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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /webidl/ecmascript-binding/has-instance.html - WPT Dashboard Interop Dashboard
<!doctype html>
<meta charset="utf-8">
<title>instanceof behavior</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<iframe></iframe>
<script>
test(function() {
var obj = Object.create(Element.prototype);
assert_true(obj instanceof Element);
assert_true(obj instanceof Node);
assert_false(obj instanceof Attr);
}, "Manually-constructed prototype chains are correctly handled by instanceof");
test(() => {
// This tests that the historical override of [[HasInstance]] was removed:
assert_false(document.body instanceof frames[0].Element);
}, "instanceof must return false across different globals, for platform objects");
test(() => {
assert_false(EventTarget.hasOwnProperty(Symbol.hasInstance));
}, "platform objects do not have Symbol.hasInstance installed");
</script>