<!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 => {
    assert_equals(window.trustedTypes.defaultPolicy, null);
  }, "defaultPolicy with no default created is not an error");

  test(t => {
    let policy = window.trustedTypes.createPolicy('default', { createHTML: s => s } );
    assert_true(policy instanceof TrustedTypePolicy);
    assert_equals(policy, window.trustedTypes.defaultPolicy);
  }, "defaultPolicy returns the correct default policy");

  test(t => {
    let foo_policy = window.trustedTypes.createPolicy('foo', { createHTML: s => s } );
    let default_policy = window.trustedTypes.defaultPolicy;
    window.trustedTypes.defaultPolicy = foo_policy;
    assert_equals(window.trustedTypes.defaultPolicy, default_policy);
    assert_not_equals(window.trustedTypes.defaultPolicy, foo_policy);
  }, "defaultPolicy is a read-only property");
</script>