benchmark,lib: var to const

benchmark/fs/readfile-partitioned.js

@@ -29,7 +29,7 @@ function main(conf) {
   fs.writeFileSync(filename, data);
   data = null;
 
-  var zipData = Buffer.alloc(1024, 'a');
+  const zipData = Buffer.alloc(1024, 'a');
 
   var reads = 0;
   var zips = 0;

benchmark/fs/write-stream-throughput.js

@@ -38,7 +38,7 @@ function main({ dur, encodingType, size }) {
   var started = false;
   var ended = false;
 
-  var f = fs.createWriteStream(filename);
+  const f = fs.createWriteStream(filename);
   f.on('drain', write);
   f.on('open', write);
   f.on('close', done);

benchmark/http/_chunky_http_client.js

@@ -54,7 +54,7 @@ function main({ len, n }) {
   const add = 11;
   var count = 0;
   const PIPE = process.env.PIPE_NAME;
-  var socket = net.connect(PIPE, () => {
+  const socket = net.connect(PIPE, () => {
     bench.start();
     WriteHTTPHeaders(socket, 1, len);
     socket.setEncoding('utf8');

benchmark/http/http_server_for_chunky_client.js

@@ -10,9 +10,7 @@ process.env.PIPE_NAME = PIPE;
 
 tmpdir.refresh();
 
-var server;
-
-server = http.createServer((req, res) => {
+const server = http.createServer((req, res) => {
   const headers = {
     'content-type': 'text/plain',
     'content-length': '2'

benchmark/http/set-header.js

@@ -17,7 +17,7 @@ const c = 50;
 // setHeaderWH: setHeader(...), writeHead(status, ...)
 function main({ res }) {
   process.env.PORT = PORT;
-  var server = require('../fixtures/simple-http-server.js')
+  const server = require('../fixtures/simple-http-server.js')
   .listen(PORT)
   .on('listening', () => {
     const path = `/${type}/${len}/${chunks}/normal/${chunkedEnc}`;

benchmark/http/simple.js

@@ -11,7 +11,7 @@ const bench = common.createBenchmark(main, {
 });
 
 function main({ type, len, chunks, c, chunkedEnc, res }) {
-  var server = require('../fixtures/simple-http-server.js')
+  const server = require('../fixtures/simple-http-server.js')
   .listen(common.PORT)
   .on('listening', () => {
     const path = `/${type}/${len}/${chunks}/normal/${chunkedEnc}`;

benchmark/http/upgrade.js

@@ -19,7 +19,7 @@ const resData = 'HTTP/1.1 101 Web Socket Protocol Handshake\r\n' +
                 '\r\n\r\n';
 
 function main({ n }) {
-  var server = require('../fixtures/simple-http-server.js')
+  const server = require('../fixtures/simple-http-server.js')
     .listen(common.PORT)
     .on('listening', () => {
       bench.start();

benchmark/tls/throughput.js

@@ -14,7 +14,6 @@ const tls = require('tls');
 
 function main({ dur, type, size }) {
   var encoding;
-  var server;
   var chunk;
   switch (type) {
     case 'buf':
@@ -39,7 +38,7 @@ function main({ dur, type, size }) {
     ciphers: 'AES256-GCM-SHA384'
   };
 
-  server = tls.createServer(options, onConnection);
+  const server = tls.createServer(options, onConnection);
   var conn;
   server.listen(common.PORT, () => {
     const opt = { port: common.PORT, rejectUnauthorized: false };

benchmark/tls/tls-connect.js

@@ -46,7 +46,7 @@ function makeConnection() {
     port: common.PORT,
     rejectUnauthorized: false
   };
-  var conn = tls.connect(options, () => {
+  const conn = tls.connect(options, () => {
     clientConn++;
     conn.on('error', (er) => {
       console.error('client error', er);

lib/_http_agent.js

@@ -60,7 +60,7 @@ function Agent(options) {
   this.maxFreeSockets = this.options.maxFreeSockets || 256;
 
   this.on('free', (socket, options) => {
-    var name = this.getName(options);
+    const name = this.getName(options);
     debug('agent.on(free)', name);
 
     if (socket.writable &&
@@ -152,13 +152,13 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
   if (!options.servername)
     options.servername = calculateServerName(options, req);
 
-  var name = this.getName(options);
+  const name = this.getName(options);
   if (!this.sockets[name]) {
     this.sockets[name] = [];
   }
 
-  var freeLen = this.freeSockets[name] ? this.freeSockets[name].length : 0;
-  var sockLen = freeLen + this.sockets[name].length;
+  const freeLen = this.freeSockets[name] ? this.freeSockets[name].length : 0;
+  const sockLen = freeLen + this.sockets[name].length;
 
   if (freeLen) {
     // We have a free socket, so use that.
@@ -199,7 +199,7 @@ Agent.prototype.createSocket = function createSocket(req, options, cb) {
   if (!options.servername)
     options.servername = calculateServerName(options, req);
 
-  var name = this.getName(options);
+  const name = this.getName(options);
   options._agentKey = name;
 
   debug('createConnection', name, options);
@@ -279,9 +279,9 @@ function installListeners(agent, s, options) {
 }
 
 Agent.prototype.removeSocket = function removeSocket(s, options) {
-  var name = this.getName(options);
+  const name = this.getName(options);
   debug('removeSocket', name, 'writable:', s.writable);
-  var sets = [this.sockets];
+  const sets = [this.sockets];
 
   // If the socket was destroyed, remove it from the free buffers too.
   if (!s.writable)
@@ -323,7 +323,7 @@ Agent.prototype.reuseSocket = function reuseSocket(socket, req) {
 };
 
 Agent.prototype.destroy = function destroy() {
-  var sets = [this.freeSockets, this.sockets];
+  const sets = [this.freeSockets, this.sockets];
   for (var s = 0; s < sets.length; s++) {
     var set = sets[s];
     var keys = Object.keys(set);

lib/_http_client.js

@@ -102,7 +102,7 @@ function ClientRequest(input, options, cb) {
   }
 
   var agent = options.agent;
-  var defaultAgent = options._defaultAgent || Agent.globalAgent;
+  const defaultAgent = options._defaultAgent || Agent.globalAgent;
   if (agent === false) {
     agent = new defaultAgent.constructor();
   } else if (agent === null || agent === undefined) {
@@ -118,7 +118,7 @@ function ClientRequest(input, options, cb) {
   }
   this.agent = agent;
 
-  var protocol = options.protocol || defaultAgent.protocol;
+  const protocol = options.protocol || defaultAgent.protocol;
   var expectedProtocol = defaultAgent.protocol;
   if (this.agent && this.agent.protocol)
     expectedProtocol = this.agent.protocol;
@@ -134,22 +134,22 @@ function ClientRequest(input, options, cb) {
     throw new ERR_INVALID_PROTOCOL(protocol, expectedProtocol);
   }
 
-  var defaultPort = options.defaultPort ||
+  const defaultPort = options.defaultPort ||
                     this.agent && this.agent.defaultPort;
 
-  var port = options.port = options.port || defaultPort || 80;
-  var host = options.host = validateHost(options.hostname, 'hostname') ||
+  const port = options.port = options.port || defaultPort || 80;
+  const host = options.host = validateHost(options.hostname, 'hostname') ||
                             validateHost(options.host, 'host') || 'localhost';
 
-  var setHost = (options.setHost === undefined || Boolean(options.setHost));
+  const setHost = (options.setHost === undefined || Boolean(options.setHost));
 
   this.socketPath = options.socketPath;
 
   if (options.timeout !== undefined)
     this.timeout = getTimerDuration(options.timeout, 'timeout');
 
   var method = options.method;
-  var methodIsString = (typeof method === 'string');
+  const methodIsString = (typeof method === 'string');
   if (method !== null && method !== undefined && !methodIsString) {
     throw new ERR_INVALID_ARG_TYPE('method', 'string', method);
   }
@@ -202,7 +202,7 @@ function ClientRequest(input, options, cb) {
     }
   }
 
-  var headersArray = Array.isArray(options.headers);
+  const headersArray = Array.isArray(options.headers);
   if (!headersArray) {
     if (options.headers) {
       var keys = Object.keys(options.headers);
@@ -249,7 +249,7 @@ function ClientRequest(input, options, cb) {
                       options.headers);
   }
 
-  var oncreate = (err, socket) => {
+  const oncreate = (err, socket) => {
     if (called)
       return;
     called = true;
@@ -331,15 +331,15 @@ function emitAbortNT() {
 
 function createHangUpError() {
   // eslint-disable-next-line no-restricted-syntax
-  var error = new Error('socket hang up');
+  const error = new Error('socket hang up');
   error.code = 'ECONNRESET';
   return error;
 }
 
 
 function socketCloseListener() {
-  var socket = this;
-  var req = socket._httpMessage;
+  const socket = this;
+  const req = socket._httpMessage;
   debug('HTTP socket close');
 
   // Pull through final chunk, if anything is buffered.
@@ -390,8 +390,8 @@ function socketCloseListener() {
 }
 
 function socketErrorListener(err) {
-  var socket = this;
-  var req = socket._httpMessage;
+  const socket = this;
+  const req = socket._httpMessage;
   debug('SOCKET ERROR:', err.message, err.stack);
 
   if (req) {
@@ -404,7 +404,7 @@ function socketErrorListener(err) {
   // Handle any pending data
   socket.read();
 
-  var parser = socket.parser;
+  const parser = socket.parser;
   if (parser) {
     parser.finish();
     freeParser(parser, req, socket);
@@ -417,16 +417,16 @@ function socketErrorListener(err) {
 }
 
 function freeSocketErrorListener(err) {
-  var socket = this;
+  const socket = this;
   debug('SOCKET ERROR on FREE socket:', err.message, err.stack);
   socket.destroy();
   socket.emit('agentRemove');
 }
 
 function socketOnEnd() {
-  var socket = this;
-  var req = this._httpMessage;
-  var parser = this.parser;
+  const socket = this;
+  const req = this._httpMessage;
+  const parser = this.parser;
 
   if (!req.res && !req.socket._hadError) {
     // If we don't have a response then we know that the socket
@@ -442,13 +442,13 @@ function socketOnEnd() {
 }
 
 function socketOnData(d) {
-  var socket = this;
-  var req = this._httpMessage;
-  var parser = this.parser;
+  const socket = this;
+  const req = this._httpMessage;
+  const parser = this.parser;
 
   assert(parser && parser.socket === socket);
 
-  var ret = parser.execute(d);
+  const ret = parser.execute(d);
   if (ret instanceof Error) {
     debug('parse error', ret);
     freeParser(parser, req, socket);
@@ -510,8 +510,8 @@ function statusIsInformational(status) {
 
 // client
 function parserOnIncomingClient(res, shouldKeepAlive) {
-  var socket = this.socket;
-  var req = socket._httpMessage;
+  const socket = this.socket;
+  const req = socket._httpMessage;
 
   debug('AGENT incoming response!');
 
@@ -561,7 +561,7 @@ function parserOnIncomingClient(res, shouldKeepAlive) {
   // Add our listener first, so that we guarantee socket cleanup
   res.on('end', responseOnEnd);
   req.on('prefinish', requestOnPrefinish);
-  var handled = req.emit('response', res);
+  const handled = req.emit('response', res);
 
   // If the user did not listen for the 'response' event, then they
   // can't possibly read the data, so we ._dump() it into the void
@@ -577,7 +577,7 @@ function parserOnIncomingClient(res, shouldKeepAlive) {
 
 // client
 function responseKeepAlive(res, req) {
-  var socket = req.socket;
+  const socket = req.socket;
 
   if (!req.shouldKeepAlive) {
     if (socket.writable) {
@@ -631,7 +631,7 @@ function emitFreeNT(socket) {
 }
 
 function tickOnSocket(req, socket) {
-  var parser = parsers.alloc();
+  const parser = parsers.alloc();
   req.socket = socket;
   req.connection = socket;
   parser.reinitialize(HTTPParser.RESPONSE, parser[is_reused_symbol]);

lib/_http_incoming.js

@@ -243,7 +243,7 @@ function matchKnownFields(field, lowercased) {
 IncomingMessage.prototype._addHeaderLine = _addHeaderLine;
 function _addHeaderLine(field, value, dest) {
   field = matchKnownFields(field);
-  var flag = field.charCodeAt(0);
+  const flag = field.charCodeAt(0);
   if (flag === 0 || flag === 2) {
     field = field.slice(1);
     // Make a delimited list

lib/_http_outgoing.js

@@ -55,8 +55,8 @@ const kIsCorked = Symbol('isCorked');
 
 const hasOwnProperty = Function.call.bind(Object.prototype.hasOwnProperty);
 
-var RE_CONN_CLOSE = /(?:^|\W)close(?:$|\W)/i;
-var RE_TE_CHUNKED = common.chunkExpression;
+const RE_CONN_CLOSE = /(?:^|\W)close(?:$|\W)/i;
+const RE_TE_CHUNKED = common.chunkExpression;
 
 // isCookieField performs a case-insensitive comparison of a provided string
 // against the word "cookie." As of V8 6.6 this is faster than handrolling or
@@ -164,7 +164,7 @@ OutgoingMessage.prototype._renderHeaders = function _renderHeaders() {
     throw new ERR_HTTP_HEADERS_SENT('render');
   }
 
-  var headersMap = this[outHeadersKey];
+  const headersMap = this[outHeadersKey];
   const headers = {};
 
   if (headersMap !== null) {
@@ -525,7 +525,7 @@ OutgoingMessage.prototype.removeHeader = function removeHeader(name) {
     throw new ERR_HTTP_HEADERS_SENT('remove');
   }
 
-  var key = name.toLowerCase();
+  const key = name.toLowerCase();
 
   switch (key) {
     case 'connection':
@@ -641,8 +641,8 @@ function connectionCorkNT(msg, conn) {
 
 OutgoingMessage.prototype.addTrailers = function addTrailers(headers) {
   this._trailer = '';
-  var keys = Object.keys(headers);
-  var isArray = Array.isArray(headers);
+  const keys = Object.keys(headers);
+  const isArray = Array.isArray(headers);
   var field, value;
   for (var i = 0, l = keys.length; i < l; i++) {
     var key = keys[i];
@@ -705,7 +705,7 @@ OutgoingMessage.prototype.end = function end(chunk, encoding, callback) {
   if (typeof callback === 'function')
     this.once('finish', callback);
 
-  var finish = onFinish.bind(undefined, this);
+  const finish = onFinish.bind(undefined, this);
 
   if (this._hasBody && this.chunkedEncoding) {
     this._send('0\r\n' + this._trailer + '\r\n', 'latin1', finish);
@@ -758,7 +758,7 @@ OutgoingMessage.prototype._finish = function _finish() {
 // This function, outgoingFlush(), is called by both the Server and Client
 // to attempt to flush any pending messages out to the socket.
 OutgoingMessage.prototype._flush = function _flush() {
-  var socket = this.socket;
+  const socket = this.socket;
   var ret;
 
   if (socket && socket.writable) {