AddEventListenerOptions-once.any.js

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This WPT test may be referenced by the following Test IDs:
- /dom/events/AddEventListenerOptions-once.any.html - WPT Dashboard Interop Dashboard
- /dom/events/AddEventListenerOptions-once.any.worker.html - WPT Dashboard Interop Dashboard

// META: title=AddEventListenerOptions.once

"use strict";

test(function() {

  var invoked_once = false;

  var invoked_normal = false;

  function handler_once() {

    invoked_once = true;

  function handler_normal() {

    invoked_normal = true;

  const et = new EventTarget();

  et.addEventListener('test', handler_once, {once: true});

  et.addEventListener('test', handler_normal);

  et.dispatchEvent(new Event('test'));

  assert_equals(invoked_once, true, "Once handler should be invoked");

  assert_equals(invoked_normal, true, "Normal handler should be invoked");

  invoked_once = false;

  invoked_normal = false;

  et.dispatchEvent(new Event('test'));

  assert_equals(invoked_once, false, "Once handler shouldn't be invoked again");

  assert_equals(invoked_normal, true, "Normal handler should be invoked again");

  et.removeEventListener('test', handler_normal);

}, "Once listener should be invoked only once");

test(function() {

  const et = new EventTarget();

  var invoked_count = 0;

  function handler() {

    invoked_count++;

    if (invoked_count == 1)

    et.dispatchEvent(new Event('test'));

  et.addEventListener('test', handler, {once: true});

  et.dispatchEvent(new Event('test'));

  assert_equals(invoked_count, 1, "Once handler should only be invoked once");

  invoked_count = 0;

  function handler2() {

    invoked_count++;

    if (invoked_count == 1)

      et.addEventListener('test', handler2, {once: true});

    if (invoked_count <= 2)

      et.dispatchEvent(new Event('test'));

  et.addEventListener('test', handler2, {once: true});

  et.dispatchEvent(new Event('test'));

  assert_equals(invoked_count, 2, "Once handler should only be invoked once after each adding");

}, "Once listener should be invoked only once even if the event is nested");

test(function() {

  var invoked_count = 0;

  function handler() {

    invoked_count++;

  const et = new EventTarget();

  et.addEventListener('test', handler, {once: true});

  et.addEventListener('test', handler);

  et.dispatchEvent(new Event('test'));

  assert_equals(invoked_count, 1, "The handler should only be added once");

  invoked_count = 0;

  et.dispatchEvent(new Event('test'));

  assert_equals(invoked_count, 0, "The handler was added as a once listener");

  invoked_count = 0;

  et.addEventListener('test', handler, {once: true});

  et.removeEventListener('test', handler);

  et.dispatchEvent(new Event('test'));

  assert_equals(invoked_count, 0, "The handler should have been removed");

}, "Once listener should be added / removed like normal listeners");

test(function() {

  const et = new EventTarget();

  var invoked_count = 0;

  for (let n = 4; n > 0; n--) {

    et.addEventListener('test', (e) => {

      invoked_count++;

      e.stopImmediatePropagation();

    }, {once: true});

  for (let n = 4; n > 0; n--) {

    et.dispatchEvent(new Event('test'));

  assert_equals(invoked_count, 4, "The listeners should be invoked");

}, "Multiple once listeners should be invoked even if the stopImmediatePropagation is set");