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, 15 insertions, 15 deletions

diff --git a/test/parallel/test-crypto-stream.js b/test/parallel/test-crypto-stream.js
index 1c3b8bbcbb..0464829f74 100644
--- a/test/parallel/test-crypto-stream.js
+++ b/test/parallel/test-crypto-stream.js
@@ -26,26 +26,26 @@ if (!common.hasCrypto)
 
 const assert = require('assert');
 const stream = require('stream');
-const util = require('util');
 const crypto = require('crypto');
 
-// Small stream to buffer converter
-function Stream2buffer(callback) {
-  stream.Writable.call(this);
+if (!common.hasFipsCrypto) {
+  // Small stream to buffer converter
+  class Stream2buffer extends stream.Writable {
+    constructor(callback) {
+      super();
 
-  this._buffers = [];
-  this.once('finish', function() {
-    callback(null, Buffer.concat(this._buffers));
-  });
-}
-util.inherits(Stream2buffer, stream.Writable);
+      this._buffers = [];
+      this.once('finish', function() {
+        callback(null, Buffer.concat(this._buffers));
+      });
+    }
 
-Stream2buffer.prototype._write = function(data, encodeing, done) {
-  this._buffers.push(data);
-  return done(null);
-};
+    _write(data, encodeing, done) {
+      this._buffers.push(data);
+      return done(null);
+    }
+  }
 
-if (!common.hasFipsCrypto) {
   // Create an md5 hash of "Hallo world"
   const hasher1 = crypto.createHash('md5');
   hasher1.pipe(new Stream2buffer(common.mustCall(function end(err, hash) {