interface-prototype-constructor-set-receiver.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>Interface.prototype.constructor is defined on [[Set]] receiver</title>
<link rel="help" href="https://webidl.spec.whatwg.org/#interface-prototype-object">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
"use strict";
const testValue = Object.freeze(function() {});

test(() => {
  Location.prototype.constructor = testValue;
  assert_false(Location.prototype.propertyIsEnumerable("constructor"));

  HTMLDocument.prototype.constructor = testValue;
  assert_false(HTMLDocument.prototype.propertyIsEnumerable("constructor"));

  HTMLDivElement.prototype.constructor = testValue;
  assert_false(HTMLDivElement.prototype.propertyIsEnumerable("constructor"));
}, "Direct [[Set]] preserves [[Enumerable]]: false property attribute");

test(() => {
  window.constructor = testValue;
  assert_equals(window.constructor, testValue);
  assert_equals(Window.prototype.constructor, Window);

  navigator.constructor = testValue;
  assert_equals(navigator.constructor, testValue);
  assert_equals(Navigator.prototype.constructor, Navigator);

  const span = document.createElement("span");
  span.constructor = testValue;
  assert_equals(span.constructor, testValue);
  assert_equals(HTMLSpanElement.prototype.constructor, HTMLSpanElement);
}, "Prototype chain [[Set]] creates property on receiver");
</script>

chromium/third_party/blink/web_tests/external/wpt/webidl/ecmascript-binding/interface-prototype-constructor-set-receiver.html