From c2ff69db4c403c8b5f410793c6be9deaff3d5eb6 Mon Sep 17 00:00:00 2001
From: Ruben Bridgewater <ruben@bridgewater.de>
Date: Mon, 6 Dec 2021 15:25:42 +0100
Subject: [PATCH] util: serialize falsy cause values while inspecting errors
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Signed-off-by: Ruben Bridgewater <ruben@bridgewater.de>

PR-URL: https://github.com/nodejs/node/pull/41097
Fixes: https://github.com/nodejs/node/issues/41096
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
---
 lib/internal/util/inspect.js       |  3 ++-
 test/parallel/test-util-inspect.js | 10 ++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
index 4457f56a8d8215..659fd7b671e742 100644
--- a/lib/internal/util/inspect.js
+++ b/lib/internal/util/inspect.js
@@ -1282,7 +1282,8 @@ function formatError(err, constructor, tag, ctx, keys) {
 
   removeDuplicateErrorKeys(ctx, keys, err, stack);
 
-  if (err.cause && (keys.length === 0 || !keys.includes('cause'))) {
+  if (err.cause !== undefined &&
+      (keys.length === 0 || !keys.includes('cause'))) {
     keys.push('cause');
   }
 
diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index 3ffaf656487395..07461224847d47 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -660,6 +660,16 @@ assert.strictEqual(util.inspect(-5e-324), '-5e-324');
   assert(ex.includes('[message]'));
 }
 
+{
+  const falsyCause1 = new Error('', { cause: false });
+  delete falsyCause1.stack;
+  const falsyCause2 = new Error(undefined, { cause: null });
+  falsyCause2.stack = '';
+
+  assert.strictEqual(util.inspect(falsyCause1), '[Error] { [cause]: false }');
+  assert.strictEqual(util.inspect(falsyCause2), '[Error] { [cause]: null }');
+}
+
 {
   const tmp = Error.stackTraceLimit;
   Error.stackTraceLimit = 0;