fix(i18n): correctly pull the ssr entry during build

.changeset/honest-bats-own.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Correctly handle the rendering of i18n routes when `output: "hybrid"` is set

packages/astro/src/core/build/buildPipeline.ts

@@ -8,7 +8,10 @@ import { routeIsFallback, routeIsRedirect } from '../redirects/helpers.js';
 import { createEnvironment } from '../render/index.js';
 import { createAssetLink } from '../render/ssr-element.js';
 import type { BuildInternals } from './internal.js';
-import { ASTRO_PAGE_RESOLVED_MODULE_ID } from './plugins/plugin-pages.js';
+import {
+	ASTRO_PAGE_RESOLVED_MODULE_ID,
+	getVirtualModulePageNameFromPath,
+} from './plugins/plugin-pages.js';
 import { RESOLVED_SPLIT_MODULE_ID } from './plugins/plugin-ssr.js';
 import { ASTRO_PAGE_EXTENSION_POST_PATTERN } from './plugins/util.js';
 import type { PageBuildData, StaticBuildOptions } from './types.js';
@@ -172,7 +175,19 @@ export class BuildPipeline extends Pipeline {
 				(i18nHasFallback(this.getConfig()) ||
 					(routeIsFallback(pageData.route) && pageData.route.route === '/'))
 			) {
-				pages.set(pageData, path);
+				// The original component is transformed during the first build, so we have to retrieve
+				// the actual `.mjs` that was created.
+				// During the build, we transform the names of our pages with some weird name, and those weird names become the keys of a map.
+				// The values of the map are the actual `.mjs` files that are generated during the build
+
+				// Here, we take the component path and transform it in the virtual module name
+				const moduleSpecifier = getVirtualModulePageNameFromPath(path);
+				// We retrieve the original JS module
+				const filePath = this.#internals.entrySpecifierToBundleMap.get(moduleSpecifier);
+				if (filePath) {
+					// it exists, added it to pages to render, using the file path that we jus retrieved
+					pages.set(pageData, filePath);
+				}
 			}
 		}
 

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

@@ -1380,6 +1380,27 @@ describe('[SSR] i18n routing', () => {
 			});
 		});
 	});
+
+	describe('i18n routing should work with hybrid rendering', () => {
+		/** @type {import('./test-utils').Fixture} */
+		let fixture;
+
+		before(async () => {
+			fixture = await loadFixture({
+				root: './fixtures/i18n-routing-prefix-always/',
+				output: 'hybrid',
+				adapter: testAdapter(),
+			});
+			await fixture.build();
+			app = await fixture.loadTestAdapterApp();
+		});
+
+		it('and render the index page, which is static', async () => {
+			const html = await fixture.readFile('/client/index.html');
+			expect(html).to.include('http-equiv="refresh');
+			expect(html).to.include('url=/new-site/en');
+		});
+	});
 });
 
 describe('i18n routing does not break assets and endpoints', () => {