<meta charset=utf-8>
<style>
.container {
  display: flex;
}
.flex-item {
  word-wrap: break-word;
  white-space: pre-wrap;
  word-break: break-all;
}
span {
  padding-right: 0.1px;
}
</style> 
PASS if no assert in debug.
<div class=container><div class=flex-item><span>​</span></div></div>
<script>
if (window.testRunner)
  testRunner.dumpAsText();
</script>