LayoutTests/accessibility/dynamic-datetime-attribute.html

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<html>
<head>
<script src="../resources/accessibility-helper.js"></script>
<script src="../resources/js-test.js"></script>
</head>
<body>

<time id="time" datetime="2017-07-08">July 8</time>

<script>
var output = "This test ensures that we report the correct datetime value after the attribute is changed dynamically.\n\n";

if (window.accessibilityController) {
    window.jsTestIsAsync = true;

    var time = accessibilityController.accessibleElementById("time");
    output += expect("time.dateTimeValue", "'2017-07-08'");
    if (accessibilityController.platformName === "mac")
        output += expect("time.isAttributeSupported('AXDateTimeValue')", "true");
    document.getElementById("time").setAttribute("datetime", "11-12");
    setTimeout(async function() {
        output += await expectAsync("time.dateTimeValue", "'11-12'");

        debug(output);
        finishJSTest();
    }, 0);
}
</script>
</body>
</html>