chromium/third_party/blink/web_tests/editing/pasteboard/paste-as-plaintext-only-has-text.html

<!DOCTYPE html>
<html>
<head>
<script>
function log(s) {
  var console = document.getElementById('console');
  console.appendChild(document.createElement('div')).appendChild(document.createTextNode(s));
}
function startTest() {
  if (window.testRunner)
    testRunner.dumpAsText();
  document.body.addEventListener('copy', onCopy);
  document.body.addEventListener('paste', onPaste);
  document.execCommand('Copy');
  document.execCommand('PasteAndMatchStyle');
}
function onCopy(e) {
  e.clipboardData.setData('text', 'Hello');
  e.clipboardData.setData('text/html', 'World');
  e.preventDefault();
}
function onPaste(e) {
  log('Types: ' + e.clipboardData.types);
  log('text/plain: "' + e.clipboardData.getData('text/plain') + '"');
  log('text/html: "' + e.clipboardData.getData('text/html') + '"');
}
</script>
</head>
<body onload="startTest()">
<div>To run this test manually, simply try invoking the copy command on this
page followed by the paste as plain text command. If it works, text/plain should
be the only MIME type, 'Hello' should be associated with text/plain, and the
empty string should be associated with text/html.</div>
<div id="console"></div>
</body>
</html>