fix(i18n): server island request (#13112)

Co-authored-by: ascorbic <213306+ascorbic@users.noreply.github.com>

Author: ematipico

.changeset/silent-worms-whisper.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes a bug where the i18n middleware was blocking a server island request when the `prefixDefaultLocale` option is set to `true`

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

@@ -29,9 +29,8 @@ import { callMiddleware } from './middleware/callMiddleware.js';
 import { sequence } from './middleware/index.js';
 import { renderRedirect } from './redirects/render.js';
 import { type Pipeline, Slots, getParams, getProps } from './render/index.js';
-import { isRoute404or500 } from './routing/match.js';
+import { isRoute404or500, isRouteServerIsland } from './routing/match.js';
 import { copyRequest, getOriginPathname, setOriginPathname } from './routing/rewrite.js';
-import { SERVER_ISLAND_COMPONENT } from './server-islands/endpoint.js';
 import { AstroSession } from './session.js';
 
 export const apiContextRoutesSymbol = Symbol.for('context.routes');
@@ -596,7 +595,7 @@ export class RenderContext {
 		}
 
 		let computedLocale;
-		if (routeData.component === SERVER_ISLAND_COMPONENT) {
+		if (isRouteServerIsland(routeData)) {
 			let referer = this.request.headers.get('referer');
 			if (referer) {
 				if (URL.canParse(referer)) {

packages/astro/src/core/routing/match.ts

@@ -1,5 +1,6 @@
 import type { RoutesList } from '../../types/astro.js';
 import type { RouteData } from '../../types/public/internal.js';
+import { SERVER_ISLAND_BASE_PREFIX, SERVER_ISLAND_COMPONENT } from '../server-islands/endpoint.js';
 
 /** Find matching route from pathname */
 export function matchRoute(pathname: string, manifest: RoutesList): RouteData | undefined {
@@ -37,3 +38,41 @@ export function isRoute500(route: string) {
 export function isRoute404or500(route: RouteData): boolean {
 	return isRoute404(route.route) || isRoute500(route.route);
 }
+
+/**
+ * Determines if a given route is associated with the server island component.
+ *
+ * @param {RouteData} route - The route data object to evaluate.
+ * @return {boolean} Returns true if the route's component is the server island component, otherwise false.
+ */
+export function isRouteServerIsland(route: RouteData): boolean {
+	return route.component === SERVER_ISLAND_COMPONENT;
+}
+
+/**
+ * Determines whether the given `Request` is targeted to a "server island" based on its URL.
+ *
+ * @param {Request} request - The request object to be evaluated.
+ * @param {string} [base=''] - The base path provided via configuration.
+ * @return {boolean} - Returns `true` if the request is for a server island, otherwise `false`.
+ */
+export function isRequestServerIsland(request: Request, base = ''): boolean {
+	const url = new URL(request.url);
+	const pathname = url.pathname.slice(base.length);
+
+	return pathname.startsWith(SERVER_ISLAND_BASE_PREFIX);
+}
+
+/**
+ * Checks if the given request corresponds to a 404 or 500 route based on the specified base path.
+ *
+ * @param {Request} request - The HTTP request object to be checked.
+ * @param {string} [base=''] - The base path to trim from the request's URL before checking the route. Default is an empty string.
+ * @return {boolean} Returns true if the request matches a 404 or 500 route; otherwise, returns false.
+ */
+export function requestIs404Or500(request: Request, base = '') {
+	const url = new URL(request.url);
+	const pathname = url.pathname.slice(base.length);
+
+	return isRoute404(pathname) || isRoute500(pathname);
+}

packages/astro/src/core/server-islands/endpoint.ts

@@ -13,6 +13,7 @@ import { getPattern } from '../routing/manifest/pattern.js';
 
 export const SERVER_ISLAND_ROUTE = '/_server-islands/[name]';
 export const SERVER_ISLAND_COMPONENT = '_server-islands.astro';
+export const SERVER_ISLAND_BASE_PREFIX = '_server-islands';
 
 type ConfigFields = Pick<SSRManifest, 'base' | 'trailingSlash'>;
 

packages/astro/src/i18n/index.ts

@@ -16,13 +16,6 @@ export function requestHasLocale(locales: Locales) {
 	};
 }
 
-export function requestIs404Or500(request: Request, base = '') {
-	const url = new URL(request.url);
-	const pathname = url.pathname.slice(base.length);
-
-	return isRoute404(pathname) || isRoute500(pathname);
-}
-
 // Checks if the pathname has any locale
 export function pathHasLocale(path: string, locales: Locales): boolean {
 	const segments = path.split('/');

packages/astro/src/i18n/middleware.ts

@@ -9,8 +9,8 @@ import {
 	redirectToDefaultLocale,
 	redirectToFallback,
 	requestHasLocale,
-	requestIs404Or500,
 } from './index.js';
+import { isRequestServerIsland, requestIs404Or500 } from '../core/routing/match.js';
 
 export function createI18nMiddleware(
 	i18n: SSRManifest['i18n'],
@@ -82,6 +82,12 @@ export function createI18nMiddleware(
 			return response;
 		}
 
+		// This is a case where the rendering phase belongs to a server island. Server island are
+		// special routes, and should be exhempt from i18n routing
+		if (isRequestServerIsland(context.request, base)) {
+			return response;
+		}
+
 		const { currentLocale } = context;
 		switch (i18n.strategy) {
 			// NOTE: theoretically, we should never hit this code path

packages/astro/test/fixtures/i18n-server-island/astro.config.mjs

@@ -0,0 +1,17 @@
+import { defineConfig } from "astro/config";
+
+export default defineConfig({
+		i18n: {
+			defaultLocale: 'en',
+			locales: [
+				'en', 'pt', 'it', {
+					path: "spanish",
+					codes: ["es", "es-ar"]
+				}
+			], 
+			routing: {
+				prefixDefaultLocale: true
+			}
+		},
+		base: "/new-site"
+})

packages/astro/test/fixtures/i18n-server-island/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@test/i18n-server-island",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*"
+  }
+}

packages/astro/test/fixtures/i18n-server-island/src/components/Island.astro

@@ -0,0 +1 @@
+<p>I am a server island</p>

packages/astro/test/fixtures/i18n-server-island/src/pages/en/island.astro

@@ -0,0 +1,5 @@
+---
+import Island from "../../components/Island.astro"
+---
+
+<Island server:defer />