<!doctype html>
<head>
<meta charset=utf-8>
<title>Modify HTMLScriptElement's text after #prepare-a-script that violates CSP</title>
<link rel=help href="https://html.spec.whatwg.org/multipage/scripting.html#prepare-a-script">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<meta http-equiv="content-security-policy" content="script-src
  'nonce-allow'
  'sha256-2+5xh6b9uuIi4GaJtmHWtgR2nwRXJpBtMY4nVaOBpfc='
">
<!-- The hash is that of the original content of `script0`. -->

<script nonce="allow">
window.t = async_test("Modify inline script element's text " +
                   "after prepare-a-script before evaluation (CSP)");

const updatedText =
  't.unreached_func("CSP check was done against the original text but the updated text was evaluated")();';

function changeScriptText() {
  document.querySelector('#script0').textContent = updatedText;
}

t.step_timeout(changeScriptText, 500);
</script>

<!-- This is "a style sheet that is blocking scripts" and thus ... -->
<link rel="stylesheet" href="/common/slow.py?pipe=trickle(d1)"></link>

<!-- This inline script becomes a parser-blocking script, and thus
the step_timeout is evaluated after script0 is inserted into DOM,
prepare-a-script'ed, but before its evaluation. -->
<script id="script0">
t.step(() => {
    // When this is evaluated after the stylesheet is loaded,
    // script0's textContent is modified by the async script above,
    // but the evaluated script is still the original script here,
    // not what is overwritten, because "child text content" is taken in
    // #prepare-a-script and passed to "creating a classic script".
    var s = document.getElementById('script0');
    assert_equals(s.textContent, updatedText,
                  "<script>'s textContent should be already modified");
    t.done();
  });
</script>
<script nonce="allow">
// If this makes the test fail, it indicates `script0` (the original or updated
// text) was not evaluated, probably blocked by CSP that was checked against the
// updated text.
t.unreached_func("CSP check was done against the updated text")();
</script>
