test_variables_order.html

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<!DOCTYPE type>

<title>CSS variables order tests</title>

<script src="/tests/SimpleTest/SimpleTest.js"></script>

<link rel="stylesheet" href="/tests/SimpleTest/test.css" type="text/css">

<style id="test">

</style>

<div id="t4"></div>

<script>

/*

 * Although the spec does not enforce any specific order, Gecko and Servo

 * implement a consistent ordering for CSSDeclaration objects in the DOM.

 * CSSDeclarations expose property names as indexed properties, which need

 * to be stable. This order is the order that properties are cascaded in.

 * We have this test just to prevent regressions, rather than testing specific

 * mandated behavior.

*/

function prepareTest() {

  var e = document.createElement("link");

  e.addEventListener("load", runTest);

  e.setAttribute("rel", "stylesheet");

  e.setAttribute("href", "support/external-variable-url.css");

  document.head.appendChild(e);

function runTest() {

  var test = document.getElementById("test");

  test.textContent = "div { --SomeVariableName: a; }";

  var declaration = test.sheet.cssRules[0].style;

  is(declaration.item(0), "--SomeVariableName", "custom property name returned by item() on style declaration");

  is(declaration[0], "--SomeVariableName", "custom property name returned by indexed getter on style declaration");

  var element = document.getElementById("t4");

  var cs = window.getComputedStyle(element);

  ["--SomeVariableName", "--a"].forEach((varName, index) => {

    is(cs.item(cs.length - (index + 1)), varName, "custom property name returned by item() on computed style");

    is(cs[cs.length - (index + 1)], varName, "custom property name returned by indexed getter on style declaration");

});

  SimpleTest.finish();

SimpleTest.waitForExplicitFinish();

prepareTest();

</script>