}
-						} else {
-							strategy = 'pathname-prefix-other-locales';
-						}
-					} else {
-						if (routing.prefixDefaultLocale === true) {
-							if (routing.redirectToDefaultLocale) {
-								strategy = 'domains-prefix-always';
-							} else {
-								strategy = 'domains-prefix-always-no-redirect';
-							}
-						} else {
-							strategy = 'domains-prefix-other-locales';
-						}
-					}
-
-					return { ...i18n, routing: strategy };
-				}
-				return undefined;
-			})
 			.superRefine((i18n, ctx) => {
 				if (i18n) {
 					const { defaultLocale, locales: _locales, fallback, domains, routing } = i18n;
@@ -436,20 +397,15 @@ export const AstroConfigSchema = z.object({
 					}
 					if (domains) {
 						const entries = Object.entries(domains);
-						if (entries.length > 0) {
-							if (
-								routing !== 'domains-prefix-other-locales' &&
-								routing !== 'domains-prefix-always-no-redirect' &&
-								routing !== 'domains-prefix-always'
-							) {
-								ctx.addIssue({
-									code: z.ZodIssueCode.custom,
-									message: `When specifying some domains, the property \`i18n.routingStrategy\` must be set to \`"domains"\`.`,
-								});
-							}
+						const hasDomains = domains ? Object.keys(domains).length > 0 : false;
+						if (entries.length > 0 && !hasDomains) {
+							ctx.addIssue({
+								code: z.ZodIssueCode.custom,
+								message: `When specifying some domains, the property \`i18n.routingStrategy\` must be set to \`"domains"\`.`,
+							});
 						}
 
-						for (const [domainKey, domainValue] of Object.entries(domains)) {
+						for (const [domainKey, domainValue] of entries) {
 							if (!locales.includes(domainKey)) {
 								ctx.addIssue({
 									code: z.ZodIssueCode.custom,
@@ -625,11 +581,8 @@ export function createRelativeSchema(cmd: string, fileProtocolRoot: string) {
 		.superRefine((configuration, ctx) => {
 			const { site, experimental, i18n, output } = configuration;
 			if (experimental.i18nDomains) {
-				if (
-					i18n?.routing === 'domains-prefix-other-locales' ||
-					i18n?.routing === 'domains-prefix-always-no-redirect' ||
-					i18n?.routing === 'domains-prefix-always'
-				) {
+				const hasDomains = i18n?.domains ? Object.keys(i18n.domains).length > 0 : false;
+				if (hasDomains) {
 					if (!site) {
 						ctx.addIssue({
 							code: z.ZodIssueCode.custom,
diff --git a/packages/astro/src/core/endpoint/index.ts b/packages/astro/src/core/endpoint/index.ts
index 54b5dff47..d65b5e6c0 100644
--- a/packages/astro/src/core/endpoint/index.ts
+++ b/packages/astro/src/core/endpoint/index.ts
@@ -6,8 +6,8 @@ import {
 	computeCurrentLocale,
 	computePreferredLocale,
 	computePreferredLocaleList,
+	type RoutingStrategies,
 } from '../../i18n/utils.js';
-import type { RoutingStrategies } from '../config/schema.js';
 
 type CreateAPIContext = {
 	request: Request;
diff --git a/packages/astro/src/core/render-context.ts b/packages/astro/src/core/render-context.ts
index 299c188af..c0cc55c81 100644
--- a/packages/astro/src/core/render-context.ts
+++ b/packages/astro/src/core/render-context.ts
@@ -190,7 +190,7 @@ export class RenderContext {
 		const { links, scripts, styles } = await pipeline.headElements(routeData);
 		const componentMetadata =
 			(await pipeline.componentMetadata(routeData)) ?? manifest.componentMetadata;
-		const { defaultLocale, locales, routing: routingStrategy } = i18n ?? {};
+		const { defaultLocale, locales, strategy } = i18n ?? {};
 		const partial = Boolean(mod.partial);
 		return createResult({
 			adapterName,
@@ -210,7 +210,7 @@ export class RenderContext {
 			resolve,
 			request,
 			route: routeData.route,
-			routingStrategy,
+			strategy,
 			site,
 			scripts,
 			ssr: serverLike,
@@ -238,9 +238,9 @@ export class RenderContext {
 				preferredLocale: undefined,
 				preferredLocaleList: undefined,
 			};
-		const { defaultLocale, locales, routing } = i18n;
+		const { defaultLocale, locales, strategy } = i18n;
 		return (this.#i18nData = {
-			currentLocale: computeCurrentLocale(routeData.route, locales, routing, defaultLocale),
+			currentLocale: computeCurrentLocale(routeData.route, locales, strategy, defaultLocale),
 			preferredLocale: computePreferredLocale(request, locales),
 			preferredLocaleList: computePreferredLocaleList(request, locales),
 		});
diff --git a/packages/astro/src/core/render/result.ts b/packages/astro/src/core/render/result.ts
index 6c1314f3c..cc7fa219e 100644
--- a/packages/astro/src/core/render/result.ts
+++ b/packages/astro/src/core/render/result.ts
@@ -17,8 +17,8 @@ import {
 	computeCurrentLocale,
 	computePreferredLocale,
 	computePreferredLocaleList,
+	type RoutingStrategies,
 } from '../../i18n/utils.js';
-import type { RoutingStrategies } from '../config/schema.js';
 import { clientAddressSymbol, responseSentSymbol } from '../constants.js';
 
 export interface CreateResultArgs {
@@ -53,7 +53,7 @@ export interface CreateResultArgs {
 	locales: Locales | undefined;
 	defaultLocale: string | undefined;
 	route: string;
-	routingStrategy: RoutingStrategies | undefined;
+	strategy: RoutingStrategies | undefined;
 }
 
 function getFunctionExpression(slot: any) {
@@ -234,7 +234,7 @@ export function createResult(args: CreateResultArgs): SSRResult {
 						currentLocale = computeCurrentLocale(
 							url.pathname,
 							args.locales,
-							args.routingStrategy,
+							args.strategy,
 							args.defaultLocale
 						);
 						if (currentLocale) {
diff --git a/packages/astro/src/core/routing/manifest/create.ts b/packages/astro/src/core/routing/manifest/create.ts
index 93b3770b1..804cacc83 100644
--- a/packages/astro/src/core/routing/manifest/create.ts
+++ b/packages/astro/src/core/routing/manifest/create.ts
@@ -20,6 +20,7 @@ import { AstroError } from '../../errors/index.js';
 import { removeLeadingForwardSlash, slash } from '../../path.js';
 import { resolvePages } from '../../util.js';
 import { getRouteGenerator } from './generator.js';
+import { toRoutingStrategy } from '../../../i18n/utils.js';
 const require = createRequire(import.meta.url);
 
 interface Item {
@@ -686,8 +687,9 @@ export function createRouteManifest(
 
 	const i18n = settings.config.i18n;
 	if (i18n) {
+		const strategy = toRoutingStrategy(i18n);
 		// First we check if the user doesn't have an index page.
-		if (i18n.routing === 'pathname-prefix-always') {
+		if (strategy === 'pathname-prefix-always') {
 			let index = routes.find((route) => route.route === '/');
 			if (!index) {
 				let relativePath = path.relative(
@@ -755,7 +757,7 @@ export function createRouteManifest(
 
 		// Work done, now we start creating "fallback" routes based on the configuration
 
-		if (i18n.routing === 'pathname-prefix-always') {
+		if (strategy === 'pathname-prefix-always') {
 			// we attempt to retrieve the index page of the default locale
 			const defaultLocaleRoutes = routesByLocale.get(i18n.defaultLocale);
 			if (defaultLocaleRoutes) {
@@ -830,7 +832,7 @@ export function createRouteManifest(
 							let route: string;
 							if (
 								fallbackToLocale === i18n.defaultLocale &&
-								i18n.routing === 'pathname-prefix-other-locales'
+								strategy === 'pathname-prefix-other-locales'
 							) {
 								if (fallbackToRoute.pathname) {
 									pathname = `/${fallbackFromLocale}${fallbackToRoute.pathname}`;
diff --git a/packages/astro/src/i18n/index.ts b/packages/astro/src/i18n/index.ts
index 4d66a56c3..0b93f1d78 100644
--- a/packages/astro/src/i18n/index.ts
+++ b/packages/astro/src/i18n/index.ts
@@ -3,7 +3,7 @@ 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';
+import type { RoutingStrategies } from './utils.js';
 
 type GetLocaleRelativeUrl = GetLocaleOptions & {
 	locale: string;
@@ -11,7 +11,7 @@ type GetLocaleRelativeUrl = GetLocaleOptions & {
 	locales: Locales;
 	trailingSlash: AstroConfig['trailingSlash'];
 	format: AstroConfig['build']['format'];
-	routing?: RoutingStrategies;
+	strategy?: RoutingStrategies;
 	defaultLocale: string;
 	domains: Record<string, string> | undefined;
 	path?: string;
@@ -45,7 +45,7 @@ export function getLocaleRelativeUrl({
 	path,
 	prependWith,
 	normalizeLocale = true,
-	routing = 'pathname-prefix-other-locales',
+	strategy = 'pathname-prefix-other-locales',
 	defaultLocale,
 }: GetLocaleRelativeUrl) {
 	const codeToUse = peekCodePathToUse(_locales, locale);
@@ -58,10 +58,10 @@ export function getLocaleRelativeUrl({
 	const pathsToJoin = [base, prependWith];
 	const normalizedLocale = normalizeLocale ? normalizeTheLocale(codeToUse) : codeToUse;
 	if (
-		routing === 'pathname-prefix-always' ||
-		routing === 'pathname-prefix-always-no-redirect' ||
-		routing === 'domains-prefix-always' ||
-		routing === 'domains-prefix-always-no-redirect'
+		strategy === 'pathname-prefix-always' ||
+		strategy === 'pathname-prefix-always-no-redirect' ||
+		strategy === 'domains-prefix-always' ||
+		strategy === 'domains-prefix-always-no-redirect'
 	) {
 		pathsToJoin.push(normalizedLocale);
 	} else if (locale !== defaultLocale) {
@@ -107,7 +107,7 @@ interface GetLocalesRelativeUrlList extends GetLocaleOptions {
 	locales: Locales;
 	trailingSlash: AstroConfig['trailingSlash'];
 	format: AstroConfig['build']['format'];
-	routing?: RoutingStrategies;
+	strategy?: RoutingStrategies;
 	defaultLocale: string;
 	domains: Record<string, string> | undefined;
 }
diff --git a/packages/astro/src/i18n/middleware.ts b/packages/astro/src/i18n/middleware.ts
index 815ac2e9c..c3f85064b 100644
--- a/packages/astro/src/i18n/middleware.ts
+++ b/packages/astro/src/i18n/middleware.ts
@@ -106,9 +106,9 @@ export function createI18nMiddleware(
 		}
 
 		const { url, currentLocale } = context;
-		const { locales, defaultLocale, fallback, routing } = i18n;
+		const { locales, defaultLocale, fallback, strategy } = i18n;
 
-		switch (i18n.routing) {
+		switch (i18n.strategy) {
 			case 'domains-prefix-other-locales': {
 				if (localeHasntDomain(i18n, currentLocale)) {
 					const result = prefixOtherLocales(url, response);
@@ -187,7 +187,7 @@ 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 === 'pathname-prefix-other-locales') {
+				if (pathFallbackLocale === defaultLocale && strategy === 'pathname-prefix-other-locales') {
 					newPathname = url.pathname.replace(`/${urlLocale}`, ``);
 				} else {
 					newPathname = url.pathname.replace(`/${urlLocale}`, `/${pathFallbackLocale}`);
diff --git a/packages/astro/src/i18n/utils.ts b/packages/astro/src/i18n/utils.ts
index 4cfec633b..d3dddba1f 100644
--- a/packages/astro/src/i18n/utils.ts
+++ b/packages/astro/src/i18n/utils.ts
@@ -1,6 +1,5 @@
-import type { Locales } from '../@types/astro.js';
+import type { AstroConfig, AstroUserConfig, Locales } from '../@types/astro.js';
 import { normalizeTheLocale, toCodes } from './index.js';
-import type { RoutingStrategies } from '../core/config/schema.js';
 
 type BrowserLocale = {
 	locale: string;
@@ -190,3 +189,39 @@ export function computeCurrentLocale(
 	}
 	return undefined;
 }
+
+export type RoutingStrategies =
+	| 'pathname-prefix-always'
+	| 'pathname-prefix-other-locales'
+	| 'pathname-prefix-always-no-redirect'
+	| 'domains-prefix-always'
+	| 'domains-prefix-other-locales'
+	| 'domains-prefix-always-no-redirect';
+export function toRoutingStrategy(i18n: NonNullable<AstroConfig['i18n']>) {
+	let { routing, domains } = i18n;
+	let strategy: RoutingStrategies;
+	const hasDomains = domains ? Object.keys(domains).length > 0 : false;
+	if (!hasDomains) {
+		if (routing?.prefixDefaultLocale === true) {
+			if (routing.redirectToDefaultLocale) {
+				strategy = 'pathname-prefix-always';
+			} else {
+				strategy = 'pathname-prefix-always-no-redirect';
+			}
+		} else {
+			strategy = 'pathname-prefix-other-locales';
+		}
+	} else {
+		if (routing?.prefixDefaultLocale === true) {
+			if (routing.redirectToDefaultLocale) {
+				strategy = 'domains-prefix-always';
+			} else {
+				strategy = 'domains-prefix-always-no-redirect';
+			}
+		} else {
+			strategy = 'domains-prefix-other-locales';
+		}
+	}
+
+	return strategy;
+}
diff --git a/packages/astro/src/virtual-modules/i18n.ts b/packages/astro/src/virtual-modules/i18n.ts
index f71068667..3358a880b 100644
--- a/packages/astro/src/virtual-modules/i18n.ts
+++ b/packages/astro/src/virtual-modules/i18n.ts
@@ -1,13 +1,16 @@
 import * as I18nInternals from '../i18n/index.js';
 import type { I18nInternalConfig } from '../i18n/vite-plugin-i18n.js';
+import { toRoutingStrategy } from '../i18n/utils.js';
 export { normalizeTheLocale, toCodes, toPaths } from '../i18n/index.js';
 
 const { trailingSlash, format, site, i18n, isBuild } =
 	// @ts-expect-error
 	__ASTRO_INTERNAL_I18N_CONFIG__ as I18nInternalConfig;
-const { defaultLocale, locales, routing, domains } = i18n!;
+const { defaultLocale, locales, domains } = i18n!;
 const base = import.meta.env.BASE_URL;
 
+const routing = toRoutingStrategy(i18n!);
+
 export type GetLocaleOptions = I18nInternals.GetLocaleOptions;
 
 /**
@@ -40,7 +43,7 @@ export const getRelativeLocaleUrl = (locale: string, path?: string, options?: Ge
 		format,
 		defaultLocale,
 		locales,
-		routing,
+		strategy: routing,
 		domains,
 		...options,
 	});
@@ -80,7 +83,7 @@ export const getAbsoluteLocaleUrl = (locale: string, path?: string, options?: Ge
 		site,
 		defaultLocale,
 		locales,
-		routing,
+		strategy: routing,
 		domains,
 		isBuild,
 		...options,
@@ -100,7 +103,7 @@ export const getRelativeLocaleUrlList = (path?: string, options?: GetLocaleOptio
 		format,
 		defaultLocale,
 		locales,
-		routing,
+		strategy: routing,
 		domains,
 		...options,
 	});
@@ -120,7 +123,7 @@ export const getAbsoluteLocaleUrlList = (path?: string, options?: GetLocaleOptio
 		format,
 		defaultLocale,
 		locales,
-		routing,
+		strategy: routing,
 		domains,
 		isBuild,
 		...options,
diff --git a/packages/astro/src/vite-plugin-astro-server/plugin.ts b/packages/astro/src/vite-plugin-astro-server/plugin.ts
index e149acad0..bea6d75ef 100644
--- a/packages/astro/src/vite-plugin-astro-server/plugin.ts
+++ b/packages/astro/src/vite-plugin-astro-server/plugin.ts
@@ -16,6 +16,7 @@ import { AsyncLocalStorage } from 'node:async_hooks';
 import { IncomingMessage } from 'node:http';
 import { setRouteError } from './server-state.js';
 import { recordServerError } from './error.js';
+import { toRoutingStrategy } from '../i18n/utils.js';
 
 export interface AstroPluginOptions {
 	settings: AstroSettings;
@@ -117,7 +118,7 @@ export function createDevelopmentManifest(settings: AstroSettings): SSRManifest
 	if (settings.config.i18n) {
 		i18nManifest = {
 			fallback: settings.config.i18n.fallback,
-			routing: settings.config.i18n.routing,
+			strategy: toRoutingStrategy(settings.config.i18n),
 			defaultLocale: settings.config.i18n.defaultLocale,
 			locales: settings.config.i18n.locales,
 			domainLookupTable: {},
diff --git a/packages/astro/test/units/i18n/astro_i18n.test.js b/packages/astro/test/units/i18n/astro_i18n.test.js
index d7702f7fd..0e8fdb4b5 100644
--- a/packages/astro/test/units/i18n/astro_i18n.test.js
+++ b/packages/astro/test/units/i18n/astro_i18n.test.js
@@ -10,6 +10,7 @@ import * as assert from 'node:assert/strict';
 import { validateConfig } from '../../../dist/core/config/config.js';
 import { AstroError } from '#astro/core/errors/index';
 import { MissingLocale } from '#astro/core/errors/errors-data';
+import { toRoutingStrategy } from '#astro/i18n/utils';
 
 describe('getLocaleRelativeUrl', () => {
 	it('should correctly return the URL with the base', () => {
@@ -231,11 +232,9 @@ describe('getLocaleRelativeUrl', () => {
 		 */
 		const config = {
 			base: '/blog',
-			experimental: {
-				i18n: {
-					defaultLocale: 'en',
-					locales: ['en', 'en_US', 'en_AU'],
-				},
+			i18n: {
+				defaultLocale: 'en',
+				locales: ['en', 'en_US', 'en_AU'],
 			},
 		};
 
@@ -243,9 +242,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'en_US',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'directory',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/en-us/'
 		);
@@ -254,10 +254,11 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'en_US',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'directory',
 				normalizeLocale: false,
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/en_US/'
 		);
@@ -266,9 +267,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'en_AU',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'directory',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/en-au/'
 		);
@@ -281,11 +283,11 @@ describe('getLocaleRelativeUrl', () => {
 		 */
 		const config = {
 			base: '/blog',
-			experimental: {
-				i18n: {
-					defaultLocale: 'en',
-					locales: ['en', 'es', 'en_US', 'en_AU'],
-					routing: 'pathname-prefix-always',
+			i18n: {
+				defaultLocale: 'en',
+				locales: ['en', 'es', 'en_US', 'en_AU'],
+				routing: {
+					prefixDefaultLocale: true,
 				},
 			},
 		};
@@ -297,7 +299,8 @@ describe('getLocaleRelativeUrl', () => {
 				base: '/blog/',
 				trailingSlash: 'always',
 				format: 'directory',
-				...config.experimental.i18n,
+				...config.i18n,
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/en/'
 		);
@@ -305,9 +308,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'es',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'directory',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/es/'
 		);
@@ -317,9 +321,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'en',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'file',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/en/'
 		);
@@ -327,9 +332,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'es',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'file',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/es/'
 		);
@@ -342,11 +348,12 @@ describe('getLocaleRelativeUrl', () => {
 		 */
 		const config = {
 			base: '/blog',
-			experimental: {
-				i18n: {
-					defaultLocale: 'en',
-					locales: ['en', 'es', 'en_US', 'en_AU'],
-					routing: 'pathname-prefix-always-no-redirect',
+			i18n: {
+				defaultLocale: 'en',
+				locales: ['en', 'es', 'en_US', 'en_AU'],
+				routing: {
+					prefixDefaultLocale: true,
+					redirectToDefaultLocale: false,
 				},
 			},
 		};
@@ -358,7 +365,8 @@ describe('getLocaleRelativeUrl', () => {
 				base: '/blog/',
 				trailingSlash: 'always',
 				format: 'directory',
-				...config.experimental.i18n,
+				...config.i18n,
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/en/'
 		);
@@ -366,9 +374,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'es',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'directory',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/es/'
 		);
@@ -378,9 +387,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'en',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'file',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/en/'
 		);
@@ -388,9 +398,10 @@ describe('getLocaleRelativeUrl', () => {
 			getLocaleRelativeUrl({
 				locale: 'es',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'always',
 				format: 'file',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			'/blog/es/'
 		);
@@ -576,11 +587,11 @@ describe('getLocaleRelativeUrlList', () => {
 		 * @type {import("../../../dist/@types").AstroUserConfig}
 		 */
 		const config = {
-			experimental: {
-				i18n: {
-					defaultLocale: 'en',
-					locales: ['en', 'en_US', 'es'],
-					routing: 'pathname-prefix-always',
+			i18n: {
+				defaultLocale: 'en',
+				locales: ['en', 'en_US', 'es'],
+				routing: {
+					prefixDefaultLocale: true,
 				},
 			},
 		};
@@ -589,9 +600,10 @@ describe('getLocaleRelativeUrlList', () => {
 			getLocaleRelativeUrlList({
 				locale: 'en',
 				base: '/blog',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'never',
 				format: 'directory',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			['/blog/en', '/blog/en-us', '/blog/es']
 		);
@@ -603,11 +615,12 @@ describe('getLocaleRelativeUrlList', () => {
 		 * @type {import("../../../dist/@types").AstroUserConfig}
 		 */
 		const config = {
-			experimental: {
-				i18n: {
-					defaultLocale: 'en',
-					locales: ['en', 'en_US', 'es'],
-					routing: 'pathname-prefix-always-no-redirect',
+			i18n: {
+				defaultLocale: 'en',
+				locales: ['en', 'en_US', 'es'],
+				routing: {
+					prefixDefaultLocale: true,
+					redirectToDefaultLocale: false,
 				},
 			},
 		};
@@ -616,9 +629,10 @@ describe('getLocaleRelativeUrlList', () => {
 			getLocaleRelativeUrlList({
 				locale: 'en',
 				base: '/blog',
-				...config.experimental.i18n,
+				...config.i18n,
 				trailingSlash: 'never',
 				format: 'directory',
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			['/blog/en', '/blog/en-us', '/blog/es']
 		);
@@ -795,14 +809,14 @@ describe('getLocaleAbsoluteUrl', () => {
 			 */
 			const config = {
 				base: '/blog',
-				experimental: {
-					i18n: {
-						defaultLocale: 'en',
-						locales: ['en', 'en_US', 'es'],
-						domains: {
-							es: 'https://es.example.com',
-						},
-						routing: 'pathname-prefix-always',
+				i18n: {
+					defaultLocale: 'en',
+					locales: ['en', 'en_US', 'es'],
+					domains: {
+						es: 'https://es.example.com',
+					},
+					routing: {
+						prefixDefaultLocale: true,
 					},
 				},
 			};
@@ -815,7 +829,8 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'always',
 					format: 'directory',
 					site: 'https://example.com',
-					...config.experimental.i18n,
+					...config.i18n,
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en/'
 			);
@@ -824,10 +839,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					trailingSlash: 'always',
 					format: 'directory',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -837,10 +853,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'en',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					trailingSlash: 'always',
 					format: 'file',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en/'
 			);
@@ -848,10 +865,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					trailingSlash: 'always',
 					format: 'file',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -860,11 +878,12 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					trailingSlash: 'always',
 					format: 'file',
 					site: 'https://example.com',
 					isBuild: true,
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://es.example.com/blog/'
 			);
@@ -874,12 +893,13 @@ describe('getLocaleAbsoluteUrl', () => {
 					locale: 'es',
 					base: '/blog/',
 					prependWith: 'some-name',
-					...config.experimental.i18n,
+					...config.i18n,
 					trailingSlash: 'always',
 					format: 'file',
 					site: 'https://example.com',
 					path: 'first-post',
 					isBuild: true,
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://es.example.com/blog/some-name/first-post/'
 			);
@@ -890,11 +910,11 @@ describe('getLocaleAbsoluteUrl', () => {
 			 * @type {import("../../../dist/@types").AstroUserConfig}
 			 */
 			const config = {
-				experimental: {
-					i18n: {
-						defaultLocale: 'en',
-						locales: ['en', 'es'],
-						routing: 'pathname-prefix-always',
+				i18n: {
+					defaultLocale: 'en',
+					locales: ['en', 'es'],
+					routing: {
+						prefixDefaultLocale: true,
 					},
 				},
 			};
@@ -903,10 +923,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'en',
 					base: '/',
-					...config.experimental.i18n,
+					...config.i18n,
 					trailingSlash: 'always',
 					format: 'directory',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/en/'
 			);
@@ -914,10 +935,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/',
-					...config.experimental.i18n,
+					...config.i18n,
 					trailingSlash: 'always',
 					format: 'directory',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/es/'
 			);
@@ -932,7 +954,9 @@ describe('getLocaleAbsoluteUrl', () => {
 				i18n: {
 					defaultLocale: 'en',
 					locales: ['en', 'es'],
-					routing: 'pathname-prefix-always',
+					routing: {
+						prefixDefaultLocale: true,
+					},
 				},
 			};
 			// directory format
@@ -944,6 +968,7 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'never',
 					format: 'directory',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en'
 			);
@@ -955,6 +980,7 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'always',
 					format: 'directory',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -967,6 +993,7 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'ignore',
 					format: 'directory',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en/'
 			);
@@ -980,6 +1007,7 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'never',
 					format: 'file',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en'
 			);
@@ -991,6 +1019,7 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'always',
 					format: 'file',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -1004,6 +1033,7 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'ignore',
 					format: 'file',
 					site: 'https://example.com',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en'
 			);
@@ -1067,11 +1097,11 @@ describe('getLocaleAbsoluteUrl', () => {
 			 */
 			const config = {
 				base: '/blog',
-				experimental: {
-					i18n: {
-						defaultLocale: 'en',
-						locales: ['en', 'es', 'en_US', 'en_AU'],
-						routing: 'pathname-prefix-always',
+				i18n: {
+					defaultLocale: 'en',
+					locales: ['en', 'es', 'en_US', 'en_AU'],
+					routing: {
+						prefixDefaultLocale: true,
 					},
 				},
 			};
@@ -1084,7 +1114,8 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'always',
 					site: 'https://example.com',
 					format: 'directory',
-					...config.experimental.i18n,
+					...config.i18n,
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en/'
 			);
@@ -1092,10 +1123,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					site: 'https://example.com',
 					trailingSlash: 'always',
 					format: 'directory',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -1105,10 +1137,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'en',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					site: 'https://example.com',
 					trailingSlash: 'always',
 					format: 'file',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en/'
 			);
@@ -1116,10 +1149,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					site: 'https://example.com',
 					trailingSlash: 'always',
 					format: 'file',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -1132,11 +1166,12 @@ describe('getLocaleAbsoluteUrl', () => {
 			 */
 			const config = {
 				base: '/blog',
-				experimental: {
-					i18n: {
-						defaultLocale: 'en',
-						locales: ['en', 'es', 'en_US', 'en_AU'],
-						routing: 'pathname-prefix-always-no-redirect',
+				i18n: {
+					defaultLocale: 'en',
+					locales: ['en', 'es', 'en_US', 'en_AU'],
+					routing: {
+						prefixDefaultLocale: true,
+						redirectToDefaultLocale: false,
 					},
 				},
 			};
@@ -1149,7 +1184,8 @@ describe('getLocaleAbsoluteUrl', () => {
 					trailingSlash: 'always',
 					site: 'https://example.com',
 					format: 'directory',
-					...config.experimental.i18n,
+					...config.i18n,
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en/'
 			);
@@ -1157,10 +1193,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					site: 'https://example.com',
 					trailingSlash: 'always',
 					format: 'directory',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -1170,10 +1207,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'en',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					site: 'https://example.com',
 					trailingSlash: 'always',
 					format: 'file',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/en/'
 			);
@@ -1181,10 +1219,11 @@ describe('getLocaleAbsoluteUrl', () => {
 				getLocaleAbsoluteUrl({
 					locale: 'es',
 					base: '/blog/',
-					...config.experimental.i18n,
+					...config.i18n,
 					site: 'https://example.com',
 					trailingSlash: 'always',
 					format: 'file',
+					strategy: toRoutingStrategy(config.i18n),
 				}),
 				'https://example.com/blog/es/'
 			);
@@ -1491,6 +1530,7 @@ describe('getLocaleAbsoluteUrlList', () => {
 				path: 'download',
 				...config,
 				...config.i18n,
+				strategy: toRoutingStrategy(config.i18n),
 			}),
 			[
 				'https://example.com/en/download/',
@@ -1530,6 +1570,7 @@ describe('getLocaleAbsoluteUrlList', () => {
 				path: 'download',
 				...config,
 				...config.i18n,
+				strategy: toRoutingStrategy(config.i18n),
 				isBuild: true,
 			}),
 			[
@@ -1671,11 +1712,11 @@ describe('getLocaleAbsoluteUrlList', () => {
 		 * @type {import("../../../dist/@types").AstroUserConfig}
 		 */
 		const config = {
-			experimental: {
-				i18n: {
-					defaultLocale: 'en',
-					locales: ['en', 'en_US', 'es'],
-					routing: 'pathname-prefix-always',
+			i18n: {
+				defaultLocale: 'en',
+				locales: ['en', 'en_US', 'es'],
+				routing: {
+					prefixDefaultLocale: true,
 				},
 			},
 		};
@@ -1684,7 +1725,8 @@ describe('getLocaleAbsoluteUrlList', () => {
 			getLocaleAbsoluteUrlList({
 				locale: 'en',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
+				strategy: toRoutingStrategy(config.i18n),
 				trailingSlash: 'ignore',
 				format: 'directory',
 				site: 'https://example.com',
@@ -1703,11 +1745,12 @@ describe('getLocaleAbsoluteUrlList', () => {
 		 * @type {import("../../../dist/@types").AstroUserConfig}
 		 */
 		const config = {
-			experimental: {
-				i18n: {
-					defaultLocale: 'en',
-					locales: ['en', 'en_US', 'es'],
-					routing: 'pathname-prefix-always-no-redirect',
+			i18n: {
+				defaultLocale: 'en',
+				locales: ['en', 'en_US', 'es'],
+				routing: {
+					prefixDefaultLocale: true,
+					redirectToDefaultLocale: false,
 				},
 			},
 		};
@@ -1716,7 +1759,8 @@ describe('getLocaleAbsoluteUrlList', () => {
 			getLocaleAbsoluteUrlList({
 				locale: 'en',
 				base: '/blog/',
-				...config.experimental.i18n,
+				...config.i18n,
+				strategy: toRoutingStrategy(config.i18n),
 				trailingSlash: 'ignore',
 				format: 'directory',
 				site: 'https://example.com',