suppress-mutation-events-in-shadow.html

<!DOCTYPE html>
<body>
<input>
<script src="../../../../../resources/js-test.js"></script>
<script>
description('Test that mutation events are not triggered in shadow DOM');
var mutationEventTriggered = false;
function doTest() {
    var input = document.querySelector('input');
    var shadowRoot = internals.shadowRoot(input);
    var firstChild = shadowRoot.firstChild;
    firstChild.addEventListener('DOMNodeInserted', function(evt) {
        mutationEventTriggered = true;
    });
    input.value = 'hello';
    shouldBeFalse('mutationEventTriggered');
}

if (window.internals)
    doTest();
else
    testFailed('This test only runs in DRT');
</script>
</body>

chromium/third_party/blink/web_tests/dom/mutation-event-tests/fast/dom/shadow/suppress-mutation-events-in-shadow.html