third_party/blink/web_tests/editing/execCommand/4128080-2.html

<div id="description">This tests to make sure that copying and pasting a paragraph or less of content inside a header preserves the header element. To run it manually, Paste, then inspect the pasted content and verify that it's in an H1 element.</div>
<div id="copy"><h1>foo</h1></div>
<div id="paste" contentEditable="true"></div>

<script>

if (window.testRunner)
    testRunner.dumpAsText();

// Test 2: Verify that a header at the end of inserted content is preserved.
copy = document.getElementById("copy");
window.getSelection().setBaseAndExtent(copy, 0, copy, copy.childNodes.length);
document.execCommand("Copy");

paste = document.getElementById("paste");
window.getSelection().collapse(paste, 0);
document.execCommand("Paste");

expected = "<h1>foo</h1>";
actual = paste.innerHTML;

if (window.testRunner && actual == expected)
    document.body.innerText = "Success";
else
    document.body.innerText = "Failure.  Found: " + actual + ", but expected: " + expected;

</script>