pointerevent_hit_test_scroll_visible_descendant.html

<!doctype html>
<meta charset=utf-8>
<title>pointer-events: auto descendant correctly targets scrolls</title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<style>
  body {
    height: 200vh;
  }

  #overlay {
    overflow: auto;
    height: 300px;
    border: 2px solid blue;
    pointer-events: none;
  }

  #scrollable {
    background: white;
    border: 3px solid green;
    height: 150px;
    /* pointer-events: auto; should allow scrolling over this element. */
    pointer-events: auto;
  }

  #spacer {
    height: 200vh;
  }

</style>

<body id="body">
  <div id="overlay">
    <div id="scrollable"></div>
    <div id="spacer"></div>
  </div>
</body>
<script>
  promise_test(async (t) => {
    let scrolled = new Promise((resolve) => {
      let scrollers = [window, document.getElementById("overlay")];
      let onscroll = (evt) => {
        for (const scroller of scrollers) {
          scroller.removeEventListener("scroll", onscroll);
        }
        resolve(evt.target.id || "root");
      }
      for (const scroller of scrollers) {
        scroller.addEventListener("scroll", onscroll);
      }
    });
    const actions = new test_driver.Actions().scroll(50, 50, 0, 50, { duration: 50 });
    actions.send();
    assert_equals(await scrolled, "overlay", "Incorrect element scrolled");
  }, "Wheel-scroll over pointer-events: auto descendant scrolls pointer-events: none scroller.");
</script>
chromium/third_party/blink/web_tests/external/wpt/pointerevents/pointerevent_hit_test_scroll_visible_descendant.html
