Add tests for constructible/subclassable EventTarget

Follows whatwg/dom#467.
web-platform-tests · Jun 21, 2017 · 8b68607 · 8b68607
1 parent 516de1c
commit 8b68607
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Showing 3 changed files with 73 additions and 1 deletion.
diff --git a/dom/events/EventTarget-constructible.html b/dom/events/EventTarget-constructible.html
@@ -0,0 +1,71 @@
+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>EventTarget is constructible and subclassable</title>
+<meta name="author" title="Domenic Denicola" href="mailto:d@domenic.me">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+
+<script>
+"use strict";
+
+test(() => {
+  const target = new EventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  function listener(e) {
+    assert_equals(e, event);
+    ++callCount;
+  }
+
+  target.addEventListener("foo", listener);
+
+  target.dispatchEvent(event);
+  assert_equals(callCount, 1);
+
+  target.dispatchEvent(event);
+  assert_equals(callCount, 2);
+
+  target.removeEventListener("foo", listener);
+  target.dispatchEvent(event);
+  assert_equals(callCount, 2);
+}, "A constructed EventTarget can be used as expected");
+
+test(() => {
+  class NicerEventTarget extends EventTarget {
+    on(...args) {
+      this.addEventListener(...args);
+    }
+
+    off(...args) {
+      this.removeEventListener(...args);
+    }
+
+    dispatch(type, detail) {
+      this.dispatchEvent(new CustomEvent(type, { detail }));
+    }
+  }
+
+  const target = new NicerEventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  function listener(e) {
+    assert_equals(e.detail, detail);
+    ++callCount;
+  }
+
+  target.on("foo", listener);
+
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 1);
+
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 2);
+
+  target.off("foo", listener);
+  target.dispatch("foo", detail);
+  assert_equals(callCount, 2);
+}, "EventTarget can be subclassed");
+
+</script>
diff --git a/dom/interfaces.html b/dom/interfaces.html
@@ -21,6 +21,7 @@ <h1>DOM IDL tests</h1>
 function doTest(idl) {
   idlArray.add_idls(idl);
   idlArray.add_objects({
+    EventTarget: ['new EventTarget()'],
     Event: ['document.createEvent("Event")', 'new Event("foo")'],
     CustomEvent: ['new CustomEvent("foo")'],
     Document: ['new Document()'],

diff --git a/interfaces/dom.idl b/interfaces/dom.idl
@@ -44,7 +44,7 @@ dictionary CustomEventInit : EventInit {
 };
 
 
-//[Exposed=(Window,Worker)]
+[Constructor/*, Exposed=(Window,Worker)*/]
 interface EventTarget {
   void addEventListener(DOMString type, EventListener? callback, optional (EventListenerOptions or boolean) options);
   void removeEventListener(DOMString type, EventListener? callback, optional (EventListenerOptions or boolean) options);