chromium/third_party/blink/web_tests/external/wpt/uievents/mouse/mouseover-at-removing-mousedown-target.html

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta name="timeout" content="long">
<meta name="variant" content="?duration=16"> <!-- 60fps -->
<meta name="variant" content="?duration=42"> <!-- 24fps -->
<title>Check whether `mouseup` events are fired after pending boundary events</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script src=/resources/testdriver.js></script>
<script src=/resources/testdriver-actions.js></script>
<script src=/resources/testdriver-vendor.js></script>
<style>
div#parent {
  width: 100%;
  height: 50px;
  background-color: gray;
}
div#child {
  width: 100%;
  height: 40px;
  background-color: lime;
}
</style>
</head>
<body>
<div id="parent"><div id="child"></div></div>
<script>
"use strict";

const searchParams = new URLSearchParams(document.location.search);
const duration = parseInt(searchParams.get("duration"));

async function runTest(t) {
  const parent = document.getElementById("parent");
  const child = document.getElementById("child");
  const mouseEvents = [];
  function onMouseOverOrUp(event) {
    // Ignore events before `mousedown` to make this test simpler.
    if (mouseEvents[0]?.startsWith("mousedown")) {
      mouseEvents.push(`${event.type}@${event.target.localName}${event.target.id ? `#${event.target.id}` : ""}`);
    }
  }
  try {
    child.getBoundingClientRect(); // flush layout
    child.addEventListener("mousedown", event => {
      event.target.remove();
      mouseEvents.push("mousedown@div#child");
    }, {once: true});
    document.addEventListener("mouseover", onMouseOverOrUp, {capture: true});
    document.addEventListener("mouseup", onMouseOverOrUp, {once: true, capture: true});
    const actions = new test_driver.Actions(duration);
    await actions.pointerMove(10, 10, {origin: child})
                .pointerDown({button: actions.ButtonType.LEFT})
                .pointerUp({button: actions.ButtonType.LEFT})
                .send();
    await new Promise(resolve => requestAnimationFrame(() => requestAnimationFrame(resolve)));
    assert_equals(
      mouseEvents.toString(),
      "mousedown@div#child,mouseover@div#parent,mouseup@div#parent",
      t.name
    );
  } finally {
    document.removeEventListener("mouseover", onMouseOverOrUp, {capture: true});
    parent.appendChild(child);
  }
}

// This test tries to detect intermittent case that mouseout might be fired
// after a while from a DOM tree change.  Therefore, trying same test 30 times.
for (let i = 0; i < 30; i++) {
  promise_test(async t => {
    await runTest(t);
    // Make things stabler to start next test.
    await new Promise(resolve => requestAnimationFrame(() => requestAnimationFrame(resolve)));
  }, `mouseover should be fired before mouseup if mousedown target is removed (${i})`);
}
</script>
</body>
</html>