chromium/third_party/blink/web_tests/editing/inserting/4278698.html

<html> 
<head>

<link rel=stylesheet href="../editingStyle.css" type="text/css">
<script src=../editing.js language="JavaScript" type="text/JavaScript" ></script>

<script>

function editingTest() {
    moveSelectionForwardByCharacterCommand();
    moveSelectionForwardByCharacterCommand();
    typeCharacterCommand(' ');
}

</script>

<title>Adding a space inside whitespace:pre text collapses space</title> 
</head> 
<body>

<p>This tests to see if inserting a space inside normal whitespace inside of a whitespace:pre element will collapse other spaces surrounding it.</p>
<p>If successful, you should see 'a' followed by 10 spaces followed by 'b'.</p>

<hr>

<div contenteditable id="root" style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space;">
<pre id="test" class="editing">a         b</pre>
</div>

<script>
runEditingTest();
</script>

</body>
</html>