<p>This tests moveTo{Beginning, End}OfLineAndModifySelection.  It should operate on line boundaries and not paragraph boundaries.  To run it manually, click inside the first line of the editable region below and do Command+Shift+Left/Right Arrow, the selection should extend to the start/end of the line, not the start/end of the paragraph.  Also, moveTo{Beginning, End}OfParagraphAndModifySelection should work.</p>
<div id="div" contenteditable="true" style="width: 200px;">The quick brown fox jumped over the lazy brown dog.</div>

<script>

if (window.layoutTestController) {

    window.layoutTestController.dumpEditingCallbacks();
    
    var div = document.getElementById("div");
    var text = div.firstChild;
    var sel = window.getSelection();
    
    sel.setPosition(text, text.length);
    layoutTestController.execCommand("MoveToBeginningOfLineAndModifySelection");
    
    sel.setPosition(text, 0);
    layoutTestController.execCommand("MoveToEndOfLineAndModifySelection");

    sel.setPosition(text, text.length);
    layoutTestController.execCommand("MoveToBeginningOfParagraphAndModifySelection");
    
    sel.setPosition(text, 0);
    layoutTestController.execCommand("MoveToEndOfParagraphAndModifySelection");
}
</script>