util: protect against monkeypatched Object prototype for inspect()

Prevent affects of monkeypatching (for example) Object.keys() when
calling util.inspect().

PR-URL: https://github.com/nodejs/node/pull/25953
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/test/parallel/test-util-primordial-monkeypatching.js b/test/parallel/test-util-primordial-monkeypatching.js
new file mode 100644
index 0000000000..bf282a1212
--- /dev/null
+++ b/test/parallel/test-util-primordial-monkeypatching.js
@@ -0,0 +1,11 @@
+'use strict';
+
+// Monkeypatch Object.keys() so that it throws an unexpected error. This tests
+// that `util.inspect()` is unaffected by monkey-patching `Object`.
+
+require('../common');
+const assert = require('assert');
+const util = require('util');
+
+Object.keys = () => { throw new Error('fhqwhgads'); };
+assert.strictEqual(util.inspect({}), '{}');