css/css-overflow/scrollable-overflow-zero-one-axis.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Overflow: Scroll Length Calculated Correctly When One Axis Has Zero Length</title>
<link rel="author" title="David Shin" href="mailto:dshin@mozilla.com">
<link rel="author" title="Mozilla" href="http://www.mozilla.org/">
<link rel="help" href="https://drafts.csswg.org/css-overflow-3/#scrollable">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1800907">
<style>
.scroll {
  overflow: scroll;
}

.zero-h {
  width: 100px;
  height: 0px;
}

.zero-w {
  width: 0;
  height: 100px;
}

.flex-row {
  display: flex;
}

.flex-col {
  display: flex;
  flex-direction: column;
}

.grid {
  display: grid;
}
</style>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/check-layout-th.js"></script>
<body onload="checkLayout('.scroll')">
<div class="scroll zero-h" data-expected-scroll-height="100">
  <div class="zero-w"></div>
</div>
<div class="scroll zero-w" data-expected-scroll-width="100">
  <div class="zero-h"></div>
</div>

<div class="scroll zero-h flex-row" data-expected-scroll-height="100">
  <div class="zero-w"></div>
</div>
<div class="scroll zero-w flex-col" data-expected-scroll-width="100">
  <div class="zero-h"></div>
</div>

<div class="scroll zero-h grid" data-expected-scroll-height="100">
  <div class="zero-w"></div>
</div>
<div class="scroll zero-w grid" data-expected-scroll-width="100">
  <div class="zero-h"></div>
</div>