third_party/WebKit/LayoutTests/fast/canvas/canvas-context-attributes-default-value.html

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>
  var trueAttributes = {
    alpha : true,
  };

  var falseAttributes = {
    alpha : false,
  };

  function testAttributes(expectedAttributes, checkValue) {

    if (arguments.length != 1 && arguments.length != 2)
      return;

    var canvas = document.createElement("canvas");
    var initialAttributes = {};
    var isUndefinedOrNull = arguments.length == 2 &&
        (checkValue == undefined || checkValue == null);

    if (isUndefinedOrNull)
      for (key in expectedAttributes)
        initialAttributes[key] = checkValue;

    var context = canvas.getContext("2d", initialAttributes);

    window.actualContextAttributes = context.getContextAttributes();

    for (key in expectedAttributes)
      assert_equals(eval("actualContextAttributes." + key),
        expectedAttributes[key]);
  }

  test(function(t) {
    testAttributes(trueAttributes);
  }, 'Test default value');

  test(function(t) {
    testAttributes(trueAttributes, undefined);
  }, 'Test undfined value');

  test(function(t) {
    testAttributes(falseAttributes, null);
  }, 'Test null value');
</script>
</body>