test: use ES6 classes instead of util.inherits

PR-URL: https://github.com/nodejs/node/pull/16938
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

1 files changed, 23 insertions, 25 deletions

diff --git a/test/parallel/test-stream2-compatibility.js b/test/parallel/test-stream2-compatibility.js
index 45834ee99e..bd0314ec1a 100644
--- a/test/parallel/test-stream2-compatibility.js
+++ b/test/parallel/test-stream2-compatibility.js
@@ -25,25 +25,23 @@ const R = require('_stream_readable');
 const W = require('_stream_writable');
 const assert = require('assert');
 
-const util = require('util');
-
 let ondataCalled = 0;
 
-function TestReader() {
-  R.apply(this);
-  this._buffer = Buffer.alloc(100, 'x');
-
-  this.on('data', function() {
-    ondataCalled++;
-  });
-}
+class TestReader extends R {
+  constructor() {
+    super();
+    this._buffer = Buffer.alloc(100, 'x');
 
-util.inherits(TestReader, R);
+    this.on('data', () => {
+      ondataCalled++;
+    });
+  }
 
-TestReader.prototype._read = function(n) {
-  this.push(this._buffer);
-  this._buffer = Buffer.alloc(0);
-};
+  _read(n) {
+    this.push(this._buffer);
+    this._buffer = Buffer.alloc(0);
+  }
+}
 
 const reader = new TestReader();
 setImmediate(function() {
@@ -52,17 +50,17 @@ setImmediate(function() {
   reader.push(null);
 });
 
-function TestWriter() {
-  W.apply(this);
-  this.write('foo');
-  this.end();
-}
-
-util.inherits(TestWriter, W);
+class TestWriter extends W {
+  constructor() {
+    super();
+    this.write('foo');
+    this.end();
+  }
 
-TestWriter.prototype._write = function(chunk, enc, cb) {
-  cb();
-};
+  _write(chunk, enc, cb) {
+    cb();
+  }
+}
 
 const writer = new TestWriter();