<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="support/helper.sub.js"></script>

<body>
<script>
  test(t => {
    const empty = trustedTypes.emptyHTML;
    assert_true(trustedTypes.isHTML(empty));
    assert_equals(empty.toString(), "");
  }, 'trustedTypes.emptyHTML returns the intended value.');

  test(t => {
    try { trustedTypes.emptyHTML = 'fake'; } catch { }
    assert_true(trustedTypes.isHTML(trustedTypes.emptyHTML));
    assert_equals(trustedTypes.emptyHTML.toString(), "");
  }, 'trustedTypes.emptyHTML cannot be redefined.');

  test(t => {
    try { Object.defineProperty(TrustedTypes, 'emptyHTML', 'fake'); } catch { }
    assert_true(trustedTypes.isHTML(trustedTypes.emptyHTML));
    assert_equals(trustedTypes.emptyHTML.toString(), "");
  }, 'trustedTypes.emptyHTML cannot be redefined via defineProperty.');

  test(t => {
    const empty = trustedTypes.emptyScript;
    assert_true(trustedTypes.isScript(empty));
    assert_equals(empty.toString(), "");
  }, 'trustedTypes.emptyScript returns the intended value.');

  test(t => {
    try { trustedTypes.emptyScript = 'fake'; } catch { }
    assert_true(trustedTypes.isScript(trustedTypes.emptyScript));
    assert_equals(trustedTypes.emptyScript.toString(), "");
  }, 'trustedTypes.emptyScript cannot be redefined.');

  test(t => {
    try { Object.defineProperty(TrustedTypes, 'emptyScript', 'fake'); } catch { }
    assert_true(trustedTypes.isScript(trustedTypes.emptyScript));
    assert_equals(trustedTypes.emptyScript.toString(), "");
  }, 'trustedTypes.emptyScript cannot be redefined via defineProperty.');
</script>
