third_party/web_platform_tests/webmessaging/without-ports/023.html

<!doctype html>
<title>Object cloning: own properties only, don't follow prototype</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<script>
var Parent = function(){
  this.c = "xyz";
};

var Child = function(a, b) {
  this.a = a;
  this.b = b;
};
Child.prototype = new Parent;

async_test(function() {
  var obj = new Child(1, 2);
  var ch = new MessageChannel();
  ch.port1.onmessage = this.step_func(function(e) {
    for (var i in e.data.obj)
      assert_not_equals(i, 'c');
    this.done();
   });
  ch.port2.start();
  ch.port2.postMessage({obj: obj});
});

</script>