<DOCTYPE html>
<html>
<body>
<script src="../../../resources/js-test.js"></script>
<script>
description("Event listeners are to be removed with immediate effect by document.open()");

const frame = document.body.appendChild(document.createElement("iframe"));
let once = false;
frame.contentDocument.addEventListener("x", () => {
    frame.contentDocument.open();
    once = true;
});
frame.contentDocument.addEventListener("x", function() {
    testFailed("second event listener not removed")
});
frame.contentDocument.dispatchEvent(new Event("x"));
shouldBeTrue("once");
frame.contentDocument.close();
</script>
</html>