diff --git a/lib/browser/api/menu.js b/lib/browser/api/menu.js
index bd89ca319b95..77d881b5d30b 100644
--- a/lib/browser/api/menu.js
+++ b/lib/browser/api/menu.js
@@ -11,6 +11,7 @@ let groupIdIndex = 0
 
 Object.setPrototypeOf(Menu.prototype, EventEmitter.prototype)
 
+// cleaned up
 Menu.prototype._init = function () {
   this.commandsMap = {}
   this.groupsMap = {}
@@ -41,6 +42,7 @@ Menu.prototype._init = function () {
   }
 }
 
+// create and show a popup
 Menu.prototype.popup = function (window, x, y, positioningItem) {
   let asyncPopup
 
@@ -78,6 +80,7 @@ Menu.prototype.popup = function (window, x, y, positioningItem) {
   this.popupAt(window, x, y, positioningItem, asyncPopup)
 }
 
+// close an existing popup
 Menu.prototype.closePopup = function (window) {
   if (window == null || window.constructor !== BrowserWindow) {
     window = BrowserWindow.getFocusedWindow()
@@ -87,11 +90,12 @@ Menu.prototype.closePopup = function (window) {
   }
 }
 
+// return a MenuItem with the specified id
 Menu.prototype.getMenuItemById = function (id) {
   const items = this.items
 
   let found = items.find(item => item.id === id) || null
-  for (let i = 0, length = items.length; !found && i < length; i++) {
+  for (let i = 0; !found && i < items.length; i++) {
     if (items[i].submenu) {
       found = items[i].submenu.getMenuItemById(id)
     }
@@ -99,58 +103,21 @@ Menu.prototype.getMenuItemById = function (id) {
   return found
 }
 
+// append a new MenuItem to an existing Menu
 Menu.prototype.append = function (item) {
   return this.insert(this.getItemCount(), item)
 }
 
+// insert a new menu item at a specified location
 Menu.prototype.insert = function (pos, item) {
-  var base, name
   if ((item != null ? item.constructor : void 0) !== MenuItem) {
     throw new TypeError('Invalid item')
   }
-  switch (item.type) {
-    case 'normal':
-      this.insertItem(pos, item.commandId, item.label)
-      break
-    case 'checkbox':
-      this.insertCheckItem(pos, item.commandId, item.label)
-      break
-    case 'separator':
-      this.insertSeparator(pos)
-      break
-    case 'submenu':
-      this.insertSubMenu(pos, item.commandId, item.label, item.submenu)
-      break
-    case 'radio':
-      // Grouping radio menu items.
-      item.overrideReadOnlyProperty('groupId', generateGroupId(this.items, pos))
-      if ((base = this.groupsMap)[name = item.groupId] == null) {
-        base[name] = []
-      }
-      this.groupsMap[item.groupId].push(item)
 
-      // Setting a radio menu item should flip other items in the group.
-      v8Util.setHiddenValue(item, 'checked', item.checked)
-      Object.defineProperty(item, 'checked', {
-        enumerable: true,
-        get: function () {
-          return v8Util.getHiddenValue(item, 'checked')
-        },
-        set: () => {
-          var j, len, otherItem, ref1
-          ref1 = this.groupsMap[item.groupId]
-          for (j = 0, len = ref1.length; j < len; j++) {
-            otherItem = ref1[j]
-            if (otherItem !== item) {
-              v8Util.setHiddenValue(otherItem, 'checked', false)
-            }
-          }
-          return v8Util.setHiddenValue(item, 'checked', true)
-        }
-      })
-      this.insertRadioItem(pos, item.commandId, item.label, item.groupId)
-  }
+  // insert item depending on its type
+  insertItemByType.call(this, item, pos)
 
+  // set item properties
   if (item.sublabel != null) this.setSublabel(pos, item.sublabel)
   if (item.icon != null) this.setIcon(pos, item.icon)
   if (item.role != null) this.setRole(pos, item.role)
@@ -164,7 +131,6 @@ Menu.prototype.insert = function (pos, item) {
 }
 
 // Force menuWillShow to be called
-// cleaned up
 Menu.prototype._callMenuWillShow = function () {
   if (this.delegate != null) this.delegate.menuWillShow()
   this.items.forEach(item => {
@@ -172,7 +138,12 @@ Menu.prototype._callMenuWillShow = function () {
   })
 }
 
-// cleaned up
+// return application menu
+Menu.getApplicationMenu = () => applicationMenu
+
+Menu.sendActionToFirstResponder = bindings.sendActionToFirstResponder
+
+// set application menu with a preexisting menu
 Menu.setApplicationMenu = function (menu) {
   if (!(menu === null || menu.constructor === Menu)) {
     throw new TypeError('Invalid menu')
@@ -189,12 +160,7 @@ Menu.setApplicationMenu = function (menu) {
   }
 }
 
-// cleaned up
-Menu.getApplicationMenu = () => applicationMenu
-
-Menu.sendActionToFirstResponder = bindings.sendActionToFirstResponder
-
-// cleaned up
+// build a menu by passing in a template
 Menu.buildFromTemplate = function (template) {
   if (!(template instanceof Array)) {
     throw new TypeError('Invalid template for Menu')
@@ -223,7 +189,7 @@ Menu.buildFromTemplate = function (template) {
 
 /* Helper Methods */
 
-// Search between separators to find a radio menu item and return its group id,
+// Search between separators to find a radio menu item and return its group id
 function generateGroupId (items, pos) {
   let i, item
   if (pos > 0) {
@@ -241,18 +207,17 @@ function generateGroupId (items, pos) {
       if (item.type === 'separator') { break }
     }
   }
-  return ++groupIdIndex
+  groupIdIndex += 1
+  return groupIdIndex
 }
 
 // Returns the index of item according to |id|.
-// cleaned up
 function indexOfItemById (items, id) {
   const foundItem = items.find(item => item.id === id) || null
   return items.indexOf(foundItem)
 }
 
 // Returns the index of where to insert the item according to |position|
-// cleaned up
 function indexToInsertByPosition (items, position) {
   if (!position) return items.length
 
@@ -287,4 +252,37 @@ function indexToInsertByPosition (items, position) {
   return (query in queries) ? queries[query](idx) : idx
 }
 
+// insert a new MenuItem depending on its type
+function insertItemByType(item, pos) {
+  const types = {
+    'normal': () => this.insertItem(pos, item.commandId, item.label),
+    'checkbox': () => this.insertCheckItem(pos, item.commandId, item.label),
+    'separator':() => this.insertSeparator(pos),
+    'submenu': () => this.insertSubMenu(pos, item.commandId, item.label, item.submenu),
+    'radio': () => {
+      // Grouping radio menu items
+      item.overrideReadOnlyProperty('groupId', generateGroupId(this.items, pos))
+      if (this.groupsMap[item.groupId] == null) {
+        this.groupsMap[item.groupId] = []
+      }
+      this.groupsMap[item.groupId].push(item)
+
+      // Setting a radio menu item should flip other items in the group.
+      v8Util.setHiddenValue(item, 'checked', item.checked)
+      Object.defineProperty(item, 'checked', {
+        enumerable: true,
+        get: () => v8Util.getHiddenValue(item, 'checked'),
+        set: () => {
+          this.groupsMap[item.groupId].forEach(other => {
+            if (other !== item) v8Util.setHiddenValue(other, 'checked', false)
+          })
+          v8Util.setHiddenValue(item, 'checked', true)
+        }
+      })
+      this.insertRadioItem(pos, item.commandId, item.label, item.groupId)
+    }
+  }
+  types[item.type]()
+}
+
 module.exports = Menu