chromium/third_party/blink/web_tests/external/wpt/html/webappapis/dynamic-markup-insertion/document-write/iframe_008.html

<!doctype html>
<title>document.write plaintext into iframe</title>
<script src="/resources/testharness.js"></script><script src="/resources/testharnessreport.js"></script>
<iframe id="test"></iframe>
<script>
test(function() {
  var iframe = document.getElementById("test");
  var s = "<plaintext><span>Filler Text";
  for (var i=0; i<s.length; i++) {
    iframe.contentDocument.write(s[i]);
  }
  iframe.contentDocument.close();
  assert_equals(iframe.contentDocument.body.childNodes[0].nodeType, document.ELEMENT_NODE);
  assert_equals(iframe.contentDocument.body.childNodes[0].localName, "plaintext");
  assert_equals(iframe.contentDocument.body.childNodes[0].textContent, "<span>Filler Text");
});
</script>
<div id="log"></div>