stream: fix isErrored/isWritable for WritableStreams

PR-URL: #60905
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

Author: Renegade334

lib/internal/webstreams/writablestream.js

@@ -76,6 +76,8 @@ const {
 
 const{
  kIsClosedPromise,
+ kIsErrored,
+ kIsWritable,
  kControllerErrorFunction,
 }=require('internal/streams/utils');
 
@@ -183,6 +185,14 @@ class WritableStream {
 size);
 }
 
+get[kIsErrored](){
+returnthis[kState].state==='errored';
+}
+
+get[kIsWritable](){
+returnthis[kState].state==='writable';
+}
+
 /**
  * @readonly
  * @type {boolean}

test/parallel/test-whatwg-writablestream.js

@@ -4,6 +4,8 @@
 constcommon=require('../common');
 constassert=require('assert');
 
+const{ isErrored, isWritable }=require('stream');
+
 const{
  WritableStream,
  WritableStreamDefaultController,
@@ -171,6 +173,27 @@ class Sink {
 }));
 }
 
+{
+conststream=newWritableStream();
+assert.strictEqual(isWritable(stream),true);
+stream.close().then(common.mustCall(()=>{
+assert.strictEqual(isWritable(stream),false);
+}));
+}
+
+{
+conststream=newWritableStream({
+write: common.mustCall((chunk,controller)=>{
+controller.error(newError());
+})
+});
+constwriter=stream.getWriter();
+assert.strictEqual(isErrored(stream),false);
+writer.write().then(common.mustCall(()=>{
+assert.strictEqual(isErrored(stream),true);
+}));
+}
+
 {
 assert.throws(()=>Reflect.get(WritableStream.prototype,'locked',{}),{
 code: 'ERR_INVALID_THIS',