feat: support both enable/disable attribute for multi value headers on ALB (#392)

Author: fredericgermain

src/event-sources/aws/alb.js

@@ -38,16 +38,24 @@ const getRequestValuesFromAlbEvent = ({ event }) => {
 }
 
 const getResponseToAlb = ({
+  event,
   statusCode,
   body,
-  headers,
+  headers: responseHeaders,
   isBase64Encoded
 }) => {
-  const multiValueHeaders = getMultiValueHeaders({ headers })
+  const multiValueHeaders = !event.headers ? getMultiValueHeaders({ headers: responseHeaders }) : undefined
+  const headers = event.headers
+    ? Object.entries(responseHeaders).reduce((acc, [k, v]) => {
+      acc[k] = Array.isArray(v) ? v[0] : v
+      return acc
+    }, {})
+    : undefined
 
   return {
     statusCode,
     body,
+    headers,
     multiValueHeaders,
     isBase64Encoded
   }

src/transport.js

@@ -10,6 +10,7 @@ function forwardResponse ({
   response,
   resolver,
   eventSource,
+  event,
   log
 }) {
   const statusCode = response.statusCode
@@ -30,6 +31,7 @@ function forwardResponse ({
   })
 
   const successResponse = eventSource.getResponse({
+    event,
     statusCode,
     body,
     headers,
@@ -158,6 +160,7 @@ async function forwardRequestToNodeServer ({
     response,
     resolver,
     eventSource,
+    event,
     log
   })
   return response