withastro · natemoo-re · Aug 1, 2023 · Jun 18, 2023 · Jul 20, 2023 · Aug 1, 2023
diff --git a/.changeset/tidy-tips-doubt.md b/.changeset/tidy-tips-doubt.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/vercel': minor
+---
+
+Add cache headers to assets in Vercel adapter
diff --git a/packages/integrations/vercel/src/edge/adapter.ts b/packages/integrations/vercel/src/edge/adapter.ts
@@ -154,6 +154,11 @@ export default function vercelEdge({
 					version: 3,
 					routes: [
 						...getRedirects(routes, _config),
+						{
+							src: `^/${_config.build.assets}/(.*)$`,
+							headers: { 'cache-control': 'public, max-age=31536000, immutable' },
+							continue: true,
+						},
 						{ handle: 'filesystem' },
 						{ src: '/.*', dest: 'render' },
 					],

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -187,7 +187,16 @@ export default function vercelServerless({
 				// https://vercel.com/docs/build-output-api/v3#build-output-configuration
 				await writeJson(new URL(`./config.json`, _config.outDir), {
 					version: 3,
-					routes: [...getRedirects(routes, _config), { handle: 'filesystem' }, ...routeDefinitions],
+					routes: [
+						...getRedirects(routes, _config),
+						{
+							src: `^/${_config.build.assets}/(.*)$`,
+							headers: { 'cache-control': 'public, max-age=31536000, immutable' },
+							continue: true,
+						},
+						{ handle: 'filesystem' },
+						...routeDefinitions,
+					],
 					...(imageService || imagesConfig
 						? { images: imagesConfig ? imagesConfig : defaultImageConfig }
 						: {}),

diff --git a/packages/integrations/vercel/src/static/adapter.ts b/packages/integrations/vercel/src/static/adapter.ts
@@ -71,7 +71,15 @@ export default function vercelStatic({
 				// https://vercel.com/docs/build-output-api/v3#build-output-configuration
 				await writeJson(new URL(`./config.json`, getVercelOutput(_config.root)), {
 					version: 3,
-					routes: [...getRedirects(routes, _config), { handle: 'filesystem' }],
+					routes: [
+						...getRedirects(routes, _config),
+						{
+							src: `^/${_config.build.assets}/(.*)$`,
+							headers: { 'cache-control': 'public, max-age=31536000, immutable' },
+							continue: true,
+						},
+						{ handle: 'filesystem' },
+					],
 					...(imageService || imagesConfig
 						? { images: imagesConfig ? imagesConfig : defaultImageConfig }
 						: {}),

diff --git a/packages/integrations/vercel/test/fixtures/static-assets/astro.config.mjs b/packages/integrations/vercel/test/fixtures/static-assets/astro.config.mjs
@@ -0,0 +1,4 @@
+import { defineConfig } from 'astro/config';
+
+export default defineConfig({
+});
diff --git a/packages/integrations/vercel/test/fixtures/static-assets/package.json b/packages/integrations/vercel/test/fixtures/static-assets/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@test/astro-vercel-static-assets",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@astrojs/vercel": "workspace:*",
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/integrations/vercel/test/fixtures/static-assets/src/pages/index.astro b/packages/integrations/vercel/test/fixtures/static-assets/src/pages/index.astro
@@ -0,0 +1,8 @@
+<html>
+	<head>
+		<title>Testing</title>
+	</head>
+	<body>
+		<h1>Testing</h1>
+	</body>
+</html>
diff --git a/packages/integrations/vercel/test/split.test.js b/packages/integrations/vercel/test/split.test.js
@@ -24,6 +24,6 @@ describe('build: split', () => {
 	it('creates the route definitions in the config.json', async () => {
 		const json = await fixture.readFile('../.vercel/output/config.json');
 		const config = JSON.parse(json);
-		expect(config.routes).to.have.a.lengthOf(3);
+		expect(config.routes).to.have.a.lengthOf(4);
 	});
 });
diff --git a/packages/integrations/vercel/test/static-assets.test.js b/packages/integrations/vercel/test/static-assets.test.js
@@ -0,0 +1,84 @@
+import { expect } from 'chai';
+import { loadFixture } from './test-utils.js';
+
+describe('Static Assets', () => {
+	/** @type {import('../../../astro/test/test-utils.js').Fixture} */
+	let fixture;
+
+	const VALID_CACHE_CONTROL = 'public, max-age=31536000, immutable';
+
+	async function build({ adapter, assets }) {
+		fixture = await loadFixture({
+			root: './fixtures/static-assets/',
+			adapter,
+			build: {
+				assets,
+			}
+		});
+		await fixture.build();
+	}
+
+	async function getConfig() {
+		const json = await fixture.readFile('../.vercel/output/config.json');
+		const config = JSON.parse(json);
+
+		return config;
+	}
+
+	async function getAssets() {
+		return fixture.config.build.assets;
+	}
+
+	async function checkValidCacheControl(assets) {
+		const config = await getConfig();
+
+		const route = config.routes.find((r) => r.src === `^/${assets ?? getAssets()}/(.*)$`);
+		expect(route.headers['cache-control']).to.equal(VALID_CACHE_CONTROL);
+		expect(route.continue).to.equal(true);
+	}
+
+	describe('static adapter', async () => {
+		const adapter = await import('@astrojs/vercel/static');
+
+		it('has cache control', async () => {
+			await build({ adapter });
+			checkValidCacheControl();
+		});
+
+		it('has cache control other assets', async () => {
+			const assets = '_foo';
+			await build({ adapter, assets });
+			checkValidCacheControl(assets);
+		});
+	});
+
+	describe('serverless adapter', async () => {
+		const adapter = await import('@astrojs/vercel/serverless');
+
+		it('has cache control', async () => {
+			await build({ adapter });
+			checkValidCacheControl();
+		});
+
+		it('has cache control other assets', async () => {
+			const assets = '_foo';
+			await build({ adapter, assets });
+			checkValidCacheControl(assets);
+		});
+	});
+
+	describe('edge adapter', async () => {
+		const adapter = await import('@astrojs/vercel/edge');
+
+		it('has cache control', async () => {
+			await build({ adapter });
+			checkValidCacheControl();
+		});
+
+		it('has cache control other assets', async () => {
+			const assets = '_foo';
+			await build({ adapter, assets });
+			checkValidCacheControl(assets);
+		});
+	});
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml