From bbff0290db8a56cf599522c5ec0abc901359a0f9 Mon Sep 17 00:00:00 2001
From: Mariusz Nowak <medyk@medikoo.com>
Date: Fri, 21 May 2021 13:57:42 +0200
Subject: [PATCH] fix(AWS Local Invocation): Fix invalid result handling

---
 lib/plugins/aws/invokeLocal/index.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/plugins/aws/invokeLocal/index.js b/lib/plugins/aws/invokeLocal/index.js
index 4d4080c5a..6e73fc60f 100644
--- a/lib/plugins/aws/invokeLocal/index.js
+++ b/lib/plugins/aws/invokeLocal/index.js
@@ -799,7 +799,17 @@ class AwsInvokeLocal {
       if (result instanceof Error) {
         handleError.call(this, result);
         return;
-      } else if (result.headers && result.headers['Content-Type'] === 'application/json') {
+      }
+      try {
+        JSON.stringify(result);
+      } catch (error) {
+        throw new ServerlessError(
+          `Function returned invalid (not a JSON stringifiable) value: ${inspect(result)}`,
+          'INVALID_INVOKE_LOCAL_RESULT'
+        );
+      }
+
+      if (result.headers && result.headers['Content-Type'] === 'application/json') {
         if (result.body) {
           try {
             Object.assign(result, {