fix(vercel): now works with monorepos

.changeset/famous-dancers-explain.md

@@ -0,0 +1,6 @@
+---
+'@astrojs/vercel': patch
+---
+
+- Upgraded @vercel/nft to 0.22.1
+- Fix monorepos (#5020)

packages/integrations/vercel/package.json

@@ -45,7 +45,7 @@
   },
   "dependencies": {
     "@astrojs/webapi": "^1.1.0",
-    "@vercel/nft": "^0.18.2"
+    "@vercel/nft": "^0.22.1"
   },
   "devDependencies": {
     "astro": "workspace:*",

packages/integrations/vercel/src/lib/fs.ts

@@ -5,8 +5,12 @@ export async function writeJson<T>(path: PathLike, data: T) {
 	await fs.writeFile(path, JSON.stringify(data), { encoding: 'utf-8' });
 }
 
-export async function emptyDir(dir: PathLike): Promise<void> {
+export async function removeDir(dir: PathLike) {
 	await fs.rm(dir, { recursive: true, force: true, maxRetries: 3 });
+}
+
+export async function emptyDir(dir: PathLike): Promise<void> {
+	await removeDir(dir);
 	await fs.mkdir(dir, { recursive: true });
 }
 

packages/integrations/vercel/src/lib/nft.ts

@@ -1,38 +1,90 @@
 import { nodeFileTrace } from '@vercel/nft';
 import * as fs from 'node:fs/promises';
+import nodePath from 'node:path';
 import { fileURLToPath } from 'node:url';
 
 export async function copyDependenciesToFunction(
-	root: URL,
-	functionFolder: URL,
-	serverEntry: string
-) {
-	const entryPath = fileURLToPath(new URL(`./${serverEntry}`, functionFolder));
+	entry: URL,
+	outDir: URL
+): Promise<{ handler: string }> {
+	const entryPath = fileURLToPath(entry);
+
+	// Get root of folder of the system (like C:\ on Windows or / on Linux)
+	let base = entry;
+	while (fileURLToPath(base) !== fileURLToPath(new URL('../', base))) {
+		base = new URL('../', base);
+	}
 
 	const result = await nodeFileTrace([entryPath], {
-		base: fileURLToPath(root),
+		base: fileURLToPath(base),
 	});
 
-	for (const file of result.fileList) {
-		if (file.startsWith('.vercel/')) continue;
-		const origin = new URL(file, root);
-		const dest = new URL(file, functionFolder);
+	if (result.fileList.size === 0) throw new Error('[@astrojs/vercel] No files found');
+
+	for (const error of result.warnings) {
+		if (error.message.startsWith('Failed to resolve dependency')) {
+			const [, module, file] = /Cannot find module '(.+?)' loaded from (.+)/.exec(error.message)!;
+
+			// The import(astroRemark) sometimes fails to resolve, but it's not a problem
+			if (module === '@astrojs/') continue;
+
+			if (entryPath === file) {
+				console.warn(
+					`[@astrojs/vercel] The module "${module}" couldn't be resolved. This may not be a problem, but it's worth checking.`
+				);
+			} else {
+				console.warn(
+					`[@astrojs/vercel] The module "${module}" inside the file "${file}" couldn't be resolved. This may not be a problem, but it's worth checking.`
+				);
+			}
+		} else {
+			throw error;
+		}
+	}
 
-		const meta = await fs.stat(origin);
-		const isSymlink = (await fs.lstat(origin)).isSymbolicLink();
+	const fileList = [...result.fileList];
+
+	let commonAncestor = nodePath.dirname(fileList[0]);
+	for (const file of fileList.slice(1)) {
+		while (!file.startsWith(commonAncestor)) {
+			commonAncestor = nodePath.dirname(commonAncestor);
+		}
+	}
+
+	for (const file of fileList) {
+		const origin = new URL(file, base);
+		const dest = new URL(nodePath.relative(commonAncestor, file), outDir);
+
+		const realpath = await fs.realpath(origin);
+		const isSymlink = realpath !== fileURLToPath(origin);
+		const isDir = (await fs.stat(origin)).isDirectory();
 
 		// Create directories recursively
-		if (meta.isDirectory() && !isSymlink) {
+		if (isDir && !isSymlink) {
 			await fs.mkdir(new URL('..', dest), { recursive: true });
 		} else {
 			await fs.mkdir(new URL('.', dest), { recursive: true });
 		}
 
 		if (isSymlink) {
-			const link = await fs.readlink(origin);
-			await fs.symlink(link, dest, meta.isDirectory() ? 'dir' : 'file');
-		} else {
+			const realdest = fileURLToPath(
+				new URL(
+					nodePath.relative(nodePath.join(fileURLToPath(base), commonAncestor), realpath),
+					outDir
+				)
+			);
+			await fs.symlink(
+				nodePath.relative(fileURLToPath(new URL('.', dest)), realdest),
+				dest,
+				isDir ? 'dir' : 'file'
+			);
+		} else if (!isDir) {
 			await fs.copyFile(origin, dest);
 		}
 	}
+
+	return {
+		// serverEntry location inside the outDir
+		handler: nodePath.relative(nodePath.join(fileURLToPath(base), commonAncestor), entryPath),
+	};
 }

packages/integrations/vercel/src/serverless/adapter.ts

@@ -1,6 +1,6 @@
 import type { AstroAdapter, AstroConfig, AstroIntegration } from 'astro';
 
-import { getVercelOutput, writeJson } from '../lib/fs.js';
+import { getVercelOutput, removeDir, writeJson } from '../lib/fs.js';
 import { copyDependenciesToFunction } from '../lib/nft.js';
 import { getRedirects } from '../lib/redirects.js';
 
@@ -16,6 +16,7 @@ function getAdapter(): AstroAdapter {
 
 export default function vercelEdge(): AstroIntegration {
 	let _config: AstroConfig;
+	let buildTempFolder: URL;
 	let functionFolder: URL;
 	let serverEntry: string;
 
@@ -39,11 +40,18 @@ export default function vercelEdge(): AstroIntegration {
 			'astro:build:start': async ({ buildConfig }) => {
 				buildConfig.serverEntry = serverEntry = 'entry.js';
 				buildConfig.client = new URL('./static/', _config.outDir);
-				buildConfig.server = functionFolder = new URL('./functions/render.func/', _config.outDir);
+				buildConfig.server = buildTempFolder = new URL('./dist/', _config.root);
+				functionFolder = new URL('./functions/render.func/', _config.outDir);
 			},
 			'astro:build:done': async ({ routes }) => {
 				// Copy necessary files (e.g. node_modules/)
-				await copyDependenciesToFunction(_config.root, functionFolder, serverEntry);
+				const { handler } = await copyDependenciesToFunction(
+					new URL(serverEntry, buildTempFolder),
+					functionFolder
+				);
+
+				// Remove temporary folder
+				await removeDir(buildTempFolder);
 
 				// Enable ESM
 				// https://aws.amazon.com/blogs/compute/using-node-js-es-modules-and-top-level-await-in-aws-lambda/
@@ -55,7 +63,7 @@ export default function vercelEdge(): AstroIntegration {
 				// https://vercel.com/docs/build-output-api/v3#vercel-primitives/serverless-functions/configuration
 				await writeJson(new URL(`./.vc-config.json`, functionFolder), {
 					runtime: getRuntime(),
-					handler: serverEntry,
+					handler,
 					launcherType: 'Nodejs',
 				});