unreachable-snap-positions-001.html

<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/css-scroll-snap-1/#unreachable" />
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
div {
  position: absolute;
  margin: 0px;
}
#scroller {
  height: 500px;
  width: 500px;
  overflow: hidden;
  scroll-snap-type: both mandatory;
}
#unreachable {
  width: 300px;
  height: 300px;
  top: -100px;
  left: -100px;
  background-color: blue;
  scroll-snap-align: start;
}
#reachable {
  width: 300px;
  height: 300px;
  top: 400px;
  left: 400px;
  background-color: blue;
  scroll-snap-align: start;
}
</style>

<div id="scroller">
  <div style="width: 2000px; height: 2000px;"></div>
  <div id="unreachable"></div>
  <div id="reachable"></div>
</div>

<script>
test(() => {
  // Firstly move to the reachable snap position.
  scroller.scrollTo(400, 400);
  assert_equals(scroller.scrollLeft, 400);
  assert_equals(scroller.scrollTop, 400);

  // Then move to a position between the unreachable snap position and the
  // reachable position but closer to the unreachable one.
  scroller.scrollTo(100, 100);
  assert_equals(scroller.scrollLeft, 0);
  assert_equals(scroller.scrollTop, 0);
}, "Snaps to the positions defined by the element as much as possible");
</script>
chromium/third_party/blink/web_tests/external/wpt/css/css-scroll-snap/unreachable-snap-positions-001.html
