MutationObserver-disconnect.html

Enable keyboard shortcuts

This WPT test may be referenced by the following Test IDs:
- /dom/nodes/MutationObserver-disconnect.html - WPT Dashboard Interop Dashboard

<!DOCTYPE HTML>

<meta charset=utf-8>

<title>MutationObservers: disconnect</title>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<h1>MutationObservers: disconnect</h1>

<div id="log"></div>

<section style="display: none">

<p id='n00'></p>

</section>

<script>

var n00 = document.getElementById('n00');

var parentTest = async_test("subtree mutations");

function masterMO(sequence, obs) {

  parentTest.step(function() {

    assert_equals(sequence.length, 4, "mutation records must match");

});

  parentTest.done();

parentTest.step(function() {

  (new MutationObserver(masterMO)).observe(n00.parentNode, {"subtree": true, "attributes": true});

});

var disconnectTest = async_test("disconnect discarded some mutations");

function observerCallback(sequence, obs) {

  disconnectTest.step(function() {

    assert_equals(sequence.length, 1);

    assert_equals(sequence[0].type, "attributes");

    assert_equals(sequence[0].attributeName, "id");

    assert_equals(sequence[0].oldValue, "latest");

    disconnectTest.done();

});

var observer;

disconnectTest.step(function() {

  observer = new MutationObserver(observerCallback);

  observer.observe(n00, {"attributes": true});

  n00.id = "foo";

  n00.id = "bar";

  observer.disconnect();

  observer.observe(n00, {"attributes": true, "attributeOldValue": true});

  n00.id = "latest";

  observer.disconnect();

  observer.observe(n00, {"attributes": true, "attributeOldValue": true});

  n00.id = "n0000";

});

</script>