util: set `super_` property to non-enumerable

Using `util.inherits()` adds a `super_` property to the constructor
and inspecting that constructor is going to show that property even
though it's not useful for the user.

Therefore the property is now set as non-enumerable and such entries
are not visible by default when using `console.log()` or
`util.inspect()`.

PR-URL: https://github.com/nodejs/node/pull/23107
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/util.js b/lib/util.js
index ae2295533d..8eaf62f0ab 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -285,7 +285,11 @@ function inherits(ctor, superCtor) {
     throw new ERR_INVALID_ARG_TYPE('superCtor.prototype',
                                    'Function', superCtor.prototype);
   }
-  ctor.super_ = superCtor;
+  Object.defineProperty(ctor, 'super_', {
+    value: superCtor,
+    writable: true,
+    configurable: true
+  });
   Object.setPrototypeOf(ctor.prototype, superCtor.prototype);
 }