From 7884c0ec577a78e4534df298f128eae7ac207956 Mon Sep 17 00:00:00 2001
From: Rich Harris <hello@rich-harris.dev>
Date: Tue, 17 May 2022 11:08:30 -0400
Subject: [PATCH] revert to using cjs for lambda

---
 .changeset/few-scissors-agree.md | 5 +++++
 packages/adapter-vercel/index.js | 8 ++++----
 2 files changed, 9 insertions(+), 4 deletions(-)
 create mode 100644 .changeset/few-scissors-agree.md

diff --git a/.changeset/few-scissors-agree.md b/.changeset/few-scissors-agree.md
new file mode 100644
index 000000000000..06e9d1d88b4c
--- /dev/null
+++ b/.changeset/few-scissors-agree.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/adapter-vercel': patch
+---
+
+Revert to cjs mode when building for lambda
diff --git a/packages/adapter-vercel/index.js b/packages/adapter-vercel/index.js
index 6c89940d8952..e987b93c4283 100644
--- a/packages/adapter-vercel/index.js
+++ b/packages/adapter-vercel/index.js
@@ -145,10 +145,10 @@ async function v1(builder, external) {
 		bundle: true,
 		platform: 'node',
 		external,
-		format: 'esm'
+		format: 'cjs'
 	});
 
-	writeFileSync(`${dirs.lambda}/package.json`, JSON.stringify({ type: 'module' }));
+	writeFileSync(`${dirs.lambda}/package.json`, JSON.stringify({ type: 'commonjs' }));
 
 	builder.log.minor('Copying assets...');
 
@@ -271,7 +271,7 @@ async function v3(builder, external, edge, split) {
 			target: `node${node_version.full}`,
 			bundle: true,
 			platform: 'node',
-			format: 'esm',
+			format: 'cjs',
 			external
 		});
 
@@ -284,7 +284,7 @@ async function v3(builder, external, edge, split) {
 			})
 		);
 
-		write(`${dirs.functions}/${name}.func/package.json`, JSON.stringify({ type: 'module' }));
+		write(`${dirs.functions}/${name}.func/package.json`, JSON.stringify({ type: 'commonjs' }));
 
 		routes.push({ src: pattern, dest: `/${name}` });
 	}