wheel-event-transactions-multiple-action-chains.html

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
<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>
<script src="scroll_support.js"></script>
<style>
body {
  margin: 0;
  padding: 0;
  height: 200vh;
}

#initial {
  background: red;
  width: 100%;
  height: 25px;
  padding: 0;
  margin: 0;
}

#second {
  background: green;
  width: 100%;
  height: 200vh;
  padding: 0;
  margin: 0;
}

</style>
<head>
<body>
<div id="initial"></div>
<div id="second"></div>
</body>

<script>

promise_test(async (t) => {
  await new Promise(resolve => addEventListener("load", resolve, {once: true}));

  await waitForCompositorReady();

  await waitForCompositorCommit();

  let firstEventTargets = [];
  let secondEventTargets = [];
  let isFirstGroup = true;
  window.addEventListener("wheel", (e) => {
    if (isFirstGroup) {
      firstEventTargets.push(e.target);
    } else {
      secondEventTargets.push(e.target);
    }
  }, {passive: true});

  await waitForCompositorCommit();

  // The first action chain should target the initial element
  await new test_driver.Actions()
    .addWheel("wheel1")
    .scroll(40, 2, 0, 30, {origin: "viewport"})
    .send();

  // Start logging event targets in the second transaction
  isFirstGroup = false;

  // The second chain should target the second element and the prior wheel event
  // group should have no impact on this action chain.
  await new test_driver.Actions()
    .addWheel("wheel1")
    .scroll(40, 30, 0, 30, {origin: "viewport"})
    .send();

  // TODO(dlrobertson): Use the scrollend event here to wait for the
  // wheel scroll to finish instead of waitForAnimationEnd().
  await waitForAnimationEnd(() => { return document.scrollingElement.scrollTop; });
  await waitForCompositorCommit();

  assert_greater_than(firstEventTargets.length, 0,
                      "There should be at least one event in the first transaction");
  assert_greater_than(secondEventTargets.length, 0,
                      "There should be at least one event in the second transaction");

  firstEventTargets.forEach((wheelEventTarget, i) => {
    assert_equals(wheelEventTarget, initial,
                  "Wheel event at index `" + i + "` did not target the initial element");
  });

  secondEventTargets.forEach((wheelEventTarget, i) => {
    assert_equals(wheelEventTarget, second,
                  "Wheel event at index `" + i + "` did not target the second element");
  });
}, "Two separate webdriver action chains should have different wheel event transactions");
</script>
</html>
chromium/third_party/blink/web_tests/external/wpt/dom/events/scrolling/wheel-event-transactions-multiple-action-chains.html
