fix: include route prefix in vercel func names, fix #8401 (#8408)

* fix: include route prefix in vercel func names

* chore: add changeset

* chore: update pnpm lockfile

* refactor: simplify logic that generates vercel func names

* fix: properly remove entryFile prefix from func name

* refactor: change how vercel function names are generated

---------

Co-authored-by: Nate Moore <natemoo-re@users.noreply.github.com>

10 files changed, 104 insertions, 6 deletions

diff --git a/.changeset/modern-guests-float.md b/.changeset/modern-guests-float.md
new file mode 100644
index 000000000..cda74642a
--- /dev/null
+++ b/.changeset/modern-guests-float.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/vercel': patch
+---
+
+Fix serverless function naming conflicts for routes with identical filenames but different directory structures
diff --git a/packages/integrations/vercel/src/serverless/adapter.ts b/packages/integrations/vercel/src/serverless/adapter.ts
index a7178b3e3..32735da03 100644
--- a/packages/integrations/vercel/src/serverless/adapter.ts
+++ b/packages/integrations/vercel/src/serverless/adapter.ts
@@ -207,14 +207,25 @@ You can set functionPerRoute: false to prevent surpassing the limit.`
 
 				// Multiple entrypoint support
 				if (_entryPoints.size) {
-					for (const [route, entryFile] of _entryPoints) {
-						const func = basename(entryFile.toString()).replace(/\.mjs$/, '');
+					const getRouteFuncName = (route: RouteData) =>
+						route.component.replace('src/pages/', '')
+
+          const getFallbackFuncName = (entryFile: URL) =>
+            basename(entryFile.toString())
+              .replace('entry.', '')
+              .replace(/\.mjs$/, '');
+
+          for (const [route, entryFile] of _entryPoints) {
+            const func = route.component.startsWith('src/pages/')
+							? getRouteFuncName(route)
+							: getFallbackFuncName(entryFile)
+						
 						await createFunctionFolder(func, entryFile, filesToInclude, logger);
 						routeDefinitions.push({
-							src: route.pattern.source,
-							dest: func,
-						});
-					}
+              src: route.pattern.source,
+              dest: func,
+            });
+          }
 				} else {
 					await createFunctionFolder(
 						'render',
diff --git a/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/astro.config.mjs b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/astro.config.mjs
new file mode 100644
index 000000000..f5a86e609
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/astro.config.mjs
@@ -0,0 +1,10 @@
+import { defineConfig } from 'astro/config';
+import vercel from '@astrojs/vercel/serverless';
+
+export default defineConfig({
+	adapter: vercel({
+		// Pass some value to make sure it doesn't error out
+		includeFiles: ['included.js'],
+	}),
+	output: 'server'
+});
diff --git a/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/included.js b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/included.js
new file mode 100644
index 000000000..4e64b2d61
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/included.js
@@ -0,0 +1 @@
+'works'
\ No newline at end of file
diff --git a/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/package.json b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/package.json
new file mode 100644
index 000000000..e22a7e932
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@test/astro-vercel-serverless-with-dynamic-routes",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@astrojs/vercel": "workspace:*",
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/[id]/index.astro b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/[id]/index.astro
new file mode 100644
index 000000000..4eab5952d
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/[id]/index.astro
@@ -0,0 +1,12 @@
+---
+export const prerender = false;
+---
+
+<html>
+	<head>
+		<title>testing {Astro.params.id}</title>
+	</head>
+	<body>
+		<h1>testing {Astro.params.id}</h1>
+	</body>
+</html>
diff --git a/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/api/[id].js b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/api/[id].js
new file mode 100644
index 000000000..f54e673a8
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/api/[id].js
@@ -0,0 +1,7 @@
+export const prerender = false;
+
+export async function GET({ params }) {
+	return Response.json({
+		id: params.id
+	});
+}
diff --git a/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/index.astro b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/index.astro
new file mode 100644
index 000000000..b6b833e53
--- /dev/null
+++ b/packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes/src/pages/index.astro
@@ -0,0 +1,12 @@
+---
+export const prerender = import.meta.env.PRERENDER;
+---
+
+<html>
+	<head>
+		<title>testing</title>
+	</head>
+	<body>
+		<h1>testing</h1>
+	</body>
+</html>
diff --git a/packages/integrations/vercel/test/serverless-with-dynamic-routes.test.js b/packages/integrations/vercel/test/serverless-with-dynamic-routes.test.js
new file mode 100644
index 000000000..325f9c5b0
--- /dev/null
+++ b/packages/integrations/vercel/test/serverless-with-dynamic-routes.test.js
@@ -0,0 +1,22 @@
+import { expect } from 'chai';
+import { loadFixture } from './test-utils.js';
+
+describe('Serverless with dynamic routes', () => {
+	/** @type {import('./test-utils.js').Fixture} */
+	let fixture;
+
+	before(async () => {
+		process.env.PRERENDER = true;
+		fixture = await loadFixture({
+			root: './fixtures/serverless-with-dynamic-routes/',
+			output: 'hybrid',
+		});
+		await fixture.build();
+	});
+
+	it('build successful', async () => {
+		expect(await fixture.readFile('../.vercel/output/static/index.html')).to.be.ok;
+		expect(await fixture.readFile('../.vercel/output/functions/[id]/index.astro.func/.vc-config.json')).to.be.ok;
+		expect(await fixture.readFile('../.vercel/output/functions/api/[id].js.func/.vc-config.json')).to.be.ok;
+	});
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 43b0c149e..ff3a57a4c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -4812,6 +4812,15 @@ importers:
         specifier: workspace:*
         version: link:../../../../../astro
 
+  packages/integrations/vercel/test/fixtures/serverless-with-dynamic-routes:
+    dependencies:
+      '@astrojs/vercel':
+        specifier: workspace:*
+        version: link:../../..
+      astro:
+        specifier: workspace:*
+        version: link:../../../../../astro
+
   packages/integrations/vercel/test/fixtures/static-assets:
     dependencies:
       '@astrojs/vercel':