fix(routing): default locale when there's a list (withastro#12151)

* fix(routing): default locale when there's a list

* fix(routing): default locale when there's a list

.changeset/stupid-seas-roll.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes an issue where `Astro.currentLocale` wasn't incorrectly computed when the `defaultLocale` belonged to a custom locale path. 

packages/astro/src/actions/runtime/middleware.ts

@@ -133,7 +133,6 @@ async function redirectWithResult({
 		if (!referer) {
 			throw new Error('Internal: Referer unexpectedly missing from Action POST request.');
 		}
-
 		return context.redirect(referer);
 	}
 

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

@@ -31,6 +31,11 @@ export type CreateContext = {
 	 * A list of locales that are supported by the user
 	 */
 	userDefinedLocales?: string[];
+
+	/**
+	 * User defined default locale
+	 */
+	defaultLocale: string;
 };
 
 /**
@@ -40,6 +45,7 @@ function createContext({
 	request,
 	params = {},
 	userDefinedLocales = [],
+	defaultLocale = '',
 }: CreateContext): APIContext {
 	let preferredLocale: string | undefined = undefined;
 	let preferredLocaleList: string[] | undefined = undefined;
@@ -75,7 +81,7 @@ function createContext({
 			return (preferredLocaleList ??= computePreferredLocaleList(request, userDefinedLocales));
 		},
 		get currentLocale(): string | undefined {
-			return (currentLocale ??= computeCurrentLocale(route, userDefinedLocales));
+			return (currentLocale ??= computeCurrentLocale(route, userDefinedLocales, defaultLocale));
 		},
 		url,
 		get clientAddress() {

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

@@ -535,8 +535,8 @@ export class RenderContext {
 		// and url.pathname to pass Astro.currentLocale tests.
 		// A single call with `routeData.pathname ?? routeData.route` as the pathname still fails.
 		return (this.#currentLocale ??=
-			computeCurrentLocale(routeData.route, locales) ??
-			computeCurrentLocale(url.pathname, locales) ??
+			computeCurrentLocale(routeData.route, locales, defaultLocale) ??
+			computeCurrentLocale(url.pathname, locales, defaultLocale) ??
 			fallbackTo);
 	}
 

packages/astro/src/i18n/utils.ts

@@ -148,7 +148,11 @@ export function computePreferredLocaleList(request: Request, locales: Locales):
 	return result;
 }
 
-export function computeCurrentLocale(pathname: string, locales: Locales): undefined | string {
+export function computeCurrentLocale(
+	pathname: string,
+	locales: Locales,
+	defaultLocale: string,
+): string | undefined {
 	for (const segment of pathname.split('/')) {
 		for (const locale of locales) {
 			if (typeof locale === 'string') {
@@ -171,6 +175,19 @@ export function computeCurrentLocale(pathname: string, locales: Locales): undefi
 			}
 		}
 	}
+	// If we didn't exit, it's probably because we don't have any code/locale in the URL.
+	// We use the default locale.
+	for (const locale of locales) {
+		if (typeof locale === 'string') {
+			if (locale === defaultLocale) {
+				return locale;
+			}
+		} else {
+			if (locale.path === defaultLocale) {
+				return locale.codes.at(0);
+			}
+		}
+	}
 }
 
 export type RoutingStrategies =

packages/astro/test/fixtures/i18n-routing/astro.config.mjs

@@ -2,7 +2,7 @@ import { defineConfig} from "astro/config";
 
 export default defineConfig({
 		i18n: {
-			defaultLocale: 'en',
+			defaultLocale: 'spanish',
 			locales: [
 				'en', 
 				'pt', 

packages/astro/test/i18n-routing.test.js

@@ -1106,7 +1106,7 @@ describe('[SSG] i18n routing', () => {
 
 			it('should return the default locale', async () => {
 				const html = await fixture.readFile('/current-locale/index.html');
-				assert.equal(html.includes('Current Locale: en'), true);
+				assert.equal(html.includes('Current Locale: es'), true);
 			});
 
 			it('should return the default locale when rendering a route with spread operator', async () => {
@@ -1121,7 +1121,7 @@ describe('[SSG] i18n routing', () => {
 
 			it('should return the default locale when a route is dynamic', async () => {
 				const html = await fixture.readFile('/dynamic/lorem/index.html');
-				assert.equal(html.includes('Current Locale: en'), true);
+				assert.equal(html.includes('Current Locale: es'), true);
 			});
 
 			it('should returns the correct locale when requesting a locale via path', async () => {
@@ -1701,7 +1701,7 @@ describe('[SSR] i18n routing', () => {
 				let request = new Request('http://example.com/current-locale', {});
 				let response = await app.render(request);
 				assert.equal(response.status, 200);
-				assert.equal((await response.text()).includes('Current Locale: en'), true);
+				assert.equal((await response.text()).includes('Current Locale: es'), true);
 			});
 
 			it('should return the default locale when rendering a route with spread operator', async () => {
@@ -1722,7 +1722,7 @@ describe('[SSR] i18n routing', () => {
 				let request = new Request('http://example.com/dynamic/lorem', {});
 				let response = await app.render(request);
 				assert.equal(response.status, 200);
-				assert.equal((await response.text()).includes('Current Locale: en'), true);
+				assert.equal((await response.text()).includes('Current Locale: es'), true);
 			});
 		});