From f66fda7cfc4208542e8f2b67d65268d9aa562045 Mon Sep 17 00:00:00 2001
From: Gus Caplan <me@gus.host>
Date: Mon, 24 Feb 2020 13:34:38 -0800
Subject: [PATCH] util: fix inspecting document.all

Fixes: https://github.com/nodejs/node/issues/31889
---
 lib/internal/util/inspect.js       | 9 +++++++--
 test/parallel/test-util-inspect.js | 9 +++++++++
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
index 42fefdd147654d..a39779838a43a6 100644
--- a/lib/internal/util/inspect.js
+++ b/lib/internal/util/inspect.js
@@ -134,6 +134,9 @@ const builtInObjects = new Set(
   ObjectGetOwnPropertyNames(global).filter((e) => /^[A-Z][a-zA-Z0-9]+$/.test(e))
 );
 
+// https://tc39.es/ecma262/#sec-IsHTMLDDA-internal-slot
+const isUndetectableObject = (v) => typeof v === 'undefined' && v !== undefined;
+
 // These options must stay in sync with `getUserOptions`. So if any option will
 // be added or removed, `getUserOptions` must also be updated accordingly.
 const inspectDefaultOptions = ObjectSeal({
@@ -482,7 +485,7 @@ function getEmptyFormatArray() {
 function getConstructorName(obj, ctx, recurseTimes, protoProps) {
   let firstProto;
   const tmp = obj;
-  while (obj) {
+  while (obj || isUndetectableObject(obj)) {
     const descriptor = ObjectGetOwnPropertyDescriptor(obj, 'constructor');
     if (descriptor !== undefined &&
         typeof descriptor.value === 'function' &&
@@ -680,7 +683,9 @@ function findTypedConstructor(value) {
 // value afterwards again.
 function formatValue(ctx, value, recurseTimes, typedArray) {
   // Primitive types cannot have properties.
-  if (typeof value !== 'object' && typeof value !== 'function') {
+  if (typeof value !== 'object' &&
+      typeof value !== 'function' &&
+      !isUndetectableObject(value)) {
     return formatPrimitive(ctx.stylize, value, ctx);
   }
   if (value === null) {
diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
index 7fb677d49524d0..5540acfee30247 100644
--- a/test/parallel/test-util-inspect.js
+++ b/test/parallel/test-util-inspect.js
@@ -26,6 +26,7 @@ const { internalBinding } = require('internal/test/binding');
 const JSStream = internalBinding('js_stream').JSStream;
 const util = require('util');
 const vm = require('vm');
+const v8 = require('v8');
 const { previewEntries } = internalBinding('util');
 const { inspect } = util;
 const { MessageChannel } = require('worker_threads');
@@ -2748,3 +2749,11 @@ assert.strictEqual(
   assert.deepStrictEqual(colors.gray, originalValue);
   assert.strictEqual(colors.grey, colors.gray);
 }
+
+// https://github.com/nodejs/node/issues/31889
+{
+  v8.setFlagsFromString('--allow-natives-syntax');
+  const undetectable = vm.runInThisContext('%GetUndetectable()');
+  v8.setFlagsFromString('--no-allow-natives-syntax');
+  assert.strictEqual(inspect(undetectable), '{}');
+}