<!doctype html>
<meta charset=utf-8>
<title>Document.createTreeWalker</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<div id=log></div>
<script>
test(function() {
  assert_throws(new TypeError(), function() {
    document.createTreeWalker();
  });
}, "Required arguments to createTreeWalker should be required.");
test(function() {
  var tw = document.createTreeWalker(document.body);
  assert_equals(tw.root, document.body);
  assert_equals(tw.currentNode, document.body);
  assert_equals(tw.whatToShow, 0xFFFFFFFF);
  assert_equals(tw.filter, null);
}, "Optional arguments to createTreeWalker should be optional (1 passed).");
test(function() {
  var tw = document.createTreeWalker(document.body, 42);
  assert_equals(tw.root, document.body);
  assert_equals(tw.currentNode, document.body);
  assert_equals(tw.whatToShow, 42);
  assert_equals(tw.filter, null);
}, "Optional arguments to createTreeWalker should be optional (2 passed).");
test(function() {
  var tw = document.createTreeWalker(document.body, 42, null);
  assert_equals(tw.root, document.body);
  assert_equals(tw.currentNode, document.body);
  assert_equals(tw.whatToShow, 42);
  assert_equals(tw.filter, null);
}, "Optional arguments to createTreeWalker should be optional (3 passed, null).");
test(function() {
  var fn = function() {};
  var tw = document.createTreeWalker(document.body, 42, fn);
  assert_equals(tw.root, document.body);
  assert_equals(tw.currentNode, document.body);
  assert_equals(tw.whatToShow, 42);
  assert_equals(tw.filter, fn);
}, "Optional arguments to createTreeWalker should be optional (3 passed, function).");
</script>