stream: rollback duplex from new api

lib/internal/streams/readable.js

@@ -41,7 +41,6 @@ Readable.ReadableState = ReadableState;
 const EE = require('events');
 const { Stream, prependListener } = require('internal/streams/legacy');
 const { Buffer } = require('buffer');
-const Duplex = require('internal/streams/duplex');
 
 const {
   addAbortSignal,
@@ -88,7 +87,7 @@ function ReadableState(options, stream, isDuplex) {
   // values for the readable and the writable sides of the duplex stream.
   // These options can be provided separately as readableXXX and writableXXX.
   if (typeof isDuplex !== 'boolean')
-    isDuplex = stream instanceof Duplex;
+    isDuplex = stream instanceof Stream.Duplex;
 
   // Object stream flag. Used to make read(n) ignore n and to
   // make all the buffer merging and length checks go away.
@@ -190,7 +189,7 @@ function Readable(options) {
 
   // Checking for a Stream.Duplex instance is faster here instead of inside
   // the ReadableState constructor, at least with V8 6.5.
-  const isDuplex = this instanceof Duplex;
+  const isDuplex = this instanceof Stream.Duplex;
 
   this._readableState = new ReadableState(options, this, isDuplex);
 

lib/internal/streams/writable.js

@@ -42,7 +42,6 @@ Writable.WritableState = WritableState;
 
 const EE = require('events');
 const Stream = require('internal/streams/legacy').Stream;
-const Duplex = require('internal/streams/duplex');
 const { Buffer } = require('buffer');
 const destroyImpl = require('internal/streams/destroy');
 
@@ -82,7 +81,7 @@ function WritableState(options, stream, isDuplex) {
   // values for the readable and the writable sides of the duplex stream,
   // e.g. options.readableObjectMode vs. options.writableObjectMode, etc.
   if (typeof isDuplex !== 'boolean')
-    isDuplex = stream instanceof Duplex;
+    isDuplex = stream instanceof Stream.Duplex;
 
   // Object stream flag to indicate whether or not this stream
   // contains buffers or objects.
@@ -229,7 +228,7 @@ function Writable(options) {
 
   // Checking for a Stream.Duplex instance is faster here instead of inside
   // the WritableState constructor, at least with V8 6.5.
-  const isDuplex = (this instanceof Duplex);
+  const isDuplex = (this instanceof Stream.Duplex);
 
   if (!isDuplex && !FunctionPrototypeSymbolHasInstance(Writable, this))
     return new Writable(options);