Avoid SSR renderer imports for API-only SSR builds (#15507)

matthewp · ematipico · web-flow · commit 07f66101ed28 · 2026-02-16T13:11:27.000-05:00
* fix: avoid SSR renderer imports for API-only builds

* fix: map Astro command to Vite env

* rebase and fix lock file

---------

Co-authored-by: ematipico &lt;estoppa@cloudflare.com&gt;
diff --git a/.changeset/quiet-owls-jump.md b/.changeset/quiet-owls-jump.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Avoid bundling SSR renderers when only API endpoints are dynamic
diff --git a/packages/astro/src/core/create-vite.ts b/packages/astro/src/core/create-vite.ts
@@ -121,7 +121,11 @@ export async function createVite(
 		appType: 'custom',
 		plugins: [
 			serializedManifestPlugin({ settings, command, sync }),
-			vitePluginRenderers({ settings }),
+			vitePluginRenderers({
+				settings,
+				routesList,
+				command: command === 'dev' ? 'serve' : 'build',
+			}),
 			vitePluginStaticPaths(),
 			await astroPluginRoutes({ routesList, settings, logger, fsMod: fs, command }),
 			astroVirtualManifestPlugin(),
diff --git a/packages/astro/src/vite-plugin-renderers/index.ts b/packages/astro/src/vite-plugin-renderers/index.ts
@@ -1,11 +1,25 @@
-import type { Plugin as VitePlugin } from 'vite';
-import type { AstroSettings } from '../types/astro.js';
+import type { ConfigEnv, Plugin as VitePlugin } from 'vite';
+import { ASTRO_VITE_ENVIRONMENT_NAMES } from '../core/constants.js';
+import type { AstroSettings, RoutesList } from '../types/astro.js';
 
 export const ASTRO_RENDERERS_MODULE_ID = 'virtual:astro:renderers';
 const RESOLVED_ASTRO_RENDERERS_MODULE_ID = `\0${ASTRO_RENDERERS_MODULE_ID}`;
 
 interface PluginOptions {
 	settings: AstroSettings;
+	routesList: RoutesList;
+	command: ConfigEnv['command'];
+}
+
+/**
+ * Checks whether any non-prerendered route needs component rendering (i.e., is a page).
+ * Internal routes like `_server-islands` are excluded because they only need renderers
+ * when server islands are actually used, and those are detected separately during the build.
+ */
+function ssrBuildNeedsRenderers(routesList: RoutesList): boolean {
+	return routesList.routes.some(
+		(route) => route.type === 'page' && !route.prerender && route.origin !== 'internal',
+	);
 }
 
 export default function vitePluginRenderers(options: PluginOptions): VitePlugin {
@@ -29,6 +43,15 @@ export default function vitePluginRenderers(options: PluginOptions): VitePlugin
 				id: new RegExp(`^${RESOLVED_ASTRO_RENDERERS_MODULE_ID}$`),
 			},
 			handler() {
+				if (
+					options.command === 'build' &&
+					this.environment.name === ASTRO_VITE_ENVIRONMENT_NAMES.ssr &&
+					renderers.length > 0 &&
+					!ssrBuildNeedsRenderers(options.routesList)
+				) {
+					return { code: `export const renderers = [];` };
+				}
+
 				if (renderers.length > 0) {
 					const imports: string[] = [];
 					const exports: string[] = [];
diff --git a/packages/astro/test/fixtures/ssr-renderers-static-vue/astro.config.mjs b/packages/astro/test/fixtures/ssr-renderers-static-vue/astro.config.mjs
@@ -0,0 +1,6 @@
+import vue from '@astrojs/vue';
+import { defineConfig } from 'astro/config';
+
+export default defineConfig({
+	integrations: [vue()],
+});
diff --git a/packages/astro/test/fixtures/ssr-renderers-static-vue/package.json b/packages/astro/test/fixtures/ssr-renderers-static-vue/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "@test/ssr-renderers-static-vue",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@astrojs/vue": "workspace:*",
+    "astro": "workspace:*",
+    "vue": "^3.5.27"
+  }
+}
diff --git a/packages/astro/test/fixtures/ssr-renderers-static-vue/src/components/Counter.vue b/packages/astro/test/fixtures/ssr-renderers-static-vue/src/components/Counter.vue
@@ -0,0 +1,3 @@
+<template>
+  <div class="counter">Hello from Vue</div>
+</template>
diff --git a/packages/astro/test/fixtures/ssr-renderers-static-vue/src/pages/api/hello.ts b/packages/astro/test/fixtures/ssr-renderers-static-vue/src/pages/api/hello.ts
@@ -0,0 +1,9 @@
+export const prerender = false;
+
+export async function GET() {
+	return new Response(JSON.stringify({ ok: true }), {
+		headers: {
+			'content-type': 'application/json',
+		},
+	});
+}
diff --git a/packages/astro/test/fixtures/ssr-renderers-static-vue/src/pages/index.astro b/packages/astro/test/fixtures/ssr-renderers-static-vue/src/pages/index.astro
@@ -0,0 +1,14 @@
+---
+export const prerender = true;
+import Counter from '../components/Counter.vue';
+---
+
+<html>
+	<head>
+		<title>Static Vue</title>
+	</head>
+	<body>
+		<h1>Static page</h1>
+		<Counter />
+	</body>
+</html>
diff --git a/packages/astro/test/ssr-renderers-static-vue.test.js b/packages/astro/test/ssr-renderers-static-vue.test.js
@@ -0,0 +1,29 @@
+import assert from 'node:assert/strict';
+import { before, describe, it } from 'node:test';
+import testAdapter from './test-adapter.js';
+import { loadFixture } from './test-utils.js';
+
+describe('SSR renderers with static framework pages', () => {
+	/** @type {import('./test-utils.js').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/ssr-renderers-static-vue/',
+			output: 'server',
+			adapter: testAdapter(),
+		});
+		await fixture.build();
+	});
+
+	it('does not include SSR renderers when only endpoints are dynamic', async () => {
+		const app = await fixture.loadTestAdapterApp();
+		assert.ok(app.manifest, 'expected runtime manifest from SSR build');
+		assert.equal(app.manifest.renderers.length, 0);
+	});
+
+	it('prerendered page renders the Vue component', async () => {
+		const html = await fixture.readFile('/client/index.html');
+		assert.ok(html.includes('Hello from Vue'));
+	});
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +'astro': patch
 +---
++
 +Avoid bundling SSR renderers when only API endpoints are dynamic
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+<template>`
	`2`	`+ <div class="counter">Hello from Vue</div>`
	`3`	`+</template>`