user-invalid-form-submission-invalidation.html

<!DOCTYPE html>
<html class=reftest-wait>
<link rel=author href="mailto:[email protected]">
<link rel=help href="https://issues.chromium.org/issues/357889498">
<link rel=match href="user-invalid-form-submission-invalidation-ref.html">

<style>
input:user-invalid {
  border: 3px solid red;
}
input:user-valid {
  border: 3px solid green;
}
</style>

<form>
  <input required>
  <input required>
  <input>
  <button>submit</button>
</form>

<script>
requestAnimationFrame(() => {
  document.querySelector('button').click();
  document.documentElement.classList.remove('reftest-wait');
});
</script>

chromium/third_party/blink/web_tests/external/wpt/css/selectors/user-invalid-form-submission-invalidation.html