changes from the code review

cmd/cmd_controller.js

@@ -127,6 +127,7 @@ class EmbarkController {
         engine.startService("codeGenerator");
         engine.startService("namingSystem");
         engine.startService("console");
+        engine.startService("pluginCommand");
 
         engine.events.on('check:backOnline:Ethereum', function () {
           engine.logger.info(__('Ethereum node detected') + '..');

lib/core/engine.js

@@ -132,7 +132,7 @@ class Engine {
   }
 
   pluginCommandService() {
-    this.registerModule('plugin_cmd', {embarkConfigFile: this.embarkConfig, packageFile: 'package.json'});
+    this.registerModule('plugin_cmd', {embarkConfigFile: this.embarkConfig, embarkConfig: this.config.embarkConfig, packageFile: 'package.json'});
   }
 
   namingSystem(_options) {

lib/modules/plugin_cmd/index.js

@@ -5,7 +5,7 @@ class PluginCommand {
   constructor(embark, config) {
     this.embark = embark;
     this.config = config;
-    this.embarkConfig = fs.readJSONSync(this.config.embarkConfigFile);
+    this.embarkConfig = this.config.embarkConfig;
     this.registerCommand();
   }
   registerCommand() {
@@ -20,16 +20,8 @@ class PluginCommand {
           if(cmdArray.length < 3 || cmdArray[1] !== 'install' || typeof cmdArray[2] === 'undefined') {
             return callback('invalid use of plugin command. Please use plugin install <package>');
           }
-          let npmInstall = ['npm', 'install'];
-          if (cmdArray[2] === '--save') {
-            if(typeof cmdArray[3] === 'undefined') {
-              return callback('package argument missing');
-            }
-          } else {
-            npmInstall.push('--save');
-          }
+          let npmInstall = ['npm', 'install', '--save'];
           npmInstall = npmInstall.concat(cmdArray.slice(2));
-
           async.waterfall([
             function npmInstallAsync(cb) {
               utils.runCmd(npmInstall.join(' '), {silent: false, exitOnError: false}, (err) => {
@@ -50,10 +42,9 @@ class PluginCommand {
             }
           ], (err) => {
             if(err) {
-              callback(err);
-            } else {
-              callback(null, 'npm package successfully installed as a plugin');
+              return callback(err);
             }
+            callback(null, 'npm package successfully installed as a plugin');
           });
         }
       };

lib/utils/utils.js

@@ -143,10 +143,12 @@ function runCmd(cmd, options, callback) {
       return callback(result, null);
     }
     if (options.exitOnError) {
-      exit();
+      return exit();
     }
   }
-  callback(null, result);
+  if(typeof callback === 'function') {
+    return callback(null, result);
+  }
 }
 
 function cd(folder) {