domain: set `.domain` non-enumerable on resources

In particular, this comes into play in the node repl, which apparently
enables domains by default. Whenever any Promise gets inspected, a
`.domain` property is displayed, which is *very confusing*, especially
since it has some kind of WeakReference attached to it, which is not yet
a language feature.

This change will prevent it from showing up in casual inspection, but
will leave it available for use.

PR-URL: https://github.com/nodejs/node/pull/26210
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/test/parallel/test-domain-async-id-map-leak.js b/test/parallel/test-domain-async-id-map-leak.js
index e720241841..8c03aa9401 100644
--- a/test/parallel/test-domain-async-id-map-leak.js
+++ b/test/parallel/test-domain-async-id-map-leak.js
@@ -6,6 +6,7 @@ const assert = require('assert');
 const async_hooks = require('async_hooks');
 const domain = require('domain');
 const EventEmitter = require('events');
+const isEnumerable = Function.call.bind(Object.prototype.propertyIsEnumerable);
 
 // This test makes sure that the (async id → domain) map which is part of the
 // domain module does not get in the way of garbage collection.
@@ -21,7 +22,9 @@ d.run(() => {
 
   emitter.linkToResource = resource;
   assert.strictEqual(emitter.domain, d);
+  assert.strictEqual(isEnumerable(emitter, 'domain'), false);
   assert.strictEqual(resource.domain, d);
+  assert.strictEqual(isEnumerable(resource, 'domain'), false);
 
   // This would otherwise be a circular chain now:
   // emitter → resource → async id ⇒ domain → emitter.