1 files changed, 69 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..a0aa78f90a
--- /dev/null
+++ b/js/src/jsapi-tests/testWindowNonConfigurable.cpp
@@ -0,0 +1,69 @@
+/* -*- 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 "js/PropertyAndElement.h"  // JS_DefineProperty
+#include "js/Proxy.h"
+#include "jsapi-tests/tests.h"
+
+class WindowProxyHandler : public js::ForwardingProxyHandler {
+ public:
+  constexpr WindowProxyHandler() : js::ForwardingProxyHandler(&family) {}
+
+  static const char family;
+
+  virtual bool defineProperty(JSContext* cx, JS::HandleObject proxy,
+                              JS::HandleId id,
+                              JS::Handle<JS::PropertyDescriptor> desc,
+                              JS::ObjectOpResult& result) const override {
+    if (desc.hasConfigurable() && !desc.configurable()) {
+      result.failCantDefineWindowNonConfigurable();
+      return true;
+    }
+    return ForwardingProxyHandler::defineProperty(cx, proxy, id, desc, result);
+  }
+};
+const char WindowProxyHandler::family = 0;
+
+static const JSClass windowProxy_class =
+    PROXY_CLASS_DEF("TestWindowProxy", JSCLASS_HAS_RESERVED_SLOTS(1));
+static const WindowProxyHandler windowProxy_handler;
+
+BEGIN_TEST(testWindowNonConfigurable) {
+  JS::RootedObject wrapped(cx, JS_NewObject(cx, nullptr));
+  CHECK(wrapped);
+  JS::RootedValue wrappedVal(cx, JS::ObjectValue(*wrapped));
+  js::ProxyOptions options;
+  options.setClass(&windowProxy_class);
+  JS::RootedObject obj(cx, NewProxyObject(cx, &windowProxy_handler, wrappedVal,
+                                          nullptr, options));
+  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)