<!DOCTYPE html>
<meta charset="utf-8">
<title>scrollIntoView on a scroller does not scroll the targeted scroll container</title>
<link rel="help" href="https://drafts.csswg.org/cssom-view/#dom-element-scrollintoview">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
  .scroller {
    overflow: scroll;
    position: relative;
    border: 2px solid black;
  }
  #outer {
    width: 300px;
    height: 400px;
    border-color: blue;
  }
  #inner {
    height: 200px;
    border-color: red;
    background: lightgreen;
    /* Scroll padding on the inner scroller makes the scroll into view
     * position of content within non-zero. */
    scroll-padding: 50px;
    /* Scroll margin is the offset in the outer scroller to preserve. */
    scroll-margin: 20px;
  }
  .spacer {
    height: 1000px;
  }
</style>

<div id="outer" class="scroller">
  <div class="spacer"></div>
  <div id="inner" class="scroller">
    <div class="spacer"></div>
  </div>
  <div class="spacer"></div>
</div>

<script>
  promise_test(async t => {
    const outerScroller = document.getElementById('outer');
    const innerScroller = document.getElementById('inner');

    innerScroller.scrollTop = 200;
    innerScroller.scrollIntoView();

    assert_equals(innerScroller.offsetTop - outerScroller.scrollTop, 20, "Should scroll inner scroller to scroll margin offset.");
    assert_equals(innerScroller.scrollTop, 200, "Inner scroller should not scroll when asked to scroll into view.");
  }, "scrollIntoView on a scrolling container should scroll its outer scrollers into view but not scroll itself.");
</script>