<!DOCTYPE html>
<meta charset="utf-8">
<title>ScrollTimeline current time algorithm - NaN cases</title>
<link rel="help" href="https://wicg.github.io/scroll-animations/#current-time-algorithm">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<style>
.scroller {
  height: 100px;
  width: 100px;
  overflow: auto;
}

.content {
  height: 500px;
  width: 500px;
}
</style>

<div id='inlineScroller' class='scroller' style='display: inline;'>
  <div class='content'></div>
</div>
<script>
'use strict';

test(function() {
  const scroller = document.querySelector('#inlineScroller');
  const scrollTimeline = new ScrollTimeline(
      { source: scroller, orientation: 'block' });

  assert_equals(scrollTimeline.currentTime, null);
}, 'currentTime should be null for a display: inline source');
</script>

<div id='displayNoneScroller' class='scroller' style='display: none;'>
  <div class='content'></div>
</div>
<script>
test(function() {
  const scroller = document.querySelector('#displayNoneScroller');
  const scrollTimeline = new ScrollTimeline(
      { source: scroller, orientation: 'block' });

  assert_equals(scrollTimeline.currentTime, null);
}, 'currentTime should be null for a display: none source');
</script>

<script>
test(function() {
  const scroller = document.createElement('div');
  const content = document.createElement('div');

  scroller.style.overflow = 'auto';
  scroller.style.height = '100px';
  scroller.style.width = '100px';
  content.style.height = '250px';
  content.style.width = '250px';

  scroller.appendChild(content);

  const scrollTimeline = new ScrollTimeline(
      { source: scroller, orientation: 'block' });

  assert_equals(scrollTimeline.currentTime, null);
}, 'currentTime should be null for an unattached source');
</script>

<div id='notAScroller' class='scroller' style='overflow: visible;'>
  <div class='content'></div>
</div>
<script>
test(function() {
  const scroller = document.querySelector('#notAScroller');
  const scrollTimeline = new ScrollTimeline(
      { source: scroller, orientation: 'block' });

  assert_equals(scrollTimeline.currentTime, null);
}, 'currentTime should be null when the source is not a scroller');
</script>
