test: check util.inspect circular Set and Map refs

Ref: #14775
PR-URL: #14790
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Alexey Orlenko <eaglexrlnk@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

test/parallel/test-util-inspect.js

@@ -790,6 +790,13 @@ if (typeof Symbol !== 'undefined') {
   );
 }
 
+// Test circular Set
+{
+  const set = new Set();
+  set.add(set);
+  assert.strictEqual(util.inspect(set), 'Set { [Circular] }');
+}
+
 // test Map
 {
   assert.strictEqual(util.inspect(new Map()), 'Map {}');
@@ -801,6 +808,18 @@ if (typeof Symbol !== 'undefined') {
                      'Map { \'foo\' => null, [size]: 1, bar: 42 }');
 }
 
+// Test circular Map
+{
+  const map = new Map();
+  map.set(map, 'map');
+  assert.strictEqual(util.inspect(map), "Map { [Circular] => 'map' }");
+  map.set(map, map);
+  assert.strictEqual(util.inspect(map), 'Map { [Circular] => [Circular] }');
+  map.delete(map);
+  map.set('map', map);
+  assert.strictEqual(util.inspect(map), "Map { 'map' => [Circular] }");
+}
+
 // test Promise
 {
   const resolved = Promise.resolve(3);