Source code
Revision control
Copy as Markdown
Other Tools
<!DOCTYPE HTML>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <script src="apz_test_utils.js"></script>
  <script src="apz_test_native_event_utils.js"></script>
  <script src="/tests/SimpleTest/paint_listener.js"></script>
  <style>
  html {
    scroll-snap-type: x mandatory;
    overflow: scroll;
    scroll-behavior: smooth;
  }
  /*
   * Layout three child divs horizontally.
   * Each div has a horizontal snap point, but
   * doesn't have any vertical valid snap point.
   */
  .container {
    flex-direction: row;
    display: flex;
    width: 100vw;
    height: 30vh;
  }
  .container div {
    background-color: grey;
    width: 30vw;
    height: 100%;
    margin: 10px;
    scroll-snap-align: none center;
    scroll-snap-stop: always;
  }
  </style>
</head>
<body>
  <div class="container">
    <div></div>
    <div></div>
    <div></div>
  </div>
  <div style="height: 200vh"></div>
</body>
<script type="application/javascript">
async function test() {
  const container = document.querySelector(".container");
  const scrollendPromise = promiseOneEvent(window, "scrollend");
  // Try to scroll down by a wheel event.
  synthesizeNativeWheel(container, 50, 50, 0, -50);
  // Wait for the end of the smooth scrolling triggered by above wheel event.
  await scrollendPromise;
  ok(window.scrollY, "`scroll-snap-type: x mandatory` doesn't trap vertical scrolling");
}
if (getPlatform() == "android") {
  ok(true, "Skipping test because native wheel events are not supported on Android");
  subtestDone();
} else if (getPlatform() == "linux") {
  subtestDone();
} else {
  waitUntilApzStable()
  .then(test)
  .then(subtestDone, subtestFailed);
}
</script>
</html>