lib: implement AbortSignal.abort()

.eslintrc.js

@@ -315,6 +315,7 @@ module.exports = {
   },
   globals: {
     AbortController: 'readable',
+    AbortSignal: 'readable',
     Atomics: 'readable',
     BigInt: 'readable',
     BigInt64Array: 'readable',

doc/api/globals.md

@@ -67,6 +67,15 @@ added: v15.0.0
 The `AbortSignal` is used to notify observers when the
 `abortController.abort()` method is called.
 
+#### Static method: `AbortSignal.abort()`
+<!-- YAML
+added: REPLACEME
+-->
+
+* Returns: {AbortSignal}
+
+Returns a new already aborted `AbortSignal`.
+
 #### Event: `'abort'`
 <!-- YAML
 added: v15.0.0

lib/internal/abort_controller.js

@@ -50,6 +50,10 @@ class AbortSignal extends EventTarget {
       aborted: this.aborted
     }, depth, options);
   }
+
+  static abort() {
+    return createAbortSignal(true);
+  }
 }
 
 ObjectDefineProperties(AbortSignal.prototype, {
@@ -65,10 +69,10 @@ ObjectDefineProperty(AbortSignal.prototype, SymbolToStringTag, {
 
 defineEventHandler(AbortSignal.prototype, 'abort');
 
-function createAbortSignal() {
+function createAbortSignal(aborted = false) {
   const signal = new EventTarget();
   ObjectSetPrototypeOf(signal, AbortSignal.prototype);
-  signal[kAborted] = false;
+  signal[kAborted] = aborted;
   return signal;
 }
 

test/fixtures/wpt/README.md

@@ -12,7 +12,7 @@ Last update:
 
 - common: https://github.com/web-platform-tests/wpt/tree/bb97a68974/common
 - console: https://github.com/web-platform-tests/wpt/tree/3b1f72e99a/console
-- dom/abort: https://github.com/web-platform-tests/wpt/tree/625e1310ce/dom/abort
+- dom/abort: https://github.com/web-platform-tests/wpt/tree/1728d198c9/dom/abort
 - encoding: https://github.com/web-platform-tests/wpt/tree/35f70910d3/encoding
 - FileAPI: https://github.com/web-platform-tests/wpt/tree/3b279420d4/FileAPI
 - hr-time: https://github.com/web-platform-tests/wpt/tree/9910784394/hr-time

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

@@ -64,4 +64,9 @@ test(t => {
   controller.abort();
 }, "the abort event should have the right properties");
 
+test(t => {
+  const signal = AbortSignal.abort();
+  assert_true(signal.aborted);
+}, "the AbortSignal.abort() static returns an already aborted signal");
+
 done();

test/fixtures/wpt/versions.json

@@ -8,7 +8,7 @@
     "path": "console"
   },
   "dom/abort": {
-    "commit": "625e1310ce19e9dde25b01f9eda0452c6ec274da",
+    "commit": "1728d198c92834d92f7f399ef35e7823d5bfa0e4",
     "path": "dom/abort"
   },
   "encoding": {

test/parallel/test-abortcontroller.js

@@ -67,3 +67,8 @@ const { ok, strictEqual, throws } = require('assert');
   strictEqual(toString(ac), '[object AbortController]');
   strictEqual(toString(ac.signal), '[object AbortSignal]');
 }
+
+{
+  const signal = AbortSignal.abort();
+  ok(signal.aborted);
+}