has-complexity.html

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This WPT test may be referenced by the following Test IDs:
- /css/selectors/invalidation/has-complexity.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<meta charset="utf-8">

<title>CSS Selector Invalidation: :has() invalidation should not be O(n^2)</title>

<link rel="author" title="Antti Koivisto" href="mailto:antti@apple.com">

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<link rel="help" href="https://drafts.csswg.org/selectors/#relational">

<style>

div, main { color: grey }

main:has(span) .subject { color: red }

main:has(span + span) .subject { color: green }

main:has(span + final) .subject { color: blue }

main:has(nonexistent + span) .subject { color: black }

main:has(span) span { color: black }

main:has(nonexistent) span { color: black }

main:has(div div span) .subject { color: purple }

</style>

<main>

    <div id=container>

        <span></span>

    </div>

    <div id=subject class=subject></div>

</main>

<script>

const grey = 'rgb(128, 128, 128)';

const red = 'rgb(255, 0, 0)';

const green = 'rgb(0, 128, 0)';

const blue = 'rgb(0, 0, 255)';

const purple = 'rgb(128, 0, 128)';

function testColor(test_name, color) {

    test(function() {

        assert_equals(getComputedStyle(subject).color, color);

    }, test_name);

const count = 25000;

testColor(`Before appending ${count} elements`, red);

for (let i = 0; i < count; ++i) {

    const span = document.createElement("span");

    container.appendChild(span);

testColor(`After appending ${count} elements. This should not time out.`, green);

for (let i = 0; i < count - 1; ++i) {

    const span = document.createElement("span");

    container.appendChild(span);

const final = document.createElement("final");

container.appendChild(final);

testColor(`After appending another ${count} elements. This should not time out.`, blue);

const div = document.createElement("div");

for (let i = 0; i < count; ++i) {

    const span = document.createElement("span");

    div.appendChild(span);

container.appendChild(div);

testColor(`After appending div with ${count} elements. This should not time out.`, purple);

div.remove();

testColor(`After removing div with ${count} elements. This should not time out.`, blue);

for (let i = 0; i < count; ++i)

    container.lastChild.remove();

testColor(`After removing ${count} elements one-by-one. This should not time out.`, green);

container.replaceChildren();

testColor(`After removing the remaining elements. This should not time out.`, grey);

</script>