Content-Length header is a number instead of a string which causes issues downstream

[colin-oos]

Hi! 👋

Firstly, thanks for your work on this project! 🙂

Today I used patch-package to patch @vendia/serverless-express@4.12.6 for the project I'm working on.

My issue is with apollo-server as described in more detail here. However, other people experience a similar issue with ALB such as the case described here. These issues have existed for a long time so I figured it is about time this gets addressed. People have been forced to switch to H4ad/serverless-adapter instead in the meantime.

I will be putting up a PR for this issue shortly and will link to this issue. Until then, here is the diff that solved my problem:

diff --git a/node_modules/@vendia/serverless-express/src/event-sources/aws/api-gateway-v2.js b/node_modules/@vendia/serverless-express/src/event-sources/aws/api-gateway-v2.js
index 56896c1..c2136cf 100644
--- a/node_modules/@vendia/serverless-express/src/event-sources/aws/api-gateway-v2.js
+++ b/node_modules/@vendia/serverless-express/src/event-sources/aws/api-gateway-v2.js
@@ -33,7 +33,7 @@ function getRequestValuesFromApiGatewayEvent ({ event }) {
   if (event.body) {
     body = getEventBody({ event })
     const isBase64Encoded = event.isBase64Encoded
-    headers['content-length'] = Buffer.byteLength(body, isBase64Encoded ? 'base64' : 'utf8')
+    headers['content-length'] = Buffer.byteLength(body, isBase64Encoded ? 'base64' : 'utf8').toString()
   }
 
   return {
diff --git a/node_modules/@vendia/serverless-express/src/event-sources/aws/lambda-edge.js b/node_modules/@vendia/serverless-express/src/event-sources/aws/lambda-edge.js
index 217fbe9..ebc135e 100644
--- a/node_modules/@vendia/serverless-express/src/event-sources/aws/lambda-edge.js
+++ b/node_modules/@vendia/serverless-express/src/event-sources/aws/lambda-edge.js
@@ -28,7 +28,7 @@ function getRequestValuesFromLambdaEdgeEvent ({ event }) {
       body: requestBodyObject.data,
       isBase64Encoded
     })
-    headers['content-length'] = Buffer.byteLength(body, isBase64Encoded ? 'base64' : 'utf8')
+    headers['content-length'] = Buffer.byteLength(body, isBase64Encoded ? 'base64' : 'utf8').toString()
   }
 
   const path = url.format({
diff --git a/node_modules/@vendia/serverless-express/src/event-sources/azure/http-function-runtime-v3.js b/node_modules/@vendia/serverless-express/src/event-sources/azure/http-function-runtime-v3.js
index c5c887e..57c464a 100644
--- a/node_modules/@vendia/serverless-express/src/event-sources/azure/http-function-runtime-v3.js
+++ b/node_modules/@vendia/serverless-express/src/event-sources/azure/http-function-runtime-v3.js
@@ -17,7 +17,7 @@ function getRequestValuesFromHttpFunctionEvent ({ event }) {
 
   const body = context.rawBody
   if (body) {
-    headers['content-length'] = Buffer.byteLength(body, 'utf8')
+    headers['content-length'] = Buffer.byteLength(body, 'utf8').toString()
   }
 
   return {
diff --git a/node_modules/@vendia/serverless-express/src/event-sources/utils.js b/node_modules/@vendia/serverless-express/src/event-sources/utils.js
index c5537e1..accd919 100644
--- a/node_modules/@vendia/serverless-express/src/event-sources/utils.js
+++ b/node_modules/@vendia/serverless-express/src/event-sources/utils.js
@@ -41,7 +41,7 @@ function getRequestValuesFromEvent ({
   if (event.body) {
     body = getEventBody({ event })
     const { isBase64Encoded } = event
-    headers['content-length'] = Buffer.byteLength(body, isBase64Encoded ? 'base64' : 'utf8')
+    headers['content-length'] = Buffer.byteLength(body, isBase64Encoded ? 'base64' : 'utf8').toString()
   }
 
   const remoteAddress = (event && event.requestContext && event.requestContext.identity && event.requestContext.identity.sourceIp) || ''

This issue body was partially generated by patch-package.