child_process: refactor internal/child_process.js

* Prefer === to == where possible
* Remove condition that will always be false
* Prefer for-loop statements to forEach where possible for perfomance reasons
PR-URL: #11366
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>

Author: notarseniy

lib/internal/child_process.js

@@ -230,12 +230,16 @@ util.inherits(ChildProcess, EventEmitter);
 
 
 functionflushStdio(subprocess){
-if(subprocess.stdio==null)return;
-subprocess.stdio.forEach(function(stream,fd,stdio){
+conststdio=subprocess.stdio;
+
+if(stdio==null)return;
+
+for(vari=0;i<stdio.length;i++){
+conststream=stdio[i];
 if(!stream||!stream.readable||stream._readableState.readableListening)
-return;
+continue;
 stream.resume();
-});
+}
 }
 
 
@@ -268,6 +272,7 @@ ChildProcess.prototype.spawn = function(options) {
 constself=this;
 varipc;
 varipcFd;
+vari;
 // If no `stdio` option was given - use default
 varstdio=options.stdio||'pipe';
 
@@ -302,11 +307,12 @@ ChildProcess.prototype.spawn = function(options) {
 if(err!==uv.UV_ENOENT)returnerr;
 }elseif(err){
 // Close all opened fds on error
-stdio.forEach(function(stdio){
-if(stdio.type==='pipe'){
-stdio.handle.close();
+for(i=0;i<stdio.length;i++){
+conststream=stdio[i];
+if(stream.type==='pipe'){
+stream.handle.close();
 }
-});
+}
 
 this._handle.close();
 this._handle=null;
@@ -315,27 +321,29 @@ ChildProcess.prototype.spawn = function(options) {
 
 this.pid=this._handle.pid;
 
-stdio.forEach(function(stdio,i){
-if(stdio.type==='ignore')return;
+for(i=0;i<stdio.length;i++){
+conststream=stdio[i];
+if(stream.type==='ignore')continue;
 
-if(stdio.ipc){
+if(stream.ipc){
 self._closesNeeded++;
-return;
+continue;
 }
 
-if(stdio.handle){
+if(stream.handle){
 // when i === 0 - we're dealing with stdin
 // (which is the only one writable pipe)
-stdio.socket=createSocket(self.pid!==0 ? stdio.handle : null,i>0);
+stream.socket=createSocket(self.pid!==0 ?
+stream.handle : null,i>0);
 
 if(i>0&&self.pid!==0){
 self._closesNeeded++;
-stdio.socket.on('close',function(){
+stream.socket.on('close',function(){
 maybeClose(self);
 });
 }
 }
-});
+}
 
 this.stdin=stdio.length>=1&&stdio[0].socket!==undefined ?
 stdio[0].socket : null;
@@ -783,11 +791,11 @@ function _validateStdio(stdio, sync) {
 }
 
 // Defaults
-if(stdio===null||stdio===undefined){
+if(stdio==null){
 stdio=i<3 ? 'pipe' : 'ignore';
 }
 
-if(stdio===null||stdio==='ignore'){
+if(stdio==='ignore'){
 acc.push({type: 'ignore'});
 }elseif(stdio==='pipe'||typeofstdio==='number'&&stdio<0){
 vara={
@@ -873,7 +881,7 @@ function getSocketList(type, slave, key) {
 functionmaybeClose(subprocess){
 subprocess._closesGot++;
 
-if(subprocess._closesGot==subprocess._closesNeeded){
+if(subprocess._closesGot===subprocess._closesNeeded){
 subprocess.emit('close',subprocess.exitCode,subprocess.signalCode);
 }
 }