src/third_party/web_platform_tests/dom/events/Event-dispatch-handlers-changed.html

<!DOCTYPE html>
<meta charset=utf-8>
<title> Dispatch additional events inside an event listener </title>
<link rel="help" href="https://dom.spec.whatwg.org/#concept-event-dispatch">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id=log></div>

<table id="table" border="1" style="display: none">
    <tbody id="table-body">
    <tr id="table-row">
        <td id="table-cell">Shady Grove</td>
        <td>Aeolian</td>
    </tr>
    <tr id="parent">
        <td id="target">Over the river, Charlie</td>
        <td>Dorian</td>
    </tr>
    </tbody>
</table>

<script>
async_test(function() {
  var event_type = "bar";
  var target = document.getElementById("target");
  var parent = document.getElementById("parent");
  var tbody = document.getElementById("table-body");
  var table = document.getElementById("table");
  var body = document.body;
  var html = document.documentElement;
  var targets = [window, document, html, body, table, tbody, parent, target];
  var expected_targets = [
    window,
    document,
    html,
    body,
    table,
    tbody,
    parent,
    target,
    target,
    parent,
    tbody,
    table,
    body,
    html,
    document,
    window
  ];
  var expected_listeners = [0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1];

  var actual_targets = [], actual_listeners = [];
  var test_event_function = function(i) {
    return this.step_func(function(evt) {
      actual_targets.push(evt.currentTarget);
      actual_listeners.push(i);

      if (evt.eventPhase != evt.BUBBLING_PHASE && evt.currentTarget.foo != 1) {
        evt.currentTarget.removeEventListener(event_type, event_handlers[0], true);
        evt.currentTarget.addEventListener(event_type, event_handlers[2], true);
        evt.currentTarget.foo = 1;
      }

      if (evt.eventPhase != evt.CAPTURING_PHASE && evt.currentTarget.foo != 3) {
        evt.currentTarget.removeEventListener(event_type, event_handlers[0], false);
        evt.currentTarget.addEventListener(event_type, event_handlers[3], false);
        evt.currentTarget.foo = 3;
      }
    });
  }.bind(this);
  var event_handlers = [
    test_event_function(0),
    test_event_function(1),
    test_event_function(2),
    test_event_function(3),
  ];

  for (var i = 0; i < targets.length; ++i) {
    targets[i].addEventListener(event_type, event_handlers[0], true);
    targets[i].addEventListener(event_type, event_handlers[1], false);
  }

  var evt = document.createEvent("Event");
  evt.initEvent(event_type, true, true);
  target.dispatchEvent(evt);

  assert_array_equals(actual_targets, expected_targets, "actual_targets");
  assert_array_equals(actual_listeners, expected_listeners, "actual_listeners");

  this.done();
});
</script>