WritableStream: remove the abortReason property

Part of #1165, which discusses moving it instead to the AbortSignal's reason property per whatwg/dom#1027.

index.bs

@@ -4288,7 +4288,6 @@ The Web IDL definition for the {{WritableStreamDefaultController}} class is give
 <xmp class="idl">
 [Exposed=(Window,Worker,Worklet)]
 interface WritableStreamDefaultController {
-  readonly attribute any abortReason;
   readonly attribute AbortSignal signal;
   undefined error(optional any e);
 };
@@ -4309,9 +4308,6 @@ the following table:
    <td><dfn>\[[abortAlgorithm]]</dfn>
    <td class="non-normative">A promise-returning algorithm, taking one argument (the abort reason),
    which communicates a requested abort to the [=underlying sink=]
-  <tr>
-   <td><dfn>\[[abortReason]]</dfn>
-   <td class="non-normative">The argument given to [$WritableStreamAbort$], or undefined.
   <tr>
    <td><dfn>\[[closeAlgorithm]]</dfn>
    <td class="non-normative">A promise-returning algorithm which communicates a requested close to
@@ -4371,13 +4367,6 @@ closed. It is only used internally, and is never exposed to web developers.
   sink=].
 </dl>
 
-<div algorithm>
- The <dfn id="ws-default-controller-abort-reason" attribute
- for="WritableStreamDefaultController">abortReason</dfn> getter steps are:
-
- 1. Return [=this=].[=WritableStreamDefaultController/[[abortReason]]=].
-</div>
-
 <div algorithm>
  The <dfn id="ws-default-controller-signal" attribute
  for="WritableStreamDefaultController">signal</dfn> getter steps are:
@@ -4528,9 +4517,6 @@ The following abstract operations operate on {{WritableStream}} instances at a h
 
  1. If |stream|.[=WritableStream/[[state]]=] is "`closed`" or "`errored`", return
     [=a promise resolved with=] undefined.
- 1. Set
-    |stream|.[=WritableStream/[[controller]]=].[=WritableStreamDefaultController/[[abortReason]]=]
-    to |reason|.
  1. [=Signal abort=] on
     |stream|.[=WritableStream/[[controller]]=].[=WritableStreamDefaultController/[[signal]]=].
  1. Let |state| be |stream|.[=WritableStream/[[state]]=].
@@ -4960,7 +4946,6 @@ The following abstract operations support the implementation of the
  1. Set |controller|.[=WritableStreamDefaultController/[[stream]]=] to |stream|.
  1. Set |stream|.[=WritableStream/[[controller]]=] to |controller|.
  1. Perform ! [$ResetQueue$](|controller|).
- 1. Set |controller|.[=WritableStreamDefaultController/[[abortReason]]=] to undefined.
  1. Set |controller|.[=WritableStreamDefaultController/[[signal]]=] to a new {{AbortSignal}}.
  1. Set |controller|.[=WritableStreamDefaultController/[[started]]=] to false.
  1. Set |controller|.[=WritableStreamDefaultController/[[strategySizeAlgorithm]]=] to

reference-implementation/lib/WritableStreamDefaultController-impl.js

@@ -5,9 +5,6 @@ const { AbortSteps, ErrorSteps } = require('./abstract-ops/internal-methods.js')
 const { ResetQueue } = require('./abstract-ops/queue-with-sizes.js');
 
 exports.implementation = class WritableStreamDefaultControllerImpl {
-  get abortReason() {
-    return this._abortReason;
-  }
   get signal() {
     return this._abortController.signal;
   }

reference-implementation/lib/WritableStreamDefaultController.webidl

@@ -1,6 +1,5 @@
 [Exposed=(Window,Worker,Worklet)]
 interface WritableStreamDefaultController {
-  readonly attribute any abortReason;
   readonly attribute AbortSignal signal;
   void error(optional any e);
 };

reference-implementation/lib/abstract-ops/writable-streams.js

@@ -107,7 +107,6 @@ function WritableStreamAbort(stream, reason) {
   if (stream._state === 'closed' || stream._state === 'errored') {
     return promiseResolvedWith(undefined);
   }
-  stream._controller._abortReason = reason;
   stream._controller._abortController.abort();
   const state = stream._state;
   if (state === 'closed' || state === 'errored') {
@@ -542,7 +541,6 @@ function SetUpWritableStreamDefaultController(stream, controller, startAlgorithm
   controller._queueTotalSize = undefined;
   ResetQueue(controller);
 
-  controller._abortReason = undefined;
   controller._abortController = new AbortController();
   controller._started = false;
 

writable-stream-abort-signal-explainer.md

@@ -21,8 +21,6 @@ streams such as [WebTransport](https://w3c.github.io/webtransport/).
 On [WritableStreamDefaultController](https://streams.spec.whatwg.org/#writablestreamdefaultcontroller)
 (the controller argument that is passed to underlying sinks):
 
-*   [`abortReason`](https://streams.spec.whatwg.org/#writablestreamdefaultcontroller-abortreason): The argument passed
-to `writable.abort()` or `writer.abort()`. Undefined if no argument was passed or `abort()` hasn't been called.
 *   [`signal`](https://streams.spec.whatwg.org/#writablestreamdefaultcontroller-signal): An AbortSignal. By using
 `signal.addEventListener('abort', …)` an underlying sink can abort the pending write or close operation when the
 stream is aborted.
@@ -44,7 +42,7 @@ const ws = new WritableStream({
     return new Promise((resolve, reject) => {
       setTimeout(resolve, 1000);
       controller.signal.addEventListener('abort',
-        () => reject(controller.abortReason));
+        () => reject(controller.signal.reason));
     });
   }
 });
@@ -117,3 +115,6 @@ would be unclear and confusing.
 *   It was initially proposed that an `AbortSignal` could be passed to each sink `write()` call. However, since the
 abort signal does not need to change between two `write()` calls, it was thought better to just add a `signal` property
 on `WritableStreamDefaultController`.
+*   Previously, [WritableStreamDefaultController](https://streams.spec.whatwg.org/#writablestreamdefaultcontroller) had
+an `abortReason` property that was an argument given to
+[WritableStreamAbort](https://streams.spec.whatwg.org/#writable-stream-abort). However, after some discussion, it was thought better to just add the `reason` property to the `AbortSignal`.