chromium/third_party/blink/web_tests/external/wpt/html/semantics/forms/the-input-element/event-select-manual.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>HTMLInputElement Test: select event</title>
<link rel="author" title="Intel" href="www.intel.com/">
<meta name="flags" content="interact">
<link rel="help" href="https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#dom-textarea/input-select">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<form id="testForm" name="testForm">
  <input id="testInput" type="text" value="0123456789"/>
</form>

<h2>Description</h2>
<p>
  This test validates that select characters in input element should fired select event.
</p>

<h2>Test steps:</h2>
<ol>
  <li>
    Select any numeric characters in the input flag below
  </li>
</ol>

<script>

let input = document.getElementById("testInput");

setup({explicit_done : true, explicit_timeout : true});

on_event(input, "select", evt => {
  test(() => {
    assert_greater_than(input.value.substring(input.selectionStart, input.selectionEnd).length, 0, "Check if the select event captured when text selected");
  });
  done();
});

</script>