add test

packages/astro/test/fixtures/preloading/package.json

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

packages/astro/test/fixtures/preloading/src/pages/module1.astro

@@ -0,0 +1,5 @@
+<script>
+    import { shared } from "../to-be-preloaded.js"
+	console.log(shared)
+</script>
+<p></p>

packages/astro/test/fixtures/preloading/src/pages/module2.astro

@@ -0,0 +1,5 @@
+<script>
+    import { shared } from "../to-be-preloaded.js"
+	console.log(shared)
+</script>
+<p></p>

packages/astro/test/fixtures/preloading/src/to-be-preloaded.js

@@ -0,0 +1 @@
+export const shared = {}

packages/astro/test/preloading.test.js

@@ -0,0 +1,23 @@
+import { expect } from 'chai';
+import { loadFixture } from './test-utils.js';
+import * as cheerio from 'cheerio';
+
+describe('preloading', () => {
+	/** @type {import('./test-utils.js').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/preloading/',
+		});
+		await fixture.build()
+	});
+
+	it('rendered page includes a link rel=modulepreload', async () => {
+		const html = await fixture.readFile('/module1/index.html');
+		const $ = cheerio.load(html);
+		const link = $('link')[0];
+		expect(link.attribs).to.deep.include({ rel: 'modulepreload' });
+		expect(link.attribs.href).to.include('to-be-preloaded');
+	});
+});

pnpm-lock.yaml

@@ -3016,6 +3016,12 @@ importers:
         specifier: ^10.17.1
         version: 10.17.1
 
+  packages/astro/test/fixtures/preloading:
+    dependencies:
+      astro:
+        specifier: workspace:*
+        version: link:../../..
+
   packages/astro/test/fixtures/public-base-404:
     dependencies:
       astro: