1 files changed, 65 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testWindowNonConfigurable.cpp b/js/src/jsapi-tests/testWindowNonConfigurable.cpp
new file mode 100644
index 0000000000..7e59678d6a
--- /dev/null
+++ b/js/src/jsapi-tests/testWindowNonConfigurable.cpp
@@ -0,0 +1,65 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "jsapi-tests/tests.h"
+
+static bool windowProxy_defineProperty(JSContext* cx, JS::HandleObject obj,
+                                       JS::HandleId id,
+                                       JS::Handle<JS::PropertyDescriptor> desc,
+                                       JS::ObjectOpResult& result) {
+  if (desc.hasConfigurable() && !desc.configurable()) {
+    result.failCantDefineWindowNonConfigurable();
+    return true;
+  }
+
+  return NativeDefineProperty(cx, obj.as<js::NativeObject>(), id, desc, result);
+}
+
+static const js::ObjectOps windowProxy_objectOps = {
+    nullptr,                     // lookupProperty
+    windowProxy_defineProperty,  // defineProperty
+    nullptr,                     // hasProperty
+    nullptr,                     // getProperty
+    nullptr,                     // setProperty
+    nullptr,                     // getOwnPropertyDescriptor
+    nullptr,                     // deleteProperty
+    nullptr,                     // getElements
+    nullptr,                     // funToString
+};
+
+static const JSClass windowProxy_class = {
+    "WindowProxy", 0, nullptr, nullptr, nullptr, &windowProxy_objectOps};
+
+BEGIN_TEST(testWindowNonConfigurable) {
+  JS::RootedObject obj(cx, JS_NewObject(cx, &windowProxy_class));
+  CHECK(obj);
+  CHECK(JS_DefineProperty(cx, global, "windowProxy", obj, 0));
+  JS::RootedValue v(cx);
+  EVAL(
+      "Object.defineProperty(windowProxy, 'bar', {value: 1, configurable: "
+      "false})",
+      &v);
+  CHECK(v.isNull());  // This is the important bit!
+  EVAL(
+      "Object.defineProperty(windowProxy, 'bar', {value: 1, configurable: "
+      "true})",
+      &v);
+  CHECK(&v.toObject() == obj);
+  EVAL(
+      "Reflect.defineProperty(windowProxy, 'foo', {value: 1, configurable: "
+      "false})",
+      &v);
+  CHECK(v.isFalse());
+  EVAL(
+      "Reflect.defineProperty(windowProxy, 'foo', {value: 1, configurable: "
+      "true})",
+      &v);
+  CHECK(v.isTrue());
+
+  return true;
+}
+END_TEST(testWindowNonConfigurable)