lib, test: integrate wpt abort_controller tests and fix onabort event

lib/internal/abort_controller.js

@@ -10,6 +10,7 @@ const {
 } = primordials;
 
 const {
+  defineEventHandler,
   EventTarget,
   Event,
   kTrustEvent
@@ -53,9 +54,6 @@ function abortSignal(signal) {
   const event = new Event('abort', {
     [kTrustEvent]: true
   });
-  if (typeof signal.onabort === 'function') {
-    signal.onabort(event);
-  }
   signal.dispatchEvent(event);
 }
 
@@ -67,6 +65,7 @@ class AbortController {
   constructor() {
     this[kSignal] = new AbortSignal();
     emitExperimentalWarning('AbortController');
+    defineEventHandler(this[kSignal], 'abort');
   }
 
   get signal() { return this[kSignal]; }

lib/internal/event_target.js

@@ -334,14 +334,13 @@ class EventTarget {
       }
       return event;
     };
+    if (event !== undefined)
+      event[kTarget] = this;
 
     const root = this[kEvents].get(type);
     if (root === undefined || root.next === undefined)
       return true;
 
-    if (event !== undefined)
-      event[kTarget] = this;
-
     let handler = root.next;
     let next;
 

test/fixtures/wpt/README.md

@@ -19,6 +19,7 @@ Last update:
 - html/webappapis/timers: https://github.com/web-platform-tests/wpt/tree/264f12bc7b/html/webappapis/timers
 - hr-time: https://github.com/web-platform-tests/wpt/tree/a5d1774ecf/hr-time
 - common: https://github.com/web-platform-tests/wpt/tree/4dacb6e2ff/common
+- dom/abort: https://github.com/web-platform-tests/wpt/tree/7caa3de747/dom/abort
 
 [Web Platform Tests]: https://github.com/web-platform-tests/wpt
 [`git node wpt`]: https://github.com/nodejs/node-core-utils/blob/master/docs/git-node.md#git-node-wpt

test/fixtures/wpt/dom/abort/event.any.js

@@ -0,0 +1,67 @@
+test(t => {
+  const c = new AbortController(),
+        s = c.signal;
+  let state = "begin";
+
+  assert_false(s.aborted);
+
+  s.addEventListener("abort",
+    t.step_func(e => {
+      assert_equals(state, "begin");
+      state = "aborted";
+    })
+  );
+  c.abort();
+
+  assert_equals(state, "aborted");
+  assert_true(s.aborted);
+
+  c.abort();
+}, "AbortController abort() should fire event synchronously");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  assert_equals(controller.signal, signal,
+                "value of controller.signal should not have changed");
+  controller.abort();
+  assert_equals(controller.signal, signal,
+                "value of controller.signal should still not have changed");
+}, "controller.signal should always return the same object");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  let eventCount = 0;
+  signal.onabort = () => {
+    ++eventCount;
+  };
+  controller.abort();
+  assert_true(signal.aborted);
+  assert_equals(eventCount, 1, "event handler should have been called once");
+  controller.abort();
+  assert_true(signal.aborted);
+  assert_equals(eventCount, 1,
+                "event handler should not have been called again");
+}, "controller.abort() should do nothing the second time it is called");
+
+test(t => {
+  const controller = new AbortController();
+  controller.abort();
+  controller.signal.onabort =
+      t.unreached_func("event handler should not be called");
+}, "event handler should not be called if added after controller.abort()");
+
+test(t => {
+  const controller = new AbortController();
+  const signal = controller.signal;
+  signal.onabort = t.step_func(e => {
+    assert_equals(e.type, "abort", "event type should be abort");
+    assert_equals(e.target, signal, "event target should be signal");
+    assert_false(e.bubbles, "event should not bubble");
+    assert_true(e.isTrusted, "event should be trusted");
+  });
+  controller.abort();
+}, "the abort event should have the right properties");
+
+done();

test/fixtures/wpt/versions.json

@@ -34,5 +34,9 @@
   "common": {
     "commit": "4dacb6e2ff8dbabbe328fde2d8c75491598e4c10",
     "path": "common"
+  },
+  "dom/abort": {
+    "commit": "7caa3de7471cf19b78ee9efa313c7341a462b5e3",
+    "path": "dom/abort"
   }
-}
+}

test/parallel/test-eventtarget.js

@@ -479,3 +479,9 @@ let asyncTest = Promise.resolve();
     throws(() => eventTarget.addEventListener('foo', Symbol()), TypeError);
   });
 }
+{
+  const eventTarget = new EventTarget();
+  const event = new Event('foo');
+  eventTarget.dispatchEvent(event);
+  strictEqual(event.target, eventTarget);
+}

test/wpt/status/dom/abort.json

@@ -0,0 +1 @@
+{}

test/wpt/test-abort.js

@@ -0,0 +1,7 @@
+'use strict';
+require('../common');
+const { WPTRunner } = require('../common/wpt');
+
+const runner = new WPTRunner('dom/abort');
+
+runner.runJsTests();