MutationObserver-disconnect.html
<!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>