lib: prefer optional chaining

PR-URL: #55045
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>

Author: avivkeller

eslint.config.mjs

@@ -313,6 +313,7 @@ export default [
       'node-core/no-unescaped-regexp-dot': 'error',
       'node-core/no-duplicate-requires': 'error',
       'node-core/prefer-proto': 'error',
+      'node-core/prefer-optional-chaining': 'error',
     },
   },
   // #endregion

lib/_http_agent.js

@@ -128,7 +128,7 @@ function Agent(options) {
     }
 
     const requests = this.requests[name];
-    if (requests && requests.length) {
+    if (requests?.length) {
       const req = requests.shift();
       const reqAsyncRes = req[kRequestAsyncResource];
       if (reqAsyncRes) {
@@ -437,7 +437,7 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
   }
 
   let req;
-  if (this.requests[name] && this.requests[name].length) {
+  if (this.requests[name]?.length) {
     debug('removeSocket, have a request, make a socket');
     req = this.requests[name][0];
   } else {
@@ -449,7 +449,7 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
     for (let i = 0; i < keys.length; i++) {
       const prop = keys[i];
       // Check whether this specific origin is already at maxSockets
-      if (this.sockets[prop] && this.sockets[prop].length) break;
+      if (this.sockets[prop]?.length) break;
       debug('removeSocket, have a request with different origin,' +
         ' make a socket');
       req = this.requests[prop][0];

lib/_http_client.js

@@ -174,7 +174,7 @@ function ClientRequest(input, options, cb) {
 
   const protocol = options.protocol || defaultAgent.protocol;
   let expectedProtocol = defaultAgent.protocol;
-  if (this.agent && this.agent.protocol)
+  if (this.agent?.protocol)
     expectedProtocol = this.agent.protocol;
 
   if (options.path) {
@@ -190,7 +190,7 @@ function ClientRequest(input, options, cb) {
   }
 
   const defaultPort = options.defaultPort ||
-                    (this.agent && this.agent.defaultPort);
+                    (this.agent?.defaultPort);
 
   const optsWithoutSignal = { __proto__: null, ...options };
 
@@ -553,7 +553,7 @@ function socketOnData(d) {
     socket.destroy();
     req.socket._hadError = true;
     emitErrorEvent(req, ret);
-  } else if (parser.incoming && parser.incoming.upgrade) {
+  } else if (parser.incoming?.upgrade) {
     // Upgrade (if status code 101) or CONNECT
     const bytesParsed = ret;
     const res = parser.incoming;
@@ -591,7 +591,7 @@ function socketOnData(d) {
       // Requested Upgrade or used CONNECT method, but have no handler.
       socket.destroy();
     }
-  } else if (parser.incoming && parser.incoming.complete &&
+  } else if (parser.incoming?.complete &&
              // When the status code is informational (100, 102-199),
              // the server will send a final response after this client
              // sends a request body, so we must not free the parser.
@@ -838,7 +838,7 @@ function tickOnSocket(req, socket) {
 
   if (
     req.timeout !== undefined ||
-    (req.agent && req.agent.options && req.agent.options.timeout)
+    (req.agent?.options?.timeout)
   ) {
     listenSocketTimeout(req);
   }

lib/_http_common.js

@@ -85,8 +85,7 @@ function parserOnHeadersComplete(versionMajor, versionMinor, headers, method,
   }
 
   // Parser is also used by http client
-  const ParserIncomingMessage = (socket && socket.server &&
-                                 socket.server[kIncomingMessage]) ||
+  const ParserIncomingMessage = (socket?.server?.[kIncomingMessage]) ||
                                  IncomingMessage;
 
   const incoming = parser.incoming = new ParserIncomingMessage(socket);

lib/_http_incoming.js

@@ -242,7 +242,7 @@ IncomingMessage.prototype._destroy = function _destroy(err, cb) {
 
 IncomingMessage.prototype._addHeaderLines = _addHeaderLines;
 function _addHeaderLines(headers, n) {
-  if (headers && headers.length) {
+  if (headers?.length) {
     let dest;
     if (this.complete) {
       this.rawTrailers = headers;

lib/_http_outgoing.js

@@ -423,7 +423,7 @@ OutgoingMessage.prototype._send = function _send(data, encoding, callback, byteL
 OutgoingMessage.prototype._writeRaw = _writeRaw;
 function _writeRaw(data, encoding, callback, size) {
   const conn = this[kSocket];
-  if (conn && conn.destroyed) {
+  if (conn?.destroyed) {
     // The socket was destroyed. If we're still trying to write to it,
     // then we haven't gotten the 'close' event yet.
     return false;
@@ -789,7 +789,7 @@ OutgoingMessage.prototype.getHeader = function getHeader(name) {
     return;
 
   const entry = headers[name.toLowerCase()];
-  return entry && entry[1];
+  return entry?.[1];
 };
 
 
@@ -1073,7 +1073,7 @@ OutgoingMessage.prototype.addTrailers = function addTrailers(headers) {
 };
 
 function onFinish(outmsg) {
-  if (outmsg && outmsg.socket && outmsg.socket._hadError) return;
+  if (outmsg?.socket?._hadError) return;
   outmsg.emit('finish');
 }
 
@@ -1188,7 +1188,7 @@ OutgoingMessage.prototype._finish = function _finish() {
 OutgoingMessage.prototype._flush = function _flush() {
   const socket = this[kSocket];
 
-  if (socket && socket.writable) {
+  if (socket?.writable) {
     // There might be remaining data in this.output; write it out
     const ret = this._flushOutput(socket);
 

lib/_http_server.js

@@ -738,7 +738,7 @@ function connectionListenerInternal(server, socket) {
   socket.setEncoding = socketSetEncoding;
 
   // We only consume the socket if it has never been consumed before.
-  if (socket._handle && socket._handle.isStreamBase &&
+  if (socket._handle?.isStreamBase &&
       !socket._handle._consumed) {
     parser._consumed = true;
     socket._handle._consumed = true;
@@ -783,7 +783,7 @@ function socketOnDrain(socket, state) {
 }
 
 function socketOnTimeout() {
-  const req = this.parser && this.parser.incoming;
+  const req = this.parser?.incoming;
   const reqTimeout = req && !req.complete && req.emit('timeout', this);
   const res = this._httpMessage;
   const resTimeout = res && res.emit('timeout', this);
@@ -918,7 +918,7 @@ function onParserExecuteCommon(server, socket, parser, state, ret, d) {
     prepareError(ret, parser, d);
     debug('parse error', ret);
     socketOnError.call(socket, ret);
-  } else if (parser.incoming && parser.incoming.upgrade) {
+  } else if (parser.incoming?.upgrade) {
     // Upgrade or CONNECT
     const req = parser.incoming;
     debug('SERVER upgrade or connect', req.method);
@@ -963,7 +963,7 @@ function onParserExecuteCommon(server, socket, parser, state, ret, d) {
 
 function clearIncoming(req) {
   req = req || this;
-  const parser = req.socket && req.socket.parser;
+  const parser = req.socket?.parser;
   // Reset the .incoming property so that the request object can be gc'ed.
   if (parser && parser.incoming === req) {
     if (req.readableEnded) {
@@ -1180,7 +1180,7 @@ function onSocketResume() {
 }
 
 function onSocketPause() {
-  if (this._handle && this._handle.reading) {
+  if (this._handle?.reading) {
     this._handle.reading = false;
     this._handle.readStop();
   }

lib/_tls_wrap.js

@@ -489,7 +489,7 @@ function initRead(tlsSocket, socket) {
     return;
 
   // Socket already has some buffered data - emulate receiving it
-  if (socket && socket.readableLength) {
+  if (socket?.readableLength) {
     let buf;
     while ((buf = socket.read()) !== null)
       tlsSocket._handle.receive(buf);
@@ -1683,7 +1683,7 @@ function onConnectSecure() {
   if (!verifyError && !this.isSessionReused()) {
     const hostname = options.servername ||
                    options.host ||
-                   (options.socket && options.socket._host) ||
+                   (options.socket?._host) ||
                    'localhost';
     const cert = this.getPeerCertificate(true);
     verifyError = options.checkServerIdentity(hostname, cert);

lib/assert.js

@@ -446,7 +446,7 @@ function expectedException(actual, expected, message, fn) {
       message = 'The error is expected to be an instance of ' +
         `"${expected.name}". Received `;
       if (isError(actual)) {
-        const name = (actual.constructor && actual.constructor.name) ||
+        const name = (actual.constructor?.name) ||
                      actual.name;
         if (expected.name === name) {
           message += 'an error with identical name but a different prototype.';
@@ -569,7 +569,7 @@ function expectsError(stackStartFn, actual, error, message) {
 
   if (actual === NO_EXCEPTION_SENTINEL) {
     let details = '';
-    if (error && error.name) {
+    if (error?.name) {
       details += ` (${error.name})`;
     }
     details += message ? `: ${message}` : '.';
@@ -627,7 +627,7 @@ function expectsNoError(stackStartFn, actual, error, message) {
       expected: error,
       operator: stackStartFn.name,
       message: `Got unwanted ${fnType}${details}\n` +
-               `Actual message: "${actual && actual.message}"`,
+               `Actual message: "${actual?.message}"`,
       stackStartFn,
     });
   }

lib/child_process.js

@@ -392,17 +392,15 @@ function execFile(file, args, options, callback) {
     let stderr;
     if (encoding ||
       (
-        child.stdout &&
-        child.stdout.readableEncoding
+        child.stdout?.readableEncoding
       )) {
       stdout = ArrayPrototypeJoin(_stdout, '');
     } else {
       stdout = Buffer.concat(_stdout);
     }
     if (encoding ||
       (
-        child.stderr &&
-        child.stderr.readableEncoding
+        child.stderr?.readableEncoding
       )) {
       stderr = ArrayPrototypeJoin(_stderr, '');
     } else {
@@ -855,7 +853,7 @@ function spawnSync(file, args, options) {
 
   // We may want to pass data in on any given fd, ensure it is a valid buffer
   for (let i = 0; i < options.stdio.length; i++) {
-    const input = options.stdio[i] && options.stdio[i].input;
+    const input = options.stdio[i]?.input;
     if (input != null) {
       const pipe = options.stdio[i] = { ...options.stdio[i] };
       if (isArrayBufferView(input)) {