move command history to its own module

lib/dashboard/command_history.js

@@ -0,0 +1,28 @@
+
+var CommandHistory = function() {
+  this.history = [];
+  this.pointer = -1;
+};
+
+CommandHistory.prototype.addCommand = function(cmd) {
+  this.history.push(cmd);
+  this.pointer = this.history.length;
+};
+
+CommandHistory.prototype.getPreviousCommand = function(cmd) {
+  if (this.pointer >= 0) {
+    this.pointer--;
+  }
+  return this.history[this.pointer];
+};
+
+CommandHistory.prototype.getNextCommand = function(cmd) {
+  if (this.pointer >= this.history.length) {
+    this.pointer = this.history.length - 1;
+    return '';
+  }
+  this.pointer++;
+  return this.history[this.pointer];
+};
+
+module.exports = CommandHistory;

lib/dashboard/monitor.js

@@ -1,32 +1,7 @@
 /*jshint esversion: 6 */
 
 var blessed = require("blessed");
-
+var CommandHistory = require('./command_history.js');
-var CommandHistory = function() {
-  this.history = [];
-  this.pointer = -1;
-};
-
-CommandHistory.prototype.addCommand = function(cmd) {
-  this.history.push(cmd);
-  this.pointer = this.history.length;
-};
-
-CommandHistory.prototype.getPreviousCommand = function(cmd) {
-  if (this.pointer >= 0) {
-    this.pointer--;
-  }
-  return this.history[this.pointer];
-};
-
-CommandHistory.prototype.getNextCommand = function(cmd) {
-  if (this.pointer >= this.history.length) {
-    this.pointer = this.history.length - 1;
-    return '';
-  }
-  this.pointer++;
-  return this.history[this.pointer];
-};
 
 function Dashboard(options) {
   var title = (options && options.title) || "Embark 2.3.0";