Fix polyfills not being available to imports on Netlify

.changeset/gold-socks-applaud.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/webapi': patch
+---
+
+Add `polyfill-ssr.js` file to apply polyfills needed for certain SSR contexts as a side effect

.changeset/silent-dragons-sell.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/netlify': patch
+---
+
+Fix polyfills not being available in certain cases

packages/integrations/netlify/src/integration-functions.ts

@@ -35,6 +35,11 @@ function netlifyFunctions({
 						client: outDir,
 						server: new URL('./.netlify/functions-internal/', config.root),
 					},
+					vite: {
+						ssr: {
+							external: ['@astrojs/webapi/polyfill-ssr.js'],
+						},
+					},
 				});
 			},
 			'astro:config:done': ({ config, setAdapter }) => {

packages/integrations/netlify/src/netlify-functions.ts

@@ -1,12 +1,9 @@
-import { polyfill } from '@astrojs/webapi';
+import '@astrojs/webapi/polyfill-ssr.js';
+
 import { builder, Handler } from '@netlify/functions';
 import { SSRManifest } from 'astro';
 import { App } from 'astro/app';
 
-polyfill(globalThis, {
-	exclude: 'window document',
-});
-
 export interface Args {
 	builders?: boolean;
 	binaryMediaTypes?: string[];

packages/integrations/netlify/test/functions/fixtures/polyfills/src/pages/index.astro

@@ -0,0 +1,4 @@
+---
+---
+
+<div>{typeof fetch}</div>

packages/integrations/netlify/test/functions/polyfills.test.js

@@ -0,0 +1,28 @@
+import { expect } from 'chai';
+import netlifyAdapter from '../../dist/index.js';
+import { loadFixture, testIntegration } from './test-utils.js';
+
+describe('Support polyfills', () => {
+	/** @type {import('./test-utils').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: new URL('./fixtures/polyfills/', import.meta.url).toString(),
+			output: 'server',
+			adapter: netlifyAdapter({
+				dist: new URL('./fixtures/polyfills/dist/', import.meta.url),
+			}),
+			site: `http://example.com`,
+			integrations: [testIntegration()],
+		});
+		await fixture.build();
+	});
+
+	it('starts with the polyfill import', async () => {
+		const entry = await fixture.readFile('../.netlify/functions-internal/entry.mjs');
+		expect(entry).to.satisfy((content) =>
+			content.startsWith("import '@astrojs/webapi/polyfill-ssr.js';")
+		);
+	});
+});

packages/webapi/package.json

@@ -10,6 +10,9 @@
     },
     "./apply": {
       "import": "./apply.js"
+    },
+    "./polyfill-ssr.js": {
+      "import": "./polyfill-ssr.js"
     }
   },
   "main": "mod.js",
@@ -18,7 +21,8 @@
     "apply.js",
     "mod.d.ts",
     "mod.js",
-    "mod.js.map"
+    "mod.js.map",
+    "polyfill-ssr.js"
   ],
   "keywords": [
     "astro",

packages/webapi/polyfill-ssr.js

@@ -0,0 +1,7 @@
+import { polyfill } from './mod.js'
+
+export * from './mod.js'
+
+polyfill(globalThis, {
+	exclude: 'window document',
+})