feat(ext/web): add AbortSignal.reason (denoland#12697)

ext/web/03_abort_signal.js

@@ -8,41 +8,49 @@
  const webidl = window.__bootstrap.webidl;
  const { setIsTrusted, defineEventHandler } = window.__bootstrap.event;
  const {
- Boolean,
  Set,
  SetPrototypeAdd,
  SetPrototypeDelete,
  Symbol,
  TypeError,
  } = window.__bootstrap.primordials;
 
- const add = Symbol("add");
- const signalAbort = Symbol("signalAbort");
- const remove = Symbol("remove");
- const aborted = Symbol("aborted");
- const abortAlgos = Symbol("abortAlgos");
+ const add = Symbol("[[add]]");
+ const signalAbort = Symbol("[[signalAbort]]");
+ const remove = Symbol("[[remove]]");
+ const abortReason = Symbol("[[abortReason]]");
+ const abortAlgos = Symbol("[[abortAlgos]]");
+ const signal = Symbol("[[signal]]");
 
  const illegalConstructorKey = Symbol("illegalConstructorKey");
 
  class AbortSignal extends EventTarget {
- static abort() {
+ static abort(reason = undefined) {
+ if (reason !== undefined) {
+ reason = webidl.converters.any(reason);
+ }
  const signal = new AbortSignal(illegalConstructorKey);
- signal[signalAbort]();
+ signal[signalAbort](reason);
  return signal;
  }
 
  [add](algorithm) {
+ if (this.aborted) {
+ return;
+ }
  if (this[abortAlgos] === null) {
  this[abortAlgos] = new Set();
  }
  SetPrototypeAdd(this[abortAlgos], algorithm);
  }
 
- [signalAbort]() {
- if (this[aborted]) {
+ [signalAbort](
+ reason = new DOMException("The signal has been aborted", "AbortError"),
+ ) {
+ if (this.aborted) {
  return;
  }
- this[aborted] = true;
+ this[abortReason] = reason;
  if (this[abortAlgos] !== null) {
  for (const algorithm of this[abortAlgos]) {
  algorithm();
@@ -63,28 +71,40 @@
  throw new TypeError("Illegal constructor.");
  }
  super();
- this[aborted] = false;
+ this[abortReason] = undefined;
  this[abortAlgos] = null;
  this[webidl.brand] = webidl.brand;
  }
 
  get aborted() {
- return Boolean(this[aborted]);
+ webidl.assertBranded(this, AbortSignal);
+ return this[abortReason] !== undefined;
+ }
+
+ get reason() {
+ webidl.assertBranded(this, AbortSignal);
+ return this[abortReason];
  }
  }
  defineEventHandler(AbortSignal.prototype, "abort");
 
  webidl.configurePrototype(AbortSignal);
 
  class AbortController {
- #signal = new AbortSignal(illegalConstructorKey);
+ [signal] = new AbortSignal(illegalConstructorKey);
+
+ constructor() {
+ this[webidl.brand] = webidl.brand;
+ }
 
  get signal() {
- return this.#signal;
+ webidl.assertBranded(this, AbortController);
+ return this[signal];
  }
 
- abort() {
- this.#signal[signalAbort]();
+ abort(reason) {
+ webidl.assertBranded(this, AbortController);
+ this[signal][signalAbort](reason);
  }
  }
 
@@ -100,10 +120,15 @@
  }
 
  function follow(followingSignal, parentSignal) {
+ if (followingSignal.aborted) {
+ return;
+ }
  if (parentSignal.aborted) {
- followingSignal[signalAbort]();
+ followingSignal[signalAbort](parentSignal.reason);
  } else {
- parentSignal[add](() => followingSignal[signalAbort]());
+ parentSignal[add](() =>
+ followingSignal[signalAbort](parentSignal.reason)
+ );
  }
  }