Use @vercel/nft to create lambdas

.changeset/few-scissors-agree.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-vercel': patch
+---
+
+Revert to cjs mode when building for lambda

packages/adapter-vercel/index.js

@@ -1,6 +1,7 @@
-import { mkdirSync, writeFileSync } from 'fs';
-import { dirname, posix } from 'path';
+import fs from 'fs';
+import path from 'path';
 import { fileURLToPath } from 'url';
+import { nodeFileTrace } from '@vercel/nft';
 import esbuild from 'esbuild';
 
 // rules for clean URLs and trailing slash handling,
@@ -80,6 +81,8 @@ const redirects = {
 	]
 };
 
+const files = fileURLToPath(new URL('./files', import.meta.url).href);
+
 /** @type {import('.')} **/
 export default function ({ external = [], edge, split } = {}) {
 	return {
@@ -113,16 +116,14 @@ async function v1(builder, external) {
 	builder.rimraf(dir);
 	builder.rimraf(tmp);
 
-	const files = fileURLToPath(new URL('./files', import.meta.url).href);
-
 	const dirs = {
 		static: `${dir}/static`,
 		lambda: `${dir}/functions/node/render`
 	};
 
 	builder.log.minor('Generating serverless function...');
 
-	const relativePath = posix.relative(tmp, builder.getServerDirectory());
+	const relativePath = path.posix.relative(tmp, builder.getServerDirectory());
 
 	builder.copy(`${files}/serverless.js`, `${tmp}/serverless.js`, {
 		replace: {
@@ -131,7 +132,7 @@ async function v1(builder, external) {
 		}
 	});
 
-	writeFileSync(
+	fs.writeFileSync(
 		`${tmp}/manifest.js`,
 		`export const manifest = ${builder.generateManifest({
 			relativePath
@@ -145,10 +146,10 @@ async function v1(builder, external) {
 		bundle: true,
 		platform: 'node',
 		external,
-		format: 'esm'
+		format: 'cjs'
 	});
 
-	writeFileSync(`${dirs.lambda}/package.json`, JSON.stringify({ type: 'module' }));
+	fs.writeFileSync(`${dirs.lambda}/package.json`, JSON.stringify({ type: 'commonjs' }));
 
 	builder.log.minor('Copying assets...');
 
@@ -173,7 +174,7 @@ async function v1(builder, external) {
 		status: redirect.status
 	}));
 
-	writeFileSync(
+	fs.writeFileSync(
 		`${dir}/config/routes.json`,
 		JSON.stringify([
 			...redirects[builder.config.kit.trailingSlash],
@@ -250,10 +251,9 @@ async function v3(builder, external, edge, split) {
 	 * @param {(options: { relativePath: string }) => string} generate_manifest
 	 */
 	async function generate_serverless_function(name, pattern, generate_manifest) {
-		const tmp = builder.getBuildDirectory(`vercel-tmp/${name}`);
-		const relativePath = posix.relative(tmp, builder.getServerDirectory());
+		const relativePath = path.posix.relative(tmp, builder.getServerDirectory());
 
-		builder.copy(`${files}/serverless.js`, `${tmp}/serverless.js`, {
+		builder.copy(`${files}/serverless.js`, `${tmp}/index.js`, {
 			replace: {
 				SERVER: `${relativePath}/index.js`,
 				MANIFEST: './manifest.js'
@@ -265,27 +265,12 @@ async function v3(builder, external, edge, split) {
 			`export const manifest = ${generate_manifest({ relativePath })};\n`
 		);
 
-		await esbuild.build({
-			entryPoints: [`${tmp}/serverless.js`],
-			outfile: `${dirs.functions}/${name}.func/index.js`,
-			target: `node${node_version.full}`,
-			bundle: true,
-			platform: 'node',
-			format: 'esm',
-			external
-		});
-
-		write(
-			`${dirs.functions}/${name}.func/.vc-config.json`,
-			JSON.stringify({
-				runtime: `nodejs${node_version.major}.x`,
-				handler: 'index.js',
-				launcherType: 'Nodejs'
-			})
+		await create_function_bundle(
+			`${tmp}/index.js`,
+			`${dirs.functions}/${name}.func`,
+			`nodejs${node_version.major}.x`
 		);
 
-		write(`${dirs.functions}/${name}.func/package.json`, JSON.stringify({ type: 'module' }));
-
 		routes.push({ src: pattern, dest: `/${name}` });
 	}
 
@@ -296,7 +281,7 @@ async function v3(builder, external, edge, split) {
 	 */
 	async function generate_edge_function(name, pattern, generate_manifest) {
 		const tmp = builder.getBuildDirectory(`vercel-tmp/${name}`);
-		const relativePath = posix.relative(tmp, builder.getServerDirectory());
+		const relativePath = path.posix.relative(tmp, builder.getServerDirectory());
 
 		builder.copy(`${files}/edge.js`, `${tmp}/edge.js`, {
 			replace: {
@@ -392,21 +377,95 @@ async function v3(builder, external, edge, split) {
  */
 function write(file, data) {
 	try {
-		mkdirSync(dirname(file), { recursive: true });
+		fs.mkdirSync(path.dirname(file), { recursive: true });
 	} catch {
 		// do nothing
 	}
 
-	writeFileSync(file, data);
+	fs.writeFileSync(file, data);
 }
 
 function get_node_version() {
 	const full = process.version.slice(1); // 'v16.5.0' --> '16.5.0'
 	const major = parseInt(full.split('.')[0]); // '16.5.0' --> 16
 
 	if (major < 16) {
-		throw new Error(`SvelteKit only supports Node.js version 16 or greater (currently using v${full}). Consult the documentation: https://vercel.com/docs/runtimes#official-runtimes/node-js/node-js-version`)
+		throw new Error(
+			`SvelteKit only supports Node.js version 16 or greater (currently using v${full}). Consult the documentation: https://vercel.com/docs/runtimes#official-runtimes/node-js/node-js-version`
+		);
 	}
 
 	return { major, full };
 }
+
+/**
+ * @param {string} entry
+ * @param {string} dir
+ * @param {string} runtime
+ */
+async function create_function_bundle(entry, dir, runtime) {
+	let base = entry;
+	while (base !== (base = path.dirname(base)));
+
+	const traced = await nodeFileTrace([entry], { base });
+
+	traced.warnings.forEach((error) => {
+		// pending https://github.com/vercel/nft/issues/284
+		if (error.message.startsWith('Failed to resolve dependency node:')) return;
+		console.error(error);
+	});
+
+	// find common ancestor directory
+	let common_parts;
+
+	for (const file of traced.fileList) {
+		if (common_parts) {
+			const parts = file.split(path.sep);
+
+			for (let i = 0; i < common_parts.length; i += 1) {
+				if (parts[i] !== common_parts[i]) {
+					common_parts = common_parts.slice(0, i);
+					break;
+				}
+			}
+		} else {
+			common_parts = path.dirname(file).split(path.sep);
+		}
+	}
+
+	const ancestor = base + common_parts.join(path.sep);
+
+	for (const file of traced.fileList) {
+		const source = base + file;
+		const dest = path.join(dir, path.relative(ancestor, source));
+
+		const stats = fs.statSync(source);
+		const is_dir = stats.isDirectory();
+
+		const realpath = fs.realpathSync(source);
+
+		try {
+			fs.mkdirSync(path.dirname(dest), { recursive: true });
+		} catch {
+			// do nothing
+		}
+
+		if (source !== realpath) {
+			const realdest = path.join(dir, path.relative(ancestor, realpath));
+			fs.symlinkSync(path.relative(path.dirname(dest), realdest), dest, is_dir ? 'dir' : 'file');
+		} else if (!is_dir) {
+			fs.copyFileSync(source, dest);
+		}
+	}
+
+	write(
+		`${dir}/.vc-config.json`,
+		JSON.stringify({
+			runtime,
+			handler: path.relative(base + ancestor, entry),
+			launcherType: 'Nodejs'
+		})
+	);
+
+	write(`${dir}/package.json`, JSON.stringify({ type: 'module' }));
+}

packages/adapter-vercel/package.json

@@ -28,6 +28,7 @@
 		"check": "tsc"
 	},
 	"dependencies": {
+		"@vercel/nft": "^0.18.2",
 		"esbuild": "^0.14.21"
 	},
 	"devDependencies": {

packages/adapter-vercel/tsconfig.json

@@ -4,8 +4,9 @@
 		"checkJs": true,
 		"noEmit": true,
 		"noImplicitAny": true,
-		"module": "es2020",
+		"module": "es2022",
 		"moduleResolution": "node",
+		"target": "es2022",
 		"allowSyntheticDefaultImports": true,
 		"baseUrl": ".",
 		"paths": {

packages/kit/test/prerendering/paths-base/svelte.config.js

@@ -7,7 +7,7 @@ const config = {
 		adapter: adapter(),
 
 		paths: {
-			base: '/path-base',
+			base: '/path-base'
 		},
 
 		prerender: {