<script>
if (window.testRunner)
     testRunner.dumpEditingCallbacks();
</script>
<style>
div {
    border: 1px solid blue;
    margin: 4px;
}
</style>

<div id="test" contenteditable="true"><div>foo</div>bar<br></div>

<script>
var s = window.getSelection();
var e = document.getElementById("test");

s.setPosition(e, 0);

s.modify("move", "forward", "character");
s.modify("extend", "forward", "line");
s.modify("extend", "forward", "line");

document.execCommand("InsertHTML", false, "<div>foo</div><br class='Apple-interchange-newline'>");

</script>