css/css-variables/css-variable-change-style-002.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Variables Test: Style changes on properties using variables</title>
<link rel="author" title="Javier Fernandez Garcia-Boente" href="mailto:jfernandez@igalia.com">
<link rel="help" href="http://www.w3.org/TR/css-variables-1/#using-variables">
<meta name="assert" content="A change in the custom property declaration must be propagated to all the descendants">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
    .test1 > div > div { color: var(--x); }
    .test2 > div > div { background-color: var(--x); }
    .test3 > div > div { white-space: var(--x); }
</style>
<div id="outer">
    <div>
        <div id="inner1"></div>
    </div>
    <div>
        <div id="inner2"></div>
    </div>
    <div>
        <div id="inner3"></div>
    </div>
</div>
<script>
    "use strict";

    let colorValues = [
        { Id: "case1", value: "red",   expected: "rgb(255, 0, 0)" },
        { Id: "case2", value: "green", expected: "rgb(0, 128, 0)" },
    ];
    let whiteSpaceValues = [
        { Id: "case1", value: "pre-wrap", expected: "pre-wrap" },
        { Id: "case2", value: "nowrap",   expected: "nowrap" },
    ];
    let testcases = [
        { property: "color",            className: "test1", values: colorValues, },
        { property: "background-color", className: "test2", values: colorValues, },
        { property: "white-space",      className: "test3", values: whiteSpaceValues},
    ];

    testcases.forEach(function (testcase) {
        test( function () {
            outer.className = testcase.className;
            testcase.values.forEach(function (entry) {
                document.body.style.cssText = "--x: " + entry.value;
                let actualValue = getComputedStyle(inner1).getPropertyValue(testcase.property);
                assert_equals(actualValue, entry.expected, entry.Id + "-1");
                actualValue = getComputedStyle(inner2).getPropertyValue(testcase.property);
                assert_equals(actualValue, entry.expected, entry.Id + "-2");
                actualValue = getComputedStyle(inner3).getPropertyValue(testcase.property);
                assert_equals(actualValue, entry.expected, entry.Id + "-3");
            });
        }, "Declaration changes on '" + testcase.property + "' propagate to all variable references");
    });
</script>