<!DOCTYPE html>
<html>
<body>
<button onclick="runTest()">1. Copy</button>
<div><br></div>
<div id="source" oncopy="copy(event)" contenteditable>dummy content</div>
<div id="destination" onpaste="paste(event)" contenteditable>2. Paste here</div>
<script>

const originalHTML = `<html xmlns:o="urn:schemas-microsoft-com:office:office"
xmlns:w="urn:schemas-microsoft-com:office:word"
xmlns:m="http://schemas.microsoft.com/office/2004/12/omml"
xmlns="http://www.w3.org/TR/REC-html40">

<head>
<style>
<!--
 /* Font Definitions */

 /* List Definitions */
@list l0
    {mso-list-id:1325861647;
    mso-list-type:hybrid;
    mso-list-template-ids:-1195895068 67698689 -655347914 67698693 67698689 67698691 67698693 67698689 67698691 67698693;}

ol
    {margin-bottom:0in;}
ul
    {margin-bottom:0in;}
-->
</style>
</head>

<p class=MsoListParagraphCxSpFirst style='text-indent:-.25in;mso-list:l0 level1 lfo1'><span
style='mso-bookmark:OLE_LINK1'><span style='mso-bookmark:OLE_LINK2'><![if !supportLists]><span
style='font-family:Symbol;mso-fareast-font-family:Symbol;mso-bidi-font-family:
Symbol'><span style='mso-list:Ignore'>Â·<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]>world<o:p></o:p></span></span></p>
`;
function copy(event) {
    event.clipboardData.setData('text/html', originalHTML);
    event.preventDefault();
}

function paste(event) {
    parent.postMessage({
        originalHTML,
        html: event.clipboardData.getData('text/html'),
        types: event.clipboardData.types,
        items: Array.from(event.clipboardData.items).map((item) => ({kind: item.kind, type: item.type})),
    }, '*');
}

function runTest() {
    if (window.internals)
        internals.withUserGesture(() => { document.getElementById('source').focus(); });
    document.execCommand('selectAll');
    document.execCommand('copy');
    if (window.internals)
        internals.withUserGesture(() => { document.getElementById('destination').focus(); });
    if (window.testRunner)
        document.execCommand('paste');
}

if (window.testRunner)
    runTest();

</script>
</body>
</html>
