<!DOCTYPE html>
<title>View transitions: event pseudo name</title>
<link rel="help" href="https://github.com/WICG/view-transitions">
<link rel="author" href="mailto:vmpstr@chromium.org">
<link rel="match" href="web-animations-api-ref.html">

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

<style>
:root { view-transition-name: none; }
#first {
  background: blue;
  width: 100px;
  height: 100px;
  contain:  paint;
  view-transition-name: shared;
}

html::view-transition-group(*),
html::view-transition-image-pair(*),
html::view-transition-new(*),
html::view-transition-old(*) {
  animation-duration: 600s;
}

@keyframes fade-in {
  from { opacity: 0; }
}
html::view-transition-image-pair(*) {
  animation: fade-in 600s both;
}

</style>
<div id=first></div>
<script>
async_test(t => {
  assert_implements(document.startViewTransition, "Missing document.startViewTransition");
  let names = [];
  document.documentElement.addEventListener("animationstart", (e) => {
    names.push(e.pseudoElement);
    if (names.length == 4) {
      t.step(() => assert_true(names.includes("::view-transition-group(shared)")));
      t.step(() => assert_true(names.includes("::view-transition-image-pair(shared)")));
      t.step(() => assert_true(names.includes("::view-transition-new(shared)")));
      t.step(() => assert_true(names.includes("::view-transition-old(shared)")));
      t.done();
    }
  });
  document.startViewTransition();
}, "verifies pseudo name includes a tag");

</script>

