Filter routes by environment and fix image loading

.changeset/memory-route-filter.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Reduces build memory by filtering routes per environment so each only builds the pages it needs

.github/workflows/preview-release.yml

@@ -2,7 +2,7 @@ name: Preview release
 
 on:
   pull_request:
-    branches: [main]
+    branches: [main, next]
     types: [labeled]
 
 concurrency:

packages/astro/src/assets/build/generate.ts

@@ -74,7 +74,8 @@ export async function prepareAssetsGenerationEnv(
 	const isServerOutput = settings.buildOutput === 'server';
 	let serverRoot: URL, clientRoot: URL;
 	if (isServerOutput) {
-		serverRoot = manifest.buildServerDir;
+		// Images are collected during prerender, which outputs to .prerender/ subdirectory
+		serverRoot = new URL('.prerender/', manifest.buildServerDir);
 		clientRoot = manifest.buildClientDir;
 	} else {
 		serverRoot = getOutDirWithinCwd(manifest.outDir);

packages/astro/src/vite-plugin-pages/pages.ts

@@ -2,6 +2,7 @@ import type { Plugin as VitePlugin } from 'vite';
 import { DEFAULT_COMPONENTS } from '../core/routing/default.js';
 import { routeIsRedirect } from '../core/routing/index.js';
 import type { RoutesList } from '../types/astro.js';
+import type { RouteData } from '../types/public/internal.js';
 import { VIRTUAL_PAGE_MODULE_ID } from './const.js';
 import { getVirtualModulePageName } from './util.js';
 import { ASTRO_VITE_ENVIRONMENT_NAMES } from '../core/constants.js';
@@ -13,6 +14,23 @@ interface PagesPluginOptions {
 	routesList: RoutesList;
 }
 
+/**
+ * Filters routes for a specific build environment.
+ * Redirects need their target route included so the redirect response can be generated at runtime.
+ */
+function getRoutesForEnvironment(routes: RouteData[], isPrerender: boolean): Set<RouteData> {
+	const result = new Set<RouteData>();
+	for (const route of routes) {
+		if (route.prerender === isPrerender) {
+			result.add(route);
+		}
+		if (route.redirectRoute) {
+			result.add(route.redirectRoute);
+		}
+	}
+	return result;
+}
+
 export function pluginPages({ routesList }: PagesPluginOptions): VitePlugin {
 	return {
 		name: '@astro/plugin-pages',
@@ -40,7 +58,20 @@ export function pluginPages({ routesList }: PagesPluginOptions): VitePlugin {
 				const pageMap: string[] = [];
 				let i = 0;
 
-				for (const route of routesList.routes) {
+				// Filter routes based on the build environment to reduce memory usage.
+				// Each environment only builds the pages it needs:
+				// - SSR environment: builds only on-demand rendered pages (prerender: false)
+				// - Prerender environment: builds only static pages (prerender: true)
+				// - Other environments (e.g. client): get all routes
+				const envName = this.environment.name;
+				const isSSR = envName === ASTRO_VITE_ENVIRONMENT_NAMES.ssr;
+				const isPrerender = envName === ASTRO_VITE_ENVIRONMENT_NAMES.prerender;
+				const routes =
+					isSSR || isPrerender
+						? getRoutesForEnvironment(routesList.routes, isPrerender)
+						: new Set(routesList.routes);
+
+				for (const route of routes) {
 					if (routeIsRedirect(route)) {
 						continue;
 					}

packages/astro/test/test-adapter.js

@@ -85,7 +85,7 @@ export default function ({
 												async render(request, { routeData, clientAddress, locals, addCookieHeader, prerenderedErrorPageFetch } = {}) {
 													const url = new URL(request.url);
 													if(this.#manifest.assets.has(url.pathname)) {
-														const filePath = new URL('../../client/' + this.removeBase(url.pathname), import.meta.url);
+														const filePath = new URL(this.removeBase(url.pathname).replace(/^\\//, ''), this.#manifest.buildClientDir);
 														const data = await fs.promises.readFile(filePath);
 														return new Response(data);
 													}