fix: Handled assigning headers in LambdaProxyWebRequest when there are no headers present (#2293)

Author: bizob2828

lib/serverless/api-gateway.js

@@ -80,7 +80,7 @@ function normalizeHeaders(event, lowerCaseKey = false) {
   const headers = event.multiValueHeaders ?? event.headers
 
   if (!headers) {
-    return
+    return {}
   }
 
   return Object.fromEntries(

test/unit/serverless/api-gateway-v2.test.js

@@ -272,3 +272,17 @@ tap.test('should capture request headers', (t) => {
     t.end()
   }
 })
+
+tap.test('should not crash when headers are non-existent', (t) => {
+  const { lambda, event, functionContext, responseBody } = t.context
+  delete event.headers
+
+  const wrappedHandler = lambda.patchLambdaHandler((event, context, callback) => {
+    callback(null, responseBody)
+  })
+
+  t.doesNotThrow(() => {
+    wrappedHandler(event, functionContext, () => {})
+  })
+  t.end()
+})