lib: remove inherits() usage

BridgeAR · refack · commit 2f443fd284b4 · 2019-01-10T10:03:54.000-05:00
This switches all `util.inherits()` calls to use `Object.setPrototypeOf()` instead. In fact, `util.inherits()` is mainly a small wrapper around exactly this function while adding the `_super` property on the object as well. Refs: nodejs#24395 PR-URL: nodejs#24755 Refs: nodejs#24395 Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
diff --git a/lib/_http_agent.js b/lib/_http_agent.js
@@ -105,8 +105,7 @@ function Agent(options) {
     }
   });
 }
-
-util.inherits(Agent, EventEmitter);
+Object.setPrototypeOf(Agent.prototype, EventEmitter.prototype);
 
 Agent.defaultMaxSockets = Infinity;
 
diff --git a/lib/_http_client.js b/lib/_http_client.js
@@ -279,9 +279,7 @@ function ClientRequest(input, options, cb) {
 
   this._deferToConnect(null, null, () => this._flush());
 }
-
-util.inherits(ClientRequest, OutgoingMessage);
-
+Object.setPrototypeOf(ClientRequest.prototype, OutgoingMessage.prototype);
 
 ClientRequest.prototype._finish = function _finish() {
   DTRACE_HTTP_CLIENT_REQUEST(this, this.connection);
diff --git a/lib/_http_incoming.js b/lib/_http_incoming.js
@@ -21,7 +21,6 @@
 
 'use strict';
 
-const util = require('util');
 const Stream = require('stream');
 
 function readStart(socket) {
@@ -72,8 +71,7 @@ function IncomingMessage(socket) {
   // read by the user, so there's no point continuing to handle it.
   this._dumped = false;
 }
-util.inherits(IncomingMessage, Stream.Readable);
-
+Object.setPrototypeOf(IncomingMessage.prototype, Stream.Readable.prototype);
 
 IncomingMessage.prototype.setTimeout = function setTimeout(msecs, callback) {
   if (callback)
diff --git a/lib/_http_outgoing.js b/lib/_http_outgoing.js
@@ -106,7 +106,7 @@ function OutgoingMessage() {
 
   this._onPendingData = noopPendingOutput;
 }
-util.inherits(OutgoingMessage, Stream);
+Object.setPrototypeOf(OutgoingMessage.prototype, Stream.prototype);
 
 
 Object.defineProperty(OutgoingMessage.prototype, '_headers', {
diff --git a/lib/_http_server.js b/lib/_http_server.js
@@ -137,7 +137,7 @@ function ServerResponse(req) {
     this.shouldKeepAlive = false;
   }
 }
-util.inherits(ServerResponse, OutgoingMessage);
+Object.setPrototypeOf(ServerResponse.prototype, OutgoingMessage.prototype);
 
 ServerResponse.prototype._finish = function _finish() {
   DTRACE_HTTP_SERVER_RESPONSE(this.connection);
diff --git a/lib/_stream_duplex.js b/lib/_stream_duplex.js
@@ -28,11 +28,10 @@
 
 module.exports = Duplex;
 
-const util = require('util');
 const Readable = require('_stream_readable');
 const Writable = require('_stream_writable');
 
-util.inherits(Duplex, Readable);
+Object.setPrototypeOf(Duplex.prototype, Readable.prototype);
 
 {
   // Allow the keys array to be GC'ed.
diff --git a/lib/_stream_passthrough.js b/lib/_stream_passthrough.js
@@ -28,8 +28,7 @@
 module.exports = PassThrough;
 
 const Transform = require('_stream_transform');
-const util = require('util');
-util.inherits(PassThrough, Transform);
+Object.setPrototypeOf(PassThrough.prototype, Transform.prototype);
 
 function PassThrough(options) {
   if (!(this instanceof PassThrough))
diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
@@ -44,7 +44,7 @@ const { emitExperimentalWarning } = require('internal/util');
 let StringDecoder;
 let createReadableStreamAsyncIterator;
 
-util.inherits(Readable, Stream);
+Object.setPrototypeOf(Readable.prototype, Stream.prototype);
 
 const { errorOrDestroy } = destroyImpl;
 const kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];
diff --git a/lib/_stream_transform.js b/lib/_stream_transform.js
@@ -71,8 +71,7 @@ const {
   ERR_TRANSFORM_WITH_LENGTH_0
 } = require('internal/errors').codes;
 const Duplex = require('_stream_duplex');
-const util = require('util');
-util.inherits(Transform, Duplex);
+Object.setPrototypeOf(Transform.prototype, Duplex.prototype);
 
 
 function afterTransform(er, data) {
diff --git a/lib/_stream_writable.js b/lib/_stream_writable.js
@@ -28,7 +28,6 @@
 module.exports = Writable;
 Writable.WritableState = WritableState;
 
-const util = require('util');
 const internalUtil = require('internal/util');
 const Stream = require('stream');
 const { Buffer } = require('buffer');
@@ -47,7 +46,7 @@ const {
 
 const { errorOrDestroy } = destroyImpl;
 
-util.inherits(Writable, Stream);
+Object.setPrototypeOf(Writable.prototype, Stream.prototype);
 
 function nop() {}
 
diff --git a/lib/dgram.js b/lib/dgram.js
@@ -108,7 +108,7 @@ function Socket(type, listener) {
     sendBufferSize
   };
 }
-util.inherits(Socket, EventEmitter);
+Object.setPrototypeOf(Socket.prototype, EventEmitter.prototype);
 
 
 function createSocket(type, listener) {
diff --git a/lib/https.js b/lib/https.js
@@ -149,7 +149,7 @@ function Agent(options) {
     list: []
   };
 }
-inherits(Agent, HttpAgent);
+Object.setPrototypeOf(Agent.prototype, HttpAgent.prototype);
 Agent.prototype.createConnection = createConnection;
 
 Agent.prototype.getName = function getName(options) {
diff --git a/lib/internal/child_process.js b/lib/internal/child_process.js
@@ -265,7 +265,7 @@ function ChildProcess() {
     maybeClose(this);
   };
 }
-util.inherits(ChildProcess, EventEmitter);
+Object.setPrototypeOf(ChildProcess.prototype, EventEmitter.prototype);
 
 
 function flushStdio(subprocess) {
diff --git a/lib/internal/cluster/worker.js b/lib/internal/cluster/worker.js
@@ -1,6 +1,5 @@
 'use strict';
 const EventEmitter = require('events');
-const util = require('util');
 
 module.exports = Worker;
 
@@ -30,7 +29,7 @@ function Worker(options) {
   }
 }
 
-util.inherits(Worker, EventEmitter);
+Object.setPrototypeOf(Worker.prototype, EventEmitter.prototype);
 
 Worker.prototype.kill = function() {
   this.destroy.apply(this, arguments);
diff --git a/lib/internal/crypto/cipher.js b/lib/internal/crypto/cipher.js
@@ -32,7 +32,6 @@ const {
 const assert = require('assert');
 const LazyTransform = require('internal/streams/lazy_transform');
 
-const { inherits } = require('util');
 const { deprecate, normalizeEncoding } = require('internal/util');
 
 // Lazy loaded for startup performance.
@@ -124,7 +123,7 @@ function Cipher(cipher, password, options) {
   createCipher.call(this, cipher, password, options, true);
 }
 
-inherits(Cipher, LazyTransform);
+Object.setPrototypeOf(Cipher.prototype, LazyTransform.prototype);
 
 Cipher.prototype._transform = function _transform(chunk, encoding, callback) {
   this.push(this[kHandle].update(chunk, encoding));
@@ -254,7 +253,7 @@ function addCipherPrototypeFunctions(constructor) {
   constructor.prototype.setAAD = Cipher.prototype.setAAD;
 }
 
-inherits(Cipheriv, LazyTransform);
+Object.setPrototypeOf(Cipheriv.prototype, LazyTransform.prototype);
 addCipherPrototypeFunctions(Cipheriv);
 legacyNativeHandle(Cipheriv);
 
@@ -265,7 +264,7 @@ function Decipher(cipher, password, options) {
   createCipher.call(this, cipher, password, options, false);
 }
 
-inherits(Decipher, LazyTransform);
+Object.setPrototypeOf(Decipher.prototype, LazyTransform.prototype);
 addCipherPrototypeFunctions(Decipher);
 legacyNativeHandle(Decipher);
 
@@ -277,7 +276,7 @@ function Decipheriv(cipher, key, iv, options) {
   createCipherWithIV.call(this, cipher, key, options, false, iv);
 }
 
-inherits(Decipheriv, LazyTransform);
+Object.setPrototypeOf(Decipheriv.prototype, LazyTransform.prototype);
 addCipherPrototypeFunctions(Decipheriv);
 legacyNativeHandle(Decipheriv);
 
diff --git a/lib/internal/crypto/hash.js b/lib/internal/crypto/hash.js
@@ -21,7 +21,6 @@ const {
   ERR_INVALID_ARG_TYPE
 } = require('internal/errors').codes;
 const { validateString } = require('internal/validators');
-const { inherits } = require('util');
 const { normalizeEncoding } = require('internal/util');
 const { isArrayBufferView } = require('internal/util/types');
 const LazyTransform = require('internal/streams/lazy_transform');
@@ -39,7 +38,7 @@ function Hash(algorithm, options) {
   LazyTransform.call(this, options);
 }
 
-inherits(Hash, LazyTransform);
+Object.setPrototypeOf(Hash.prototype, LazyTransform.prototype);
 
 Hash.prototype._transform = function _transform(chunk, encoding, callback) {
   this[kHandle].update(chunk, encoding);
@@ -100,7 +99,7 @@ function Hmac(hmac, key, options) {
   LazyTransform.call(this, options);
 }
 
-inherits(Hmac, LazyTransform);
+Object.setPrototypeOf(Hmac.prototype, LazyTransform.prototype);
 
 Hmac.prototype.update = Hash.prototype.update;
 
diff --git a/lib/internal/crypto/sig.js b/lib/internal/crypto/sig.js
@@ -18,7 +18,6 @@ const {
   validateArrayBufferView,
 } = require('internal/crypto/util');
 const { Writable } = require('stream');
-const { inherits } = require('util');
 
 function Sign(algorithm, options) {
   if (!(this instanceof Sign))
@@ -30,7 +29,7 @@ function Sign(algorithm, options) {
   Writable.call(this, options);
 }
 
-inherits(Sign, Writable);
+Object.setPrototypeOf(Sign.prototype, Writable.prototype);
 
 Sign.prototype._write = function _write(chunk, encoding, callback) {
   this.update(chunk, encoding);
@@ -101,7 +100,7 @@ function Verify(algorithm, options) {
   Writable.call(this, options);
 }
 
-inherits(Verify, Writable);
+Object.setPrototypeOf(Verify.prototype, Writable.prototype);
 
 Verify.prototype._write = Sign.prototype._write;
 Verify.prototype.update = Sign.prototype.update;
diff --git a/lib/internal/fs/streams.js b/lib/internal/fs/streams.js
@@ -17,7 +17,6 @@ const {
 } = require('internal/fs/utils');
 const { Readable, Writable } = require('stream');
 const { toPathIfFileURL } = require('internal/url');
-const util = require('util');
 
 const kMinPoolSpace = 128;
 
@@ -119,7 +118,7 @@ function ReadStream(path, options) {
     }
   });
 }
-util.inherits(ReadStream, Readable);
+Object.setPrototypeOf(ReadStream.prototype, Readable.prototype);
 
 ReadStream.prototype.open = function() {
   fs.open(this.path, this.flags, this.mode, (er, fd) => {
@@ -273,7 +272,7 @@ function WriteStream(path, options) {
   if (typeof this.fd !== 'number')
     this.open();
 }
-util.inherits(WriteStream, Writable);
+Object.setPrototypeOf(WriteStream.prototype, Writable.prototype);
 
 WriteStream.prototype._final = function(callback) {
   if (this.autoClose) {
diff --git a/lib/internal/fs/sync_write_stream.js b/lib/internal/fs/sync_write_stream.js
@@ -1,7 +1,6 @@
 'use strict';
 
 const { Writable } = require('stream');
-const { inherits } = require('util');
 const { closeSync, writeSync } = require('fs');
 
 function SyncWriteStream(fd, options) {
@@ -16,7 +15,7 @@ function SyncWriteStream(fd, options) {
   this.on('end', () => this._destroy());
 }
 
-inherits(SyncWriteStream, Writable);
+Object.setPrototypeOf(SyncWriteStream.prototype, Writable.prototype);
 
 SyncWriteStream.prototype._write = function(chunk, encoding, cb) {
   writeSync(this.fd, chunk, 0, chunk.length);
diff --git a/lib/internal/fs/watchers.js b/lib/internal/fs/watchers.js
@@ -19,7 +19,6 @@ const {
 const { toNamespacedPath } = require('path');
 const { validateUint32 } = require('internal/validators');
 const { toPathIfFileURL } = require('internal/url');
-const util = require('util');
 const assert = require('assert');
 
 const kOldStatus = Symbol('kOldStatus');
@@ -36,7 +35,7 @@ function StatWatcher(bigint) {
   this[kOldStatus] = -1;
   this[kUseBigint] = bigint;
 }
-util.inherits(StatWatcher, EventEmitter);
+Object.setPrototypeOf(StatWatcher.prototype, EventEmitter.prototype);
 
 function onchange(newStatus, stats) {
   const self = this[owner_symbol];
@@ -132,7 +131,7 @@ function FSWatcher() {
     }
   };
 }
-util.inherits(FSWatcher, EventEmitter);
+Object.setPrototypeOf(FSWatcher.prototype, EventEmitter.prototype);
 
 
 // FIXME(joyeecheung): this method is not documented.
diff --git a/lib/internal/streams/legacy.js b/lib/internal/streams/legacy.js
@@ -1,12 +1,11 @@
 'use strict';
 
 const EE = require('events');
-const util = require('util');
 
 function Stream() {
   EE.call(this);
 }
-util.inherits(Stream, EE);
+Object.setPrototypeOf(Stream.prototype, EE.prototype);
 
 Stream.prototype.pipe = function(dest, options) {
   var source = this;
diff --git a/lib/net.js b/lib/net.js
@@ -1145,7 +1145,7 @@ function Server(options, connectionListener) {
   this.allowHalfOpen = options.allowHalfOpen || false;
   this.pauseOnConnect = !!options.pauseOnConnect;
 }
-util.inherits(Server, EventEmitter);
+Object.setPrototypeOf(Server.prototype, EventEmitter.prototype);
 
 
 function toNumber(x) { return (x = Number(x)) >= 0 ? x : false; }
diff --git a/lib/perf_hooks.js b/lib/perf_hooks.js
@@ -33,7 +33,6 @@ const {
 const { AsyncResource } = require('async_hooks');
 const L = require('internal/linkedlist');
 const kInspect = require('internal/util').customInspectSymbol;
-const { inherits } = require('util');
 
 const kCallback = Symbol('callback');
 const kTypes = Symbol('types');
@@ -208,10 +207,8 @@ class PerformanceNodeTiming {
     };
   }
 }
-// Use this instead of Extends because we want PerformanceEntry in the
-// prototype chain but we do not want to use the PerformanceEntry
-// constructor for this.
-inherits(PerformanceNodeTiming, PerformanceEntry);
+Object.setPrototypeOf(
+  PerformanceNodeTiming.prototype, PerformanceEntry.prototype);
 
 const nodeTiming = new PerformanceNodeTiming();
 
diff --git a/lib/readline.js b/lib/readline.js
@@ -32,7 +32,7 @@ const {
   ERR_INVALID_CURSOR_POS,
   ERR_INVALID_OPT_VALUE
 } = require('internal/errors').codes;
-const { debug, inherits } = require('util');
+const { debug } = require('util');
 const { emitExperimentalWarning } = require('internal/util');
 const { Buffer } = require('buffer');
 const EventEmitter = require('events');
@@ -245,7 +245,7 @@ function Interface(input, output, completer, terminal) {
   input.resume();
 }
 
-inherits(Interface, EventEmitter);
+Object.setPrototypeOf(Interface.prototype, EventEmitter.prototype);
 
 Object.defineProperty(Interface.prototype, 'columns', {
   configurable: true,
diff --git a/lib/repl.js b/lib/repl.js
diff --git a/lib/zlib.js b/lib/zlib.js

Original file line number	Diff line number	Diff line change
`@@ -105,8 +105,7 @@ function Agent(options) {`
`105`	`105`	`}`
`106`	`106`	`});`
`107`	`107`	`}`
`108`		`-`
`109`		`-util.inherits(Agent, EventEmitter);`
	`108`	`+Object.setPrototypeOf(Agent.prototype, EventEmitter.prototype);`
`110`	`109`
`111`	`110`	`Agent.defaultMaxSockets = Infinity;`
`112`	`111`
Original file line number	Diff line number	Diff line change
`@@ -279,9 +279,7 @@ function ClientRequest(input, options, cb) {`
`279`	`279`
`280`	`280`	`this._deferToConnect(null, null, () => this._flush());`
`281`	`281`	`}`
`282`		`-`
`283`		`-util.inherits(ClientRequest, OutgoingMessage);`
`284`		`-`
	`282`	`+Object.setPrototypeOf(ClientRequest.prototype, OutgoingMessage.prototype);`
`285`	`283`
`286`	`284`	`ClientRequest.prototype._finish = function _finish() {`
`287`	`285`	`DTRACE_HTTP_CLIENT_REQUEST(this, this.connection);`
Original file line number	Diff line number	Diff line change
`@@ -106,7 +106,7 @@ function OutgoingMessage() {`
`106`	`106`
`107`	`107`	`this._onPendingData = noopPendingOutput;`
`108`	`108`	`}`
`109`		`-util.inherits(OutgoingMessage, Stream);`
	`109`	`+Object.setPrototypeOf(OutgoingMessage.prototype, Stream.prototype);`
`110`	`110`
`111`	`111`
`112`	`112`	`Object.defineProperty(OutgoingMessage.prototype, '_headers', {`
Original file line number	Diff line number	Diff line change
`@@ -137,7 +137,7 @@ function ServerResponse(req) {`
`137`	`137`	`this.shouldKeepAlive = false;`
`138`	`138`	`}`
`139`	`139`	`}`
`140`		`-util.inherits(ServerResponse, OutgoingMessage);`
	`140`	`+Object.setPrototypeOf(ServerResponse.prototype, OutgoingMessage.prototype);`
`141`	`141`
`142`	`142`	`ServerResponse.prototype._finish = function _finish() {`
`143`	`143`	`DTRACE_HTTP_SERVER_RESPONSE(this.connection);`
Original file line number	Diff line number	Diff line change
`@@ -28,11 +28,10 @@`
`28`	`28`
`29`	`29`	`module.exports = Duplex;`
`30`	`30`
`31`		`-const util = require('util');`
`32`	`31`	`const Readable = require('_stream_readable');`
`33`	`32`	`const Writable = require('_stream_writable');`
`34`	`33`
`35`		`-util.inherits(Duplex, Readable);`
	`34`	`+Object.setPrototypeOf(Duplex.prototype, Readable.prototype);`
`36`	`35`
`37`	`36`	`{`
`38`	`37`	`// Allow the keys array to be GC'ed.`