<!DOCTYPE html>
<html>
<body>
<script src="../../../resources/js-test-pre.js"></script>
<div id="testDiv"><p></p><p></p></div>
<script>
description("Tests that calls of insertBefore() lead to mutation events even if they are no-ops.");
jsTestIsAsync = true;

var testDiv = document.getElementById("testDiv");
var p1 = testDiv.firstChild;
var p2 = testDiv.lastChild;

var operations = [
    function() { testDiv.insertBefore(p1, p1); },
    function() { testDiv.insertBefore(p1, p2); }
];
var currentOperation = 0;

function testMutationObserver()
{
    var config = { childList: true };
    var observer = new MutationObserver(function(mutations) {
        testPassed("Mutation observer was notified");
        observer.disconnect();
        testMutationEventListener();
    });

    observer.observe(testDiv, config);
    operations[currentOperation]();
}

function subtreeModifiedHandler()
{
    wasMutationEventListenerCalled = true;
}

function testMutationEventListener()
{
    wasMutationEventListenerCalled = false;
    testDiv.addEventListener("DOMSubtreeModified", subtreeModifiedHandler);
    operations[currentOperation]();
    shouldBeTrue("wasMutationEventListenerCalled");
    testDiv.removeEventListener("DOMSubtreeModified", subtreeModifiedHandler);

    currentOperation++;
    if (currentOperation < operations.length)
        testMutationObserver();
    else
        finishJSTest();
}

testMutationObserver();
</script>
<script src="../../../resources/js-test-post.js"></script>
</body>
</html>