chromium/third_party/blink/web_tests/external/wpt/html/webappapis/dynamic-markup-insertion/document-write/iframe_010.html

<!doctype html>
<title>document.write plaintext</title>
<script src="/resources/testharness.js"></script><script src="/resources/testharnessreport.js"></script>
<iframe id="test"></iframe>
<script>
var t = async_test();
var iframe = document.getElementById("test");

function check_dom() {
  assert_equals(iframe.contentDocument.body.childNodes[0].localName, "plaintext")
  assert_equals(iframe.contentDocument.body.childNodes[0].textContent, "Filler ")
  assert_equals(iframe.contentDocument.body.childNodes[1].localName, "table")
}

t.step(function() {
  var s = "<script>document.write('<table><plaintext>Filler '); document.close(); top.t.step(function() {top.check_dom()})</script" + ">";
  for (var i=0; i<s.length; i++) {
    iframe.contentDocument.write(s[i]);
  }
  t.done();
});
</script>
<div id="log"></div>