chromium/third_party/blink/web_tests/external/wpt/pointerevents/pointerevent_predicted_coalesced_targets-manual.html

<!doctype html>
<html>
<head>
<title>Manual test for the target of predicted and coalesced events</title>
<script>

let counter = 0;
let host;
let shadowDiv;

function end(succeeded, txt) {
  host.removeEventListener("pointermove", moveListener);
  shadowDiv.removeEventListener("pointermove", moveListener);
  host.firstChild.textContent = txt;
  if (succeeded) {
    host.style.backgroundColor = "green";
  } else {
    host.style.backgroundColor = "red";
  }
}

function moveListener(event) {
  if (++counter > 50) {
    host.removeEventListener("pointermove", moveListener);
    shadowDiv.removeEventListener("pointermove", moveListener);
    host.firstChild.textContent = "done";
    end(true, "succeeded");
  }

  let cEvents = event.getCoalescedEvents();
  for (e of cEvents) {
    if (e.target != event.target) {
      end(false, "Coalesced events should have the same target as the parent event! " + e.target.id + "!=" + event.target.id);
      return;
    }
  }

  let pEvents = event.getPredictedEvents();
  for (e of pEvents) {
    if (e.target != event.target) {
      end(false, "Predicted events should have the same target as the parent event! " + e.target.id + "!=" + event.target.id);
      return;
    }
  }
}

function init() {
  host = document.getElementsByTagName("div")[0];
  let sr = host.attachShadow({mode: "open"});
  sr.innerHTML = '<div id="shadowDiv" style="border: 2px solid green; width: 200px; height: 200px;""><slot></slot></div>';
  shadowDiv = sr.firstChild;
  host.addEventListener("pointermove", moveListener);
  shadowDiv.addEventListener("pointermove", moveListener);
}

</script>
</head>
<body onload="init()">
<div id="host" style="border: 2px solid blue; width: 204px; height: 204px;">
  Move the pointer fast over this area.
</div>
</body>
</html>