cludes("after"));
  }, "Regression test: Bypass via insertAdjacentText, textContent.");

  // Variant: Create a <script> element and create & insert a text node. Then
  // insert it into the document container to make it live.
  promise_test(async t => {
    // Setup: Create a <script> element, and insert text via a text node.
    let s = createScriptElement();
    let text = document.createTextNode("postMessage('appendChild with a " +
                                       "text node should be blocked', '*