css/css-view-transitions/element-is-grouping-during-animation.html

<!DOCTYPE html>
<html class=reftest-wait>
<title>View transitions: view transition element remains grouping during animation</title>
<link rel="help" href="https://www.w3.org/TR/css-view-transitions-1/">
<link rel="author" href="mailto:vmpstr@chromium.org">
<link rel="match" href="element-is-grouping-during-animation-ref.html">
<script src="/common/reftest-wait.js"></script>

<style>
.parent {
  top: 0;
  width: 100px;
  height: 100px;
  position: absolute;
  background: red;
  transform-style: preserve-3d;
}
.named {
  view-transition-name: target;
}

.child {
  background: green;
  width: 100px;
  height: 100px;
  top: 0;
  left: 0;
  position: absolute;
  transform: translateZ(-500px);
}

body {
  perspective: 1000px;
  height: 500px;
}

::view-transition-group(root) {
  animation-duration: 500s;
  opacity: 0;
}
::view-transition-image-pair(root) {
  display: none;
}
::view-transition-group(target) {
  animation-duration: 0s;
}
::view-transition-new(target) {
  animation: unset;
  opacity: 1;
}
::view-transition-old(target) {
  animation: unset;
  opacity: 0;
}

::view-transition {
  background: pink;
}
</style>

<div id=target class="parent named"><div class=child></div></div>

<script>
failIfNot(document.startViewTransition, "Missing document.startViewTransition");

function runTest() {
  let transition = document.startViewTransition();
  transition.ready.then(() => {
    requestAnimationFrame(() => {
      target.classList.remove("named");
      requestAnimationFrame(takeScreenshot);
    });
  });
}

onload = () => requestAnimationFrame(() => requestAnimationFrame(runTest));
</script>