1 files changed, 109 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testObjectEmulatingUndefined.cpp b/js/src/jsapi-tests/testObjectEmulatingUndefined.cpp
new file mode 100644
index 0000000000..732bde7147
--- /dev/null
+++ b/js/src/jsapi-tests/testObjectEmulatingUndefined.cpp
@@ -0,0 +1,109 @@
+/* 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 const JSClass ObjectEmulatingUndefinedClass = {
+    "ObjectEmulatingUndefined", JSCLASS_EMULATES_UNDEFINED};
+
+static bool ObjectEmulatingUndefinedConstructor(JSContext* cx, unsigned argc,
+                                                JS::Value* vp) {
+  JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
+  JSObject* obj =
+      JS_NewObjectForConstructor(cx, &ObjectEmulatingUndefinedClass, args);
+  if (!obj) {
+    return false;
+  }
+  args.rval().setObject(*obj);
+  return true;
+}
+
+BEGIN_TEST(testObjectEmulatingUndefined_truthy) {
+  CHECK(JS_InitClass(cx, global, nullptr, nullptr, "ObjectEmulatingUndefined",
+                     ObjectEmulatingUndefinedConstructor, 0, nullptr, nullptr,
+                     nullptr, nullptr));
+
+  JS::RootedValue result(cx);
+
+  EVAL("if (new ObjectEmulatingUndefined()) true; else false;", &result);
+  CHECK(result.isFalse());
+
+  EVAL("if (!new ObjectEmulatingUndefined()) true; else false;", &result);
+  CHECK(result.isTrue());
+
+  EVAL(
+      "var obj = new ObjectEmulatingUndefined(); \n"
+      "var res = []; \n"
+      "for (var i = 0; i < 50; i++) \n"
+      "  res.push(Boolean(obj)); \n"
+      "res.every(function(v) { return v === false; });",
+      &result);
+  CHECK(result.isTrue());
+
+  return true;
+}
+END_TEST(testObjectEmulatingUndefined_truthy)
+
+BEGIN_TEST(testObjectEmulatingUndefined_equal) {
+  CHECK(JS_InitClass(cx, global, nullptr, nullptr, "ObjectEmulatingUndefined",
+                     ObjectEmulatingUndefinedConstructor, 0, nullptr, nullptr,
+                     nullptr, nullptr));
+
+  JS::RootedValue result(cx);
+
+  EVAL("if (new ObjectEmulatingUndefined() == undefined) true; else false;",
+       &result);
+  CHECK(result.isTrue());
+
+  EVAL("if (new ObjectEmulatingUndefined() == null) true; else false;",
+       &result);
+  CHECK(result.isTrue());
+
+  EVAL("if (new ObjectEmulatingUndefined() != undefined) true; else false;",
+       &result);
+  CHECK(result.isFalse());
+
+  EVAL("if (new ObjectEmulatingUndefined() != null) true; else false;",
+       &result);
+  CHECK(result.isFalse());
+
+  EVAL(
+      "var obj = new ObjectEmulatingUndefined(); \n"
+      "var res = []; \n"
+      "for (var i = 0; i < 50; i++) \n"
+      "  res.push(obj == undefined); \n"
+      "res.every(function(v) { return v === true; });",
+      &result);
+  CHECK(result.isTrue());
+
+  EVAL(
+      "var obj = new ObjectEmulatingUndefined(); \n"
+      "var res = []; \n"
+      "for (var i = 0; i < 50; i++) \n"
+      "  res.push(obj == null); \n"
+      "res.every(function(v) { return v === true; });",
+      &result);
+  CHECK(result.isTrue());
+
+  EVAL(
+      "var obj = new ObjectEmulatingUndefined(); \n"
+      "var res = []; \n"
+      "for (var i = 0; i < 50; i++) \n"
+      "  res.push(obj != undefined); \n"
+      "res.every(function(v) { return v === false; });",
+      &result);
+  CHECK(result.isTrue());
+
+  EVAL(
+      "var obj = new ObjectEmulatingUndefined(); \n"
+      "var res = []; \n"
+      "for (var i = 0; i < 50; i++) \n"
+      "  res.push(obj != null); \n"
+      "res.every(function(v) { return v === false; });",
+      &result);
+  CHECK(result.isTrue());
+
+  return true;
+}
+END_TEST(testObjectEmulatingUndefined_equal)