css/css-variables/variable-definition-keywords.html

<!DOCTYPE html>
<html>
<head>
    <title>CSS Variable definitions and keywords</title>

    <meta rel="author" title="Kevin Babbitt">
    <meta rel="author" title="Greg Whitworth">
    <link rel="author" title="Microsoft Corporation" href="http://microsoft.com" />
    <link rel="help" href="http://www.w3.org/TR/css-variables-1/#using-variables">

    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <style>
        /* Specify a value in a rule hitting keyword targets so that the keywords
           have something to override in the cascade. */
        div > div
        {
            --var: 10px;
        }
    </style>
</head>
<body>

    <div id="inheritParent" style="--var: 20px;">
        <div id="inheritTest" style="--var: inherit;"></div>
    </div>

    <div id="initialParent" style="--var: 20px;">
        <div id="initialTest" style="--var: initial;"></div>
    </div>

    <div id="unsetParent" style="--var: 20px;">
        <div id="unsetTest" style="--var: unset;"></div>
    </div>

    <div id="revertParent" style="--var: 20px;">
        <div id="revertTest" style="--var: revert;"></div>
    </div>

    <script type="text/javascript">
        "use strict";

        let computedStyle = [
            { elementId: "inheritTest", property: "--var", expectedValue: "20px", testName: "computed style inherit" },
            { elementId: "initialTest", property: "--var", expectedValue: "", testName: "computed style initial" },
            { elementId: "unsetTest", property: "--var", expectedValue: "20px", testName: "computed style unset" },
            { elementId: "revertTest", property: "--var", expectedValue: "20px", testName: "computed style revert" }
        ];

        let specifiedStyle = [
            { elementId: "inheritTest", property: "--var", expectedValue: "inherit", testName: "specified style inherit" },
            { elementId: "initialTest", property: "--var", expectedValue: "initial", testName: "specified style initial" },
            { elementId: "unsetTest", property: "--var", expectedValue: "unset", testName: "specified style unset" },
            { elementId: "revertTest", property: "--var", expectedValue: "revert", testName: "specified style revert" }
        ];

        computedStyle.forEach(function (csTest) {
            test( function () {
                var elem = document.getElementById(csTest.elementId);
                var actualValue = window.getComputedStyle(elem).getPropertyValue(csTest.property).trim();
                assert_equals(csTest.expectedValue, actualValue);
            }, csTest.testName);
        });

        specifiedStyle.forEach(function (ssTest) {
            test( function () {
                var elem = document.getElementById(ssTest.elementId);
                var actualValue = elem.style.getPropertyValue(ssTest.property);
                assert_equals(ssTest.expectedValue, actualValue);
            }, ssTest.testName);
        });
    </script>
</body>
</html>