chromium/third_party/blink/web_tests/editing/inserting/line-break.html

<!doctype html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../assert_selection.js"></script>
<script>
// This testcase used to break InsertLineBreak. The editable should have two
// empty paragraphs in it, and the caret should be in the second.
selection_test(
    [
        '<div contenteditable>',
            '<div>|<br></div>',
        '</div>',
    ],
    'InsertLineBreak',
    [
        '<div contenteditable>',
            '<div><br>|<br></div>',
        '</div>',
    ]);
</script>