HasSiblingDescendantInvalidation.html

<!DOCTYPE html>
<html>
<head>
<script src="../resources/runner.js"></script>
<style>
  div { color: grey }
  .a:has(~ .b .c) { color: green }
</style>
</head>
<body>
<div id=container><div class=a></div></div>
<script>

function addChildren(element, numChildren, idPrefix)
{
    for (var i = 0; i < numChildren; i++) {
        var child = document.createElement("div");
        child.id = idPrefix  + i;
        element.appendChild(child);
    }
}

function makeTree(element, depth, fanOut, idPrefix)
{
    if (depth <= 0)
        return;
    addChildren(element, fanOut, idPrefix);
    for (var child = element.firstChild; child.nextSibling; child = child.nextSibling) {
        makeTree(child, depth - 1, fanOut, child.id);
    }
    if (child)
        makeTree(child, depth - 1, fanOut, child.id);
}

for (var i = 0; i < 32; i++) {
    var child = document.createElement("div");
    child.id = "child"  + i;
    child.classList.add("b");
    container.appendChild(child);
    makeTree(child, 6, 2, child.id + "_")
}

container.offsetHeight; // force recalc style

var runFunction = function()
{
  child0_0.classList.toggle("c");
  container.offsetHeight; // force recalc style
  child0_0.classList.toggle("c");
  container.offsetHeight; // force recalc style

  child31_111111.classList.toggle("c");
  container.offsetHeight; // force recalc style
  child31_111111.classList.toggle("c");
  container.offsetHeight; // force recalc style
}

PerfTestRunner.measureRunsPerSecond({
  description: "Measures performance of the '.a:has(~ .b .c)' invalidation with a single subject element.",
  run: runFunction
});

</script>
</body>
</html>
chromium/third_party/blink/perf_tests/css/HasSiblingDescendantInvalidation.html
