From 385b447aa1d25eb74e40a2eb58c6e522ed67b083 Mon Sep 17 00:00:00 2001
From: Slawek Kolodziej <hfrntt@gmail.com>
Date: Mon, 10 Feb 2025 20:41:01 +0100
Subject: [PATCH] feat(vercel): allow defining ISR exclusions with regular
 expressions

---
 packages/integrations/vercel/src/index.ts     | 38 +++++++++++++++----
 .../vercel/test/fixtures/isr/astro.config.mjs |  2 +-
 .../fixtures/isr/src/pages/api/[dynamic].ts   |  3 ++
 .../test/fixtures/isr/src/pages/api/index.ts  |  3 ++
 packages/integrations/vercel/test/isr.test.js | 22 +++++------
 5 files changed, 46 insertions(+), 22 deletions(-)
 create mode 100644 packages/integrations/vercel/test/fixtures/isr/src/pages/api/[dynamic].ts
 create mode 100644 packages/integrations/vercel/test/fixtures/isr/src/pages/api/index.ts

diff --git a/packages/integrations/vercel/src/index.ts b/packages/integrations/vercel/src/index.ts
index 4aeb3e568d20..4779b8412014 100644
--- a/packages/integrations/vercel/src/index.ts
+++ b/packages/integrations/vercel/src/index.ts
@@ -157,7 +157,7 @@ interface VercelISRConfig {
 	 *
 	 * @default `[]`
 	 */
-	exclude?: string[];
+	exclude?: (string | RegExp)[];
 }
 
 export default function vercelAdapter({
@@ -407,20 +407,42 @@ export default function vercelAdapter({
 							const isrConfig = typeof isr === 'object' ? isr : {};
 							await builder.buildServerlessFolder(entryFile, NODE_PATH, _config.root);
 							if (isrConfig.exclude?.length) {
+								const expandedExclusions = isrConfig.exclude.reduce<string[]>((acc, exclusion) => {
+										if (exclusion instanceof RegExp) {
+											return [
+												...acc,
+												...routes.filter(route => exclusion.test(route.pattern)).map(route => route.pattern)
+											]
+										}
+		
+										return [...acc, exclusion];
+									}, []);
+
 								const dest = _middlewareEntryPoint ? MIDDLEWARE_PATH : NODE_PATH;
-								for (const route of isrConfig.exclude) {
+								for (const route of expandedExclusions) {
 									// vercel interprets src as a regex pattern, so we need to escape it
 									routeDefinitions.push({ src: escapeRegex(route), dest });
 								}
 							}
 							await builder.buildISRFolder(entryFile, '_isr', isrConfig, _config.root);
 							for (const route of routes) {
-								const src = route.patternRegex.source;
-								const dest =
-									src.startsWith('^\\/_image') || src.startsWith('^\\/_server-islands')
-										? NODE_PATH
-										: ISR_PATH;
-								if (!route.isPrerendered) routeDefinitions.push({ src, dest });
+								// Do not create _isr route entries for excluded routes
+								const excludeRouteFromIsr = isrConfig.exclude?.some(exclusion => {
+									if (exclusion instanceof RegExp) {
+										return exclusion.test(route.pattern);
+									}
+
+									return exclusion === route.pattern;
+								});
+	
+								if (!excludeRouteFromIsr) {
+									const src = route.patternRegex.source;
+									const dest =
+										src.startsWith('^\\/_image') || src.startsWith('^\\/_server-islands')
+											? NODE_PATH
+											: ISR_PATH;
+									if (!route.isPrerendered) routeDefinitions.push({ src, dest });
+								}
 							}
 						} else {
 							await builder.buildServerlessFolder(entryFile, NODE_PATH, _config.root);
diff --git a/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs b/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
index 5e2ce8263502..3bc1a44b51a7 100644
--- a/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
+++ b/packages/integrations/vercel/test/fixtures/isr/astro.config.mjs
@@ -7,7 +7,7 @@ export default defineConfig({
 		isr: {
 			bypassToken: "1c9e601d-9943-4e7c-9575-005556d774a8",
 			expiration: 120,
-			exclude: ["/two", "/excluded/[dynamic]", "/excluded/[...rest]"]
+			exclude: ["/two", "/excluded/[dynamic]", "/excluded/[...rest]", /^\/api/]
 		}
 	})
 });
diff --git a/packages/integrations/vercel/test/fixtures/isr/src/pages/api/[dynamic].ts b/packages/integrations/vercel/test/fixtures/isr/src/pages/api/[dynamic].ts
new file mode 100644
index 000000000000..ecbac57c951d
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/isr/src/pages/api/[dynamic].ts
@@ -0,0 +1,3 @@
+export async function GET({ params }) {
+  return new Response(`OK ${params.dynamic}`)
+}
diff --git a/packages/integrations/vercel/test/fixtures/isr/src/pages/api/index.ts b/packages/integrations/vercel/test/fixtures/isr/src/pages/api/index.ts
new file mode 100644
index 000000000000..fd34254521e2
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/isr/src/pages/api/index.ts
@@ -0,0 +1,3 @@
+export async function GET() {
+  return new Response("OK")
+}
diff --git a/packages/integrations/vercel/test/isr.test.js b/packages/integrations/vercel/test/isr.test.js
index 1e5b329ef6dd..c2cf9833def2 100644
--- a/packages/integrations/vercel/test/isr.test.js
+++ b/packages/integrations/vercel/test/isr.test.js
@@ -42,29 +42,25 @@ describe('ISR', () => {
 				dest: '_render',
 			},
 			{
-				src: '^/_server-islands/([^/]+?)/?$',
-				dest: '_render',
+				src: "^/api/([^/]+?)$",
+				dest: "_render"
 			},
 			{
-				src: '^/_image/?$',
-				dest: '_render',
+				src: "^/api$",
+				dest: "_render"
 			},
 			{
-				src: '^/excluded/([^/]+?)/?$',
-				dest: '/_isr?x_astro_path=$0',
+				src: '^/_server-islands/([^/]+?)/?$',
+				dest: '_render',
 			},
 			{
-				src: '^/excluded(?:/(.*?))?/?$',
-				dest: '/_isr?x_astro_path=$0',
+				src: '^/_image/?$',
+				dest: '_render',
 			},
 			{
 				src: '^/one/?$',
 				dest: '/_isr?x_astro_path=$0',
-			},
-			{
-				src: '^/two/?$',
-				dest: '/_isr?x_astro_path=$0',
-			},
+			}
 		]);
 	});
 });