From f5c7fb3c2d21fb262fc4c263175737b8e12a9b4d Mon Sep 17 00:00:00 2001
From: Robert Nagy <ronagy@icloud.com>
Date: Sun, 26 Apr 2020 19:38:43 +0200
Subject: [PATCH] stream: Duplex re-use Writable properties

Instead of reimplementing Writable properties, fetch them
from the Writable prototype.
---
 lib/_stream_duplex.js | 51 ++++++++++++-------------------------------
 1 file changed, 14 insertions(+), 37 deletions(-)

diff --git a/lib/_stream_duplex.js b/lib/_stream_duplex.js
index 07a16175ffcd73..ced361c8d60898 100644
--- a/lib/_stream_duplex.js
+++ b/lib/_stream_duplex.js
@@ -71,7 +71,20 @@ function Duplex(options) {
 }
 
 ObjectDefineProperties(Duplex.prototype, {
-  writable: ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writable'),
+  writable:
+    ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writable'),
+  writableHighWaterMark:
+    ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writableHighWaterMark'),
+  writableBuffer:
+    ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writableBuffer'),
+  writableLength:
+    ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writableLength'),
+  writableFinished:
+    ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writableFinished'),
+  writableCorked:
+    ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writableCorked'),
+  writableEnded:
+    ObjectGetOwnPropertyDescriptor(Writable.prototype, 'writableEnded'),
 
   destroyed: {
     get() {
@@ -89,41 +102,5 @@ ObjectDefineProperties(Duplex.prototype, {
         this._writableState.destroyed = value;
       }
     }
-  },
-
-  writableHighWaterMark: {
-    get() {
-      return this._writableState && this._writableState.highWaterMark;
-    }
-  },
-
-  writableBuffer: {
-    get() {
-      return this._writableState && this._writableState.getBuffer();
-    }
-  },
-
-  writableLength: {
-    get() {
-      return this._writableState && this._writableState.length;
-    }
-  },
-
-  writableFinished: {
-    get() {
-      return this._writableState ? this._writableState.finished : false;
-    }
-  },
-
-  writableCorked: {
-    get() {
-      return this._writableState ? this._writableState.corked : 0;
-    }
-  },
-
-  writableEnded: {
-    get() {
-      return this._writableState ? this._writableState.ending : false;
-    }
   }
 });