infrastructure/testdriver/send_keys.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>TestDriver send keys method</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>

<input type="text" id="text">Text Input</button>

<script>
async_test(t => {
  let input_text = "Hello, wpt!";
  let text_box = document.getElementById("text");
  test_driver
    .send_keys(text_box, input_text)
    .then(() => {
      assert_equals(text_box.value, input_text);
      t.done();
    })
    .catch(t.unreached_func("send keys failed"));
});
</script>