<!DOCTYPE html>
<title>position:sticky elements should respect the right constraint</title>
<link rel="help" href="https://www.w3.org/TR/css-position-3/#sticky-pos" />
<meta name="assert" content="This test checks that position:sticky elements obey their right anchor after scrolling" />

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script src="../resources/sticky-util.js"></script>

<body></body>

<script>
test(() => {
  const elements = setupStickyTest('right', 25);
  elements.scroller.scrollLeft = 200;
  const nonStickyLeftX = elements.container.offsetLeft +
    elements.filler.clientWidth;
  assert_equals(elements.sticky.offsetLeft, nonStickyLeftX);
}, 'before reaching the sticking point the sticky box should not be offset');

test(() => {
  const elements = setupStickyTest('right', 25);
  elements.scroller.scrollLeft = 75;

  const nonStickyLeftX = elements.container.offsetLeft +
      elements.filler.clientWidth;
  const nonStickyRightX = nonStickyLeftX + elements.sticky.clientWidth;
  const targetRightX = elements.scroller.clientWidth +
      elements.scroller.scrollLeft - 25;
  const stickyOffset = nonStickyRightX - targetRightX;

  assert_equals(elements.sticky.offsetLeft, nonStickyLeftX - stickyOffset);
}, 'after reaching the sticking point the sticky box should be offset');

test(() => {
  const elements = setupStickyTest('right', 25);
  elements.scroller.scrollLeft = 15;
  assert_equals(elements.sticky.offsetLeft, elements.container.offsetLeft);
}, 'the sticky box should not be pushed outside its containing block');
</script>
