lib: use const to define constants

This commit replaces a number of var statements throughout
the lib code with const statements.

PR-URL: #541
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

lib/_debug_agent.js

@@ -1,17 +1,16 @@
 'use strict';
 
-var assert = require('assert');
-var net = require('net');
-var util = require('util');
-var Buffer = require('buffer').Buffer;
-
-var Transform = require('stream').Transform;
+const assert = require('assert');
+const net = require('net');
+const util = require('util');
+const Buffer = require('buffer').Buffer;
+const Transform = require('stream').Transform;
 
 exports.start = function start() {
   var agent = new Agent();
 
   // Do not let `agent.listen()` request listening from cluster master
-  var cluster = require('cluster');
+  const cluster = require('cluster');
   cluster.isWorker = false;
   cluster.isMaster = true;
 

lib/_debugger.js

@@ -1,14 +1,14 @@
 'use strict';
 
-var util = require('util'),
-    path = require('path'),
-    net = require('net'),
-    vm = require('vm'),
-    module = require('module'),
-    repl = module.requireRepl(),
-    inherits = util.inherits,
-    assert = require('assert'),
-    spawn = require('child_process').spawn;
+const util = require('util');
+const path = require('path');
+const net = require('net');
+const vm = require('vm');
+const module = require('module');
+const repl = module.requireRepl();
+const inherits = util.inherits;
+const assert = require('assert');
+const spawn = require('child_process').spawn;
 
 exports.start = function(argv, stdin, stdout) {
   argv || (argv = process.argv.slice(2));
@@ -137,7 +137,7 @@ Protocol.prototype.serialize = function(req) {
 };
 
 
-var NO_FRAME = -1;
+const NO_FRAME = -1;
 
 function Client() {
   net.Stream.call(this);
@@ -176,7 +176,7 @@ Client.prototype._addHandle = function(desc) {
 };
 
 
-var natives = process.binding('natives');
+const natives = process.binding('natives');
 
 
 Client.prototype._addScript = function(desc) {
@@ -645,7 +645,7 @@ Client.prototype.fullTrace = function(cb) {
 
 
 
-var commands = [
+const commands = [
   [
     'run (r)',
     'cont (c)',
@@ -772,22 +772,22 @@ function Interface(stdin, stdout, args) {
   process.once('SIGTERM', process.exit.bind(process, 0));
   process.once('SIGHUP', process.exit.bind(process, 0));
 
-  var proto = Interface.prototype,
-      ignored = ['pause', 'resume', 'exitRepl', 'handleBreak',
-                 'requireConnection', 'killChild', 'trySpawn',
-                 'controlEval', 'debugEval', 'print', 'childPrint',
-                 'clearline'],
-      shortcut = {
-        'run': 'r',
-        'cont': 'c',
-        'next': 'n',
-        'step': 's',
-        'out': 'o',
-        'backtrace': 'bt',
-        'setBreakpoint': 'sb',
-        'clearBreakpoint': 'cb',
-        'pause_': 'pause'
-      };
+  var proto = Interface.prototype;
+  const ignored = ['pause', 'resume', 'exitRepl', 'handleBreak',
+                   'requireConnection', 'killChild', 'trySpawn',
+                   'controlEval', 'debugEval', 'print', 'childPrint',
+                   'clearline'];
+  const shortcut = {
+    'run': 'r',
+    'cont': 'c',
+    'next': 'n',
+    'step': 's',
+    'out': 'o',
+    'backtrace': 'bt',
+    'setBreakpoint': 'sb',
+    'clearBreakpoint': 'cb',
+    'pause_': 'pause'
+  };
 
   function defineProperty(key, protoKey) {
     // Check arity

lib/_http_agent.js

@@ -1,9 +1,9 @@
 'use strict';
 
-var net = require('net');
-var util = require('util');
-var EventEmitter = require('events').EventEmitter;
-var debug = util.debuglog('http');
+const net = require('net');
+const util = require('util');
+const EventEmitter = require('events').EventEmitter;
+const debug = util.debuglog('http');
 
 // New Agent code.
 

lib/_http_client.js

@@ -1,22 +1,18 @@
 'use strict';
 
-var util = require('util');
-var net = require('net');
-var url = require('url');
-var EventEmitter = require('events').EventEmitter;
-var HTTPParser = process.binding('http_parser').HTTPParser;
-var assert = require('assert').ok;
-
-var common = require('_http_common');
-
-var httpSocketSetup = common.httpSocketSetup;
-var parsers = common.parsers;
-var freeParser = common.freeParser;
-var debug = common.debug;
-
-var OutgoingMessage = require('_http_outgoing').OutgoingMessage;
-
-var Agent = require('_http_agent');
+const util = require('util');
+const net = require('net');
+const url = require('url');
+const EventEmitter = require('events').EventEmitter;
+const HTTPParser = process.binding('http_parser').HTTPParser;
+const assert = require('assert').ok;
+const common = require('_http_common');
+const httpSocketSetup = common.httpSocketSetup;
+const parsers = common.parsers;
+const freeParser = common.freeParser;
+const debug = common.debug;
+const OutgoingMessage = require('_http_outgoing').OutgoingMessage;
+const Agent = require('_http_agent');
 
 
 function ClientRequest(options, cb) {
@@ -56,7 +52,8 @@ function ClientRequest(options, cb) {
                     'Expected "' + expectedProtocol + '".');
   }
 
-  var defaultPort = options.defaultPort || self.agent && self.agent.defaultPort;
+  const defaultPort = options.defaultPort ||
+                      self.agent && self.agent.defaultPort;
 
   var port = options.port = options.port || defaultPort || 80;
   var host = options.host = options.hostname || options.host || 'localhost';

lib/_http_common.js

@@ -1,26 +1,26 @@
 'use strict';
 
-var FreeList = require('freelist').FreeList;
-var HTTPParser = process.binding('http_parser').HTTPParser;
+const FreeList = require('freelist').FreeList;
+const HTTPParser = process.binding('http_parser').HTTPParser;
 
-var incoming = require('_http_incoming');
-var IncomingMessage = incoming.IncomingMessage;
-var readStart = incoming.readStart;
-var readStop = incoming.readStop;
+const incoming = require('_http_incoming');
+const IncomingMessage = incoming.IncomingMessage;
+const readStart = incoming.readStart;
+const readStop = incoming.readStop;
 
-var isNumber = require('util').isNumber;
-var debug = require('util').debuglog('http');
+const isNumber = require('util').isNumber;
+const debug = require('util').debuglog('http');
 exports.debug = debug;
 
 exports.CRLF = '\r\n';
 exports.chunkExpression = /chunk/i;
 exports.continueExpression = /100-continue/i;
 exports.methods = HTTPParser.methods;
 
-var kOnHeaders = HTTPParser.kOnHeaders | 0;
-var kOnHeadersComplete = HTTPParser.kOnHeadersComplete | 0;
-var kOnBody = HTTPParser.kOnBody | 0;
-var kOnMessageComplete = HTTPParser.kOnMessageComplete | 0;
+const kOnHeaders = HTTPParser.kOnHeaders | 0;
+const kOnHeadersComplete = HTTPParser.kOnHeadersComplete | 0;
+const kOnBody = HTTPParser.kOnBody | 0;
+const kOnMessageComplete = HTTPParser.kOnMessageComplete | 0;
 
 // Only called in the slow case where slow means
 // that the request headers were either fragmented

lib/_http_incoming.js

@@ -1,7 +1,7 @@
 'use strict';
 
-var util = require('util');
-var Stream = require('stream');
+const util = require('util');
+const Stream = require('stream');
 
 function readStart(socket) {
   if (socket && !socket._paused && socket.readable)

lib/_http_outgoing.js

@@ -1,25 +1,23 @@
 'use strict';
 
-var assert = require('assert').ok;
-var Stream = require('stream');
-var timers = require('timers');
-var util = require('util');
-
-var common = require('_http_common');
-
-var CRLF = common.CRLF;
-var chunkExpression = common.chunkExpression;
-var debug = common.debug;
-
-
-var connectionExpression = /Connection/i;
-var transferEncodingExpression = /Transfer-Encoding/i;
-var closeExpression = /close/i;
-var contentLengthExpression = /Content-Length/i;
-var dateExpression = /Date/i;
-var expectExpression = /Expect/i;
-
-var automaticHeaders = {
+const assert = require('assert').ok;
+const Stream = require('stream');
+const timers = require('timers');
+const util = require('util');
+const common = require('_http_common');
+
+const CRLF = common.CRLF;
+const chunkExpression = common.chunkExpression;
+const debug = common.debug;
+
+const connectionExpression = /Connection/i;
+const transferEncodingExpression = /Transfer-Encoding/i;
+const closeExpression = /close/i;
+const contentLengthExpression = /Content-Length/i;
+const dateExpression = /Date/i;
+const expectExpression = /Expect/i;
+
+const automaticHeaders = {
   connection: true,
   'content-length': true,
   'transfer-encoding': true,
@@ -477,7 +475,7 @@ OutgoingMessage.prototype.addTrailers = function(headers) {
 };
 
 
-var crlf_buf = new Buffer('\r\n');
+const crlf_buf = new Buffer('\r\n');
 
 
 OutgoingMessage.prototype.end = function(data, encoding, callback) {

lib/_http_server.js

@@ -1,24 +1,21 @@
 'use strict';
 
-var util = require('util');
-var net = require('net');
-var EventEmitter = require('events').EventEmitter;
-var HTTPParser = process.binding('http_parser').HTTPParser;
-var assert = require('assert').ok;
-
-var common = require('_http_common');
-var parsers = common.parsers;
-var freeParser = common.freeParser;
-var debug = common.debug;
-var CRLF = common.CRLF;
-var continueExpression = common.continueExpression;
-var chunkExpression = common.chunkExpression;
-var httpSocketSetup = common.httpSocketSetup;
-
-var OutgoingMessage = require('_http_outgoing').OutgoingMessage;
-
-
-var STATUS_CODES = exports.STATUS_CODES = {
+const util = require('util');
+const net = require('net');
+const EventEmitter = require('events').EventEmitter;
+const HTTPParser = process.binding('http_parser').HTTPParser;
+const assert = require('assert').ok;
+const common = require('_http_common');
+const parsers = common.parsers;
+const freeParser = common.freeParser;
+const debug = common.debug;
+const CRLF = common.CRLF;
+const continueExpression = common.continueExpression;
+const chunkExpression = common.chunkExpression;
+const httpSocketSetup = common.httpSocketSetup;
+const OutgoingMessage = require('_http_outgoing').OutgoingMessage;
+
+const STATUS_CODES = exports.STATUS_CODES = {
   100 : 'Continue',
   101 : 'Switching Protocols',
   102 : 'Processing',                 // RFC 2518, obsoleted by RFC 4918

lib/_stream_duplex.js

@@ -6,9 +6,10 @@
 'use strict';
 
 module.exports = Duplex;
-var util = require('util');
-var Readable = require('_stream_readable');
-var Writable = require('_stream_writable');
+
+const util = require('util');
+const Readable = require('_stream_readable');
+const Writable = require('_stream_writable');
 
 util.inherits(Duplex, Readable);
 

lib/_stream_passthrough.js

@@ -6,8 +6,8 @@
 
 module.exports = PassThrough;
 
-var Transform = require('_stream_transform');
-var util = require('util');
+const Transform = require('_stream_transform');
+const util = require('util');
 util.inherits(PassThrough, Transform);
 
 function PassThrough(options) {

lib/_stream_readable.js

@@ -3,11 +3,11 @@
 module.exports = Readable;
 Readable.ReadableState = ReadableState;
 
-var EE = require('events').EventEmitter;
-var Stream = require('stream');
-var util = require('util');
+const EE = require('events').EventEmitter;
+const Stream = require('stream');
+const util = require('util');
+const debug = util.debuglog('stream');
 var StringDecoder;
-var debug = util.debuglog('stream');
 
 util.inherits(Readable, Stream);
 
@@ -189,7 +189,7 @@ Readable.prototype.setEncoding = function(enc) {
 };
 
 // Don't raise the hwm > 128MB
-var MAX_HWM = 0x800000;
+const MAX_HWM = 0x800000;
 function roundUpToNextPowerOf2(n) {
   if (n >= MAX_HWM) {
     n = MAX_HWM;
@@ -781,7 +781,7 @@ Readable.prototype.wrap = function(stream) {
   }
 
   // proxy certain important events.
-  var events = ['error', 'close', 'destroy', 'pause', 'resume'];
+  const events = ['error', 'close', 'destroy', 'pause', 'resume'];
   events.forEach(function(ev) {
     stream.on(ev, self.emit.bind(self, ev));
   });

lib/_stream_transform.js

@@ -44,8 +44,8 @@
 
 module.exports = Transform;
 
-var Duplex = require('_stream_duplex');
-var util = require('util');
+const Duplex = require('_stream_duplex');
+const util = require('util');
 util.inherits(Transform, Duplex);