(document.documentElement);
  const actualText = selection.toString().trim();
  assert_equals(actualText, expectedText);
}

test(function() {
  checkSelection("dialog child");
}, "Modal dialog only marks outside nodes as inert");

test(function() {
  child.inert = true;
  this.add_cleanup(() => { child.inert = false; });
  checkSelection("dialog");
}, "Inner nodes with 'inert' attribute become inert anyways");

test(function() {
  dialog.inert = true;
  this.add_cleanup(() => { dialog.inert = false; });
  c