chromium/third_party/blink/web_tests/fast/dom/html-attribute-types.html

<head>
<script src="../../resources/js-test.js"></script>
<script>
var img;
var pre;

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

    img = document.createElement('img');
    shouldBe("typeof img.border", "'string'");

    pre = document.createElement('pre');
    shouldBe("typeof pre.width", "'number'");
}
</script>
</head>
<body onload="test()">
This checks the types of some HTML DOM attributes whose types currently clash with our implementation.
<div id="console"></div>
</body>