chromium/third_party/blink/web_tests/fast/forms/label/label-selection-by-dragging.html

<!DOCTYPE html>
<html>
<script src="../../../resources/js-test.js"></script>

<label id="labelWithInput" for="inputText">Some, Text associated with input</label>
<input type="checkbox" id="checkbox" checked>

<script>
description('Test the value of checkbox after selecting the associated label\'s text');

var labelElement = document.getElementById('labelWithInput');
var checkbox = document.getElementById('checkbox');

testByDraggingOnLabel(labelElement);

// As checkbox is already checked, dragging over the label text,
// should only select the text and not change the value of
// checkbox.
shouldBeTrue('checkbox.checked');

// To check if selection happened or not.
shouldBeEqualToString('window.getSelection().toString()', 'Some, Text associated with input');

labelElement.style.display = 'none';

function testByDraggingOnLabel(element)
{
    eventSender.mouseMoveTo(element.offsetLeft, element.offsetTop + element.offsetHeight / 2);
    eventSender.mouseDown();
    eventSender.mouseMoveTo(element.offsetLeft + element.offsetWidth, element.offsetTop + element.offsetHeight / 2);
    eventSender.mouseUp();
}
</script>
</html>