From 34aeedd87027f3bc7d62d5dc38c40f69792e740b Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 14:11:20 -0300
Subject: [PATCH 01/10] Added runtime option

---
 packages/adapter-vercel/index.d.ts |  1 +
 packages/adapter-vercel/index.js   | 17 ++++++++++-------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/packages/adapter-vercel/index.d.ts b/packages/adapter-vercel/index.d.ts
index 1566ac142b82..901288895a08 100644
--- a/packages/adapter-vercel/index.d.ts
+++ b/packages/adapter-vercel/index.d.ts
@@ -4,6 +4,7 @@ type Options = {
 	edge?: boolean;
 	external?: string[];
 	split?: boolean;
+	runtime?: '16.x' | '14.x' | '12.x';
 };
 
 declare function plugin(options?: Options): Adapter;
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index f98c2c4b5137..e2cb7b875249 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -81,16 +81,18 @@ const redirects = {
 };
 
 /** @type {import('.')} **/
-export default function ({ external = [], edge, split } = {}) {
+export default function ({ external = [], edge, split, runtime } = {}) {
 	return {
 		name: '@sveltejs/adapter-vercel',
 
 		async adapt(builder) {
 			if (process.env.ENABLE_VC_BUILD) {
-				await v3(builder, external, edge, split);
+				await v3(builder, external, edge, split, runtime || '16.x');
 			} else {
-				if (edge || split) {
-					throw new Error('edge and split options can only be used with ENABLE_VC_BUILD');
+				if (edge || split || runtime) {
+					throw new Error(
+						'`edge`, `split` and `runtime` options can only be used with ENABLE_VC_BUILD'
+					);
 				}
 
 				await v1(builder, external);
@@ -198,8 +200,9 @@ async function v1(builder, external) {
  * @param {string[]} external
  * @param {boolean} edge
  * @param {boolean} split
+ * @param {'16.x' | '14.x' | '12.x'} runtime
  */
-async function v3(builder, external, edge, split) {
+async function v3(builder, external, edge, split, runtime) {
 	const dir = '.vercel/output';
 
 	const tmp = builder.getBuildDirectory('vercel-tmp');
@@ -263,7 +266,7 @@ async function v3(builder, external, edge, split) {
 		await esbuild.build({
 			entryPoints: [`${tmp}/serverless.js`],
 			outfile: `${dirs.functions}/${name}.func/index.js`,
-			target: 'node14',
+			target: `node${runtime}`,
 			bundle: true,
 			platform: 'node',
 			format: 'cjs',
@@ -273,7 +276,7 @@ async function v3(builder, external, edge, split) {
 		write(
 			`${dirs.functions}/${name}.func/.vc-config.json`,
 			JSON.stringify({
-				runtime: 'nodejs14.x',
+				runtime: `nodejs${runtime}`,
 				handler: 'index.js',
 				launcherType: 'Nodejs'
 			})

From 17642135d748db662646cba52c6ca78b4e8de11b Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 14:12:00 -0300
Subject: [PATCH 02/10] Added support for ESM

---
 packages/adapter-vercel/index.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index e2cb7b875249..82f763000162 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -269,7 +269,7 @@ async function v3(builder, external, edge, split, runtime) {
 			target: `node${runtime}`,
 			bundle: true,
 			platform: 'node',
-			format: 'cjs',
+			format: 'esm',
 			external
 		});
 
@@ -282,7 +282,7 @@ async function v3(builder, external, edge, split, runtime) {
 			})
 		);
 
-		write(`${dirs.functions}/${name}.func/package.json`, JSON.stringify({ type: 'commonjs' }));
+		write(`${dirs.functions}/${name}.func/package.json`, JSON.stringify({ type: 'module' }));
 
 		routes.push({ src: pattern, dest: `/${name}` });
 	}

From c266ec6097bd938dc809a97d8545a657645e5c46 Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 14:18:30 -0300
Subject: [PATCH 03/10] Renamed runtime to nodeVersion

---
 packages/adapter-vercel/index.d.ts |  2 +-
 packages/adapter-vercel/index.js   | 17 +++++++++--------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/packages/adapter-vercel/index.d.ts b/packages/adapter-vercel/index.d.ts
index 901288895a08..b943b9895908 100644
--- a/packages/adapter-vercel/index.d.ts
+++ b/packages/adapter-vercel/index.d.ts
@@ -4,7 +4,7 @@ type Options = {
 	edge?: boolean;
 	external?: string[];
 	split?: boolean;
-	runtime?: '16.x' | '14.x' | '12.x';
+	nodeVersion?: '16.x' | '14.x' | '12.x';
 };
 
 declare function plugin(options?: Options): Adapter;
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 82f763000162..ba3735ecdb32 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -81,17 +81,17 @@ const redirects = {
 };
 
 /** @type {import('.')} **/
-export default function ({ external = [], edge, split, runtime } = {}) {
+export default function ({ external = [], edge, split, nodeVersion } = {}) {
 	return {
 		name: '@sveltejs/adapter-vercel',
 
 		async adapt(builder) {
 			if (process.env.ENABLE_VC_BUILD) {
-				await v3(builder, external, edge, split, runtime || '16.x');
+				await v3(builder, external, edge, split, nodeVersion || '16.x');
 			} else {
-				if (edge || split || runtime) {
+				if (edge || split || nodeVersion) {
 					throw new Error(
-						'`edge`, `split` and `runtime` options can only be used with ENABLE_VC_BUILD'
+						'`edge`, `split` and `nodeVersion` options can only be used with ENABLE_VC_BUILD'
 					);
 				}
 
@@ -200,9 +200,9 @@ async function v1(builder, external) {
  * @param {string[]} external
  * @param {boolean} edge
  * @param {boolean} split
- * @param {'16.x' | '14.x' | '12.x'} runtime
+ * @param {'16.x' | '14.x' | '12.x'} nodeVersion
  */
-async function v3(builder, external, edge, split, runtime) {
+async function v3(builder, external, edge, split, nodeVersion) {
 	const dir = '.vercel/output';
 
 	const tmp = builder.getBuildDirectory('vercel-tmp');
@@ -266,7 +266,8 @@ async function v3(builder, external, edge, split, runtime) {
 		await esbuild.build({
 			entryPoints: [`${tmp}/serverless.js`],
 			outfile: `${dirs.functions}/${name}.func/index.js`,
-			target: `node${runtime}`,
+			target:
+				nodeVersion === '12.x' ? 'node12.22' : nodeVersion === '14.x' ? 'node14.19' : 'node16.15',
 			bundle: true,
 			platform: 'node',
 			format: 'esm',
@@ -276,7 +277,7 @@ async function v3(builder, external, edge, split, runtime) {
 		write(
 			`${dirs.functions}/${name}.func/.vc-config.json`,
 			JSON.stringify({
-				runtime: `nodejs${runtime}`,
+				runtime: `nodejs${nodeVersion}`,
 				handler: 'index.js',
 				launcherType: 'Nodejs'
 			})

From cffeeb57d22fa7097279395fcfe030881697d81f Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 14:31:06 -0300
Subject: [PATCH 04/10] Added warning

---
 packages/adapter-vercel/index.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index ba3735ecdb32..ca98dc913ddb 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -87,6 +87,12 @@ export default function ({ external = [], edge, split, nodeVersion } = {}) {
 
 		async adapt(builder) {
 			if (process.env.ENABLE_VC_BUILD) {
+				if (edge && nodeVersion) {
+					throw new Error(
+						'`nodeVersion` option can only be used with serverless functions, not edge functions'
+					);
+				}
+
 				await v3(builder, external, edge, split, nodeVersion || '16.x');
 			} else {
 				if (edge || split || nodeVersion) {

From 06254d68d30b8adfd9d3b3f15362efef18902553 Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 14:31:16 -0300
Subject: [PATCH 05/10] Changeset

---
 .changeset/breezy-grapes-smash.md | 5 +++++
 .changeset/tall-ties-juggle.md    | 5 +++++
 2 files changed, 10 insertions(+)
 create mode 100644 .changeset/breezy-grapes-smash.md
 create mode 100644 .changeset/tall-ties-juggle.md

diff --git a/.changeset/breezy-grapes-smash.md b/.changeset/breezy-grapes-smash.md
new file mode 100644
index 000000000000..f1b5a62da1fb
--- /dev/null
+++ b/.changeset/breezy-grapes-smash.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-vercel': patch
+---
+
+You can now select a Node.js version for your serverless functions
diff --git a/.changeset/tall-ties-juggle.md b/.changeset/tall-ties-juggle.md
new file mode 100644
index 000000000000..9ba00a39f1a3
--- /dev/null
+++ b/.changeset/tall-ties-juggle.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-vercel': patch
+---
+
+The output of serverless now is ESM instead of CJS

From cdcd3be2f98ab56085fe21bc142a083ec59e2fab Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 14:37:50 -0300
Subject: [PATCH 06/10] Added note to readme

---
 packages/adapter-vercel/README.md | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/adapter-vercel/README.md b/packages/adapter-vercel/README.md
index 34a0999fbe0c..a3a6e4694dd1 100644
--- a/packages/adapter-vercel/README.md
+++ b/packages/adapter-vercel/README.md
@@ -31,6 +31,11 @@ export default {
       // if true, will split your app into multiple functions
       // instead of creating a single one for the entire app
       split: false
+
+			// which version of Node.js you want your serverless
+			// function to run on - it only works with edge=false
+			// and ENABLE_VC_BUILD=1
+      nodeVersion: '16.x'
     })
   }
 };

From 817b7da3762acbfb58baab2268161e8574add004 Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 14:39:08 -0300
Subject: [PATCH 07/10] Readme with spaces instead of tabs

---
 packages/adapter-vercel/README.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/adapter-vercel/README.md b/packages/adapter-vercel/README.md
index a3a6e4694dd1..1214c918f4bf 100644
--- a/packages/adapter-vercel/README.md
+++ b/packages/adapter-vercel/README.md
@@ -32,9 +32,9 @@ export default {
       // instead of creating a single one for the entire app
       split: false
 
-			// which version of Node.js you want your serverless
-			// function to run on - it only works with edge=false
-			// and ENABLE_VC_BUILD=1
+      // which version of Node.js you want your serverless
+      // function to run on - it only works with edge=false
+      // and ENABLE_VC_BUILD=1
       nodeVersion: '16.x'
     })
   }

From aa396c24167af880186c4ed3eab8ad4fe5ab08b3 Mon Sep 17 00:00:00 2001
From: JuanM04 <me@juanm04.com>
Date: Fri, 13 May 2022 15:36:09 -0300
Subject: [PATCH 08/10] Detect node version automatically

---
 .changeset/breezy-grapes-smash.md  |  2 +-
 packages/adapter-vercel/README.md  |  5 ----
 packages/adapter-vercel/index.d.ts |  1 -
 packages/adapter-vercel/index.js   | 43 ++++++++++++++++++------------
 4 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/.changeset/breezy-grapes-smash.md b/.changeset/breezy-grapes-smash.md
index f1b5a62da1fb..43b7d732414f 100644
--- a/.changeset/breezy-grapes-smash.md
+++ b/.changeset/breezy-grapes-smash.md
@@ -2,4 +2,4 @@
 '@sveltejs/adapter-vercel': patch
 ---
 
-You can now select a Node.js version for your serverless functions
+Support for Node.js 16
diff --git a/packages/adapter-vercel/README.md b/packages/adapter-vercel/README.md
index 1214c918f4bf..34a0999fbe0c 100644
--- a/packages/adapter-vercel/README.md
+++ b/packages/adapter-vercel/README.md
@@ -31,11 +31,6 @@ export default {
       // if true, will split your app into multiple functions
       // instead of creating a single one for the entire app
       split: false
-
-      // which version of Node.js you want your serverless
-      // function to run on - it only works with edge=false
-      // and ENABLE_VC_BUILD=1
-      nodeVersion: '16.x'
     })
   }
 };
diff --git a/packages/adapter-vercel/index.d.ts b/packages/adapter-vercel/index.d.ts
index b943b9895908..1566ac142b82 100644
--- a/packages/adapter-vercel/index.d.ts
+++ b/packages/adapter-vercel/index.d.ts
@@ -4,7 +4,6 @@ type Options = {
 	edge?: boolean;
 	external?: string[];
 	split?: boolean;
-	nodeVersion?: '16.x' | '14.x' | '12.x';
 };
 
 declare function plugin(options?: Options): Adapter;
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index ca98dc913ddb..7992d144c417 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -81,24 +81,23 @@ const redirects = {
 };
 
 /** @type {import('.')} **/
-export default function ({ external = [], edge, split, nodeVersion } = {}) {
+export default function ({ external = [], edge, split } = {}) {
 	return {
 		name: '@sveltejs/adapter-vercel',
 
 		async adapt(builder) {
-			if (process.env.ENABLE_VC_BUILD) {
-				if (edge && nodeVersion) {
-					throw new Error(
-						'`nodeVersion` option can only be used with serverless functions, not edge functions'
-					);
-				}
+			const nodeVersion = getNodeVersion();
+			if (nodeVersion.major < 14) {
+				throw new Error(
+					`SvelteKit only support Node.js version 14 or greater (v${nodeVersion.full} was detected). Learn how to change the Node.js version of your Functiones here: https://vercel.com/docs/runtimes#official-runtimes/node-js/node-js-version`
+				);
+			}
 
-				await v3(builder, external, edge, split, nodeVersion || '16.x');
+			if (process.env.ENABLE_VC_BUILD) {
+				await v3(builder, external, edge, split);
 			} else {
-				if (edge || split || nodeVersion) {
-					throw new Error(
-						'`edge`, `split` and `nodeVersion` options can only be used with ENABLE_VC_BUILD'
-					);
+				if (edge || split) {
+					throw new Error('`edge` and `split` options can only be used with ENABLE_VC_BUILD');
 				}
 
 				await v1(builder, external);
@@ -206,9 +205,8 @@ async function v1(builder, external) {
  * @param {string[]} external
  * @param {boolean} edge
  * @param {boolean} split
- * @param {'16.x' | '14.x' | '12.x'} nodeVersion
  */
-async function v3(builder, external, edge, split, nodeVersion) {
+async function v3(builder, external, edge, split) {
 	const dir = '.vercel/output';
 
 	const tmp = builder.getBuildDirectory('vercel-tmp');
@@ -256,6 +254,7 @@ async function v3(builder, external, edge, split, nodeVersion) {
 	async function generate_serverless_function(name, pattern, generate_manifest) {
 		const tmp = builder.getBuildDirectory(`vercel-tmp/${name}`);
 		const relativePath = posix.relative(tmp, builder.getServerDirectory());
+		const nodeVersion = getNodeVersion();
 
 		builder.copy(`${files}/serverless.js`, `${tmp}/serverless.js`, {
 			replace: {
@@ -272,8 +271,7 @@ async function v3(builder, external, edge, split, nodeVersion) {
 		await esbuild.build({
 			entryPoints: [`${tmp}/serverless.js`],
 			outfile: `${dirs.functions}/${name}.func/index.js`,
-			target:
-				nodeVersion === '12.x' ? 'node12.22' : nodeVersion === '14.x' ? 'node14.19' : 'node16.15',
+			target: `node${nodeVersion.full}`,
 			bundle: true,
 			platform: 'node',
 			format: 'esm',
@@ -283,7 +281,7 @@ async function v3(builder, external, edge, split, nodeVersion) {
 		write(
 			`${dirs.functions}/${name}.func/.vc-config.json`,
 			JSON.stringify({
-				runtime: `nodejs${nodeVersion}`,
+				runtime: `nodejs${nodeVersion.major}.x`,
 				handler: 'index.js',
 				launcherType: 'Nodejs'
 			})
@@ -395,3 +393,14 @@ function write(file, data) {
 
 	writeFileSync(file, data);
 }
+
+function getNodeVersion() {
+	const full = process.version.slice(1); // 'v16.5.0' --> '16.5.0'
+	const major = parseInt(full.split('.')[0]); // '16.5.0' --> 16
+
+	if (!Number.isFinite(major)) {
+		throw new Error('There was an error getting the current Node version');
+	}
+
+	return { major, full };
+}

From 38f5707a54b52e0444786cad08e2109da9c571fc Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Fri, 13 May 2022 17:25:38 -0400
Subject: [PATCH 09/10] put check inside get_node_version

---
 packages/adapter-vercel/index.js | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 7992d144c417..64b36ff9f38c 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -86,13 +86,6 @@ export default function ({ external = [], edge, split } = {}) {
 		name: '@sveltejs/adapter-vercel',
 
 		async adapt(builder) {
-			const nodeVersion = getNodeVersion();
-			if (nodeVersion.major < 14) {
-				throw new Error(
-					`SvelteKit only support Node.js version 14 or greater (v${nodeVersion.full} was detected). Learn how to change the Node.js version of your Functiones here: https://vercel.com/docs/runtimes#official-runtimes/node-js/node-js-version`
-				);
-			}
-
 			if (process.env.ENABLE_VC_BUILD) {
 				await v3(builder, external, edge, split);
 			} else {
@@ -394,12 +387,12 @@ function write(file, data) {
 	writeFileSync(file, data);
 }
 
-function getNodeVersion() {
+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 (!Number.isFinite(major)) {
-		throw new Error('There was an error getting the current Node version');
+	if (major < 14) {
+		throw new Error(`SvelteKit only support Node.js version 14 or greater (currently using v${full}). Consult the documentation: https://vercel.com/docs/runtimes#official-runtimes/node-js/node-js-version`)
 	}
 
 	return { major, full };

From 419dc8df6fdfc1411d66cc1e68e079f19cc9d86e Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Fri, 13 May 2022 17:26:15 -0400
Subject: [PATCH 10/10] use esm everywhere, base target on env for v1 output as
 well as v3

---
 packages/adapter-vercel/index.js | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 64b36ff9f38c..e246c8891c23 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -104,6 +104,8 @@ export default function ({ external = [], edge, split } = {}) {
  * @param {string[]} external
  */
 async function v1(builder, external) {
+	const node_version = get_node_version();
+
 	const dir = '.vercel_build_output';
 
 	const tmp = builder.getBuildDirectory('vercel-tmp');
@@ -139,13 +141,14 @@ async function v1(builder, external) {
 	await esbuild.build({
 		entryPoints: [`${tmp}/serverless.js`],
 		outfile: `${dirs.lambda}/index.js`,
-		target: 'node14',
+		target: `node${node_version.full}`,
 		bundle: true,
 		platform: 'node',
-		external
+		external,
+		format: 'esm'
 	});
 
-	writeFileSync(`${dirs.lambda}/package.json`, JSON.stringify({ type: 'commonjs' }));
+	writeFileSync(`${dirs.lambda}/package.json`, JSON.stringify({ type: 'module' }));
 
 	builder.log.minor('Copying assets...');
 
@@ -200,6 +203,8 @@ async function v1(builder, external) {
  * @param {boolean} split
  */
 async function v3(builder, external, edge, split) {
+	const node_version = get_node_version();
+
 	const dir = '.vercel/output';
 
 	const tmp = builder.getBuildDirectory('vercel-tmp');
@@ -247,7 +252,6 @@ async function v3(builder, external, edge, split) {
 	async function generate_serverless_function(name, pattern, generate_manifest) {
 		const tmp = builder.getBuildDirectory(`vercel-tmp/${name}`);
 		const relativePath = posix.relative(tmp, builder.getServerDirectory());
-		const nodeVersion = getNodeVersion();
 
 		builder.copy(`${files}/serverless.js`, `${tmp}/serverless.js`, {
 			replace: {
@@ -264,7 +268,7 @@ async function v3(builder, external, edge, split) {
 		await esbuild.build({
 			entryPoints: [`${tmp}/serverless.js`],
 			outfile: `${dirs.functions}/${name}.func/index.js`,
-			target: `node${nodeVersion.full}`,
+			target: `node${node_version.full}`,
 			bundle: true,
 			platform: 'node',
 			format: 'esm',
@@ -274,7 +278,7 @@ async function v3(builder, external, edge, split) {
 		write(
 			`${dirs.functions}/${name}.func/.vc-config.json`,
 			JSON.stringify({
-				runtime: `nodejs${nodeVersion.major}.x`,
+				runtime: `nodejs${node_version.major}.x`,
 				handler: 'index.js',
 				launcherType: 'Nodejs'
 			})
@@ -309,7 +313,7 @@ async function v3(builder, external, edge, split) {
 		await esbuild.build({
 			entryPoints: [`${tmp}/edge.js`],
 			outfile: `${dirs.functions}/${name}.func/index.js`,
-			target: 'node14',
+			target: 'es2020', // TODO verify what the edge runtime supports
 			bundle: true,
 			platform: 'node',
 			format: 'esm',