From 25e187a021203ea0dfaf45ba65ad5d2a67312045 Mon Sep 17 00:00:00 2001
From: Colton Ehrman <coltonje95@gmail.com>
Date: Sat, 10 Aug 2024 19:06:50 -0500
Subject: [PATCH] feat: handle err.cause & err.stack

This is a replacement for https://github.com/pillarjs/finalhandler/pull/49.
I just pulled out the specific change related to this issue and added it here.

Closes: https://github.com/expressjs/express/issues/5630
---
 index.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index f628e42..26b1fba 100644
--- a/index.js
+++ b/index.js
@@ -175,8 +175,12 @@ function getErrorMessage (err, status, env) {
     // use err.stack, which typically includes err.message
     msg = err.stack
 
-    // fallback to err.toString() when possible
-    if (!msg && typeof err.toString === 'function') {
+    if (err && err.cause && err.cause.stack) {
+      msg += '\n[cause]: ' + err.cause.stack
+    } else if (err && err.stack) {
+      msg += '\n[stack]: ' + err.stack
+    } else if (!msg && typeof err.toString === 'function') {
+      // fallback to err.toString() when possible
       msg = err.toString()
     }
   }