lib: reduce util.is*() usage

Many of the util.is*() methods used to check data types
simply compare against a single value or the result of
typeof. This commit replaces calls to these methods with
equivalent checks. This commit does not touch calls to the
more complex methods (isRegExp(), isDate(), etc.).

Fixes: #607
PR-URL: #647
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

lib/_debugger.js

@@ -164,7 +164,8 @@ exports.Client = Client;
 
 
 Client.prototype._addHandle = function(desc) {
-  if (!util.isObject(desc) || !util.isNumber(desc.handle)) {
+  if (desc === null || typeof desc !== 'object' ||
+      typeof desc.handle !== 'number') {
     return;
   }
 
@@ -282,7 +283,7 @@ Client.prototype.reqLookup = function(refs, cb) {
   this.req(req, function(err, res) {
     if (err) return cb(err);
     for (var ref in res) {
-      if (util.isObject(res[ref])) {
+      if (res[ref] !== null && typeof res[ref] === 'object') {
         self._addHandle(res[ref]);
       }
     }
@@ -544,8 +545,7 @@ Client.prototype.mirrorObject = function(handle, depth, cb) {
           mirrorValue = '[?]';
         }
 
-
-        if (util.isArray(mirror) && !util.isNumber(prop.name)) {
+        if (Array.isArray(mirror) && typeof prop.name !== 'number') {
           // Skip the 'length' property.
           return;
         }
@@ -578,7 +578,7 @@ Client.prototype.mirrorObject = function(handle, depth, cb) {
     val = function() {};
   } else if (handle.type === 'null') {
     val = null;
-  } else if (!util.isUndefined(handle.value)) {
+  } else if (handle.value !== undefined) {
     val = handle.value;
   } else if (handle.type === 'undefined') {
     val = undefined;
@@ -879,7 +879,7 @@ Interface.prototype.print = function(text, oneline) {
   if (this.killed) return;
   this.clearline();
 
-  this.stdout.write(util.isString(text) ? text : util.inspect(text));
+  this.stdout.write(typeof text === 'string' ? text : util.inspect(text));
 
   if (oneline !== true) {
     this.stdout.write('\n');
@@ -1194,7 +1194,7 @@ Interface.prototype.scripts = function() {
   this.pause();
   for (var id in client.scripts) {
     var script = client.scripts[id];
-    if (util.isObject(script) && script.name) {
+    if (script !== null && typeof script === 'object' && script.name) {
       if (displayNatives ||
           script.name == client.currentScript ||
           !script.isNative) {
@@ -1332,13 +1332,13 @@ Interface.prototype.setBreakpoint = function(script, line,
       ambiguous;
 
   // setBreakpoint() should insert breakpoint on current line
-  if (util.isUndefined(script)) {
+  if (script === undefined) {
     script = this.client.currentScript;
     line = this.client.currentSourceLine + 1;
   }
 
   // setBreakpoint(line-number) should insert breakpoint in current script
-  if (util.isUndefined(line) && util.isNumber(script)) {
+  if (line === undefined && typeof script === 'number') {
     line = script;
     script = this.client.currentScript;
   }
@@ -1442,7 +1442,7 @@ Interface.prototype.clearBreakpoint = function(script, line) {
     if (bp.scriptId === script ||
         bp.scriptReq === script ||
         (bp.script && bp.script.indexOf(script) !== -1)) {
-      if (!util.isUndefined(index)) {
+      if (index !== undefined) {
         ambiguous = true;
       }
       scriptId = script;
@@ -1470,11 +1470,11 @@ Interface.prototype.clearBreakpoint = function(script, line) {
 
   if (ambiguous) return this.error('Script name is ambiguous');
 
-  if (util.isUndefined(scriptId)) {
+  if (scriptId === undefined) {
     return this.error('Script ' + script + ' not found');
   }
 
-  if (util.isUndefined(breakpoint)) {
+  if (breakpoint === undefined) {
     return this.error('Breakpoint not found on line ' + line);
   }
 

lib/_http_client.js

@@ -19,15 +19,16 @@ function ClientRequest(options, cb) {
   var self = this;
   OutgoingMessage.call(self);
 
-  if (util.isString(options)) {
+  if (typeof options === 'string') {
     options = url.parse(options);
   }
 
   var agent = options.agent;
   var defaultAgent = options._defaultAgent || Agent.globalAgent;
   if (agent === false) {
     agent = new defaultAgent.constructor();
-  } else if (util.isNullOrUndefined(agent) && !options.createConnection) {
+  } else if ((agent === null || agent === undefined) &&
+             !options.createConnection) {
     agent = defaultAgent;
   }
   self.agent = agent;
@@ -56,7 +57,7 @@ function ClientRequest(options, cb) {
   var port = options.port = options.port || defaultPort || 80;
   var host = options.host = options.hostname || options.host || 'localhost';
 
-  if (util.isUndefined(options.setHost)) {
+  if (options.setHost === undefined) {
     var setHost = true;
   }
 
@@ -68,7 +69,7 @@ function ClientRequest(options, cb) {
     self.once('response', cb);
   }
 
-  if (!util.isArray(options.headers)) {
+  if (!Array.isArray(options.headers)) {
     if (options.headers) {
       var keys = Object.keys(options.headers);
       for (var i = 0, l = keys.length; i < l; i++) {
@@ -101,7 +102,7 @@ function ClientRequest(options, cb) {
     self.useChunkedEncodingByDefault = true;
   }
 
-  if (util.isArray(options.headers)) {
+  if (Array.isArray(options.headers)) {
     self._storeHeader(self.method + ' ' + self.path + ' HTTP/1.1\r\n',
                       options.headers);
   } else if (self.getHeader('expect')) {
@@ -446,7 +447,7 @@ function tickOnSocket(req, socket) {
   httpSocketSetup(socket);
 
   // Propagate headers limit from request object to parser
-  if (util.isNumber(req.maxHeadersCount)) {
+  if (typeof req.maxHeadersCount === 'number') {
     parser.maxHeaderPairs = req.maxHeadersCount << 1;
   } else {
     // Set default value because parser may be reused from FreeList

lib/_http_common.js

@@ -8,7 +8,6 @@ const IncomingMessage = incoming.IncomingMessage;
 const readStart = incoming.readStart;
 const readStop = incoming.readStop;
 
-const isNumber = require('util').isNumber;
 const debug = require('util').debuglog('http');
 exports.debug = debug;
 
@@ -69,7 +68,7 @@ function parserOnHeadersComplete(versionMajor, versionMinor, headers, method,
 
   parser.incoming._addHeaderLines(headers, n);
 
-  if (isNumber(method)) {
+  if (typeof method === 'number') {
     // server only
     parser.incoming.method = HTTPParser.methods[method];
   } else {

lib/_http_incoming.js

@@ -130,7 +130,7 @@ IncomingMessage.prototype._addHeaderLine = function(field, value, dest) {
   switch (field) {
     // Array headers:
     case 'set-cookie':
-      if (!util.isUndefined(dest[field])) {
+      if (dest[field] !== undefined) {
         dest[field].push(value);
       } else {
         dest[field] = [value];
@@ -152,13 +152,13 @@ IncomingMessage.prototype._addHeaderLine = function(field, value, dest) {
     case 'location':
     case 'max-forwards':
       // drop duplicates
-      if (util.isUndefined(dest[field]))
+      if (dest[field] === undefined)
         dest[field] = value;
       break;
 
     default:
       // make comma-separated list
-      if (!util.isUndefined(dest[field]))
+      if (dest[field] !== undefined)
         dest[field] += ', ' + value;
       else {
         dest[field] = value;

lib/_http_outgoing.js

@@ -106,7 +106,7 @@ OutgoingMessage.prototype._send = function(data, encoding, callback) {
   // the same packet. Future versions of Node are going to take care of
   // this at a lower level and in a more general way.
   if (!this._headerSent) {
-    if (util.isString(data) &&
+    if (typeof data === 'string' &&
         encoding !== 'hex' &&
         encoding !== 'base64') {
       data = this._header + data;
@@ -122,13 +122,13 @@ OutgoingMessage.prototype._send = function(data, encoding, callback) {
 
 
 OutgoingMessage.prototype._writeRaw = function(data, encoding, callback) {
-  if (util.isFunction(encoding)) {
+  if (typeof encoding === 'function') {
     callback = encoding;
     encoding = null;
   }
 
   if (data.length === 0) {
-    if (util.isFunction(callback))
+    if (typeof callback === 'function')
       process.nextTick(callback);
     return true;
   }
@@ -187,7 +187,7 @@ OutgoingMessage.prototype._storeHeader = function(firstLine, headers) {
 
   if (headers) {
     var keys = Object.keys(headers);
-    var isArray = util.isArray(headers);
+    var isArray = Array.isArray(headers);
     var field, value;
 
     for (var i = 0, l = keys.length; i < l; i++) {
@@ -200,7 +200,7 @@ OutgoingMessage.prototype._storeHeader = function(firstLine, headers) {
         value = headers[key];
       }
 
-      if (util.isArray(value)) {
+      if (Array.isArray(value)) {
         for (var j = 0; j < value.length; j++) {
           storeHeader(this, state, field, value[j]);
         }
@@ -408,7 +408,7 @@ OutgoingMessage.prototype.write = function(chunk, encoding, callback) {
     return true;
   }
 
-  if (!util.isString(chunk) && !util.isBuffer(chunk)) {
+  if (typeof chunk !== 'string' && !(chunk instanceof Buffer)) {
     throw new TypeError('first argument must be a string or Buffer');
   }
 
@@ -419,7 +419,7 @@ OutgoingMessage.prototype.write = function(chunk, encoding, callback) {
 
   var len, ret;
   if (this.chunkedEncoding) {
-    if (util.isString(chunk) &&
+    if (typeof chunk === 'string' &&
         encoding !== 'hex' &&
         encoding !== 'base64' &&
         encoding !== 'binary') {
@@ -428,7 +428,7 @@ OutgoingMessage.prototype.write = function(chunk, encoding, callback) {
       ret = this._send(chunk, encoding, callback);
     } else {
       // buffer, or a non-toString-friendly encoding
-      if (util.isString(chunk))
+      if (typeof chunk === 'string')
         len = Buffer.byteLength(chunk, encoding);
       else
         len = chunk.length;
@@ -458,7 +458,7 @@ OutgoingMessage.prototype.write = function(chunk, encoding, callback) {
 OutgoingMessage.prototype.addTrailers = function(headers) {
   this._trailer = '';
   var keys = Object.keys(headers);
-  var isArray = util.isArray(headers);
+  var isArray = Array.isArray(headers);
   var field, value;
   for (var i = 0, l = keys.length; i < l; i++) {
     var key = keys[i];
@@ -479,15 +479,15 @@ const crlf_buf = new Buffer('\r\n');
 
 
 OutgoingMessage.prototype.end = function(data, encoding, callback) {
-  if (util.isFunction(data)) {
+  if (typeof data === 'function') {
     callback = data;
     data = null;
-  } else if (util.isFunction(encoding)) {
+  } else if (typeof encoding === 'function') {
     callback = encoding;
     encoding = null;
   }
 
-  if (data && !util.isString(data) && !util.isBuffer(data)) {
+  if (data && typeof data !== 'string' && !(data instanceof Buffer)) {
     throw new TypeError('first argument must be a string or Buffer');
   }
 
@@ -500,10 +500,9 @@ OutgoingMessage.prototype.end = function(data, encoding, callback) {
     self.emit('finish');
   }
 
-  if (util.isFunction(callback))
+  if (typeof callback === 'function')
     this.once('finish', callback);
 
-
   if (!this._header) {
     this._implicitHeader();
   }

lib/_http_server.js

@@ -153,7 +153,7 @@ ServerResponse.prototype._implicitHeader = function() {
 ServerResponse.prototype.writeHead = function(statusCode, reason, obj) {
   var headers;
 
-  if (util.isString(reason)) {
+  if (typeof reason === 'string') {
     // writeHead(statusCode, reasonPhrase[, headers])
     this.statusMessage = reason;
   } else {
@@ -297,7 +297,7 @@ function connectionListener(socket) {
   parser.incoming = null;
 
   // Propagate headers limit from server instance to parser
-  if (util.isNumber(this.maxHeadersCount)) {
+  if (typeof this.maxHeadersCount === 'number') {
     parser.maxHeaderPairs = this.maxHeadersCount << 1;
   } else {
     // Set default value because parser may be reused from FreeList
@@ -455,7 +455,7 @@ function connectionListener(socket) {
       }
     }
 
-    if (!util.isUndefined(req.headers.expect) &&
+    if (req.headers.expect !== undefined &&
         (req.httpVersionMajor == 1 && req.httpVersionMinor == 1) &&
         continueExpression.test(req.headers['expect'])) {
       res._expect_continue = true;