1 files changed, 46 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/ShadowRealm/instance-extensibility.js b/js/src/tests/test262/built-ins/ShadowRealm/instance-extensibility.js
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+++ b/js/src/tests/test262/built-ins/ShadowRealm/instance-extensibility.js
@@ -0,0 +1,46 @@
+// |reftest| shell-option(--enable-shadow-realms) skip-if(!xulRuntime.shell) -- requires shell-options
+// Copyright (C) 2021 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-shadowrealm
+description: >
+  The new instance is extensible
+info: |
+  ShadowRealm ( )
+
+  ...
+  2. Let O be ? OrdinaryCreateFromConstructor(NewTarget, "%ShadowRealm.prototype%",
+  « [[ShadowRealm]], [[ExecutionContext]] »).
+  ...
+  13. Return O.
+
+  OrdinaryCreateFromConstructor creates a new ordinary objects including the
+  internal slots [[Prototype]] and [[Extensible]]. The latter will have its
+  value set to true.
+includes: [propertyHelper.js]
+features: [ShadowRealm]
+---*/
+
+const realm = new ShadowRealm();
+
+assert(Object.isExtensible(realm));
+
+Object.defineProperty(realm, 'foo', { configurable: true });
+assert(realm.hasOwnProperty('foo'), 'confirms extensibility adding a new property');
+
+Object.defineProperty(realm, 'foo', {
+  value: 'bar',
+  writable: true,
+  configurable: true,
+  enumerable: false,
+});
+
+verifyProperty(realm, 'foo', {
+  value: 'bar',
+  writable: true,
+  configurable: true,
+  enumerable: false,
+});
+
+reportCompare(0, 0);