LayoutTests/editing/mac/input/NSBackgroundColor-transparent.html

<div id="target" contenteditable>T</div>
<p>
    Test that an NSAttributedString from a range with transparent background color does not include
    the NSBackgroundColor attribute.
</p>
<pre id="console"></pre>
<script>
    function log(message)
    {
        document.getElementById("console").appendChild(document.createTextNode(message + "\n"));
    }

    if (window.testRunner) {
        testRunner.dumpAsText();

        var target = document.getElementById("target");
        target.focus();

        var attributedString = textInputController.attributedSubstringFromRange(0, 1);
        var attributeNames = attributedString.getAttributeNamesAtIndex(0);
        for (var i = 0; i < attributeNames.length; ++i) {
            if (attributeNames[i] == "NSBackgroundColor") {
                log("FAIL: Attributes included NSBackgroundColor with value " + attributedString.getAttributeValueAtIndex("NSBackgroundColor", 0));
                break;
            }
        }
        if (i == attributeNames.length)
            log("PASS: Attributes did not include NSBackgroundColor");

        target.parentNode.removeChild(target);
    } else
        log("This test can only run in DumpRenderTree.");
</script>