From 84683f2582ab26e5d173c4128287edf223531a98 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Sat, 23 Dec 2023 13:44:47 +0000
Subject: [PATCH 01/19] feat(vercel): isr

---
 .../vercel/src/serverless/adapter.ts          | 21 +++++++++++++++++++
 .../vercel/src/serverless/entrypoint.ts       |  3 +++
 2 files changed, 24 insertions(+)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index f1c75e4b4d9e..0f5683cdf88c 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -122,6 +122,9 @@ export interface VercelServerlessConfig {
 
 	/** The maximum duration (in seconds) that Serverless Functions can run before timing out. See the [Vercel documentation](https://vercel.com/docs/functions/serverless-functions/runtimes#maxduration) for the default and maximum limit for your account plan. */
 	maxDuration?: number;
+
+	/** Whether to cache on-demand rendered pages in the same way as static files. */
+	isr?: boolean;
 }
 
 export default function vercelServerless({
@@ -135,6 +138,7 @@ export default function vercelServerless({
 	functionPerRoute = false,
 	edgeMiddleware = false,
 	maxDuration,
+	isr = false,
 }: VercelServerlessConfig = {}): AstroIntegration {
 	if (maxDuration) {
 		if (typeof maxDuration !== 'number') {
@@ -189,6 +193,9 @@ export default function vercelServerless({
 					},
 					vite: {
 						...getSpeedInsightsViteConfig(speedInsights?.enabled),
+						define: {
+							"import.meta.env.ASTRO_VERCEL_ISR": isr ? "true" : "false"
+						},
 						ssr: {
 							external: ['@vercel/nft'],
 						},
@@ -282,6 +289,7 @@ export default function vercelServerless({
 							includeFiles,
 							excludeFiles,
 							maxDuration,
+							isr,
 						});
 						routeDefinitions.push({
 							src: route.pattern.source,
@@ -299,6 +307,7 @@ export default function vercelServerless({
 						includeFiles,
 						excludeFiles,
 						maxDuration,
+						isr,
 					});
 					const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
 					for (const route of routes) {
@@ -396,6 +405,7 @@ interface CreateFunctionFolderArgs {
 	includeFiles: URL[];
 	excludeFiles: URL[];
 	maxDuration: number | undefined;
+	isr: boolean
 }
 
 async function createFunctionFolder({
@@ -408,11 +418,13 @@ async function createFunctionFolder({
 	includeFiles,
 	excludeFiles,
 	maxDuration,
+	isr
 }: CreateFunctionFolderArgs) {
 	// .vercel/output/functions/<name>.func/
 	const functionFolder = new URL(`./functions/${functionName}.func/`, config.outDir);
 	const packageJson = new URL(`./functions/${functionName}.func/package.json`, config.outDir);
 	const vcConfig = new URL(`./functions/${functionName}.func/.vc-config.json`, config.outDir);
+	const prerenderConfig = new URL(`./functions/${functionName}.prerender-config.json`, config.outDir)
 
 	// Copy necessary files (e.g. node_modules/)
 	const { handler } = await copyDependenciesToFunction(
@@ -439,6 +451,15 @@ async function createFunctionFolder({
 		maxDuration,
 		supportsResponseStreaming: true,
 	});
+
+	if (isr) {
+		// https://vercel.com/docs/build-output-api/v3/primitives#prerender-configuration-file
+		await writeJson(prerenderConfig, {
+			expiration: false,
+			allowQuery: ["vercel_original_path"],
+			passQuery: true
+		});
+	}
 }
 
 function getRuntime(process: NodeJS.Process, logger: AstroIntegrationLogger): Runtime {
diff --git a/packages/integrations/vercel/src/serverless/entrypoint.ts b/packages/integrations/vercel/src/serverless/entrypoint.ts
index fe88c367d320..b1e6ff125249 100644
--- a/packages/integrations/vercel/src/serverless/entrypoint.ts
+++ b/packages/integrations/vercel/src/serverless/entrypoint.ts
@@ -8,6 +8,9 @@ applyPolyfills();
 export const createExports = (manifest: SSRManifest) => {
 	const app = new NodeApp(manifest);
 	const handler = async (req: IncomingMessage, res: ServerResponse) => {
+		const url = new URL(`https://example.com${req.url}`)
+		const originalPath = url.searchParams.get('vercel_original_path')
+		if (originalPath) req.url = originalPath
 		const clientAddress = req.headers['x-forwarded-for'] as string | undefined;
 		const localsHeader = req.headers[ASTRO_LOCALS_HEADER];
 		const realPath = req.headers[ASTRO_PATH_HEADER];

From 85d02971d071987e95861c712749063c8084e409 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Sat, 23 Dec 2023 13:45:26 +0000
Subject: [PATCH 02/19] bypass token

---
 .../integrations/vercel/src/serverless/adapter.ts    | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 0f5683cdf88c..655a1252c760 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -124,7 +124,12 @@ export interface VercelServerlessConfig {
 	maxDuration?: number;
 
 	/** Whether to cache on-demand rendered pages in the same way as static files. */
-	isr?: boolean;
+	isr?: boolean | VercelISRConfig;
+}
+
+interface VercelISRConfig {
+	/** A random string that you create. Its presence in the `__prerender_bypass` cookie will result in fresh responses being served. */
+	bypassToken?: string;
 }
 
 export default function vercelServerless({
@@ -405,7 +410,7 @@ interface CreateFunctionFolderArgs {
 	includeFiles: URL[];
 	excludeFiles: URL[];
 	maxDuration: number | undefined;
-	isr: boolean
+	isr: boolean | VercelISRConfig;
 }
 
 async function createFunctionFolder({
@@ -451,11 +456,12 @@ async function createFunctionFolder({
 		maxDuration,
 		supportsResponseStreaming: true,
 	});
-
+	
 	if (isr) {
 		// https://vercel.com/docs/build-output-api/v3/primitives#prerender-configuration-file
 		await writeJson(prerenderConfig, {
 			expiration: false,
+			bypassToken: typeof isr === "object" ? isr.bypassToken : undefined,
 			allowQuery: ["vercel_original_path"],
 			passQuery: true
 		});

From 33df953247404b035bd1fd755b0fcaea69177880 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Wed, 10 Jan 2024 18:59:59 +0000
Subject: [PATCH 03/19] exclusion of certain paths

---
 .../vercel/src/serverless/adapter.ts          | 92 +++++++++++++++----
 .../vercel/src/serverless/entrypoint.ts       | 10 +-
 2 files changed, 79 insertions(+), 23 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 655a1252c760..216519263889 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -35,6 +35,7 @@ const PACKAGE_NAME = '@astrojs/vercel/serverless';
  * with the original path as the value of this header.
  */
 export const ASTRO_PATH_HEADER = 'x-astro-path';
+export const ASTRO_PATH_PARAM = 'x_astro_path';
 
 /**
  * The edge function calls the node server at /_render,
@@ -48,6 +49,11 @@ export const VERCEL_EDGE_MIDDLEWARE_FILE = 'vercel-edge-middleware';
 export const NODE_PATH = '_render';
 const MIDDLEWARE_PATH = '_middleware';
 
+// This isn't documented by vercel anywhere, but unlike serverless
+// and edge functions, isr functions are not passed the original path.
+// Instead, we have to use $0 to refer to the regex match from "src".
+const ISR_PATH = `/_isr?${ASTRO_PATH_PARAM}=$0`;
+
 // https://vercel.com/docs/concepts/functions/serverless-functions/runtimes/node-js#node.js-version
 const SUPPORTED_NODE_VERSIONS: Record<
 	string,
@@ -128,8 +134,27 @@ export interface VercelServerlessConfig {
 }
 
 interface VercelISRConfig {
-	/** A random string that you create. Its presence in the `__prerender_bypass` cookie will result in fresh responses being served. */
+	/**
+	 * A random string that you create.
+	 * Its presence in the `__prerender_bypass` cookie will result in fresh responses being served, bypassing the cache.
+	 * 
+	 * By default, none.
+	 */
 	bypassToken?: string;
+
+	/**
+	 * Expiration time (in seconds) before the pages will be re-generated.
+	 * 
+	 * By default, as long as the current deployment is in production.
+	 */
+	revalidate?: number;
+
+	/**
+	 * Paths that will always be served fresh.
+	 * 
+	 * By default, none.
+	 */
+	exclude?: string[];
 }
 
 export default function vercelServerless({
@@ -198,9 +223,6 @@ export default function vercelServerless({
 					},
 					vite: {
 						...getSpeedInsightsViteConfig(speedInsights?.enabled),
-						define: {
-							"import.meta.env.ASTRO_VERCEL_ISR": isr ? "true" : "false"
-						},
 						ssr: {
 							external: ['@vercel/nft'],
 						},
@@ -302,21 +324,49 @@ export default function vercelServerless({
 						});
 					}
 				} else {
-					await createFunctionFolder({
-						functionName: NODE_PATH,
-						runtime,
-						entry: new URL(_serverEntry, _buildTempFolder),
-						config: _config,
-						logger,
-						NTF_CACHE,
-						includeFiles,
-						excludeFiles,
-						maxDuration,
-						isr,
-					});
+					if (isr) {
+						await createFunctionFolder({
+							functionName: '_isr',
+							runtime,
+							entry: new URL(_serverEntry, _buildTempFolder),
+							config: _config,
+							logger,
+							NTF_CACHE,
+							includeFiles,
+							excludeFiles,
+							maxDuration,
+							isr,
+						});
+					}
+					if (isr === false || (typeof isr === "object" && isr.exclude)) {
+						await createFunctionFolder({
+							functionName: NODE_PATH,
+							runtime,
+							entry: new URL(_serverEntry, _buildTempFolder),
+							config: _config,
+							logger,
+							NTF_CACHE,
+							includeFiles,
+							excludeFiles,
+							maxDuration,
+							isr: false,
+						});
+					}
+					if (typeof isr === "object" && isr.exclude) {
+						for (const route of isr.exclude) {
+							routeDefinitions.push({
+								src: route,
+								dest: NODE_PATH,
+							})
+						}
+					}
 					const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
 					for (const route of routes) {
 						if (!route.prerender) routeDefinitions.push({ src: route.pattern.source, dest });
+						routeDefinitions.push({
+							src: route.pattern.source,
+							dest: isr ? ISR_PATH : NODE_PATH,
+						});
 					}
 				}
 				if (_middlewareEntryPoint) {
@@ -458,11 +508,15 @@ async function createFunctionFolder({
 	});
 	
 	if (isr) {
+		const {
+			revalidate: expiration = false,
+			bypassToken = undefined,
+		} = typeof isr === "object" ? isr : {};
 		// https://vercel.com/docs/build-output-api/v3/primitives#prerender-configuration-file
 		await writeJson(prerenderConfig, {
-			expiration: false,
-			bypassToken: typeof isr === "object" ? isr.bypassToken : undefined,
-			allowQuery: ["vercel_original_path"],
+			expiration,
+			bypassToken,
+			allowQuery: [ASTRO_PATH_PARAM],
 			passQuery: true
 		});
 	}
diff --git a/packages/integrations/vercel/src/serverless/entrypoint.ts b/packages/integrations/vercel/src/serverless/entrypoint.ts
index b1e6ff125249..31777ed6ce70 100644
--- a/packages/integrations/vercel/src/serverless/entrypoint.ts
+++ b/packages/integrations/vercel/src/serverless/entrypoint.ts
@@ -1,7 +1,7 @@
 import type { SSRManifest } from 'astro';
 import { applyPolyfills, NodeApp } from 'astro/app/node';
 import type { IncomingMessage, ServerResponse } from 'node:http';
-import { ASTRO_PATH_HEADER, ASTRO_LOCALS_HEADER } from './adapter.js';
+import { ASTRO_PATH_HEADER, ASTRO_PATH_PARAM, ASTRO_LOCALS_HEADER } from './adapter.js';
 
 applyPolyfills();
 
@@ -9,11 +9,9 @@ export const createExports = (manifest: SSRManifest) => {
 	const app = new NodeApp(manifest);
 	const handler = async (req: IncomingMessage, res: ServerResponse) => {
 		const url = new URL(`https://example.com${req.url}`)
-		const originalPath = url.searchParams.get('vercel_original_path')
-		if (originalPath) req.url = originalPath
 		const clientAddress = req.headers['x-forwarded-for'] as string | undefined;
 		const localsHeader = req.headers[ASTRO_LOCALS_HEADER];
-		const realPath = req.headers[ASTRO_PATH_HEADER];
+		const realPath = req.headers[ASTRO_PATH_HEADER] ?? url.searchParams.get(ASTRO_PATH_PARAM);
 		if (typeof realPath === 'string') {
 			req.url = realPath;
 		}
@@ -29,3 +27,7 @@ export const createExports = (manifest: SSRManifest) => {
 
 	return { default: handler };
 };
+
+// HACK: prevent warning
+// @astrojs-ssr-virtual-entry (22:23) "start" is not exported by "dist/serverless/entrypoint.js", imported by "@astrojs-ssr-virtual-entry".
+export function start() {}

From 8d763090a9d57b99cb20626ea2c7348926cab85c Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Thu, 25 Jan 2024 21:22:57 +0000
Subject: [PATCH 04/19] add test

---
 .../vercel/test/fixtures/isr/astro.config.mjs | 13 ++++++++++
 .../vercel/test/fixtures/isr/package.json     |  9 +++++++
 .../test/fixtures/isr/src/pages/one.astro     |  8 ++++++
 .../test/fixtures/isr/src/pages/two.astro     |  8 ++++++
 packages/integrations/vercel/test/isr.test.js | 26 +++++++++++++++++++
 pnpm-lock.yaml                                |  9 +++++++
 6 files changed, 73 insertions(+)
 create mode 100644 packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
 create mode 100644 packages/integrations/vercel/test/fixtures/isr/package.json
 create mode 100644 packages/integrations/vercel/test/fixtures/isr/src/pages/one.astro
 create mode 100644 packages/integrations/vercel/test/fixtures/isr/src/pages/two.astro
 create mode 100644 packages/integrations/vercel/test/isr.test.js

diff --git a/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs b/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
new file mode 100644
index 000000000000..cdc8c1f22ad0
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
@@ -0,0 +1,13 @@
+import { defineConfig } from 'astro/config';
+import vercel from '@astrojs/vercel/serverless';
+
+export default defineConfig({
+	output: "server",
+	adapter: vercel({
+		isr: {
+			bypassToken: "1c9e601d-9943-4e7c-9575-005556d774a8",
+			revalidate: 120,
+			exclude: ["/two"]
+		}
+	})
+});
diff --git a/packages/integrations/vercel/test/fixtures/isr/package.json b/packages/integrations/vercel/test/fixtures/isr/package.json
new file mode 100644
index 000000000000..a1fd601d3b1a
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/isr/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@test/vercel-isr",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@astrojs/vercel": "workspace:*",
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/integrations/vercel/test/fixtures/isr/src/pages/one.astro b/packages/integrations/vercel/test/fixtures/isr/src/pages/one.astro
new file mode 100644
index 000000000000..0c7fb90a735e
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/isr/src/pages/one.astro
@@ -0,0 +1,8 @@
+<html>
+	<head>
+		<title>One</title>
+	</head>
+	<body>
+		<h1>One</h1>
+	</body>
+</html>
diff --git a/packages/integrations/vercel/test/fixtures/isr/src/pages/two.astro b/packages/integrations/vercel/test/fixtures/isr/src/pages/two.astro
new file mode 100644
index 000000000000..e7ba9910e2a6
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/isr/src/pages/two.astro
@@ -0,0 +1,8 @@
+<html>
+	<head>
+		<title>Two</title>
+	</head>
+	<body>
+		<h1>Two</h1>
+	</body>
+</html>
diff --git a/packages/integrations/vercel/test/isr.test.js b/packages/integrations/vercel/test/isr.test.js
new file mode 100644
index 000000000000..a8a7064aefb8
--- /dev/null
+++ b/packages/integrations/vercel/test/isr.test.js
@@ -0,0 +1,26 @@
+import { loadFixture } from "./test-utils.js";
+import { expect } from "chai";
+
+describe("ISR", () => {
+	/** @type {import('./test-utils.js').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: "./fixtures/isr/",
+		});
+		await fixture.build();
+	});
+
+	it("generates expected prerender config", async () => {
+		const vcConfig = JSON.parse(
+			await fixture.readFile("../.vercel/output/functions/_isr.prerender-config.json")
+		);
+		expect(vcConfig).to.deep.include({
+			"expiration": 120,
+			"bypassToken": "1c9e601d-9943-4e7c-9575-005556d774a8",
+			"allowQuery": ["x_astro_path"],
+			"passQuery": true
+		})
+	})
+})
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index c85679e9a996..dd8b13407618 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -4797,6 +4797,15 @@ importers:
         specifier: workspace:*
         version: link:../../../../../astro
 
+  packages/integrations/vercel/test/fixtures/isr:
+    dependencies:
+      '@astrojs/vercel':
+        specifier: workspace:*
+        version: link:../../..
+      astro:
+        specifier: workspace:*
+        version: link:../../../../../astro
+
   packages/integrations/vercel/test/fixtures/max-duration:
     dependencies:
       '@astrojs/vercel':

From 8c4af724cd481af8be4c5c9984e444ce8bf2aaff Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Thu, 25 Jan 2024 21:51:35 +0000
Subject: [PATCH 05/19] remove search params in dev mode

---
 .../integrations/vercel/src/serverless/adapter.ts   | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 216519263889..86c0691d516d 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -258,6 +258,19 @@ export default function vercelServerless({
 					);
 				}
 			},
+			'astro:server:setup' ({ server }) {
+				// isr functions do not have access to search params, this middleware removes them for the dev mode
+				if (isr) {
+					const exclude_ = typeof isr === "object" ? isr.exclude ?? [] : [];
+					const exclude = exclude_.concat("/_image").map(ex => new RegExp(ex));
+					server.middlewares.use(function removeIsrParams(req, _, next) {
+						const { pathname } = new URL(`https://example.com${req.url}`);
+						if (exclude.some(ex => ex.test(pathname))) return next();
+						req.url = pathname;
+						return next();
+					})
+				}
+			},
 			'astro:build:ssr': async ({ entryPoints, middlewareEntryPoint }) => {
 				_entryPoints = entryPoints;
 				_middlewareEntryPoint = middlewareEntryPoint;

From 3d9800d55b5bcc837fc31cac15d22ca814e70e7c Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Sat, 27 Jan 2024 00:31:24 +0530
Subject: [PATCH 06/19] Apply suggestions from code review

Co-authored-by: Nate Moore <natemoo-re@users.noreply.github.com>
---
 packages/integrations/vercel/src/serverless/adapter.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 86c0691d516d..f163693585b3 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -351,7 +351,7 @@ export default function vercelServerless({
 							isr,
 						});
 					}
-					if (isr === false || (typeof isr === "object" && isr.exclude)) {
+					if (isr === false || (isr && typeof isr === "object" && isr.exclude)) {
 						await createFunctionFolder({
 							functionName: NODE_PATH,
 							runtime,
@@ -365,7 +365,7 @@ export default function vercelServerless({
 							isr: false,
 						});
 					}
-					if (typeof isr === "object" && isr.exclude) {
+					if (isr && typeof isr === "object" && isr.exclude) {
 						for (const route of isr.exclude) {
 							routeDefinitions.push({
 								src: route,

From cff749a3be229011511b49d6a5b1921c2f77e9db Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Sat, 27 Jan 2024 00:44:16 +0530
Subject: [PATCH 07/19] Apply suggestions from code review

---
 packages/integrations/vercel/src/serverless/adapter.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index f163693585b3..789d852ecf69 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -135,8 +135,9 @@ export interface VercelServerlessConfig {
 
 interface VercelISRConfig {
 	/**
-	 * A random string that you create.
+	 * A secret random string that you create.
 	 * Its presence in the `__prerender_bypass` cookie will result in fresh responses being served, bypassing the cache.
+	 * Its presence in the `x-prerender-revalidate` header will result in a fresh response which will then be cached for all future requests to be used.
 	 * 
 	 * By default, none.
 	 */

From a34c215cce49b75da7f2824fe1e5c79cfccaad5f Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 29 Jan 2024 15:13:46 +0000
Subject: [PATCH 08/19] Apply suggestions from code review

---
 .../vercel/src/serverless/adapter.ts          | 165 +++++++-----------
 1 file changed, 63 insertions(+), 102 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 789d852ecf69..2794732f302a 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -305,6 +305,7 @@ export default function vercelServerless({
 				const excludeFiles = _excludeFiles.map((file) => new URL(file, _config.root));
 
 				const runtime = getRuntime(process, logger);
+				const builder = new VercelBuilder(_config, excludeFiles, includeFiles, logger, maxDuration);
 
 				// Multiple entrypoint support
 				if (_entryPoints.size) {
@@ -320,18 +321,8 @@ export default function vercelServerless({
 							? getRouteFuncName(route)
 							: getFallbackFuncName(entryFile);
 
-						await createFunctionFolder({
-							functionName: func,
-							runtime,
-							entry: entryFile,
-							config: _config,
-							logger,
-							NTF_CACHE,
-							includeFiles,
-							excludeFiles,
-							maxDuration,
-							isr,
-						});
+						await builder.buildServerlessFolder(entryFile, func);
+
 						routeDefinitions.push({
 							src: route.pattern.source,
 							dest: func,
@@ -339,41 +330,18 @@ export default function vercelServerless({
 					}
 				} else {
 					if (isr) {
-						await createFunctionFolder({
-							functionName: '_isr',
-							runtime,
-							entry: new URL(_serverEntry, _buildTempFolder),
-							config: _config,
-							logger,
-							NTF_CACHE,
-							includeFiles,
-							excludeFiles,
-							maxDuration,
-							isr,
-						});
-					}
-					if (isr === false || (isr && typeof isr === "object" && isr.exclude)) {
-						await createFunctionFolder({
-							functionName: NODE_PATH,
-							runtime,
-							entry: new URL(_serverEntry, _buildTempFolder),
-							config: _config,
-							logger,
-							NTF_CACHE,
-							includeFiles,
-							excludeFiles,
-							maxDuration,
-							isr: false,
-						});
-					}
-					if (isr && typeof isr === "object" && isr.exclude) {
-						for (const route of isr.exclude) {
-							routeDefinitions.push({
-								src: route,
-								dest: NODE_PATH,
-							})
+						const isrConfig = typeof isr === "object" ? isr : {};
+						await builder.buildISRFolder(new URL(_serverEntry, _buildTempFolder), '_isr', isrConfig);
+						if (isrConfig.exclude?.length) {
+							await builder.buildServerlessFolder(new URL(_serverEntry, _buildTempFolder), NODE_PATH);
+							for (const route of isrConfig.exclude) {
+								routeDefinitions.push({ src: route, dest: NODE_PATH })
+							}
 						}
 					}
+					else {
+						await builder.buildServerlessFolder(new URL(_serverEntry, _buildTempFolder), NODE_PATH);
+					}
 					const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
 					for (const route of routes) {
 						if (!route.prerender) routeDefinitions.push({ src: route.pattern.source, dest });
@@ -466,70 +434,63 @@ async function createMiddlewareFolder({ functionName, entry, config }: CreateMid
 
 interface CreateFunctionFolderArgs {
 	functionName: string;
-	runtime: Runtime;
 	entry: URL;
-	config: AstroConfig;
-	logger: AstroIntegrationLogger;
-	NTF_CACHE: any;
-	includeFiles: URL[];
-	excludeFiles: URL[];
-	maxDuration: number | undefined;
 	isr: boolean | VercelISRConfig;
 }
 
-async function createFunctionFolder({
-	functionName,
-	runtime,
-	entry,
-	config,
-	logger,
-	NTF_CACHE,
-	includeFiles,
-	excludeFiles,
-	maxDuration,
-	isr
-}: CreateFunctionFolderArgs) {
-	// .vercel/output/functions/<name>.func/
-	const functionFolder = new URL(`./functions/${functionName}.func/`, config.outDir);
-	const packageJson = new URL(`./functions/${functionName}.func/package.json`, config.outDir);
-	const vcConfig = new URL(`./functions/${functionName}.func/.vc-config.json`, config.outDir);
-	const prerenderConfig = new URL(`./functions/${functionName}.prerender-config.json`, config.outDir)
-
-	// Copy necessary files (e.g. node_modules/)
-	const { handler } = await copyDependenciesToFunction(
-		{
-			entry,
-			outDir: functionFolder,
-			includeFiles,
-			excludeFiles,
-			logger,
-		},
-		NTF_CACHE
-	);
+class VercelBuilder {
+	readonly NTF_CACHE = {}
+
+	constructor(
+		readonly config: AstroConfig,
+		readonly excludeFiles: URL[],
+		readonly includeFiles: URL[],
+		readonly logger: AstroIntegrationLogger,
+		readonly maxDuration?: number,
+		readonly runtime = getRuntime(process, logger)
+	) {}
+
+	async buildServerlessFolder(entry: URL, functionName: string) {
+		const { config, includeFiles, excludeFiles, logger, NTF_CACHE, runtime, maxDuration } = this;
+		// .vercel/output/functions/<name>.func/
+		const functionFolder = new URL(`./functions/${functionName}.func/`, config.outDir);
+		const packageJson = new URL(`./functions/${functionName}.func/package.json`, config.outDir);
+		const vcConfig = new URL(`./functions/${functionName}.func/.vc-config.json`, config.outDir);
+
+		// Copy necessary files (e.g. node_modules/)
+		const { handler } = await copyDependenciesToFunction(
+			{
+				entry,
+				outDir: functionFolder,
+				includeFiles,
+				excludeFiles,
+				logger,
+			},
+			NTF_CACHE
+		);
 
-	// Enable ESM
-	// https://aws.amazon.com/blogs/compute/using-node-js-es-modules-and-top-level-await-in-aws-lambda/
-	await writeJson(packageJson, { type: 'module' });
-
-	// Serverless function config
-	// https://vercel.com/docs/build-output-api/v3#vercel-primitives/serverless-functions/configuration
-	await writeJson(vcConfig, {
-		runtime,
-		handler: handler.replaceAll('\\', '/'),
-		launcherType: 'Nodejs',
-		maxDuration,
-		supportsResponseStreaming: true,
-	});
-	
-	if (isr) {
-		const {
-			revalidate: expiration = false,
-			bypassToken = undefined,
-		} = typeof isr === "object" ? isr : {};
+		// Enable ESM
+		// https://aws.amazon.com/blogs/compute/using-node-js-es-modules-and-top-level-await-in-aws-lambda/
+		await writeJson(packageJson, { type: 'module' });
+
+		// Serverless function config
+		// https://vercel.com/docs/build-output-api/v3#vercel-primitives/serverless-functions/configuration
+		await writeJson(vcConfig, {
+			runtime,
+			handler: handler.replaceAll('\\', '/'),
+			launcherType: 'Nodejs',
+			maxDuration,
+			supportsResponseStreaming: true,
+		});
+	}
+
+	async buildISRFolder(entry: URL, functionName: string, isr: VercelISRConfig) {
+		this.buildServerlessFolder(entry, functionName);
+		const prerenderConfig = new URL(`./functions/${functionName}.prerender-config.json`, this.config.outDir)
 		// https://vercel.com/docs/build-output-api/v3/primitives#prerender-configuration-file
 		await writeJson(prerenderConfig, {
-			expiration,
-			bypassToken,
+			expiration: isr.revalidate ?? false,
+			bypassToken: isr.bypassToken,
 			allowQuery: [ASTRO_PATH_PARAM],
 			passQuery: true
 		});

From 469bf447acdb27caffae525032c51adb00ee1b3e Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 29 Jan 2024 15:34:36 +0000
Subject: [PATCH 09/19] fix missing await

---
 packages/integrations/vercel/src/serverless/adapter.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 2794732f302a..eeb309fb1448 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -304,7 +304,6 @@ export default function vercelServerless({
 					.concat(extraFilesToInclude);
 				const excludeFiles = _excludeFiles.map((file) => new URL(file, _config.root));
 
-				const runtime = getRuntime(process, logger);
 				const builder = new VercelBuilder(_config, excludeFiles, includeFiles, logger, maxDuration);
 
 				// Multiple entrypoint support
@@ -329,18 +328,19 @@ export default function vercelServerless({
 						});
 					}
 				} else {
+					const entryFile = new URL(_serverEntry, _buildTempFolder)
 					if (isr) {
 						const isrConfig = typeof isr === "object" ? isr : {};
-						await builder.buildISRFolder(new URL(_serverEntry, _buildTempFolder), '_isr', isrConfig);
+						await builder.buildISRFolder(entryFile, '_isr', isrConfig);
 						if (isrConfig.exclude?.length) {
-							await builder.buildServerlessFolder(new URL(_serverEntry, _buildTempFolder), NODE_PATH);
+							await builder.buildServerlessFolder(entryFile, NODE_PATH);
 							for (const route of isrConfig.exclude) {
 								routeDefinitions.push({ src: route, dest: NODE_PATH })
 							}
 						}
 					}
 					else {
-						await builder.buildServerlessFolder(new URL(_serverEntry, _buildTempFolder), NODE_PATH);
+						await builder.buildServerlessFolder(entryFile, NODE_PATH);
 					}
 					const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
 					for (const route of routes) {
@@ -485,7 +485,7 @@ class VercelBuilder {
 	}
 
 	async buildISRFolder(entry: URL, functionName: string, isr: VercelISRConfig) {
-		this.buildServerlessFolder(entry, functionName);
+		await this.buildServerlessFolder(entry, functionName);
 		const prerenderConfig = new URL(`./functions/${functionName}.prerender-config.json`, this.config.outDir)
 		// https://vercel.com/docs/build-output-api/v3/primitives#prerender-configuration-file
 		await writeJson(prerenderConfig, {

From 96be331f917ae34992179ff9517c2996fa403399 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 29 Jan 2024 16:24:58 +0000
Subject: [PATCH 10/19] escape src for regex

---
 packages/integrations/vercel/src/lib/redirects.ts      | 4 ++++
 packages/integrations/vercel/src/serverless/adapter.ts | 8 +++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/packages/integrations/vercel/src/lib/redirects.ts b/packages/integrations/vercel/src/lib/redirects.ts
index 46c97d349691..6e03f8a37dfc 100644
--- a/packages/integrations/vercel/src/lib/redirects.ts
+++ b/packages/integrations/vercel/src/lib/redirects.ts
@@ -76,6 +76,10 @@ function getRedirectStatus(route: RouteData): number {
 	return 301;
 }
 
+export function escapeRegex(content: string) {
+	return `^${getMatchPattern([[{ content, dynamic: false, spread: false }]])}$`
+}
+
 export function getRedirects(routes: RouteData[], config: AstroConfig): VercelRoute[] {
 	let redirects: VercelRoute[] = [];
 
diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index eeb309fb1448..783fb75fe2ef 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -17,7 +17,7 @@ import {
 } from '../image/shared.js';
 import { removeDir, writeJson } from '../lib/fs.js';
 import { copyDependenciesToFunction } from '../lib/nft.js';
-import { getRedirects } from '../lib/redirects.js';
+import { escapeRegex, getRedirects } from '../lib/redirects.js';
 import {
 	getSpeedInsightsViteConfig,
 	type VercelSpeedInsightsConfig,
@@ -263,7 +263,8 @@ export default function vercelServerless({
 				// isr functions do not have access to search params, this middleware removes them for the dev mode
 				if (isr) {
 					const exclude_ = typeof isr === "object" ? isr.exclude ?? [] : [];
-					const exclude = exclude_.concat("/_image").map(ex => new RegExp(ex));
+					// we create a regex to emulate vercel's production behavior
+					const exclude = exclude_.concat("/_image").map(ex => new RegExp(escapeRegex(ex)));
 					server.middlewares.use(function removeIsrParams(req, _, next) {
 						const { pathname } = new URL(`https://example.com${req.url}`);
 						if (exclude.some(ex => ex.test(pathname))) return next();
@@ -335,7 +336,8 @@ export default function vercelServerless({
 						if (isrConfig.exclude?.length) {
 							await builder.buildServerlessFolder(entryFile, NODE_PATH);
 							for (const route of isrConfig.exclude) {
-								routeDefinitions.push({ src: route, dest: NODE_PATH })
+								// vercel interprets src as a regex pattern, so we need to escape it
+								routeDefinitions.push({ src: escapeRegex(route), dest: NODE_PATH })
 							}
 						}
 					}

From ab64e3decd3ed4f4bcdb7c11b43f77de0142541d Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 29 Jan 2024 16:28:36 +0000
Subject: [PATCH 11/19] cleanup

---
 .../vercel/src/serverless/adapter.ts          | 50 ++++++-------------
 1 file changed, 16 insertions(+), 34 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 783fb75fe2ef..eecc360bb306 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -188,8 +188,6 @@ export default function vercelServerless({
 	// Extra files to be merged with `includeFiles` during build
 	const extraFilesToInclude: URL[] = [];
 
-	const NTF_CACHE = Object.create(null);
-
 	return {
 		name: PACKAGE_NAME,
 		hooks: {
@@ -354,11 +352,7 @@ export default function vercelServerless({
 					}
 				}
 				if (_middlewareEntryPoint) {
-					await createMiddlewareFolder({
-						functionName: MIDDLEWARE_PATH,
-						entry: _middlewareEntryPoint,
-						config: _config,
-					});
+					await builder.buildMiddlewareFolder(_middlewareEntryPoint, MIDDLEWARE_PATH);
 				}
 				const fourOhFourRoute = routes.find((route) => route.pathname === '/404');
 				// Output configuration
@@ -413,33 +407,6 @@ export default function vercelServerless({
 
 type Runtime = `nodejs${string}.x`;
 
-interface CreateMiddlewareFolderArgs {
-	config: AstroConfig;
-	entry: URL;
-	functionName: string;
-}
-
-async function createMiddlewareFolder({ functionName, entry, config }: CreateMiddlewareFolderArgs) {
-	const functionFolder = new URL(`./functions/${functionName}.func/`, config.outDir);
-
-	await generateEdgeMiddleware(
-		entry,
-		new URL(VERCEL_EDGE_MIDDLEWARE_FILE, config.srcDir),
-		new URL('./middleware.mjs', functionFolder)
-	);
-
-	await writeJson(new URL(`./.vc-config.json`, functionFolder), {
-		runtime: 'edge',
-		entrypoint: 'middleware.mjs',
-	});
-}
-
-interface CreateFunctionFolderArgs {
-	functionName: string;
-	entry: URL;
-	isr: boolean | VercelISRConfig;
-}
-
 class VercelBuilder {
 	readonly NTF_CACHE = {}
 
@@ -497,6 +464,21 @@ class VercelBuilder {
 			passQuery: true
 		});
 	}
+
+	async buildMiddlewareFolder(entry: URL, functionName: string) {
+		const functionFolder = new URL(`./functions/${functionName}.func/`, this.config.outDir);
+
+		await generateEdgeMiddleware(
+			entry,
+			new URL(VERCEL_EDGE_MIDDLEWARE_FILE, this.config.srcDir),
+			new URL('./middleware.mjs', functionFolder)
+		);
+	
+		await writeJson(new URL(`./.vc-config.json`, functionFolder), {
+			runtime: 'edge',
+			entrypoint: 'middleware.mjs',
+		});
+	}
 }
 
 function getRuntime(process: NodeJS.Process, logger: AstroIntegrationLogger): Runtime {

From 280823a903b212ec6504f35d80dad2bd4c446641 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 29 Jan 2024 17:40:10 +0000
Subject: [PATCH 12/19] revalidate -> expiration

---
 .../integrations/vercel/src/serverless/adapter.ts    | 12 +++++++-----
 .../vercel/test/fixtures/isr/astro.config.mjs        |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index eecc360bb306..b066b9c1112d 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -139,21 +139,23 @@ interface VercelISRConfig {
 	 * Its presence in the `__prerender_bypass` cookie will result in fresh responses being served, bypassing the cache.
 	 * Its presence in the `x-prerender-revalidate` header will result in a fresh response which will then be cached for all future requests to be used.
 	 * 
-	 * By default, none.
+	 * @default `undefined`
 	 */
 	bypassToken?: string;
 
 	/**
 	 * Expiration time (in seconds) before the pages will be re-generated.
 	 * 
-	 * By default, as long as the current deployment is in production.
+	 * Setting to `false` means that the page will stay cached as long as the current deployment is in production.
+	 * 
+	 * @default `false`
 	 */
-	revalidate?: number;
+	expiration?: number | false;
 
 	/**
 	 * Paths that will always be served fresh.
 	 * 
-	 * By default, none.
+	 * @default `[]`
 	 */
 	exclude?: string[];
 }
@@ -458,7 +460,7 @@ class VercelBuilder {
 		const prerenderConfig = new URL(`./functions/${functionName}.prerender-config.json`, this.config.outDir)
 		// https://vercel.com/docs/build-output-api/v3/primitives#prerender-configuration-file
 		await writeJson(prerenderConfig, {
-			expiration: isr.revalidate ?? false,
+			expiration: isr.expiration ?? false,
 			bypassToken: isr.bypassToken,
 			allowQuery: [ASTRO_PATH_PARAM],
 			passQuery: true
diff --git a/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs b/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
index cdc8c1f22ad0..e7545c6f2a34 100644
--- a/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
+++ b/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
@@ -6,7 +6,7 @@ export default defineConfig({
 	adapter: vercel({
 		isr: {
 			bypassToken: "1c9e601d-9943-4e7c-9575-005556d774a8",
-			revalidate: 120,
+			expiration: 120,
 			exclude: ["/two"]
 		}
 	})

From 3e87dbf020d0aa64fd160f06868a9c96cb921b87 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 29 Jan 2024 17:47:42 +0000
Subject: [PATCH 13/19] update type docs

---
 packages/integrations/vercel/src/serverless/adapter.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index b066b9c1112d..e3917b545127 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -136,8 +136,8 @@ export interface VercelServerlessConfig {
 interface VercelISRConfig {
 	/**
 	 * A secret random string that you create.
-	 * Its presence in the `__prerender_bypass` cookie will result in fresh responses being served, bypassing the cache.
-	 * Its presence in the `x-prerender-revalidate` header will result in a fresh response which will then be cached for all future requests to be used.
+	 * Its presence in the `__prerender_bypass` cookie will result in fresh responses being served, bypassing the cache. See Vercel’s documentation on [Draft Mode](https://vercel.com/docs/build-output-api/v3/features#draft-mode) for more information.
+	 * Its presence in the `x-prerender-revalidate` header will result in a fresh response which will then be cached for all future requests to be used. See Vercel’s documentation on [On-Demand Incremental Static Regeneration (ISR)](https://vercel.com/docs/build-output-api/v3/features#on-demand-incremental-static-regeneration-isr) for more information.
 	 * 
 	 * @default `undefined`
 	 */
@@ -153,7 +153,7 @@ interface VercelISRConfig {
 	expiration?: number | false;
 
 	/**
-	 * Paths that will always be served fresh.
+	 * Paths that will always be served by a serverless function instead of an ISR function.
 	 * 
 	 * @default `[]`
 	 */

From 550538b4bb716783cd9c2b39e612a13f74b76275 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 29 Jan 2024 19:06:23 +0000
Subject: [PATCH 14/19] always exclude /_image

---
 .../vercel/src/serverless/adapter.ts          | 22 ++++++++--------
 packages/integrations/vercel/test/isr.test.js | 25 +++++++++++++++++++
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index e3917b545127..67d7477b939a 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -332,25 +332,27 @@ export default function vercelServerless({
 					const entryFile = new URL(_serverEntry, _buildTempFolder)
 					if (isr) {
 						const isrConfig = typeof isr === "object" ? isr : {};
-						await builder.buildISRFolder(entryFile, '_isr', isrConfig);
 						if (isrConfig.exclude?.length) {
 							await builder.buildServerlessFolder(entryFile, NODE_PATH);
+							const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
 							for (const route of isrConfig.exclude) {
 								// vercel interprets src as a regex pattern, so we need to escape it
-								routeDefinitions.push({ src: escapeRegex(route), dest: NODE_PATH })
+								routeDefinitions.push({ src: escapeRegex(route), dest })
 							}
 						}
+						await builder.buildISRFolder(entryFile, '_isr', isrConfig);
+						for (const route of routes) {
+							const src = route.pattern.source;
+							const dest = src.startsWith("^\\/_image") ? NODE_PATH : ISR_PATH;
+							if (!route.prerender) routeDefinitions.push({ src, dest });
+						}
 					}
 					else {
 						await builder.buildServerlessFolder(entryFile, NODE_PATH);
-					}
-					const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
-					for (const route of routes) {
-						if (!route.prerender) routeDefinitions.push({ src: route.pattern.source, dest });
-						routeDefinitions.push({
-							src: route.pattern.source,
-							dest: isr ? ISR_PATH : NODE_PATH,
-						});
+						const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
+						for (const route of routes) {
+							if (!route.prerender) routeDefinitions.push({ src: route.pattern.source, dest });
+						}
 					}
 				}
 				if (_middlewareEntryPoint) {
diff --git a/packages/integrations/vercel/test/isr.test.js b/packages/integrations/vercel/test/isr.test.js
index a8a7064aefb8..d10181c8d3a0 100644
--- a/packages/integrations/vercel/test/isr.test.js
+++ b/packages/integrations/vercel/test/isr.test.js
@@ -23,4 +23,29 @@ describe("ISR", () => {
 			"passQuery": true
 		})
 	})
+
+	it("generates expected routes", async () => {
+		const deploymentConfig = JSON.parse(
+			await fixture.readFile("../.vercel/output/config.json")
+		);
+		// the first two are /_astro/*, and filesystem routes
+		expect(deploymentConfig.routes.slice(2)).to.deep.equal([
+			{
+				"src": "^/two$",
+				"dest": "_render"
+			},
+			{
+				"src": "^\\/_image$",
+				"dest": "_render"
+			},
+			{
+				"src": "^\\/one\\/?$",
+				"dest": "/_isr?x_astro_path=$0"
+			},
+			{
+				"src": "^\\/two\\/?$",
+				"dest": "/_isr?x_astro_path=$0"
+			}
+		])
+	})
 })

From 102fc1cfbc2b49a0a92ba16f8671e1c8f9b47487 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Thu, 1 Feb 2024 15:30:03 +0000
Subject: [PATCH 15/19] add changeset

---
 .changeset/flat-snakes-hammer.md | 50 ++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 .changeset/flat-snakes-hammer.md

diff --git a/.changeset/flat-snakes-hammer.md b/.changeset/flat-snakes-hammer.md
new file mode 100644
index 000000000000..ce93a34466ce
--- /dev/null
+++ b/.changeset/flat-snakes-hammer.md
@@ -0,0 +1,50 @@
+---
+"@astrojs/vercel": minor
+---
+
+Introduces a new config options, `isr`, that allows to deploy your project as an ISR function. [ISR (Incremental Static Regeneration)](https://vercel.com/docs/incremental-static-regeneration) caches your on-demand rendered pages in the same way as prerendered pages after first request.
+
+To enable this feature, set `isr` to true in your `astro.config.mjs`:
+
+```js
+export default defineConfig({
+    output: "server",
+    adapter: vercel({ isr: true })
+})
+```
+
+##### Time-based invalidation
+
+By default, ISR responses are cached for the duration of your deployment. You can change this by setting `isr` to an object with an `expiration` field:
+
+```js
+export default defineConfig({
+    output: "server",
+    adapter: vercel({
+        isr: {
+            // caches all pages on first request and saves for 1 day
+            revalidate: 60 * 60 * 24
+        }
+    })
+})
+```
+
+##### Manual invalidation
+
+To implement [Draft mode](https://vercel.com/docs/build-output-api/v3/features#draft-mode), or [On-Demand Incremental Static Regeneration (ISR)](https://vercel.com/docs/build-output-api/v3/features#on-demand-incremental-static-regeneration-isr), you can create a bypass token and provide it to the `isr` config: 
+
+```js
+export default defineConfig({
+    output: "server",
+    adapter: vercel({
+        isr: {
+            // A secret random string that you create.
+            bypassToken: "005556d774a8",
+            // Paths that will always be served fresh.
+            exclude: [ "/api/invalidate" ] 
+        }
+    })
+})
+```
+
+Note that ISR function requests do not include search params, similar to [requests](https://docs.astro.build/en/reference/api-reference/#astrorequest) in static mode.

From aa27e59bcdf38cab8cebddc03d249fd5771022a2 Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 5 Feb 2024 20:16:20 +0530
Subject: [PATCH 16/19] Apply suggestions from code review

---
 .changeset/flat-snakes-hammer.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.changeset/flat-snakes-hammer.md b/.changeset/flat-snakes-hammer.md
index ce93a34466ce..f7540f2a9288 100644
--- a/.changeset/flat-snakes-hammer.md
+++ b/.changeset/flat-snakes-hammer.md
@@ -23,7 +23,7 @@ export default defineConfig({
     adapter: vercel({
         isr: {
             // caches all pages on first request and saves for 1 day
-            revalidate: 60 * 60 * 24
+            expiration: 60 * 60 * 24
         }
     })
 })

From 9b8f1afa715a693ce004b544c9d45dbd5ae81600 Mon Sep 17 00:00:00 2001
From: lilnasy <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 5 Feb 2024 15:01:53 +0000
Subject: [PATCH 17/19] always create serverless function for /_image

---
 packages/integrations/vercel/src/serverless/adapter.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index 67d7477b939a..880e35acf703 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -332,8 +332,8 @@ export default function vercelServerless({
 					const entryFile = new URL(_serverEntry, _buildTempFolder)
 					if (isr) {
 						const isrConfig = typeof isr === "object" ? isr : {};
+						await builder.buildServerlessFolder(entryFile, NODE_PATH);
 						if (isrConfig.exclude?.length) {
-							await builder.buildServerlessFolder(entryFile, NODE_PATH);
 							const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
 							for (const route of isrConfig.exclude) {
 								// vercel interprets src as a regex pattern, so we need to escape it

From 89544980d4e9dab739cb3a87faff01eee8050b68 Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 5 Feb 2024 21:09:22 +0530
Subject: [PATCH 18/19] Apply suggestions from code review

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>
---
 .changeset/flat-snakes-hammer.md | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/.changeset/flat-snakes-hammer.md b/.changeset/flat-snakes-hammer.md
index f7540f2a9288..49b8d2ca5617 100644
--- a/.changeset/flat-snakes-hammer.md
+++ b/.changeset/flat-snakes-hammer.md
@@ -2,9 +2,9 @@
 "@astrojs/vercel": minor
 ---
 
-Introduces a new config options, `isr`, that allows to deploy your project as an ISR function. [ISR (Incremental Static Regeneration)](https://vercel.com/docs/incremental-static-regeneration) caches your on-demand rendered pages in the same way as prerendered pages after first request.
+Introduces a new config option, `isr`, that allows you to deploy your project as an ISR function. [ISR (Incremental Static Regeneration)](https://vercel.com/docs/incremental-static-regeneration) caches your on-demand rendered pages in the same way as prerendered pages after first request.
 
-To enable this feature, set `isr` to true in your `astro.config.mjs`:
+To enable this feature, set `isr` to true in your Vercel adapter configuration in `astro.config.mjs`:
 
 ```js
 export default defineConfig({
@@ -13,9 +13,14 @@ export default defineConfig({
 })
 ```
 
-##### Time-based invalidation
 
-By default, ISR responses are cached for the duration of your deployment. You can change this by setting `isr` to an object with an `expiration` field:
+## Cache invalidation options
+
+By default, ISR responses are cached for the duration of your deployment. You can further control caching by setting an `expiration` time or prevent caching entirely for certain routes.
+
+### Time-based invalidation
+
+You can change the length of time to cache routes this by configuring an `expiration` value in seconds:
 
 ```js
 export default defineConfig({
@@ -29,9 +34,9 @@ export default defineConfig({
 })
 ```
 
-##### Manual invalidation
+### Manual invalidation
 
-To implement [Draft mode](https://vercel.com/docs/build-output-api/v3/features#draft-mode), or [On-Demand Incremental Static Regeneration (ISR)](https://vercel.com/docs/build-output-api/v3/features#on-demand-incremental-static-regeneration-isr), you can create a bypass token and provide it to the `isr` config: 
+To implement Vercel's [Draft mode](https://vercel.com/docs/build-output-api/v3/features#draft-mode), or [On-Demand Incremental Static Regeneration (ISR)](https://vercel.com/docs/build-output-api/v3/features#on-demand-incremental-static-regeneration-isr), you can create a bypass token and provide it to the `isr` config along with the paths to exclude from caching: 
 
 ```js
 export default defineConfig({

From f51f9a870552576e9b6a5d2026e4f308cc026138 Mon Sep 17 00:00:00 2001
From: Arsh <69170106+lilnasy@users.noreply.github.com>
Date: Mon, 5 Feb 2024 23:55:03 +0530
Subject: [PATCH 19/19] Apply suggestions from code review

---
 .changeset/flat-snakes-hammer.md | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.changeset/flat-snakes-hammer.md b/.changeset/flat-snakes-hammer.md
index 49b8d2ca5617..787d2899dfa9 100644
--- a/.changeset/flat-snakes-hammer.md
+++ b/.changeset/flat-snakes-hammer.md
@@ -52,4 +52,3 @@ export default defineConfig({
 })
 ```
 
-Note that ISR function requests do not include search params, similar to [requests](https://docs.astro.build/en/reference/api-reference/#astrorequest) in static mode.