add WPT AddEventListenerOptions-once test

add reference comments for WPT tests

convert to common mustCall

Update test/parallel/test-eventtarget-whatwg-once.js

Co-authored-by: James M Snell <[email protected]>

Update test/parallel/test-eventtarget-whatwg-passive.js

Co-authored-by: James M Snell <[email protected]>

convert other tests to utilize common mustcall

improve test with bind

add customevent wpt

add no-unused-vars comment

reorder header

utilize common.mustcall

remove internal and use global EventTarget

test/parallel/test-eventtarget-whatwg-customevent.js

@@ -0,0 +1,33 @@
+'use strict';
+
+const common = require('../common');
+
+const { strictEqual, throws, equal } = require('assert');
+
+// Manually converted from https://github.com/web-platform-tests/wpt/blob/master/dom/events/CustomEvent.html
+// in order to define the `document` ourselves
+
+{
+  const type = 'foo';
+  const target = new EventTarget();
+
+  target.addEventListener(type, common.mustCall((evt) => {
+    strictEqual(evt.type, type);
+  }));
+
+  target.dispatchEvent(new Event(type));
+}
+
+{
+  throws(() => {
+    new Event();
+  }, TypeError);
+}
+
+{
+  const event = new Event('foo');
+  equal(event.type, 'foo');
+  equal(event.bubbles, false);
+  equal(event.cancelable, false);
+  equal(event.detail, null);
+}

test/parallel/test-eventtarget-whatwg-once.js

@@ -1,3 +1,5 @@
+// Flags: --expose-internals
+
 'use strict';
 
 const common = require('../common');
@@ -83,3 +85,50 @@ const {
   document.dispatchEvent(new Event('test'));
   strictEqual(invoked_count, 2, 'Once handler should only be invoked once');
 }
+
+// Manually converted from https://github.com/web-platform-tests/wpt/blob/master/dom/events/AddEventListenerOptions-once.html
+// in order to define the `document` ourselves
+
+{
+  const document = new EventTarget();
+
+  // Should only fire for first event
+  document.addEventListener('test', common.mustCall(1), { once: true });
+  // Should fire for both events
+  document.addEventListener('test', common.mustCall(2));
+  // Fire events
+  document.dispatchEvent(new Event('test'));
+  document.dispatchEvent(new Event('test'));
+}
+{
+  const document = new EventTarget();
+
+  const handler = common.mustCall(2);
+  // Both should only fire on first event
+  document.addEventListener('test', handler.bind(), { once: true });
+  document.addEventListener('test', handler.bind(), { once: true });
+  // Fire events
+  document.dispatchEvent(new Event('test'));
+  document.dispatchEvent(new Event('test'));
+}
+{
+  const document = new EventTarget();
+
+  const handler = common.mustCall(2);
+
+  // Should only fire once on first event
+  document.addEventListener('test', common.mustCall(1), { once: true });
+  // Should fire twice until removed
+  document.addEventListener('test', handler);
+  // Fire two events
+  document.dispatchEvent(new Event('test'));
+  document.dispatchEvent(new Event('test'));
+
+  // Should only fire once on the next event
+  document.addEventListener('test', common.mustCall(1), { once: true });
+  // The previous handler should no longer fire
+  document.removeEventListener('test', handler);
+
+  // Fire final event triggering
+  document.dispatchEvent(new Event('test'));
+}

test/parallel/test-eventtarget-whatwg-passive.js

@@ -2,13 +2,15 @@
 
 const common = require('../common');
 
+// Manually converted from https://github.com/web-platform-tests/wpt/blob/master/dom/events/AddEventListenerOptions-passive.html
+// in order to define the `document` ourselves
+
 const {
   fail,
   ok,
   strictEqual
 } = require('assert');
 
-// Manually ported from WPT AddEventListenerOptions-passive.html
 {
   const document = new EventTarget();
   let supportsPassive = false;