Run lebab: convert let/const and arrow functions

src/js/ContextMenu.js

@@ -1,8 +1,8 @@
 'use strict'
 
-var createAbsoluteAnchor = require('./createAbsoluteAnchor').createAbsoluteAnchor
+const createAbsoluteAnchor = require('./createAbsoluteAnchor').createAbsoluteAnchor
-var util = require('./util')
+const util = require('./util')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
 
 /**
  * A context menu
@@ -16,8 +16,8 @@ var translate = require('./i18n').translate
 function ContextMenu (items, options) {
   this.dom = {}
 
-  var me = this
+  const me = this
-  var dom = this.dom
+  const dom = this.dom
   this.anchor = undefined
   this.items = items
   this.eventListeners = {}
@@ -25,51 +25,51 @@ function ContextMenu (items, options) {
   this.onClose = options ? options.close : undefined
 
   // create root element
-  var root = document.createElement('div')
+  const root = document.createElement('div')
   root.className = 'jsoneditor-contextmenu-root'
   dom.root = root
 
   // create a container element
-  var menu = document.createElement('div')
+  const menu = document.createElement('div')
   menu.className = 'jsoneditor-contextmenu'
   dom.menu = menu
   root.appendChild(menu)
 
   // create a list to hold the menu items
-  var list = document.createElement('ul')
+  const list = document.createElement('ul')
   list.className = 'jsoneditor-menu'
   menu.appendChild(list)
   dom.list = list
   dom.items = [] // list with all buttons
 
   // create a (non-visible) button to set the focus to the menu
-  var focusButton = document.createElement('button')
+  const focusButton = document.createElement('button')
   focusButton.type = 'button'
   dom.focusButton = focusButton
-  var li = document.createElement('li')
+  const li = document.createElement('li')
   li.style.overflow = 'hidden'
   li.style.height = '0'
   li.appendChild(focusButton)
   list.appendChild(li)
 
   function createMenuItems (list, domItems, items) {
-    items.forEach(function (item) {
+    items.forEach(item => {
       if (item.type === 'separator') {
         // create a separator
-        var separator = document.createElement('div')
+        const separator = document.createElement('div')
         separator.className = 'jsoneditor-separator'
         const li = document.createElement('li')
         li.appendChild(separator)
         list.appendChild(li)
       } else {
-        var domItem = {}
+        const domItem = {}
 
         // create a menu item
         const li = document.createElement('li')
         list.appendChild(li)
 
         // create a button in the menu item
-        var button = document.createElement('button')
+        const button = document.createElement('button')
         button.type = 'button'
         button.className = item.className
         domItem.button = button
@@ -77,7 +77,7 @@ function ContextMenu (items, options) {
           button.title = item.title
         }
         if (item.click) {
-          button.onclick = function (event) {
+          button.onclick = event => {
             event.preventDefault()
             me.hide()
             item.click()
@@ -88,21 +88,21 @@ function ContextMenu (items, options) {
         // create the contents of the button
         if (item.submenu) {
           // add the icon to the button
-          var divIcon = document.createElement('div')
+          const divIcon = document.createElement('div')
           divIcon.className = 'jsoneditor-icon'
           button.appendChild(divIcon)
-          var divText = document.createElement('div')
+          const divText = document.createElement('div')
           divText.className = 'jsoneditor-text' +
               (item.click ? '' : ' jsoneditor-right-margin')
           divText.appendChild(document.createTextNode(item.text))
           button.appendChild(divText)
 
-          var buttonSubmenu
+          let buttonSubmenu
           if (item.click) {
             // submenu and a button with a click handler
             button.className += ' jsoneditor-default'
 
-            var buttonExpand = document.createElement('button')
+            const buttonExpand = document.createElement('button')
             buttonExpand.type = 'button'
             domItem.buttonExpand = buttonExpand
             buttonExpand.className = 'jsoneditor-expand'
@@ -115,7 +115,7 @@ function ContextMenu (items, options) {
             buttonSubmenu = buttonExpand
           } else {
             // submenu and a button without a click handler
-            var divExpand = document.createElement('div')
+            const divExpand = document.createElement('div')
             divExpand.className = 'jsoneditor-expand'
             button.appendChild(divExpand)
 
@@ -123,16 +123,16 @@ function ContextMenu (items, options) {
           }
 
           // attach a handler to expand/collapse the submenu
-          buttonSubmenu.onclick = function (event) {
+          buttonSubmenu.onclick = event => {
             event.preventDefault()
             me._onExpandItem(domItem)
             buttonSubmenu.focus()
           }
 
           // create the submenu
-          var domSubItems = []
+          const domSubItems = []
           domItem.subItems = domSubItems
-          var ul = document.createElement('ul')
+          const ul = document.createElement('ul')
           domItem.ul = ul
           ul.className = 'jsoneditor-menu'
           ul.style.height = '0'
@@ -154,8 +154,8 @@ function ContextMenu (items, options) {
 
   // calculate the max height of the menu with one submenu expanded
   this.maxHeight = 0 // height in pixels
-  items.forEach(function (item) {
+  items.forEach(item => {
-    var height = (items.length + (item.submenu ? item.submenu.length : 0)) * 24
+    const height = (items.length + (item.submenu ? item.submenu.length : 0)) * 24
     me.maxHeight = Math.max(me.maxHeight, height)
   })
 }
@@ -166,15 +166,15 @@ function ContextMenu (items, options) {
  * @private
  */
 ContextMenu.prototype._getVisibleButtons = function () {
-  var buttons = []
+  const buttons = []
-  var me = this
+  const me = this
-  this.dom.items.forEach(function (item) {
+  this.dom.items.forEach(item => {
     buttons.push(item.button)
     if (item.buttonExpand) {
       buttons.push(item.buttonExpand)
     }
     if (item.subItems && item === me.expandedItem) {
-      item.subItems.forEach(function (subItem) {
+      item.subItems.forEach(subItem => {
         buttons.push(subItem.button)
         if (subItem.buttonExpand) {
           buttons.push(subItem.buttonExpand)
@@ -200,14 +200,14 @@ ContextMenu.prototype.show = function (anchor, frame, ignoreParent) {
   this.hide()
 
   // determine whether to display the menu below or above the anchor
-  var showBelow = true
+  let showBelow = true
-  var parent = anchor.parentNode
+  const parent = anchor.parentNode
-  var anchorRect = anchor.getBoundingClientRect()
+  const anchorRect = anchor.getBoundingClientRect()
-  var parentRect = parent.getBoundingClientRect()
+  const parentRect = parent.getBoundingClientRect()
-  var frameRect = frame.getBoundingClientRect()
+  const frameRect = frame.getBoundingClientRect()
 
-  var me = this
+  const me = this
-  this.dom.absoluteAnchor = createAbsoluteAnchor(anchor, frame, function () {
+  this.dom.absoluteAnchor = createAbsoluteAnchor(anchor, frame, () => {
     me.hide()
   })
 
@@ -220,12 +220,12 @@ ContextMenu.prototype.show = function (anchor, frame, ignoreParent) {
     // doesn't fit above nor below -> show below
   }
 
-  var topGap = ignoreParent ? 0 : (anchorRect.top - parentRect.top)
+  const topGap = ignoreParent ? 0 : (anchorRect.top - parentRect.top)
 
   // position the menu
   if (showBelow) {
     // display the menu below the anchor
-    var anchorHeight = anchor.offsetHeight
+    const anchorHeight = anchor.offsetHeight
     this.dom.menu.style.left = '0'
     this.dom.menu.style.top = topGap + anchorHeight + 'px'
     this.dom.menu.style.bottom = ''
@@ -243,7 +243,7 @@ ContextMenu.prototype.show = function (anchor, frame, ignoreParent) {
   // move focus to the first button in the context menu
   this.selection = util.getSelection()
   this.anchor = anchor
-  setTimeout(function () {
+  setTimeout(() => {
     me.dom.focusButton.focus()
   }, 0)
 
@@ -283,16 +283,16 @@ ContextMenu.prototype.hide = function () {
  * @private
  */
 ContextMenu.prototype._onExpandItem = function (domItem) {
-  var me = this
+  const me = this
-  var alreadyVisible = (domItem === this.expandedItem)
+  const alreadyVisible = (domItem === this.expandedItem)
 
   // hide the currently visible submenu
-  var expandedItem = this.expandedItem
+  const expandedItem = this.expandedItem
   if (expandedItem) {
     // var ul = expandedItem.ul;
     expandedItem.ul.style.height = '0'
     expandedItem.ul.style.padding = ''
-    setTimeout(function () {
+    setTimeout(() => {
       if (me.expandedItem !== expandedItem) {
         expandedItem.ul.style.display = ''
         util.removeClassName(expandedItem.ul.parentNode, 'jsoneditor-selected')
@@ -302,14 +302,14 @@ ContextMenu.prototype._onExpandItem = function (domItem) {
   }
 
   if (!alreadyVisible) {
-    var ul = domItem.ul
+    const ul = domItem.ul
     ul.style.display = 'block'
     // eslint-disable-next-line no-unused-expressions
     ul.clientHeight // force a reflow in Firefox
-    setTimeout(function () {
+    setTimeout(() => {
       if (me.expandedItem === domItem) {
-        var childsHeight = 0
+        let childsHeight = 0
-        for (var i = 0; i < ul.childNodes.length; i++) {
+        for (let i = 0; i < ul.childNodes.length; i++) {
           childsHeight += ul.childNodes[i].clientHeight
         }
         ul.style.height = childsHeight + 'px'
@@ -327,10 +327,10 @@ ContextMenu.prototype._onExpandItem = function (domItem) {
  * @private
  */
 ContextMenu.prototype._onKeyDown = function (event) {
-  var target = event.target
+  const target = event.target
-  var keynum = event.which
+  const keynum = event.which
-  var handled = false
+  let handled = false
-  var buttons, targetIndex, prevButton, nextButton
+  let buttons, targetIndex, prevButton, nextButton
 
   if (keynum === 27) { // ESC
     // hide the menu on ESC key

src/js/ErrorTable.js

@@ -10,28 +10,28 @@
 function ErrorTable (config) {
   this.errorTableVisible = config.errorTableVisible
   this.onToggleVisibility = config.onToggleVisibility
-  this.onFocusLine = config.onFocusLine || function () {}
+  this.onFocusLine = config.onFocusLine || (() => {})
   this.onChangeHeight = config.onChangeHeight
 
   this.dom = {}
 
-  var validationErrorsContainer = document.createElement('div')
+  const validationErrorsContainer = document.createElement('div')
   validationErrorsContainer.className = 'jsoneditor-validation-errors-container'
   this.dom.validationErrorsContainer = validationErrorsContainer
 
-  var additionalErrorsIndication = document.createElement('div')
+  const additionalErrorsIndication = document.createElement('div')
   additionalErrorsIndication.style.display = 'none'
   additionalErrorsIndication.className = 'jsoneditor-additional-errors fadein'
   additionalErrorsIndication.innerHTML = 'Scroll for more ▿'
   this.dom.additionalErrorsIndication = additionalErrorsIndication
   validationErrorsContainer.appendChild(additionalErrorsIndication)
 
-  var validationErrorIcon = document.createElement('span')
+  const validationErrorIcon = document.createElement('span')
   validationErrorIcon.className = 'jsoneditor-validation-error-icon'
   validationErrorIcon.style.display = 'none'
   this.dom.validationErrorIcon = validationErrorIcon
 
-  var validationErrorCount = document.createElement('span')
+  const validationErrorCount = document.createElement('span')
   validationErrorCount.className = 'jsoneditor-validation-error-count'
   validationErrorCount.style.display = 'none'
   this.dom.validationErrorCount = validationErrorCount
@@ -63,7 +63,7 @@ ErrorTable.prototype.toggleTableVisibility = function () {
 }
 
 ErrorTable.prototype.setErrors = function (errors, errorLocations) {
-  var me = this
+  const me = this
 
   // clear any previous errors
   if (this.dom.validationErrors) {
@@ -75,13 +75,13 @@ ErrorTable.prototype.setErrors = function (errors, errorLocations) {
   // create the table with errors
   // keep default behavior for parse errors
   if (this.errorTableVisible && errors.length > 0) {
-    var validationErrors = document.createElement('div')
+    const validationErrors = document.createElement('div')
     validationErrors.className = 'jsoneditor-validation-errors'
     validationErrors.innerHTML = '<table class="jsoneditor-text-errors"><tbody></tbody></table>'
-    var tbody = validationErrors.getElementsByTagName('tbody')[0]
+    const tbody = validationErrors.getElementsByTagName('tbody')[0]
 
-    errors.forEach(function (error) {
+    errors.forEach(error => {
-      var message
+      let message
       if (typeof error === 'string') {
         message = '<td colspan="2"><pre>' + error + '</pre></td>'
       } else {
@@ -90,18 +90,18 @@ ErrorTable.prototype.setErrors = function (errors, errorLocations) {
             '<td><pre>' + error.message + '</pre></td>'
       }
 
-      var line
+      let line
 
       if (!isNaN(error.line)) {
         line = error.line
       } else if (error.dataPath) {
-        var errLoc = errorLocations.find(function (loc) { return loc.path === error.dataPath })
+        const errLoc = errorLocations.find(loc => loc.path === error.dataPath)
         if (errLoc) {
           line = errLoc.line + 1
         }
       }
 
-      var trEl = document.createElement('tr')
+      const trEl = document.createElement('tr')
       trEl.className = !isNaN(line) ? 'jump-to-line' : ''
       if (error.type === 'error') {
         trEl.className += ' parse-error'
@@ -110,7 +110,7 @@ ErrorTable.prototype.setErrors = function (errors, errorLocations) {
       }
 
       trEl.innerHTML = ('<td><button class="jsoneditor-schema-error"></button></td><td style="white-space:nowrap;">' + (!isNaN(line) ? ('Ln ' + line) : '') + '</td>' + message)
-      trEl.onclick = function () {
+      trEl.onclick = () => {
         me.onFocusLine(line)
       }
 
@@ -123,7 +123,7 @@ ErrorTable.prototype.setErrors = function (errors, errorLocations) {
 
     if (this.dom.validationErrorsContainer.clientHeight < this.dom.validationErrorsContainer.scrollHeight) {
       this.dom.additionalErrorsIndication.style.display = 'block'
-      this.dom.validationErrorsContainer.onscroll = function () {
+      this.dom.validationErrorsContainer.onscroll = () => {
         me.dom.additionalErrorsIndication.style.display =
             (me.dom.validationErrorsContainer.clientHeight > 0 && me.dom.validationErrorsContainer.scrollTop === 0) ? 'block' : 'none'
       }
@@ -131,7 +131,7 @@ ErrorTable.prototype.setErrors = function (errors, errorLocations) {
       this.dom.validationErrorsContainer.onscroll = undefined
     }
 
-    var height = this.dom.validationErrorsContainer.clientHeight + (this.dom.statusBar ? this.dom.statusBar.clientHeight : 0)
+    const height = this.dom.validationErrorsContainer.clientHeight + (this.dom.statusBar ? this.dom.statusBar.clientHeight : 0)
     // this.content.style.marginBottom = (-height) + 'px';
     // this.content.style.paddingBottom = height + 'px';
     this.onChangeHeight(height)
@@ -140,9 +140,7 @@ ErrorTable.prototype.setErrors = function (errors, errorLocations) {
   }
 
   // update the status bar
-  var validationErrorsCount = errors.filter(function (error) {
+  const validationErrorsCount = errors.filter(error => error.type !== 'error').length
-    return error.type !== 'error'
-  }).length
   if (validationErrorsCount > 0) {
     this.dom.validationErrorCount.style.display = 'inline'
     this.dom.validationErrorCount.innerText = validationErrorsCount
@@ -157,11 +155,9 @@ ErrorTable.prototype.setErrors = function (errors, errorLocations) {
   }
 
   // update the parse error icon
-  var hasParseErrors = errors.some(function (error) {
+  const hasParseErrors = errors.some(error => error.type === 'error')
-    return error.type === 'error'
-  })
   if (hasParseErrors) {
-    var line = errors[0].line
+    const line = errors[0].line
     this.dom.parseErrorIndication.style.display = 'block'
     this.dom.parseErrorIndication.title = !isNaN(line)
       ? ('parse error on line ' + line)

src/js/Highlighter.js

@@ -42,14 +42,14 @@ Highlighter.prototype.unhighlight = function () {
     return
   }
 
-  var me = this
+  const me = this
   if (this.node) {
     this._cancelUnhighlight()
 
     // do the unhighlighting after a small delay, to prevent re-highlighting
     // the same node when moving from the drag-icon to the contextmenu-icon
     // or vice versa.
-    this.unhighlightTimer = setTimeout(function () {
+    this.unhighlightTimer = setTimeout(() => {
       me.node.setHighlight(false)
       me.node = undefined
       me.unhighlightTimer = undefined

src/js/History.js

@@ -8,9 +8,7 @@
  */
 function History (onChange, calculateItemSize, limit) {
   this.onChange = onChange
-  this.calculateItemSize = calculateItemSize || function () {
+  this.calculateItemSize = calculateItemSize || (() => 1)
-    return 1
-  }
   this.limit = limit
 
   this.items = []
@@ -35,10 +33,10 @@ History.prototype.add = function (item) {
 }
 
 History.prototype._calculateHistorySize = function () {
-  var calculateItemSize = this.calculateItemSize
+  const calculateItemSize = this.calculateItemSize
-  var totalSize = 0
+  let totalSize = 0
 
-  this.items.forEach(function (item) {
+  this.items.forEach(item => {
     totalSize += calculateItemSize(item)
   })
 

src/js/JSONEditor.js

@@ -1,19 +1,19 @@
 'use strict'
 
-var Ajv
+let Ajv
 try {
   Ajv = require('ajv')
 } catch (err) {
   // no problem... when we need Ajv we will throw a neat exception
 }
 
-var ace = require('./ace') // may be undefined in case of minimalist bundle
+const ace = require('./ace') // may be undefined in case of minimalist bundle
-var VanillaPicker = require('./vanilla-picker') // may be undefined in case of minimalist bundle
+const VanillaPicker = require('./vanilla-picker') // may be undefined in case of minimalist bundle
 
-var treemode = require('./treemode')
+const treemode = require('./treemode')
-var textmode = require('./textmode')
+const textmode = require('./textmode')
-var previewmode = require('./previewmode')
+const previewmode = require('./previewmode')
-var util = require('./util')
+const util = require('./util')
 
 if (typeof Promise === 'undefined') {
   console.error('Promise undefined. Please load a Promise polyfill in the browser in order to use JSONEditor')
@@ -101,7 +101,7 @@ function JSONEditor (container, options, json) {
   }
 
   // check for unsupported browser (IE8 and older)
-  var ieVersion = util.getInternetExplorerVersion()
+  const ieVersion = util.getInternetExplorerVersion()
   if (ieVersion !== -1 && ieVersion < 9) {
     throw new Error('Unsupported browser, IE9 or newer required. ' +
         'Please install the newest version of your browser.')
@@ -136,7 +136,7 @@ function JSONEditor (container, options, json) {
 
     // validate options
     if (options) {
-      Object.keys(options).forEach(function (option) {
+      Object.keys(options).forEach(option => {
         if (JSONEditor.VALID_OPTIONS.indexOf(option) === -1) {
           console.warn('Unknown option "' + option + '". This option will be ignored')
         }
@@ -194,14 +194,14 @@ JSONEditor.prototype._create = function (container, options, json) {
   this.options = options || {}
   this.json = json || {}
 
-  var mode = this.options.mode || (this.options.modes && this.options.modes[0]) || 'tree'
+  const mode = this.options.mode || (this.options.modes && this.options.modes[0]) || 'tree'
   this.setMode(mode)
 }
 
 /**
  * Destroy the editor. Clean up DOM, event listeners, and web workers.
  */
-JSONEditor.prototype.destroy = function () {}
+JSONEditor.prototype.destroy = () => {}
 
 /**
  * Set JSON object in editor
@@ -266,17 +266,17 @@ JSONEditor.prototype.setMode = function (mode) {
     return
   }
 
-  var container = this.container
+  const container = this.container
-  var options = util.extend({}, this.options)
+  const options = util.extend({}, this.options)
-  var oldMode = options.mode
+  const oldMode = options.mode
-  var data
+  let data
-  var name
+  let name
 
   options.mode = mode
-  var config = JSONEditor.modes[mode]
+  const config = JSONEditor.modes[mode]
   if (config) {
     try {
-      var asText = (config.data === 'text')
+      const asText = (config.data === 'text')
       name = this.getName()
       data = this[asText ? 'getText' : 'get']() // get text or json
 
@@ -343,7 +343,7 @@ JSONEditor.prototype._onError = function (err) {
 JSONEditor.prototype.setSchema = function (schema, schemaRefs) {
   // compile a JSON schema validator if a JSON schema is provided
   if (schema) {
-    var ajv
+    let ajv
     try {
       // grab ajv from options if provided, else create a new instance
       if (this.options.ajv) {
@@ -366,7 +366,7 @@ JSONEditor.prototype.setSchema = function (schema, schemaRefs) {
 
     if (ajv) {
       if (schemaRefs) {
-        for (var ref in schemaRefs) {
+        for (const ref in schemaRefs) {
           ajv.removeSchema(ref) // When updating a schema - old refs has to be removed first
           if (schemaRefs[ref]) {
             ajv.addSchema(schemaRefs[ref], ref)
@@ -399,14 +399,14 @@ JSONEditor.prototype.setSchema = function (schema, schemaRefs) {
  * Validate current JSON object against the configured JSON schema
  * Throws an exception when no JSON schema is configured
  */
-JSONEditor.prototype.validate = function () {
+JSONEditor.prototype.validate = () => {
   // must be implemented by treemode and textmode
 }
 
 /**
  * Refresh the rendered contents
  */
-JSONEditor.prototype.refresh = function () {
+JSONEditor.prototype.refresh = () => {
   // can be implemented by treemode and textmode
 }
 
@@ -429,8 +429,8 @@ JSONEditor.prototype.refresh = function () {
  *
  * @param {Object | Array} mode  A mode object or an array with multiple mode objects.
  */
-JSONEditor.registerMode = function (mode) {
+JSONEditor.registerMode = mode => {
-  var i, prop
+  let i, prop
 
   if (util.isArray(mode)) {
     // multiple modes
@@ -442,7 +442,7 @@ JSONEditor.registerMode = function (mode) {
     if (!('mode' in mode)) throw new Error('Property "mode" missing')
     if (!('mixin' in mode)) throw new Error('Property "mixin" missing')
     if (!('data' in mode)) throw new Error('Property "data" missing')
-    var name = mode.mode
+    const name = mode.mode
     if (name in JSONEditor.modes) {
       throw new Error('Mode "' + name + '" already registered')
     }
@@ -451,7 +451,7 @@ JSONEditor.registerMode = function (mode) {
     if (typeof mode.mixin.create !== 'function') {
       throw new Error('Required function "create" missing on mixin')
     }
-    var reserved = ['setMode', 'registerMode', 'modes']
+    const reserved = ['setMode', 'registerMode', 'modes']
     for (i = 0; i < reserved.length; i++) {
       prop = reserved[i]
       if (prop in mode.mixin) {

src/js/ModeSwitcher.js

@@ -1,7 +1,7 @@
 'use strict'
 
-var ContextMenu = require('./ContextMenu')
+const ContextMenu = require('./ContextMenu')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
 
 /**
  * Create a select box to be used in the editor menu's, which allows to switch mode
@@ -13,7 +13,7 @@ var translate = require('./i18n').translate
  */
 function ModeSwitcher (container, modes, current, onSwitch) {
   // available modes
-  var availableModes = {
+  const availableModes = {
     code: {
       text: translate('modeCodeText'),
       title: translate('modeCodeTitle'),
@@ -59,10 +59,10 @@ function ModeSwitcher (container, modes, current, onSwitch) {
   }
 
   // list the selected modes
-  var items = []
+  const items = []
-  for (var i = 0; i < modes.length; i++) {
+  for (let i = 0; i < modes.length; i++) {
-    var mode = modes[i]
+    const mode = modes[i]
-    var item = availableModes[mode]
+    const item = availableModes[mode]
     if (!item) {
       throw new Error('Unknown mode "' + mode + '"')
     }
@@ -72,24 +72,24 @@ function ModeSwitcher (container, modes, current, onSwitch) {
   }
 
   // retrieve the title of current mode
-  var currentMode = availableModes[current]
+  const currentMode = availableModes[current]
   if (!currentMode) {
     throw new Error('Unknown mode "' + current + '"')
   }
-  var currentTitle = currentMode.text
+  const currentTitle = currentMode.text
 
   // create the html element
-  var box = document.createElement('button')
+  const box = document.createElement('button')
   box.type = 'button'
   box.className = 'jsoneditor-modes jsoneditor-separator'
   box.innerHTML = currentTitle + ' &#x25BE;'
   box.title = 'Switch editor mode'
-  box.onclick = function () {
+  box.onclick = () => {
-    var menu = new ContextMenu(items)
+    const menu = new ContextMenu(items)
     menu.show(box, container)
   }
 
-  var frame = document.createElement('div')
+  const frame = document.createElement('div')
   frame.className = 'jsoneditor-modes'
   frame.style.position = 'relative'
   frame.appendChild(box)

src/js/NodeHistory.js

@@ -1,6 +1,6 @@
 'use strict'
 
-var util = require('./util')
+const util = require('./util')
 
 /**
  * @constructor History
@@ -23,13 +23,13 @@ function NodeHistory (editor) {
   this.actions = {
     editField: {
       undo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        var node = parentNode.childs[params.index]
+        const node = parentNode.childs[params.index]
         node.updateField(params.oldValue)
       },
       redo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        var node = parentNode.childs[params.index]
+        const node = parentNode.childs[params.index]
         node.updateField(params.newValue)
       }
     },
@@ -52,44 +52,44 @@ function NodeHistory (editor) {
 
     appendNodes: {
       undo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        params.paths.map(findNode).forEach(function (node) {
+        params.paths.map(findNode).forEach(node => {
           parentNode.removeChild(node)
         })
       },
       redo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        params.nodes.forEach(function (node) {
+        params.nodes.forEach(node => {
           parentNode.appendChild(node)
         })
       }
     },
     insertBeforeNodes: {
       undo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        params.paths.map(findNode).forEach(function (node) {
+        params.paths.map(findNode).forEach(node => {
           parentNode.removeChild(node)
         })
       },
       redo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        var beforeNode = findNode(params.beforePath)
+        const beforeNode = findNode(params.beforePath)
-        params.nodes.forEach(function (node) {
+        params.nodes.forEach(node => {
           parentNode.insertBefore(node, beforeNode)
         })
       }
     },
     insertAfterNodes: {
       undo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        params.paths.map(findNode).forEach(function (node) {
+        params.paths.map(findNode).forEach(node => {
           parentNode.removeChild(node)
         })
       },
       redo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        var afterNode = findNode(params.afterPath)
+        let afterNode = findNode(params.afterPath)
-        params.nodes.forEach(function (node) {
+        params.nodes.forEach(node => {
           parentNode.insertAfter(node, afterNode)
           afterNode = node
         })
@@ -97,34 +97,34 @@ function NodeHistory (editor) {
     },
     removeNodes: {
       undo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        var beforeNode = parentNode.childs[params.index] || parentNode.append
+        const beforeNode = parentNode.childs[params.index] || parentNode.append
-        params.nodes.forEach(function (node) {
+        params.nodes.forEach(node => {
           parentNode.insertBefore(node, beforeNode)
         })
       },
       redo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        params.paths.map(findNode).forEach(function (node) {
+        params.paths.map(findNode).forEach(node => {
           parentNode.removeChild(node)
         })
       }
     },
     duplicateNodes: {
       undo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        params.clonePaths.map(findNode).forEach(function (node) {
+        params.clonePaths.map(findNode).forEach(node => {
           parentNode.removeChild(node)
         })
       },
       redo: function (params) {
-        var parentNode = findNode(params.parentPath)
+        const parentNode = findNode(params.parentPath)
-        var afterNode = findNode(params.afterPath)
+        let afterNode = findNode(params.afterPath)
-        var nodes = params.paths.map(findNode)
+        const nodes = params.paths.map(findNode)
-        nodes.forEach(function (node) {
+        nodes.forEach(node => {
-          var clone = node.clone()
+          const clone = node.clone()
           if (parentNode.type === 'object') {
-            var existingFieldNames = parentNode.getFieldNames()
+            const existingFieldNames = parentNode.getFieldNames()
             clone.field = util.findUniqueName(node.field, existingFieldNames)
           }
           parentNode.insertAfter(clone, afterNode)
@@ -134,14 +134,14 @@ function NodeHistory (editor) {
     },
     moveNodes: {
       undo: function (params) {
-        var oldParentNode = findNode(params.oldParentPath)
+        const oldParentNode = findNode(params.oldParentPath)
-        var newParentNode = findNode(params.newParentPath)
+        const newParentNode = findNode(params.newParentPath)
-        var oldBeforeNode = oldParentNode.childs[params.oldIndex] || oldParentNode.append
+        const oldBeforeNode = oldParentNode.childs[params.oldIndex] || oldParentNode.append
 
         // first copy the nodes, then move them
-        var nodes = newParentNode.childs.slice(params.newIndex, params.newIndex + params.count)
+        const nodes = newParentNode.childs.slice(params.newIndex, params.newIndex + params.count)
 
-        nodes.forEach(function (node, index) {
+        nodes.forEach((node, index) => {
           node.field = params.fieldNames[index]
           oldParentNode.moveBefore(node, oldBeforeNode)
         })
@@ -153,14 +153,14 @@ function NodeHistory (editor) {
         }
       },
       redo: function (params) {
-        var oldParentNode = findNode(params.oldParentPathRedo)
+        const oldParentNode = findNode(params.oldParentPathRedo)
-        var newParentNode = findNode(params.newParentPathRedo)
+        const newParentNode = findNode(params.newParentPathRedo)
-        var newBeforeNode = newParentNode.childs[params.newIndexRedo] || newParentNode.append
+        const newBeforeNode = newParentNode.childs[params.newIndexRedo] || newParentNode.append
 
         // first copy the nodes, then move them
-        var nodes = oldParentNode.childs.slice(params.oldIndexRedo, params.oldIndexRedo + params.count)
+        const nodes = oldParentNode.childs.slice(params.oldIndexRedo, params.oldIndexRedo + params.count)
 
-        nodes.forEach(function (node, index) {
+        nodes.forEach((node, index) => {
           node.field = params.fieldNames[index]
           newParentNode.moveBefore(node, newBeforeNode)
         })
@@ -169,14 +169,14 @@ function NodeHistory (editor) {
 
     sort: {
       undo: function (params) {
-        var node = findNode(params.path)
+        const node = findNode(params.path)
         node.hideChilds()
         node.childs = params.oldChilds
         node.updateDom({ updateIndexes: true })
         node.showChilds()
       },
       redo: function (params) {
-        var node = findNode(params.path)
+        const node = findNode(params.path)
         node.hideChilds()
         node.childs = params.newChilds
         node.updateDom({ updateIndexes: true })
@@ -206,7 +206,7 @@ function NodeHistory (editor) {
  * The method onChange is executed when the History is changed, and can
  * be overloaded.
  */
-NodeHistory.prototype.onChange = function () {}
+NodeHistory.prototype.onChange = () => {}
 
 /**
  * Add a new action to the history
@@ -268,9 +268,9 @@ NodeHistory.prototype.canRedo = function () {
  */
 NodeHistory.prototype.undo = function () {
   if (this.canUndo()) {
-    var obj = this.history[this.index]
+    const obj = this.history[this.index]
     if (obj) {
-      var action = this.actions[obj.action]
+      const action = this.actions[obj.action]
       if (action && action.undo) {
         action.undo(obj.params)
         if (obj.params.oldSelection) {
@@ -298,9 +298,9 @@ NodeHistory.prototype.redo = function () {
   if (this.canRedo()) {
     this.index++
 
-    var obj = this.history[this.index]
+    const obj = this.history[this.index]
     if (obj) {
-      var action = this.actions[obj.action]
+      const action = this.actions[obj.action]
       if (action && action.redo) {
         action.redo(obj.params)
         if (obj.params.newSelection) {

src/js/SearchBox.js

@@ -8,7 +8,7 @@
  *                                          create the search box
  */
 function SearchBox (editor, container) {
-  var searchBox = this
+  const searchBox = this
 
   this.editor = editor
   this.timeout = undefined
@@ -18,65 +18,65 @@ function SearchBox (editor, container) {
   this.dom = {}
   this.dom.container = container
 
-  var wrapper = document.createElement('div')
+  const wrapper = document.createElement('div')
   this.dom.wrapper = wrapper
   wrapper.className = 'jsoneditor-search'
   container.appendChild(wrapper)
 
-  var results = document.createElement('div')
+  const results = document.createElement('div')
   this.dom.results = results
   results.className = 'jsoneditor-results'
   wrapper.appendChild(results)
 
-  var divInput = document.createElement('div')
+  const divInput = document.createElement('div')
   this.dom.input = divInput
   divInput.className = 'jsoneditor-frame'
   divInput.title = 'Search fields and values'
   wrapper.appendChild(divInput)
 
-  var refreshSearch = document.createElement('button')
+  const refreshSearch = document.createElement('button')
   refreshSearch.type = 'button'
   refreshSearch.className = 'jsoneditor-refresh'
   divInput.appendChild(refreshSearch)
 
-  var search = document.createElement('input')
+  const search = document.createElement('input')
   search.type = 'text'
   this.dom.search = search
-  search.oninput = function (event) {
+  search.oninput = event => {
     searchBox._onDelayedSearch(event)
   }
-  search.onchange = function (event) {
+  search.onchange = event => {
     // For IE 9
     searchBox._onSearch()
   }
-  search.onkeydown = function (event) {
+  search.onkeydown = event => {
     searchBox._onKeyDown(event)
   }
-  search.onkeyup = function (event) {
+  search.onkeyup = event => {
     searchBox._onKeyUp(event)
   }
-  refreshSearch.onclick = function (event) {
+  refreshSearch.onclick = event => {
     search.select()
   }
 
   // TODO: ESC in FF restores the last input, is a FF bug, https://bugzilla.mozilla.org/show_bug.cgi?id=598819
   divInput.appendChild(search)
 
-  var searchNext = document.createElement('button')
+  const searchNext = document.createElement('button')
   searchNext.type = 'button'
   searchNext.title = 'Next result (Enter)'
   searchNext.className = 'jsoneditor-next'
-  searchNext.onclick = function () {
+  searchNext.onclick = () => {
     searchBox.next()
   }
 
   divInput.appendChild(searchNext)
 
-  var searchPrevious = document.createElement('button')
+  const searchPrevious = document.createElement('button')
   searchPrevious.type = 'button'
   searchPrevious.title = 'Previous result (Shift+Enter)'
   searchPrevious.className = 'jsoneditor-previous'
-  searchPrevious.onclick = function () {
+  searchPrevious.onclick = () => {
     searchBox.previous()
   }
 
@@ -90,7 +90,7 @@ function SearchBox (editor, container) {
  */
 SearchBox.prototype.next = function (focus) {
   if (this.results !== null) {
-    var index = this.resultIndex !== null ? this.resultIndex + 1 : 0
+    let index = this.resultIndex !== null ? this.resultIndex + 1 : 0
     if (index > this.results.length - 1) {
       index = 0
     }
@@ -105,8 +105,8 @@ SearchBox.prototype.next = function (focus) {
  */
 SearchBox.prototype.previous = function (focus) {
   if (this.results !== null) {
-    var max = this.results.length - 1
+    const max = this.results.length - 1
-    var index = this.resultIndex !== null ? this.resultIndex - 1 : max
+    let index = this.resultIndex !== null ? this.resultIndex - 1 : max
     if (index < 0) {
       index = max
     }
@@ -124,8 +124,8 @@ SearchBox.prototype.previous = function (focus) {
 SearchBox.prototype._setActiveResult = function (index, focus) {
   // de-activate current active result
   if (this.activeResult) {
-    var prevNode = this.activeResult.node
+    const prevNode = this.activeResult.node
-    var prevElem = this.activeResult.elem
+    const prevElem = this.activeResult.elem
     if (prevElem === 'field') {
       delete prevNode.searchFieldActive
     } else {
@@ -144,8 +144,8 @@ SearchBox.prototype._setActiveResult = function (index, focus) {
   this.resultIndex = index
 
   // set new node active
-  var node = this.results[this.resultIndex].node
+  const node = this.results[this.resultIndex].node
-  var elem = this.results[this.resultIndex].elem
+  const elem = this.results[this.resultIndex].elem
   if (elem === 'field') {
     node.searchFieldActive = true
   } else {
@@ -155,7 +155,7 @@ SearchBox.prototype._setActiveResult = function (index, focus) {
   node.updateDom()
 
   // TODO: not so nice that the focus is only set after the animation is finished
-  node.scrollTo(function () {
+  node.scrollTo(() => {
     if (focus) {
       node.focus(elem)
     }
@@ -183,8 +183,8 @@ SearchBox.prototype._onDelayedSearch = function (event) {
   // execute the search after a short delay (reduces the number of
   // search actions while typing in the search text box)
   this._clearDelay()
-  var searchBox = this
+  const searchBox = this
-  this.timeout = setTimeout(function (event) {
+  this.timeout = setTimeout(event => {
     searchBox._onSearch()
   }, this.delay)
 }
@@ -199,20 +199,20 @@ SearchBox.prototype._onDelayedSearch = function (event) {
 SearchBox.prototype._onSearch = function (forceSearch) {
   this._clearDelay()
 
-  var value = this.dom.search.value
+  const value = this.dom.search.value
-  var text = value.length > 0 ? value : undefined
+  const text = value.length > 0 ? value : undefined
   if (text !== this.lastText || forceSearch) {
     // only search again when changed
     this.lastText = text
     this.results = this.editor.search(text)
-    var MAX_SEARCH_RESULTS = this.results[0]
+    const MAX_SEARCH_RESULTS = this.results[0]
       ? this.results[0].node.MAX_SEARCH_RESULTS
       : Infinity
 
     // try to maintain the current active result if this is still part of the new search results
-    var activeResultIndex = 0
+    let activeResultIndex = 0
     if (this.activeResult) {
-      for (var i = 0; i < this.results.length; i++) {
+      for (let i = 0; i < this.results.length; i++) {
         if (this.results[i].node === this.activeResult.node) {
           activeResultIndex = i
           break
@@ -224,7 +224,7 @@ SearchBox.prototype._onSearch = function (forceSearch) {
 
     // display search results
     if (text !== undefined) {
-      var resultCount = this.results.length
+      const resultCount = this.results.length
       if (resultCount === 0) {
         this.dom.results.innerHTML = 'no&nbsp;results'
       } else if (resultCount === 1) {
@@ -246,7 +246,7 @@ SearchBox.prototype._onSearch = function (forceSearch) {
  * @private
  */
 SearchBox.prototype._onKeyDown = function (event) {
-  var keynum = event.which
+  const keynum = event.which
   if (keynum === 27) {
     // ESC
     this.dom.search.value = '' // clear search
@@ -276,7 +276,7 @@ SearchBox.prototype._onKeyDown = function (event) {
  * @private
  */
 SearchBox.prototype._onKeyUp = function (event) {
-  var keynum = event.keyCode
+  const keynum = event.keyCode
   if (keynum !== 27 && keynum !== 13) {
     // !show and !Enter
     this._onDelayedSearch(event) // For IE 9

src/js/TreePath.js

@@ -1,8 +1,8 @@
 'use strict'
 
-var ContextMenu = require('./ContextMenu')
+const ContextMenu = require('./ContextMenu')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
-var util = require('./util')
+const util = require('./util')
 
 /**
  * Creates a component that visualize path selection in tree based editors
@@ -35,14 +35,14 @@ TreePath.prototype.reset = function () {
  *
  */
 TreePath.prototype.setPath = function (pathObjs) {
-  var me = this
+  const me = this
 
   this.path.innerHTML = ''
 
   if (pathObjs && pathObjs.length) {
-    pathObjs.forEach(function (pathObj, idx) {
+    pathObjs.forEach((pathObj, idx) => {
-      var pathEl = document.createElement('span')
+      const pathEl = document.createElement('span')
-      var sepEl
+      let sepEl
       pathEl.className = 'jsoneditor-treepath-element'
       pathEl.innerText = pathObj.name
       pathEl.onclick = _onSegmentClick.bind(me, pathObj)
@@ -54,17 +54,17 @@ TreePath.prototype.setPath = function (pathObjs) {
         sepEl.className = 'jsoneditor-treepath-seperator'
         sepEl.innerHTML = '►'
 
-        sepEl.onclick = function () {
+        sepEl.onclick = () => {
           me.contentMenuClicked = true
-          var items = []
+          const items = []
-          pathObj.children.forEach(function (child) {
+          pathObj.children.forEach(child => {
             items.push({
               text: child.name,
               className: 'jsoneditor-type-modes' + (pathObjs[idx + 1] + 1 && pathObjs[idx + 1].name === child.name ? ' jsoneditor-selected' : ''),
               click: _onContextMenuItemClick.bind(me, pathObj, child.name)
             })
           })
-          var menu = new ContextMenu(items)
+          const menu = new ContextMenu(items)
           menu.show(sepEl, me.root, true)
         }
 
@@ -72,13 +72,13 @@ TreePath.prototype.setPath = function (pathObjs) {
       }
 
       if (idx === pathObjs.length - 1) {
-        var leftRectPos = (sepEl || pathEl).getBoundingClientRect().right
+        const leftRectPos = (sepEl || pathEl).getBoundingClientRect().right
         if (me.path.offsetWidth < leftRectPos) {
           me.path.scrollLeft = leftRectPos
         }
 
         if (me.path.scrollLeft) {
-          var showAllBtn = document.createElement('span')
+          const showAllBtn = document.createElement('span')
           showAllBtn.className = 'jsoneditor-treepath-show-all-btn'
           showAllBtn.title = 'show all path'
           showAllBtn.innerHTML = '...'
@@ -93,7 +93,7 @@ TreePath.prototype.setPath = function (pathObjs) {
     me.contentMenuClicked = false
     util.addClassName(me.path, 'show-all')
     me.path.style.width = me.path.parentNode.getBoundingClientRect().width - 10 + 'px'
-    me.path.onblur = function () {
+    me.path.onblur = () => {
       if (me.contentMenuClicked) {
         me.contentMenuClicked = false
         me.path.focus()

src/js/ace/index.js

@@ -1,4 +1,4 @@
-var ace
+let ace
 if (window.ace) {
   // use the already loaded instance of Ace
   ace = window.ace

src/js/ace/theme-jsoneditor.js

@@ -28,7 +28,7 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
-window.ace.define('ace/theme/jsoneditor', ['require', 'exports', 'module', 'ace/lib/dom'], function (acequire, exports, module) {
+window.ace.define('ace/theme/jsoneditor', ['require', 'exports', 'module', 'ace/lib/dom'], (acequire, exports, module) => {
   exports.isDark = false
   exports.cssClass = 'ace-jsoneditor'
   exports.cssText = `.ace-jsoneditor .ace_gutter {
@@ -139,6 +139,6 @@ text-decoration: underline
 background: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAACCAYAAACZgbYnAAAAE0lEQVQImWP4////f4bLly//BwAmVgd1/w11/gAAAABJRU5ErkJggg==") right repeat-y
 }`
 
-  var dom = acequire('../lib/dom')
+  const dom = acequire('../lib/dom')
   dom.importCssString(exports.cssText, exports.cssClass)
 })

src/js/appendNodeFactory.js

@@ -1,8 +1,8 @@
 'use strict'
 
-var util = require('./util')
+const util = require('./util')
-var ContextMenu = require('./ContextMenu')
+const ContextMenu = require('./ContextMenu')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
 
 /**
  * A factory function to create an AppendNode, which depends on a Node
@@ -30,7 +30,7 @@ function appendNodeFactory (Node) {
    */
   AppendNode.prototype.getDom = function () {
     // TODO: implement a new solution for the append node
-    var dom = this.dom
+    const dom = this.dom
 
     if (dom.tr) {
       return dom.tr
@@ -39,7 +39,7 @@ function appendNodeFactory (Node) {
     this._updateEditability()
 
     // a row for the append button
-    var trAppend = document.createElement('tr')
+    const trAppend = document.createElement('tr')
     trAppend.className = 'jsoneditor-append'
     trAppend.node = this
     dom.tr = trAppend
@@ -51,9 +51,9 @@ function appendNodeFactory (Node) {
       dom.tdDrag = document.createElement('td')
 
       // create context menu
-      var tdMenu = document.createElement('td')
+      const tdMenu = document.createElement('td')
       dom.tdMenu = tdMenu
-      var menu = document.createElement('button')
+      const menu = document.createElement('button')
       menu.type = 'button'
       menu.className = 'jsoneditor-button jsoneditor-contextmenu'
       menu.title = 'Click to open the actions menu (Ctrl+M)'
@@ -62,8 +62,8 @@ function appendNodeFactory (Node) {
     }
 
     // a cell for the contents (showing text 'empty')
-    var tdAppend = document.createElement('td')
+    const tdAppend = document.createElement('td')
-    var domText = document.createElement('div')
+    const domText = document.createElement('div')
     domText.innerHTML = '(' + translate('empty') + ')'
     domText.className = 'jsoneditor-readonly'
     tdAppend.appendChild(domText)
@@ -79,37 +79,33 @@ function appendNodeFactory (Node) {
    * Append node doesn't have a path
    * @returns {null}
    */
-  AppendNode.prototype.getPath = function () {
+  AppendNode.prototype.getPath = () => null
-    return null
-  }
 
   /**
    * Append node doesn't have an index
    * @returns {null}
    */
-  AppendNode.prototype.getIndex = function () {
+  AppendNode.prototype.getIndex = () => null
-    return null
-  }
 
   /**
    * Update the HTML dom of the Node
    */
   AppendNode.prototype.updateDom = function (options) {
-    var dom = this.dom
+    const dom = this.dom
-    var tdAppend = dom.td
+    const tdAppend = dom.td
     if (tdAppend) {
       tdAppend.style.paddingLeft = (this.getLevel() * 24 + 26) + 'px'
       // TODO: not so nice hard coded offset
     }
 
-    var domText = dom.text
+    const domText = dom.text
     if (domText) {
       domText.innerHTML = '(' + translate('empty') + ' ' + this.parent.type + ')'
     }
 
     // attach or detach the contents of the append node:
     // hide when the parent has childs, show when the parent has no childs
-    var trAppend = dom.tr
+    const trAppend = dom.tr
     if (!this.isVisible()) {
       if (dom.tr.firstChild) {
         if (dom.tdDrag) {
@@ -149,9 +145,9 @@ function appendNodeFactory (Node) {
    *                               is being closed.
    */
   AppendNode.prototype.showContextMenu = function (anchor, onClose) {
-    var node = this
+    const node = this
-    var titles = Node.TYPE_TITLES
+    const titles = Node.TYPE_TITLES
-    var appendSubmenu = [
+    const appendSubmenu = [
       {
         text: translate('auto'),
         className: 'jsoneditor-type-auto',
@@ -186,7 +182,7 @@ function appendNodeFactory (Node) {
       }
     ]
     node.addTemplates(appendSubmenu, true)
-    var items = [
+    let items = [
       // create append button
       {
         text: translate('appendText'),
@@ -201,7 +197,7 @@ function appendNodeFactory (Node) {
     ]
 
     if (this.editor.options.onCreateMenu) {
-      var path = node.parent.getPath()
+      const path = node.parent.getPath()
 
       items = this.editor.options.onCreateMenu(items, {
         type: 'append',
@@ -210,7 +206,7 @@ function appendNodeFactory (Node) {
       })
     }
 
-    var menu = new ContextMenu(items, { close: onClose })
+    const menu = new ContextMenu(items, { close: onClose })
     menu.show(anchor, this.editor.frame)
   }
 
@@ -219,12 +215,12 @@ function appendNodeFactory (Node) {
    * @param {Event} event
    */
   AppendNode.prototype.onEvent = function (event) {
-    var type = event.type
+    const type = event.type
-    var target = event.target || event.srcElement
+    const target = event.target || event.srcElement
-    var dom = this.dom
+    const dom = this.dom
 
     // highlight the append nodes parent
-    var menu = dom.menu
+    const menu = dom.menu
     if (target === menu) {
       if (type === 'mouseover') {
         this.editor.highlighter.highlight(this.parent)
@@ -235,11 +231,11 @@ function appendNodeFactory (Node) {
 
     // context menu events
     if (type === 'click' && target === dom.menu) {
-      var highlighter = this.editor.highlighter
+      const highlighter = this.editor.highlighter
       highlighter.highlight(this.parent)
       highlighter.lock()
       util.addClassName(dom.menu, 'jsoneditor-selected')
-      this.showContextMenu(dom.menu, function () {
+      this.showContextMenu(dom.menu, () => {
         util.removeClassName(dom.menu, 'jsoneditor-selected')
         highlighter.unlock()
         highlighter.unhighlight()

src/js/autocomplete.js

@@ -1,6 +1,6 @@
 'use strict'
 
-var defaultFilterFunction = {
+const defaultFilterFunction = {
   start: function (token, match, config) {
     return match.indexOf(token) === 0
   },
@@ -16,31 +16,31 @@ function completely (config) {
   config.confirmKeys = config.confirmKeys || [39, 35, 9] // right, end, tab
   config.caseSensitive = config.caseSensitive || false // autocomplete case sensitive
 
-  var fontSize = ''
+  let fontSize = ''
-  var fontFamily = ''
+  let fontFamily = ''
 
-  var wrapper = document.createElement('div')
+  const wrapper = document.createElement('div')
   wrapper.style.position = 'relative'
   wrapper.style.outline = '0'
   wrapper.style.border = '0'
   wrapper.style.margin = '0'
   wrapper.style.padding = '0'
 
-  var dropDown = document.createElement('div')
+  const dropDown = document.createElement('div')
   dropDown.className = 'autocomplete dropdown'
   dropDown.style.position = 'absolute'
   dropDown.style.visibility = 'hidden'
 
-  var spacer
+  let spacer
-  var leftSide // <-- it will contain the leftSide part of the textfield (the bit that was already autocompleted)
+  let leftSide // <-- it will contain the leftSide part of the textfield (the bit that was already autocompleted)
-  var createDropDownController = function (elem, rs) {
+  const createDropDownController = (elem, rs) => {
-    var rows = []
+    let rows = []
-    var ix = 0
+    let ix = 0
-    var oldIndex = -1
+    let oldIndex = -1
 
-    var onMouseOver = function () { this.style.outline = '1px solid #ddd' }
+    const onMouseOver = function () { this.style.outline = '1px solid #ddd' }
-    var onMouseOut = function () { this.style.outline = '0' }
+    const onMouseOut = function () { this.style.outline = '0' }
-    var onMouseDown = function () { p.hide(); p.onmouseselection(this.__hint, p.rs) }
+    const onMouseDown = function () { p.hide(); p.onmouseselection(this.__hint, p.rs) }
 
     var p = {
       rs: rs,
@@ -52,20 +52,18 @@ function completely (config) {
         elem.style.visibility = 'hidden'
         ix = 0
         elem.innerHTML = ''
-        var vph = (window.innerHeight || document.documentElement.clientHeight)
+        const vph = (window.innerHeight || document.documentElement.clientHeight)
-        var rect = elem.parentNode.getBoundingClientRect()
+        const rect = elem.parentNode.getBoundingClientRect()
-        var distanceToTop = rect.top - 6 // heuristic give 6px
+        const distanceToTop = rect.top - 6 // heuristic give 6px
-        var distanceToBottom = vph - rect.bottom - 6 // distance from the browser border.
+        const distanceToBottom = vph - rect.bottom - 6 // distance from the browser border.
 
         rows = []
-        var filterFn = typeof config.filter === 'function' ? config.filter : defaultFilterFunction[config.filter]
+        const filterFn = typeof config.filter === 'function' ? config.filter : defaultFilterFunction[config.filter]
 
-        var filtered = !filterFn ? [] : array.filter(function (match) {
+        const filtered = !filterFn ? [] : array.filter(match => filterFn(config.caseSensitive ? token : token.toLowerCase(), config.caseSensitive ? match : match.toLowerCase(), config))
-          return filterFn(config.caseSensitive ? token : token.toLowerCase(), config.caseSensitive ? match : match.toLowerCase(), config)
-        })
 
-        rows = filtered.map(function (row) {
+        rows = filtered.map(row => {
-          var divRow = document.createElement('div')
+          const divRow = document.createElement('div')
           divRow.className = 'item'
           // divRow.style.color = config.color;
           divRow.onmouseover = onMouseOver
@@ -119,7 +117,7 @@ function completely (config) {
   }
 
   function setEndOfContenteditable (contentEditableElement) {
-    var range, selection
+    let range, selection
     if (document.createRange) {
       // Firefox, Chrome, Opera, Safari, IE 9+
       range = document.createRange()// Create a range (a range is a like the selection but invisible)
@@ -164,7 +162,7 @@ function completely (config) {
     return spacer.getBoundingClientRect().right
   }
 
-  var rs = {
+  const rs = {
     onArrowDown: function () { }, // defaults to no action.
     onArrowUp: function () { }, // defaults to no action.
     onEnter: function () { }, // defaults to no action.
@@ -213,7 +211,7 @@ function completely (config) {
       this.elementHint.className = 'autocomplete hint'
       this.elementHint.style.zIndex = 2
       this.elementHint.style.position = 'absolute'
-      this.elementHint.onfocus = function () { this.element.focus() }.bind(this)
+      this.elementHint.onfocus = () => { this.element.focus() }
 
       if (this.element.addEventListener) {
         this.element.removeEventListener('keydown', keyDownHandler)
@@ -247,18 +245,18 @@ function completely (config) {
       }
     },
     repaint: function (element) {
-      var text = element.innerText
+      let text = element.innerText
       text = text.replace('\n', '')
 
-      var optionsLength = this.options.length
+      const optionsLength = this.options.length
 
       // breaking text in leftSide and token.
 
-      var token = text.substring(this.startFrom)
+      const token = text.substring(this.startFrom)
       leftSide = text.substring(0, this.startFrom)
 
-      for (var i = 0; i < optionsLength; i++) {
+      for (let i = 0; i < optionsLength; i++) {
-        var opt = this.options[i]
+        const opt = this.options[i]
         if ((!config.caseSensitive && opt.toLowerCase().indexOf(token.toLowerCase()) === 0) ||
                     (config.caseSensitive && opt.indexOf(token) === 0)) { // <-- how about upperCase vs. lowercase
           this.elementHint.innerText = leftSide + token + opt.substring(token.length)
@@ -270,7 +268,7 @@ function completely (config) {
       dropDown.style.left = calculateWidthForText(leftSide) + 'px'
       dropDownController.refresh(token, this.options)
       this.elementHint.style.width = calculateWidthForText(this.elementHint.innerText) + 10 + 'px'
-      var wasDropDownHidden = (dropDown.style.visibility === 'hidden')
+      const wasDropDownHidden = (dropDown.style.visibility === 'hidden')
       if (!wasDropDownHidden) { this.elementHint.style.width = calculateWidthForText(this.elementHint.innerText) + dropDown.clientWidth + 'px' }
     }
   }
@@ -280,7 +278,7 @@ function completely (config) {
   var keyDownHandler = function (e) {
     // console.log("Keydown:" + e.keyCode);
     e = e || window.event
-    var keyCode = e.keyCode
+    const keyCode = e.keyCode
 
     if (this.elementHint == null) return
 
@@ -295,7 +293,7 @@ function completely (config) {
       return
     }
 
-    var text = this.element.innerText
+    let text = this.element.innerText
     text = text.replace('\n', '')
 
     if (config.confirmKeys.indexOf(keyCode) >= 0) { //  (autocomplete triggered)
@@ -323,7 +321,7 @@ function completely (config) {
       if (this.elementHint.innerText.length === 0) { // if there is a hint
         rs.onEnter()
       } else {
-        var wasDropDownHidden = (dropDown.style.visibility === 'hidden')
+        const wasDropDownHidden = (dropDown.style.visibility === 'hidden')
         dropDownController.hide()
 
         if (wasDropDownHidden) {
@@ -364,15 +362,15 @@ function completely (config) {
     }
   }.bind(rs)
 
-  var onBlurHandler = function (e) {
+  var onBlurHandler = e => {
     rs.hideDropDown()
     // console.log("Lost focus.");
   }
 
-  dropDownController.onmouseselection = function (text, rs) {
+  dropDownController.onmouseselection = (text, rs) => {
     rs.element.innerText = rs.elementHint.innerText = leftSide + text
     rs.hideDropDown()
-    window.setTimeout(function () {
+    window.setTimeout(() => {
       rs.element.focus()
       setEndOfContenteditable(rs.element)
     }, 1)

src/js/createAbsoluteAnchor.js

@@ -1,4 +1,4 @@
-var util = require('./util')
+const util = require('./util')
 
 /**
  * Create an anchor element absolutely positioned in the `parent`
@@ -8,14 +8,14 @@ var util = require('./util')
  * @param [onDestroy(function(anchor)]  Callback when the anchor is destroyed
  * @returns {HTMLElement}
  */
-exports.createAbsoluteAnchor = function (anchor, parent, onDestroy) {
+exports.createAbsoluteAnchor = (anchor, parent, onDestroy) => {
-  var root = getRootNode(anchor)
+  const root = getRootNode(anchor)
-  var eventListeners = {}
+  const eventListeners = {}
 
-  var anchorRect = anchor.getBoundingClientRect()
+  const anchorRect = anchor.getBoundingClientRect()
-  var frameRect = parent.getBoundingClientRect()
+  const frameRect = parent.getBoundingClientRect()
 
-  var absoluteAnchor = document.createElement('div')
+  const absoluteAnchor = document.createElement('div')
   absoluteAnchor.className = 'jsoneditor-anchor'
   absoluteAnchor.style.position = 'absolute'
   absoluteAnchor.style.left = (anchorRect.left - frameRect.left) + 'px'
@@ -32,9 +32,9 @@ exports.createAbsoluteAnchor = function (anchor, parent, onDestroy) {
 
       // remove all event listeners
       // all event listeners are supposed to be attached to document.
-      for (var name in eventListeners) {
+      for (const name in eventListeners) {
         if (hasOwnProperty(eventListeners, name)) {
-          var fn = eventListeners[name]
+          const fn = eventListeners[name]
           if (fn) {
             util.removeEventListener(root, name, fn)
           }
@@ -49,8 +49,8 @@ exports.createAbsoluteAnchor = function (anchor, parent, onDestroy) {
   }
 
   // create and attach event listeners
-  var destroyIfOutside = function (event) {
+  const destroyIfOutside = event => {
-    var target = event.target
+    const target = event.target
     if ((target !== absoluteAnchor) && !util.isChildOf(target, absoluteAnchor)) {
       destroy()
     }

src/js/i18n.js

@@ -4,8 +4,8 @@
 
 require('./polyfills')
 
-var _locales = ['en', 'pt-BR', 'zh-CN', 'tr']
+const _locales = ['en', 'pt-BR', 'zh-CN', 'tr']
-var _defs = {
+const _defs = {
   en: {
     array: 'Array',
     auto: 'Auto',
@@ -376,14 +376,12 @@ var _defs = {
   }
 }
 
-var _defaultLang = 'en'
+const _defaultLang = 'en'
-var _lang
+let _lang
-var userLang = typeof navigator !== 'undefined'
+const userLang = typeof navigator !== 'undefined'
   ? navigator.language || navigator.userLanguage
   : undefined
-_lang = _locales.find(function (l) {
+_lang = _locales.find(l => l === userLang)
-  return l === userLang
-})
 if (!_lang) {
   _lang = _defaultLang
 }
@@ -397,9 +395,7 @@ module.exports = {
     if (!lang) {
       return
     }
-    var langFound = _locales.find(function (l) {
+    const langFound = _locales.find(l => l === lang)
-      return l === lang
-    })
     if (langFound) {
       _lang = langFound
     } else {
@@ -410,10 +406,8 @@ module.exports = {
     if (!languages) {
       return
     }
-    for (var key in languages) {
+    for (const key in languages) {
-      var langFound = _locales.find(function (l) {
+      const langFound = _locales.find(l => l === key)
-        return l === key
-      })
       if (!langFound) {
         _locales.push(key)
       }
@@ -424,7 +418,7 @@ module.exports = {
     if (!lang) {
       lang = _lang
     }
-    var text = _defs[lang][key]
+    let text = _defs[lang][key]
     if (data) {
       for (key in data) {
         text = text.replace('${' + key + '}', data[key])

src/js/jsonUtils.js

@@ -22,7 +22,7 @@
  * @returns {string | undefined} Returns the string representation of the JSON object.
  */
 function stringifyPartial (value, space, limit) {
-  var _space // undefined by default
+  let _space // undefined by default
   if (typeof space === 'number') {
     if (space > 10) {
       _space = repeat(' ', 10)
@@ -34,7 +34,7 @@ function stringifyPartial (value, space, limit) {
     _space = space
   }
 
-  var output = stringifyValue(value, _space, '', limit)
+  const output = stringifyValue(value, _space, '', limit)
 
   return output.length > limit
     ? (slice(output, limit) + '...')
@@ -81,11 +81,11 @@ function stringifyValue (value, space, indent, limit) {
  * @return {string}
  */
 function stringifyArray (array, space, indent, limit) {
-  var childIndent = space ? (indent + space) : undefined
+  const childIndent = space ? (indent + space) : undefined
-  var str = space ? '[\n' : '['
+  let str = space ? '[\n' : '['
 
-  for (var i = 0; i < array.length; i++) {
+  for (let i = 0; i < array.length; i++) {
-    var item = array[i]
+    const item = array[i]
 
     if (space) {
       str += childIndent
@@ -120,17 +120,17 @@ function stringifyArray (array, space, indent, limit) {
  * @return {string}
  */
 function stringifyObject (object, space, indent, limit) {
-  var childIndent = space ? (indent + space) : undefined
+  const childIndent = space ? (indent + space) : undefined
-  var first = true
+  let first = true
-  var str = space ? '{\n' : '{'
+  let str = space ? '{\n' : '{'
 
   if (typeof object.toJSON === 'function') {
     return stringifyValue(object.toJSON(), space, indent, limit)
   }
 
-  for (var key in object) {
+  for (const key in object) {
     if (hasOwnProperty(object, key)) {
-      var value = object[key]
+      const value = object[key]
 
       if (first) {
         first = false
@@ -163,7 +163,7 @@ function stringifyObject (object, space, indent, limit) {
  * @return {string}
  */
 function repeat (text, times) {
-  var res = ''
+  let res = ''
   while (times-- > 0) {
     res += text
   }

src/js/polyfills.js

@@ -1,7 +1,7 @@
 
 if (typeof Element !== 'undefined') {
   // Polyfill for array remove
-  (function () {
+  (() => {
     function polyfill (item) {
       if ('remove' in item) {
         return
@@ -26,8 +26,8 @@ if (typeof Element !== 'undefined') {
 if (!Array.prototype.find) {
   // eslint-disable-next-line no-extend-native
   Array.prototype.find = function (callback) {
-    for (var i = 0; i < this.length; i++) {
+    for (let i = 0; i < this.length; i++) {
-      var element = this[i]
+      const element = this[i]
       if (callback.call(this, element, i, this)) {
         return element
       }

src/js/previewmode.js

@@ -1,21 +1,21 @@
 'use strict'
 
-var jmespath = require('jmespath')
+const jmespath = require('jmespath')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
-var ModeSwitcher = require('./ModeSwitcher')
+const ModeSwitcher = require('./ModeSwitcher')
-var ErrorTable = require('./ErrorTable')
+const ErrorTable = require('./ErrorTable')
-var textmode = require('./textmode')[0].mixin
+const textmode = require('./textmode')[0].mixin
-var showSortModal = require('./showSortModal')
+const showSortModal = require('./showSortModal')
-var showTransformModal = require('./showTransformModal')
+const showTransformModal = require('./showTransformModal')
-var MAX_PREVIEW_CHARACTERS = require('./constants').MAX_PREVIEW_CHARACTERS
+const MAX_PREVIEW_CHARACTERS = require('./constants').MAX_PREVIEW_CHARACTERS
-var DEFAULT_MODAL_ANCHOR = require('./constants').DEFAULT_MODAL_ANCHOR
+const DEFAULT_MODAL_ANCHOR = require('./constants').DEFAULT_MODAL_ANCHOR
-var SIZE_LARGE = require('./constants').SIZE_LARGE
+const SIZE_LARGE = require('./constants').SIZE_LARGE
-var PREVIEW_HISTORY_LIMIT = require('./constants').PREVIEW_HISTORY_LIMIT
+const PREVIEW_HISTORY_LIMIT = require('./constants').PREVIEW_HISTORY_LIMIT
-var util = require('./util')
+const util = require('./util')
-var History = require('./History')
+const History = require('./History')
 
 // create a mixin with the functions for text mode
-var previewmode = {}
+const previewmode = {}
 
 /**
  * Create a JSON document preview, suitable for processing of large documents
@@ -48,7 +48,7 @@ previewmode.create = function (container, options) {
   // determine mode
   this.mode = 'preview'
 
-  var me = this
+  const me = this
   this.container = container
   this.dom = {}
 
@@ -65,7 +65,7 @@ previewmode.create = function (container, options) {
 
   this.frame = document.createElement('div')
   this.frame.className = 'jsoneditor jsoneditor-mode-preview'
-  this.frame.onclick = function (event) {
+  this.frame.onclick = event => {
     // prevent default submit action when the editor is located inside a form
     event.preventDefault()
   }
@@ -95,13 +95,13 @@ previewmode.create = function (container, options) {
     this.frame.appendChild(this.menu)
 
     // create format button
-    var buttonFormat = document.createElement('button')
+    const buttonFormat = document.createElement('button')
     buttonFormat.type = 'button'
     buttonFormat.className = 'jsoneditor-format'
     buttonFormat.title = 'Format JSON data, with proper indentation and line feeds (Ctrl+\\)'
     this.menu.appendChild(buttonFormat)
     buttonFormat.onclick = function handleFormat () {
-      me.executeWithBusyMessage(function () {
+      me.executeWithBusyMessage(() => {
         try {
           me.format()
         } catch (err) {
@@ -111,13 +111,13 @@ previewmode.create = function (container, options) {
     }
 
     // create compact button
-    var buttonCompact = document.createElement('button')
+    const buttonCompact = document.createElement('button')
     buttonCompact.type = 'button'
     buttonCompact.className = 'jsoneditor-compact'
     buttonCompact.title = 'Compact JSON data, remove all whitespaces (Ctrl+Shift+\\)'
     this.menu.appendChild(buttonCompact)
     buttonCompact.onclick = function handleCompact () {
-      me.executeWithBusyMessage(function () {
+      me.executeWithBusyMessage(() => {
         try {
           me.compact()
         } catch (err) {
@@ -128,11 +128,11 @@ previewmode.create = function (container, options) {
 
     // create sort button
     if (this.options.enableSort) {
-      var sort = document.createElement('button')
+      const sort = document.createElement('button')
       sort.type = 'button'
       sort.className = 'jsoneditor-sort'
       sort.title = translate('sortTitleShort')
-      sort.onclick = function () {
+      sort.onclick = () => {
         me._showSortModal()
       }
       this.menu.appendChild(sort)
@@ -140,11 +140,11 @@ previewmode.create = function (container, options) {
 
     // create transform button
     if (this.options.enableTransform) {
-      var transform = document.createElement('button')
+      const transform = document.createElement('button')
       transform.type = 'button'
       transform.title = translate('transformTitleShort')
       transform.className = 'jsoneditor-transform'
-      transform.onclick = function () {
+      transform.onclick = () => {
         me._showTransformModal()
       }
       this.dom.transform = transform
@@ -152,14 +152,14 @@ previewmode.create = function (container, options) {
     }
 
     // create repair button
-    var buttonRepair = document.createElement('button')
+    const buttonRepair = document.createElement('button')
     buttonRepair.type = 'button'
     buttonRepair.className = 'jsoneditor-repair'
     buttonRepair.title = 'Repair JSON: fix quotes and escape characters, remove comments and JSONP notation, turn JavaScript objects into JSON.'
     this.menu.appendChild(buttonRepair)
-    buttonRepair.onclick = function () {
+    buttonRepair.onclick = () => {
       if (me.json === undefined) { // only repair if we don't have valid JSON
-        me.executeWithBusyMessage(function () {
+        me.executeWithBusyMessage(() => {
           try {
             me.repair()
           } catch (err) {
@@ -171,24 +171,23 @@ previewmode.create = function (container, options) {
 
     // create history and undo/redo buttons
     if (this.options.history !== false) { // default option value is true
-      var onHistoryChange = function () {
+      const onHistoryChange = () => {
         me.dom.undo.disabled = !me.history.canUndo()
         me.dom.redo.disabled = !me.history.canRedo()
       }
 
-      var calculateItemSize = function (item) {
+      const calculateItemSize = item => // times two to account for the json object
-        return item.text.length * 2 // times two to account for the json object
+        item.text.length * 2
-      }
 
       this.history = new History(onHistoryChange, calculateItemSize, PREVIEW_HISTORY_LIMIT)
 
       // create undo button
-      var undo = document.createElement('button')
+      const undo = document.createElement('button')
       undo.type = 'button'
       undo.className = 'jsoneditor-undo jsoneditor-separator'
       undo.title = translate('undo')
-      undo.onclick = function () {
+      undo.onclick = () => {
-        var action = me.history.undo()
+        const action = me.history.undo()
         if (action) {
           me._applyHistory(action)
         }
@@ -197,12 +196,12 @@ previewmode.create = function (container, options) {
       this.dom.undo = undo
 
       // create redo button
-      var redo = document.createElement('button')
+      const redo = document.createElement('button')
       redo.type = 'button'
       redo.className = 'jsoneditor-redo'
       redo.title = translate('redo')
-      redo.onclick = function () {
+      redo.onclick = () => {
-        var action = me.history.redo()
+        const action = me.history.redo()
         if (action) {
           me._applyHistory(action)
         }
@@ -232,8 +231,8 @@ previewmode.create = function (container, options) {
     onFocusLine: null,
     onChangeHeight: function (height) {
       // TODO: change CSS to using flex box, remove setting height using JavaScript
-      var statusBarHeight = me.dom.statusBar ? me.dom.statusBar.clientHeight : 0
+      const statusBarHeight = me.dom.statusBar ? me.dom.statusBar.clientHeight : 0
-      var totalHeight = height + statusBarHeight + 1
+      const totalHeight = height + statusBarHeight + 1
       me.content.style.marginBottom = (-totalHeight) + 'px'
       me.content.style.paddingBottom = totalHeight + 'px'
     }
@@ -246,7 +245,7 @@ previewmode.create = function (container, options) {
   if (options.statusBar) {
     util.addClassName(this.content, 'has-status-bar')
 
-    var statusBar = document.createElement('div')
+    const statusBar = document.createElement('div')
     this.dom.statusBar = statusBar
     statusBar.className = 'jsoneditor-statusbar'
     this.frame.appendChild(statusBar)
@@ -272,7 +271,7 @@ previewmode.create = function (container, options) {
 }
 
 previewmode._renderPreview = function () {
-  var text = this.getText()
+  const text = this.getText()
 
   this.dom.previewText.nodeValue = util.limitCharacters(text, MAX_PREVIEW_CHARACTERS)
 
@@ -332,31 +331,31 @@ previewmode._onChange = function () {
  * @private
  */
 previewmode._showSortModal = function () {
-  var me = this
+  const me = this
 
   function onSort (json, sortedBy) {
     if (Array.isArray(json)) {
-      var sortedArray = util.sort(json, sortedBy.path, sortedBy.direction)
+      const sortedArray = util.sort(json, sortedBy.path, sortedBy.direction)
 
       me.sortedBy = sortedBy
       me._setAndFireOnChange(sortedArray)
     }
 
     if (util.isObject(json)) {
-      var sortedObject = util.sortObjectKeys(json, sortedBy.direction)
+      const sortedObject = util.sortObjectKeys(json, sortedBy.direction)
 
       me.sortedBy = sortedBy
       me._setAndFireOnChange(sortedObject)
     }
   }
 
-  this.executeWithBusyMessage(function () {
+  this.executeWithBusyMessage(() => {
-    var container = me.options.modalAnchor || DEFAULT_MODAL_ANCHOR
+    const container = me.options.modalAnchor || DEFAULT_MODAL_ANCHOR
-    var json = me.get()
+    const json = me.get()
     me._renderPreview() // update array count
 
-    showSortModal(container, json, function (sortedBy) {
+    showSortModal(container, json, sortedBy => {
-      me.executeWithBusyMessage(function () {
+      me.executeWithBusyMessage(() => {
         onSort(json, sortedBy)
       }, 'sorting...')
     }, me.sortedBy)
@@ -368,16 +367,16 @@ previewmode._showSortModal = function () {
  * @private
  */
 previewmode._showTransformModal = function () {
-  var me = this
+  const me = this
 
-  this.executeWithBusyMessage(function () {
+  this.executeWithBusyMessage(() => {
-    var anchor = me.options.modalAnchor || DEFAULT_MODAL_ANCHOR
+    const anchor = me.options.modalAnchor || DEFAULT_MODAL_ANCHOR
-    var json = me.get()
+    const json = me.get()
     me._renderPreview() // update array count
 
-    showTransformModal(anchor, json, function (query) {
+    showTransformModal(anchor, json, query => {
-      me.executeWithBusyMessage(function () {
+      me.executeWithBusyMessage(() => {
-        var updatedJson = jmespath.search(json, query)
+        const updatedJson = jmespath.search(json, query)
         me._setAndFireOnChange(updatedJson)
       }, 'transforming...')
     })
@@ -407,8 +406,8 @@ previewmode.destroy = function () {
  * Compact the code in the text editor
  */
 previewmode.compact = function () {
-  var json = this.get()
+  const json = this.get()
-  var text = JSON.stringify(json)
+  const text = JSON.stringify(json)
 
   // we know that in this case the json is still the same, so we pass json too
   this._setTextAndFireOnChange(text, json)
@@ -418,8 +417,8 @@ previewmode.compact = function () {
  * Format the code in the text editor
  */
 previewmode.format = function () {
-  var json = this.get()
+  const json = this.get()
-  var text = JSON.stringify(json, null, this.indentation)
+  const text = JSON.stringify(json, null, this.indentation)
 
   // we know that in this case the json is still the same, so we pass json too
   this._setTextAndFireOnChange(text, json)
@@ -429,8 +428,8 @@ previewmode.format = function () {
  * Repair the code in the text editor
  */
 previewmode.repair = function () {
-  var text = this.getText()
+  const text = this.getText()
-  var repairedText = util.repair(text)
+  const repairedText = util.repair(text)
 
   this._setTextAndFireOnChange(repairedText)
 }
@@ -491,7 +490,7 @@ previewmode._setAndFireOnChange = function (json) {
  */
 previewmode.get = function () {
   if (this.json === undefined) {
-    var text = this.getText()
+    const text = this.getText()
 
     this.json = util.parse(text) // this can throw an error
   }
@@ -557,8 +556,8 @@ previewmode._setText = function (jsonText, json) {
   this._renderPreview()
 
   if (this.json === undefined) {
-    var me = this
+    const me = this
-    this.executeWithBusyMessage(function () {
+    this.executeWithBusyMessage(() => {
       try {
         // force parsing the json now, else it will be done in validate without feedback
         me.json = me.get()
@@ -609,7 +608,7 @@ previewmode._pushHistory = function () {
     return
   }
 
-  var action = {
+  const action = {
     text: this.text,
     json: this.json
   }
@@ -624,14 +623,14 @@ previewmode._pushHistory = function () {
  * @param {string} message
  */
 previewmode.executeWithBusyMessage = function (fn, message) {
-  var size = this.getText().length
+  const size = this.getText().length
 
   if (size > SIZE_LARGE) {
-    var me = this
+    const me = this
     util.addClassName(me.frame, 'busy')
     me.dom.busyContent.innerText = message
 
-    setTimeout(function () {
+    setTimeout(() => {
       fn()
       util.removeClassName(me.frame, 'busy')
       me.dom.busyContent.innerText = ''

src/js/showMoreNodeFactory.js

@@ -1,6 +1,6 @@
 'use strict'
 
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
 
 /**
  * A factory function to create an ShowMoreNode, which depends on a Node
@@ -37,12 +37,12 @@ function showMoreNodeFactory (Node) {
 
     // display "show more"
     if (!this.dom.tr) {
-      var me = this
+      const me = this
-      var parent = this.parent
+      const parent = this.parent
-      var showMoreButton = document.createElement('a')
+      const showMoreButton = document.createElement('a')
       showMoreButton.appendChild(document.createTextNode(translate('showMore')))
       showMoreButton.href = '#'
-      showMoreButton.onclick = function (event) {
+      showMoreButton.onclick = event => {
         // TODO: use callback instead of accessing a method of the parent
         parent.visibleChilds = Math.floor(parent.visibleChilds / parent.getMaxVisibleChilds() + 1) *
             parent.getMaxVisibleChilds()
@@ -53,10 +53,10 @@ function showMoreNodeFactory (Node) {
         return false
       }
 
-      var showAllButton = document.createElement('a')
+      const showAllButton = document.createElement('a')
       showAllButton.appendChild(document.createTextNode(translate('showAll')))
       showAllButton.href = '#'
-      showAllButton.onclick = function (event) {
+      showAllButton.onclick = event => {
         // TODO: use callback instead of accessing a method of the parent
         parent.visibleChilds = Infinity
         me.updateDom()
@@ -66,8 +66,8 @@ function showMoreNodeFactory (Node) {
         return false
       }
 
-      var moreContents = document.createElement('div')
+      const moreContents = document.createElement('div')
-      var moreText = document.createTextNode(this._getShowMoreText())
+      const moreText = document.createTextNode(this._getShowMoreText())
       moreContents.className = 'jsoneditor-show-more'
       moreContents.appendChild(moreText)
       moreContents.appendChild(showMoreButton)
@@ -75,10 +75,10 @@ function showMoreNodeFactory (Node) {
       moreContents.appendChild(showAllButton)
       moreContents.appendChild(document.createTextNode('. '))
 
-      var tdContents = document.createElement('td')
+      const tdContents = document.createElement('td')
       tdContents.appendChild(moreContents)
 
-      var moreTr = document.createElement('tr')
+      const moreTr = document.createElement('tr')
       if (this.editor.options.mode === 'tree') {
         moreTr.appendChild(document.createElement('td'))
         moreTr.appendChild(document.createElement('td'))
@@ -104,7 +104,7 @@ function showMoreNodeFactory (Node) {
       this.dom.tr.node = this.parent.childs[this.parent.visibleChilds]
 
       if (!this.dom.tr.parentNode) {
-        var nextTr = this.parent._getNextTr()
+        const nextTr = this.parent._getNextTr()
         if (nextTr) {
           nextTr.parentNode.insertBefore(this.dom.tr, nextTr)
         }
@@ -144,7 +144,7 @@ function showMoreNodeFactory (Node) {
    * @param {Event} event
    */
   ShowMoreNode.prototype.onEvent = function (event) {
-    var type = event.type
+    const type = event.type
     if (type === 'keydown') {
       this.onKeyDown(event)
     }

src/js/showSortModal.js

@@ -1,6 +1,6 @@
-var picoModal = require('picomodal')
+const picoModal = require('picomodal')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
-var util = require('./util')
+const util = require('./util')
 
 /**
  * Show advanced sorting modal
@@ -16,15 +16,15 @@ var util = require('./util')
  *                - {'asc' | 'desc'} direction The selected direction
  */
 function showSortModal (container, json, onSort, options) {
-  var paths = Array.isArray(json)
+  const paths = Array.isArray(json)
     ? util.getChildPaths(json)
     : ['']
-  var selectedPath = options && options.path && util.contains(paths, options.path)
+  const selectedPath = options && options.path && util.contains(paths, options.path)
     ? options.path
     : paths[0]
-  var selectedDirection = (options && options.direction) || 'asc'
+  const selectedDirection = (options && options.direction) || 'asc'
 
-  var content = '<div class="pico-modal-contents">' +
+  const content = '<div class="pico-modal-contents">' +
       '<div class="pico-modal-header">' + translate('sort') + '</div>' +
       '<form>' +
       '<table>' +
@@ -75,11 +75,11 @@ function showSortModal (container, json, onSort, options) {
     },
     modalClass: 'jsoneditor-modal jsoneditor-modal-sort'
   })
-    .afterCreate(function (modal) {
+    .afterCreate(modal => {
-      var form = modal.modalElem().querySelector('form')
+      const form = modal.modalElem().querySelector('form')
-      var ok = modal.modalElem().querySelector('#ok')
+      const ok = modal.modalElem().querySelector('#ok')
-      var field = modal.modalElem().querySelector('#field')
+      const field = modal.modalElem().querySelector('#field')
-      var direction = modal.modalElem().querySelector('#direction')
+      const direction = modal.modalElem().querySelector('#direction')
 
       function preprocessPath (path) {
         return (path === '')
@@ -89,8 +89,8 @@ function showSortModal (container, json, onSort, options) {
             : path
       }
 
-      paths.forEach(function (path) {
+      paths.forEach(path => {
-        var option = document.createElement('option')
+        const option = document.createElement('option')
         option.text = preprocessPath(path)
         option.value = path
         field.appendChild(option)
@@ -104,11 +104,11 @@ function showSortModal (container, json, onSort, options) {
       field.value = selectedPath || paths[0]
       setDirection(selectedDirection || 'asc')
 
-      direction.onclick = function (event) {
+      direction.onclick = event => {
         setDirection(event.target.getAttribute('data-value'))
       }
 
-      ok.onclick = function (event) {
+      ok.onclick = event => {
         event.preventDefault()
         event.stopPropagation()
 
@@ -124,7 +124,7 @@ function showSortModal (container, json, onSort, options) {
         form.onsubmit = ok.onclick
       }
     })
-    .afterClose(function (modal) {
+    .afterClose(modal => {
       modal.destroy()
     })
     .show()

src/js/showTransformModal.js

@@ -1,11 +1,11 @@
-var jmespath = require('jmespath')
+const jmespath = require('jmespath')
-var picoModal = require('picomodal')
+const picoModal = require('picomodal')
-var Selectr = require('./assets/selectr/selectr')
+const Selectr = require('./assets/selectr/selectr')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
-var stringifyPartial = require('./jsonUtils').stringifyPartial
+const stringifyPartial = require('./jsonUtils').stringifyPartial
-var util = require('./util')
+const util = require('./util')
-var MAX_PREVIEW_CHARACTERS = require('./constants').MAX_PREVIEW_CHARACTERS
+const MAX_PREVIEW_CHARACTERS = require('./constants').MAX_PREVIEW_CHARACTERS
-var debounce = util.debounce
+const debounce = util.debounce
 
 /**
  * Show advanced filter and transform modal using JMESPath
@@ -16,9 +16,9 @@ var debounce = util.debounce
  *                                  query as callback
  */
 function showTransformModal (container, json, onTransform) {
-  var value = json
+  const value = json
 
-  var content = '<label class="pico-modal-contents">' +
+  const content = '<label class="pico-modal-contents">' +
       '<div class="pico-modal-header">' + translate('transform') + '</div>' +
       '<p>' +
       'Enter a <a href="http://jmespath.org" target="_blank">JMESPath</a> query to filter, sort, or transform the JSON data.<br/>' +
@@ -106,63 +106,61 @@ function showTransformModal (container, json, onTransform) {
     modalClass: 'jsoneditor-modal jsoneditor-modal-transform',
     focus: false
   })
-    .afterCreate(function (modal) {
+    .afterCreate(modal => {
-      var elem = modal.modalElem()
+      const elem = modal.modalElem()
 
-      var wizard = elem.querySelector('#wizard')
+      const wizard = elem.querySelector('#wizard')
-      var ok = elem.querySelector('#ok')
+      const ok = elem.querySelector('#ok')
-      var filterField = elem.querySelector('#filterField')
+      const filterField = elem.querySelector('#filterField')
-      var filterRelation = elem.querySelector('#filterRelation')
+      const filterRelation = elem.querySelector('#filterRelation')
-      var filterValue = elem.querySelector('#filterValue')
+      const filterValue = elem.querySelector('#filterValue')
-      var sortField = elem.querySelector('#sortField')
+      const sortField = elem.querySelector('#sortField')
-      var sortOrder = elem.querySelector('#sortOrder')
+      const sortOrder = elem.querySelector('#sortOrder')
-      var selectFields = elem.querySelector('#selectFields')
+      const selectFields = elem.querySelector('#selectFields')
-      var query = elem.querySelector('#query')
+      const query = elem.querySelector('#query')
-      var preview = elem.querySelector('#preview')
+      const preview = elem.querySelector('#preview')
 
       if (!Array.isArray(value)) {
         wizard.style.fontStyle = 'italic'
         wizard.innerHTML = '(wizard not available for objects, only for arrays)'
       }
 
-      var sortablePaths = util.getChildPaths(json)
+      const sortablePaths = util.getChildPaths(json)
 
-      sortablePaths.forEach(function (path) {
+      sortablePaths.forEach(path => {
-        var formattedPath = preprocessPath(path)
+        const formattedPath = preprocessPath(path)
-        var filterOption = document.createElement('option')
+        const filterOption = document.createElement('option')
         filterOption.text = formattedPath
         filterOption.value = formattedPath
         filterField.appendChild(filterOption)
 
-        var sortOption = document.createElement('option')
+        const sortOption = document.createElement('option')
         sortOption.text = formattedPath
         sortOption.value = formattedPath
         sortField.appendChild(sortOption)
       })
 
-      var selectablePaths = util.getChildPaths(json, true).filter(function (path) {
+      const selectablePaths = util.getChildPaths(json, true).filter(path => path !== '')
-        return path !== ''
-      })
       if (selectablePaths.length > 0) {
-        selectablePaths.forEach(function (path) {
+        selectablePaths.forEach(path => {
-          var formattedPath = preprocessPath(path)
+          const formattedPath = preprocessPath(path)
-          var option = document.createElement('option')
+          const option = document.createElement('option')
           option.text = formattedPath
           option.value = formattedPath
           selectFields.appendChild(option)
         })
       } else {
-        var selectFieldsPart = elem.querySelector('#selectFieldsPart')
+        const selectFieldsPart = elem.querySelector('#selectFieldsPart')
         if (selectFieldsPart) {
           selectFieldsPart.style.display = 'none'
         }
       }
 
-      var selectrFilterField = new Selectr(filterField, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'field...' })
+      const selectrFilterField = new Selectr(filterField, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'field...' })
-      var selectrFilterRelation = new Selectr(filterRelation, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'compare...' })
+      const selectrFilterRelation = new Selectr(filterRelation, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'compare...' })
-      var selectrSortField = new Selectr(sortField, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'field...' })
+      const selectrSortField = new Selectr(sortField, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'field...' })
-      var selectrSortOrder = new Selectr(sortOrder, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'order...' })
+      const selectrSortOrder = new Selectr(sortOrder, { defaultSelected: false, clearable: true, allowDeselect: true, placeholder: 'order...' })
-      var selectrSelectFields = new Selectr(selectFields, { multiple: true, clearable: true, defaultSelected: false, placeholder: 'select fields...' })
+      const selectrSelectFields = new Selectr(selectFields, { multiple: true, clearable: true, defaultSelected: false, placeholder: 'select fields...' })
 
       selectrFilterField.on('selectr.change', generateQueryFromWizard)
       selectrFilterRelation.on('selectr.change', generateQueryFromWizard)
@@ -171,7 +169,7 @@ function showTransformModal (container, json, onTransform) {
       selectrSortOrder.on('selectr.change', generateQueryFromWizard)
       selectrSelectFields.on('selectr.change', generateQueryFromWizard)
 
-      elem.querySelector('.pico-modal-contents').onclick = function (event) {
+      elem.querySelector('.pico-modal-contents').onclick = event => {
         // prevent the first clear button (in any select box) from getting
         // focus when clicking anywhere in the modal. Only allow clicking links.
         if (event.target.nodeName !== 'A') {
@@ -191,12 +189,12 @@ function showTransformModal (container, json, onTransform) {
 
       function generateQueryFromWizard () {
         if (filterField.value && filterRelation.value && filterValue.value) {
-          var field1 = filterField.value
+          const field1 = filterField.value
-          var examplePath = field1 !== '@'
+          const examplePath = field1 !== '@'
             ? ['0'].concat(util.parsePath('.' + field1))
             : ['0']
-          var exampleValue = util.get(value, examplePath)
+          const exampleValue = util.get(value, examplePath)
-          var value1 = typeof exampleValue === 'string'
+          const value1 = typeof exampleValue === 'string'
             ? filterValue.value
             : util.parseString(filterValue.value)
 
@@ -210,7 +208,7 @@ function showTransformModal (container, json, onTransform) {
         }
 
         if (sortField.value && sortOrder.value) {
-          var field2 = sortField.value
+          const field2 = sortField.value
           if (sortOrder.value === 'desc') {
             query.value += ' | reverse(sort_by(@, &' + field2 + '))'
           } else {
@@ -219,10 +217,10 @@ function showTransformModal (container, json, onTransform) {
         }
 
         if (selectFields.value) {
-          var values = []
+          const values = []
-          for (var i = 0; i < selectFields.options.length; i++) {
+          for (let i = 0; i < selectFields.options.length; i++) {
             if (selectFields.options[i].selected) {
-              var selectedValue = selectFields.options[i].value
+              const selectedValue = selectFields.options[i].value
               values.push(selectedValue)
             }
           }
@@ -235,9 +233,9 @@ function showTransformModal (container, json, onTransform) {
             query.value += '.' + values[0]
           } else if (values.length > 1) {
             query.value += '.{' +
-                  values.map(function (value) {
+                  values.map(value => {
-                    var parts = value.split('.')
+                    const parts = value.split('.')
-                    var last = parts[parts.length - 1]
+                    const last = parts[parts.length - 1]
                     return last + ': ' + value
                   }).join(', ') +
                   '}'
@@ -251,7 +249,7 @@ function showTransformModal (container, json, onTransform) {
 
       function updatePreview () {
         try {
-          var transformed = jmespath.search(value, query.value)
+          const transformed = jmespath.search(value, query.value)
 
           preview.className = 'jsoneditor-transform-preview'
           preview.value = stringifyPartial(transformed, 2, MAX_PREVIEW_CHARACTERS)
@@ -269,7 +267,7 @@ function showTransformModal (container, json, onTransform) {
       query.oninput = debouncedUpdatePreview
       debouncedUpdatePreview()
 
-      ok.onclick = function (event) {
+      ok.onclick = event => {
         event.preventDefault()
         event.stopPropagation()
 
@@ -278,14 +276,14 @@ function showTransformModal (container, json, onTransform) {
         onTransform(query.value)
       }
 
-      setTimeout(function () {
+      setTimeout(() => {
         query.select()
         query.focus()
         query.selectionStart = 3
         query.selectionEnd = 3
       })
     })
-    .afterClose(function (modal) {
+    .afterClose(modal => {
       modal.destroy()
     })
     .show()

src/js/textmode.js

@@ -1,20 +1,20 @@
 'use strict'
 
-var ace = require('./ace')
+const ace = require('./ace')
-var jmespath = require('jmespath')
+const jmespath = require('jmespath')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
-var ModeSwitcher = require('./ModeSwitcher')
+const ModeSwitcher = require('./ModeSwitcher')
-var ErrorTable = require('./ErrorTable')
+const ErrorTable = require('./ErrorTable')
-var validateCustom = require('./validationUtils').validateCustom
+const validateCustom = require('./validationUtils').validateCustom
-var showSortModal = require('./showSortModal')
+const showSortModal = require('./showSortModal')
-var showTransformModal = require('./showTransformModal')
+const showTransformModal = require('./showTransformModal')
-var util = require('./util')
+const util = require('./util')
-var DEFAULT_MODAL_ANCHOR = require('./constants').DEFAULT_MODAL_ANCHOR
+const DEFAULT_MODAL_ANCHOR = require('./constants').DEFAULT_MODAL_ANCHOR
 
 // create a mixin with the functions for text mode
-var textmode = {}
+const textmode = {}
 
-var DEFAULT_THEME = 'ace/theme/jsoneditor'
+const DEFAULT_THEME = 'ace/theme/jsoneditor'
 
 /**
  * Create a text editor
@@ -45,7 +45,7 @@ textmode.create = function (container, options) {
   }
 
   // grab ace from options if provided
-  var _ace = options.ace ? options.ace : ace
+  const _ace = options.ace ? options.ace : ace
   // TODO: make the option options.ace deprecated, it's not needed anymore (see #309)
 
   // determine mode
@@ -72,7 +72,7 @@ textmode.create = function (container, options) {
     this.onTextSelectionChange(options.onTextSelectionChange)
   }
 
-  var me = this
+  const me = this
   this.container = container
   this.dom = {}
   this.aceEditor = undefined // ace code editor
@@ -88,11 +88,11 @@ textmode.create = function (container, options) {
 
   this.frame = document.createElement('div')
   this.frame.className = 'jsoneditor jsoneditor-mode-' + this.options.mode
-  this.frame.onclick = function (event) {
+  this.frame.onclick = event => {
     // prevent default submit action when the editor is located inside a form
     event.preventDefault()
   }
-  this.frame.onkeydown = function (event) {
+  this.frame.onkeydown = event => {
     me._onKeyDown(event)
   }
 
@@ -108,12 +108,12 @@ textmode.create = function (container, options) {
     this.frame.appendChild(this.menu)
 
     // create format button
-    var buttonFormat = document.createElement('button')
+    const buttonFormat = document.createElement('button')
     buttonFormat.type = 'button'
     buttonFormat.className = 'jsoneditor-format'
     buttonFormat.title = 'Format JSON data, with proper indentation and line feeds (Ctrl+\\)'
     this.menu.appendChild(buttonFormat)
-    buttonFormat.onclick = function () {
+    buttonFormat.onclick = () => {
       try {
         me.format()
         me._onChange()
@@ -123,12 +123,12 @@ textmode.create = function (container, options) {
     }
 
     // create compact button
-    var buttonCompact = document.createElement('button')
+    const buttonCompact = document.createElement('button')
     buttonCompact.type = 'button'
     buttonCompact.className = 'jsoneditor-compact'
     buttonCompact.title = 'Compact JSON data, remove all whitespaces (Ctrl+Shift+\\)'
     this.menu.appendChild(buttonCompact)
-    buttonCompact.onclick = function () {
+    buttonCompact.onclick = () => {
       try {
         me.compact()
         me._onChange()
@@ -139,11 +139,11 @@ textmode.create = function (container, options) {
 
     // create sort button
     if (this.options.enableSort) {
-      var sort = document.createElement('button')
+      const sort = document.createElement('button')
       sort.type = 'button'
       sort.className = 'jsoneditor-sort'
       sort.title = translate('sortTitleShort')
-      sort.onclick = function () {
+      sort.onclick = () => {
         me._showSortModal()
       }
       this.menu.appendChild(sort)
@@ -151,23 +151,23 @@ textmode.create = function (container, options) {
 
     // create transform button
     if (this.options.enableTransform) {
-      var transform = document.createElement('button')
+      const transform = document.createElement('button')
       transform.type = 'button'
       transform.title = translate('transformTitleShort')
       transform.className = 'jsoneditor-transform'
-      transform.onclick = function () {
+      transform.onclick = () => {
         me._showTransformModal()
       }
       this.menu.appendChild(transform)
     }
 
     // create repair button
-    var buttonRepair = document.createElement('button')
+    const buttonRepair = document.createElement('button')
     buttonRepair.type = 'button'
     buttonRepair.className = 'jsoneditor-repair'
     buttonRepair.title = 'Repair JSON: fix quotes and escape characters, remove comments and JSONP notation, turn JavaScript objects into JSON.'
     this.menu.appendChild(buttonRepair)
-    buttonRepair.onclick = function () {
+    buttonRepair.onclick = () => {
       try {
         me.repair()
         me._onChange()
@@ -186,12 +186,12 @@ textmode.create = function (container, options) {
     }
 
     if (this.mode === 'code') {
-      var poweredBy = document.createElement('a')
+      const poweredBy = document.createElement('a')
       poweredBy.appendChild(document.createTextNode('powered by ace'))
       poweredBy.href = 'http://ace.ajax.org'
       poweredBy.target = '_blank'
       poweredBy.className = 'jsoneditor-poweredBy'
-      poweredBy.onclick = function () {
+      poweredBy.onclick = () => {
         // TODO: this anchor falls below the margin of the content,
         // therefore the normal a.href does not work. We use a click event
         // for now, but this should be fixed.
@@ -201,8 +201,8 @@ textmode.create = function (container, options) {
     }
   }
 
-  var emptyNode = {}
+  const emptyNode = {}
-  var isReadOnly = (this.options.onEditable &&
+  const isReadOnly = (this.options.onEditable &&
   typeof (this.options.onEditable === 'function') &&
   !this.options.onEditable(emptyNode))
 
@@ -215,8 +215,8 @@ textmode.create = function (container, options) {
     this.editorDom.style.width = '100%' // TODO: move to css
     this.content.appendChild(this.editorDom)
 
-    var aceEditor = _ace.edit(this.editorDom)
+    const aceEditor = _ace.edit(this.editorDom)
-    var aceSession = aceEditor.getSession()
+    const aceSession = aceEditor.getSession()
     aceEditor.$blockScrolling = Infinity
     aceEditor.setTheme(this.theme)
     aceEditor.setOptions({ readOnly: isReadOnly })
@@ -228,7 +228,7 @@ textmode.create = function (container, options) {
     aceSession.setUseWrapMode(true)
 
     // replace ace setAnnotations with custom function that also covers jsoneditor annotations
-    var originalSetAnnotations = aceSession.setAnnotations
+    const originalSetAnnotations = aceSession.setAnnotations
     aceSession.setAnnotations = function (annotations) {
       originalSetAnnotations.call(this, annotations && annotations.length ? annotations : me.annotations)
     }
@@ -242,7 +242,7 @@ textmode.create = function (container, options) {
     aceEditor.on('changeSelection', this._onSelect.bind(this))
   } else {
     // load a plain text textarea
-    var textarea = document.createElement('textarea')
+    const textarea = document.createElement('textarea')
     textarea.className = 'jsoneditor-text'
     textarea.spellcheck = false
     this.content.appendChild(textarea)
@@ -275,8 +275,8 @@ textmode.create = function (container, options) {
     },
     onChangeHeight: function (height) {
       // TODO: change CSS to using flex box, remove setting height using JavaScript
-      var statusBarHeight = me.dom.statusBar ? me.dom.statusBar.clientHeight : 0
+      const statusBarHeight = me.dom.statusBar ? me.dom.statusBar.clientHeight : 0
-      var totalHeight = height + statusBarHeight + 1
+      const totalHeight = height + statusBarHeight + 1
       me.content.style.marginBottom = (-totalHeight) + 'px'
       me.content.style.paddingBottom = totalHeight + 'px'
     }
@@ -287,27 +287,27 @@ textmode.create = function (container, options) {
     util.addClassName(this.content, 'has-status-bar')
 
     this.curserInfoElements = {}
-    var statusBar = document.createElement('div')
+    const statusBar = document.createElement('div')
     this.dom.statusBar = statusBar
     statusBar.className = 'jsoneditor-statusbar'
     this.frame.appendChild(statusBar)
 
-    var lnLabel = document.createElement('span')
+    const lnLabel = document.createElement('span')
     lnLabel.className = 'jsoneditor-curserinfo-label'
     lnLabel.innerText = 'Ln:'
 
-    var lnVal = document.createElement('span')
+    const lnVal = document.createElement('span')
     lnVal.className = 'jsoneditor-curserinfo-val'
     lnVal.innerText = '1'
 
     statusBar.appendChild(lnLabel)
     statusBar.appendChild(lnVal)
 
-    var colLabel = document.createElement('span')
+    const colLabel = document.createElement('span')
     colLabel.className = 'jsoneditor-curserinfo-label'
     colLabel.innerText = 'Col:'
 
-    var colVal = document.createElement('span')
+    const colVal = document.createElement('span')
     colVal.className = 'jsoneditor-curserinfo-val'
     colVal.innerText = '1'
 
@@ -317,12 +317,12 @@ textmode.create = function (container, options) {
     this.curserInfoElements.colVal = colVal
     this.curserInfoElements.lnVal = lnVal
 
-    var countLabel = document.createElement('span')
+    const countLabel = document.createElement('span')
     countLabel.className = 'jsoneditor-curserinfo-label'
     countLabel.innerText = 'characters selected'
     countLabel.style.display = 'none'
 
-    var countVal = document.createElement('span')
+    const countVal = document.createElement('span')
     countVal.className = 'jsoneditor-curserinfo-count'
     countVal.innerText = '0'
     countVal.style.display = 'none'
@@ -407,11 +407,11 @@ textmode._showSortModal = function () {
  * @private
  */
 textmode._showTransformModal = function () {
-  var me = this
+  const me = this
-  var anchor = this.options.modalAnchor || DEFAULT_MODAL_ANCHOR
+  const anchor = this.options.modalAnchor || DEFAULT_MODAL_ANCHOR
-  var json = this.get()
+  const json = this.get()
-  showTransformModal(anchor, json, function (query) {
+  showTransformModal(anchor, json, query => {
-    var updatedJson = jmespath.search(json, query)
+    const updatedJson = jmespath.search(json, query)
     me.set(updatedJson)
   })
 }
@@ -432,8 +432,8 @@ textmode._onSelect = function () {
  * @private
  */
 textmode._onKeyDown = function (event) {
-  var keynum = event.which || event.keyCode
+  const keynum = event.which || event.keyCode
-  var handled = false
+  let handled = false
 
   if (keynum === 220 && event.ctrlKey) {
     if (event.shiftKey) { // Ctrl+Shift+\
@@ -469,10 +469,10 @@ textmode._onMouseDown = function () {
  * @private
  */
 textmode._onBlur = function () {
-  var me = this
+  const me = this
   // this allows to avoid blur when clicking inner elements (like the errors panel)
   // just make sure to set the isFocused to true on the inner element onclick callback
-  setTimeout(function () {
+  setTimeout(() => {
     if (!me.isFocused) {
       me._updateCursorInfo()
       me._emitSelectionChange()
@@ -485,12 +485,12 @@ textmode._onBlur = function () {
  * Update the cursor info and the status bar, if presented
  */
 textmode._updateCursorInfo = function () {
-  var me = this
+  const me = this
-  var line, col, count
+  let line, col, count
 
   if (this.textarea) {
-    setTimeout(function () { // this to verify we get the most updated textarea cursor selection
+    setTimeout(() => { // this to verify we get the most updated textarea cursor selection
-      var selectionRange = util.getInputSelection(me.textarea)
+      const selectionRange = util.getInputSelection(me.textarea)
 
       if (selectionRange.startIndex !== selectionRange.endIndex) {
         count = selectionRange.endIndex - selectionRange.startIndex
@@ -515,8 +515,8 @@ textmode._updateCursorInfo = function () {
       }
     }, 0)
   } else if (this.aceEditor && this.curserInfoElements) {
-    var curserPos = this.aceEditor.getCursorPosition()
+    const curserPos = this.aceEditor.getCursorPosition()
-    var selectedText = this.aceEditor.getSelectedText()
+    const selectedText = this.aceEditor.getSelectedText()
 
     line = curserPos.row + 1
     col = curserPos.column + 1
@@ -550,7 +550,7 @@ textmode._updateCursorInfo = function () {
  */
 textmode._emitSelectionChange = function () {
   if (this._selectionChangedHandler) {
-    var currentSelection = this.getTextSelection()
+    const currentSelection = this.getTextSelection()
     this._selectionChangedHandler(currentSelection.start, currentSelection.end, currentSelection.text)
   }
 }
@@ -563,9 +563,9 @@ textmode._emitSelectionChange = function () {
  * @private
  */
 textmode._refreshAnnotations = function () {
-  var session = this.aceEditor && this.aceEditor.getSession()
+  const session = this.aceEditor && this.aceEditor.getSession()
   if (session) {
-    var errEnnotations = session.getAnnotations().filter(function (annotation) { return annotation.type === 'error' })
+    const errEnnotations = session.getAnnotations().filter(annotation => annotation.type === 'error')
     session.setAnnotations(errEnnotations)
   }
 }
@@ -598,8 +598,8 @@ textmode.destroy = function () {
  * Compact the code in the text editor
  */
 textmode.compact = function () {
-  var json = this.get()
+  const json = this.get()
-  var text = JSON.stringify(json)
+  const text = JSON.stringify(json)
   this._setText(text, false)
 }
 
@@ -607,8 +607,8 @@ textmode.compact = function () {
  * Format the code in the text editor
  */
 textmode.format = function () {
-  var json = this.get()
+  const json = this.get()
-  var text = JSON.stringify(json, null, this.indentation)
+  const text = JSON.stringify(json, null, this.indentation)
   this._setText(text, false)
 }
 
@@ -616,8 +616,8 @@ textmode.format = function () {
  * Repair the code in the text editor
  */
 textmode.repair = function () {
-  var text = this.getText()
+  const text = this.getText()
-  var repairedText = util.repair(text)
+  const repairedText = util.repair(text)
   this._setText(repairedText, false)
 }
 
@@ -638,7 +638,7 @@ textmode.focus = function () {
  */
 textmode.resize = function () {
   if (this.aceEditor) {
-    var force = false
+    const force = false
     this.aceEditor.resize(force)
   }
 }
@@ -664,7 +664,7 @@ textmode.update = function (json) {
  * @return {*} json
  */
 textmode.get = function () {
-  var text = this.getText()
+  const text = this.getText()
 
   return util.parse(text) // this can throw an error
 }
@@ -690,7 +690,7 @@ textmode.getText = function () {
  * @private
  */
 textmode._setText = function (jsonText, clearHistory) {
-  var text
+  let text
 
   if (this.options.escapeUnicode === true) {
     text = util.escapeUnicodeChars(jsonText)
@@ -709,8 +709,8 @@ textmode._setText = function (jsonText, clearHistory) {
 
     if (clearHistory) {
       // prevent initial undo action clearing the initial contents
-      var me = this
+      const me = this
-      setTimeout(function () {
+      setTimeout(() => {
         me.aceEditor.session.getUndoManager().reset()
       }, 0)
     }
@@ -747,17 +747,17 @@ textmode.updateText = function (jsonText) {
  * Throws an exception when no JSON schema is configured
  */
 textmode.validate = function () {
-  var schemaErrors = []
+  let schemaErrors = []
-  var parseErrors = []
+  let parseErrors = []
-  var json
+  let json
   try {
     json = this.get() // this can fail when there is no valid json
 
     // execute JSON schema validation (ajv)
     if (this.validateSchema) {
-      var valid = this.validateSchema(json)
+      const valid = this.validateSchema(json)
       if (!valid) {
-        schemaErrors = this.validateSchema.errors.map(function (error) {
+        schemaErrors = this.validateSchema.errors.map(error => {
           error.type = 'validation'
           return util.improveSchemaError(error)
         })
@@ -767,24 +767,24 @@ textmode.validate = function () {
     // execute custom validation and after than merge and render all errors
     // TODO: implement a better mechanism for only using the last validation action
     this.validationSequence = (this.validationSequence || 0) + 1
-    var me = this
+    const me = this
-    var seq = this.validationSequence
+    const seq = this.validationSequence
     validateCustom(json, this.options.onValidate)
-      .then(function (customValidationErrors) {
+      .then(customValidationErrors => {
         // only apply when there was no other validation started whilst resolving async results
         if (seq === me.validationSequence) {
-          var errors = schemaErrors.concat(parseErrors).concat(customValidationErrors)
+          const errors = schemaErrors.concat(parseErrors).concat(customValidationErrors)
           me._renderErrors(errors)
         }
       })
-      .catch(function (err) {
+      .catch(err => {
         console.error('Custom validation function did throw an error', err)
       })
   } catch (err) {
     if (this.getText()) {
       // try to extract the line number from the jsonlint error message
-      var match = /\w*line\s*(\d+)\w*/g.exec(err.message)
+      const match = /\w*line\s*(\d+)\w*/g.exec(err.message)
-      var line
+      let line
       if (match) {
         line = +match[1]
       }
@@ -800,21 +800,21 @@ textmode.validate = function () {
 }
 
 textmode._renderErrors = function (errors) {
-  var jsonText = this.getText()
+  const jsonText = this.getText()
-  var errorPaths = []
+  const errorPaths = []
-  errors.reduce(function (acc, curr) {
+  errors.reduce((acc, curr) => {
     if (acc.indexOf(curr.dataPath) === -1) {
       acc.push(curr.dataPath)
     }
     return acc
   }, errorPaths)
-  var errorLocations = util.getPositionForPath(jsonText, errorPaths)
+  const errorLocations = util.getPositionForPath(jsonText, errorPaths)
 
   // render annotations in Ace Editor (if any)
   if (this.aceEditor) {
-    this.annotations = errorLocations.map(function (errLoc) {
+    this.annotations = errorLocations.map(errLoc => {
-      var validationErrors = errors.filter(function (err) { return err.dataPath === errLoc.path })
+      const validationErrors = errors.filter(err => err.dataPath === errLoc.path)
-      var message = validationErrors.map(function (err) { return err.message }).join('\n')
+      const message = validationErrors.map(err => err.message).join('\n')
       if (message) {
         return {
           row: errLoc.line,
@@ -835,7 +835,7 @@ textmode._renderErrors = function (errors) {
 
   // update the height of the ace editor
   if (this.aceEditor) {
-    var force = false
+    const force = false
     this.aceEditor.resize(force)
   }
 }
@@ -845,9 +845,9 @@ textmode._renderErrors = function (errors) {
  * @returns {{start:{row:Number, column:Number},end:{row:Number, column:Number},text:String}}
  */
 textmode.getTextSelection = function () {
-  var selection = {}
+  let selection = {}
   if (this.textarea) {
-    var selectionRange = util.getInputSelection(this.textarea)
+    const selectionRange = util.getInputSelection(this.textarea)
 
     if (this.cursorInfo && this.cursorInfo.line === selectionRange.end.row && this.cursorInfo.column === selectionRange.end.column) {
       // selection direction is bottom => up
@@ -865,10 +865,10 @@ textmode.getTextSelection = function () {
   }
 
   if (this.aceEditor) {
-    var aceSelection = this.aceEditor.getSelection()
+    const aceSelection = this.aceEditor.getSelection()
-    var selectedText = this.aceEditor.getSelectedText()
+    const selectedText = this.aceEditor.getSelectedText()
-    var range = aceSelection.getRange()
+    const range = aceSelection.getRange()
-    var lead = aceSelection.getSelectionLead()
+    const lead = aceSelection.getSelectionLead()
 
     if (lead.row === range.end.row && lead.column === range.end.column) {
       selection = range
@@ -913,8 +913,8 @@ textmode.setTextSelection = function (startPos, endPos) {
   if (!startPos || !endPos) return
 
   if (this.textarea) {
-    var startIndex = util.getIndexForPosition(this.textarea, startPos.row, startPos.column)
+    const startIndex = util.getIndexForPosition(this.textarea, startPos.row, startPos.column)
-    var endIndex = util.getIndexForPosition(this.textarea, endPos.row, endPos.column)
+    const endIndex = util.getIndexForPosition(this.textarea, endPos.row, endPos.column)
     if (startIndex > -1 && endIndex > -1) {
       if (this.textarea.setSelectionRange) {
         this.textarea.focus()
@@ -926,9 +926,9 @@ textmode.setTextSelection = function (startPos, endPos) {
         range.moveStart('character', startIndex)
         range.select()
       }
-      var rows = (this.textarea.value.match(/\n/g) || []).length + 1
+      const rows = (this.textarea.value.match(/\n/g) || []).length + 1
-      var lineHeight = this.textarea.scrollHeight / rows
+      const lineHeight = this.textarea.scrollHeight / rows
-      var selectionScrollPos = (startPos.row * lineHeight)
+      const selectionScrollPos = (startPos.row * lineHeight)
       this.textarea.scrollTop = selectionScrollPos > this.textarea.clientHeight ? (selectionScrollPos - (this.textarea.clientHeight / 2)) : 0
     }
   } else if (this.aceEditor) {

src/js/treemode.js

@@ -1,21 +1,21 @@
 'use strict'
 
-var VanillaPicker = require('./vanilla-picker')
+const VanillaPicker = require('./vanilla-picker')
-var Highlighter = require('./Highlighter')
+const Highlighter = require('./Highlighter')
-var NodeHistory = require('./NodeHistory')
+const NodeHistory = require('./NodeHistory')
-var SearchBox = require('./SearchBox')
+const SearchBox = require('./SearchBox')
-var ContextMenu = require('./ContextMenu')
+const ContextMenu = require('./ContextMenu')
-var TreePath = require('./TreePath')
+const TreePath = require('./TreePath')
-var Node = require('./Node')
+const Node = require('./Node')
-var ModeSwitcher = require('./ModeSwitcher')
+const ModeSwitcher = require('./ModeSwitcher')
-var util = require('./util')
+const util = require('./util')
-var autocomplete = require('./autocomplete')
+const autocomplete = require('./autocomplete')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
-var setLanguages = require('./i18n').setLanguages
+const setLanguages = require('./i18n').setLanguages
-var setLanguage = require('./i18n').setLanguage
+const setLanguage = require('./i18n').setLanguage
 
 // create a mixin with the functions for tree mode
-var treemode = {}
+const treemode = {}
 
 /**
  * Create a tree editor
@@ -115,8 +115,8 @@ treemode._setOptions = function (options) {
           color: color,
           popup: 'bottom',
           onDone: function (color) {
-            var alpha = color.rgba[3]
+            const alpha = color.rgba[3]
-            var hex = (alpha === 1)
+            const hex = (alpha === 1)
               ? color.hex.substr(0, 7) // return #RRGGBB
               : color.hex // return #RRGGBBAA
             onChange(hex)
@@ -168,18 +168,18 @@ treemode.set = function (json) {
     this.content.removeChild(this.table) // Take the table offline
 
     // replace the root node
-    var params = {
+    const params = {
       field: this.options.name,
       value: json
     }
-    var node = new Node(this, params)
+    const node = new Node(this, params)
     this._setRoot(node)
 
     // validate JSON schema (if configured)
     this.validate()
 
     // expand
-    var recurse = false
+    const recurse = false
     this.node.expand(recurse)
 
     this.content.appendChild(this.table) // Put the table online again
@@ -208,7 +208,7 @@ treemode.update = function (json) {
     return
   }
 
-  var selection = this.getSelection()
+  const selection = this.getSelection()
 
   // apply the changed json
   this.onChangeDisabled = true // don't fire an onChange event
@@ -227,8 +227,8 @@ treemode.update = function (json) {
   if (selection && selection.start && selection.end) {
     // only keep/update the selection if both start and end node still exists,
     // else we clear the selection
-    var startNode = this.node.findNodeByPath(selection.start.path)
+    const startNode = this.node.findNodeByPath(selection.start.path)
-    var endNode = this.node.findNodeByPath(selection.end.path)
+    const endNode = this.node.findNodeByPath(selection.end.path)
     if (startNode && endNode) {
       this.setSelection(selection.start, selection.end)
     } else {
@@ -271,7 +271,7 @@ treemode.setText = function (jsonText) {
     this.set(util.parse(jsonText)) // this can throw an error
   } catch (err) {
     // try to repair json, replace JavaScript notation with JSON notation
-    var repairedJsonText = util.repair(jsonText)
+    const repairedJsonText = util.repair(jsonText)
 
     // try to parse again
     this.set(util.parse(repairedJsonText)) // this can throw an error
@@ -288,7 +288,7 @@ treemode.updateText = function (jsonText) {
     this.update(util.parse(jsonText)) // this can throw an error
   } catch (err) {
     // try to repair json, replace JavaScript notation with JSON notation
-    var repairJsonText = util.repair(jsonText)
+    const repairJsonText = util.repair(jsonText)
 
     // try to parse again
     this.update(util.parse(repairJsonText)) // this can throw an error
@@ -322,7 +322,7 @@ treemode.getName = function () {
  * - to the first button in the top menu
  */
 treemode.focus = function () {
-  var input = this.scrollableContent.querySelector('[contenteditable=true]')
+  let input = this.scrollableContent.querySelector('[contenteditable=true]')
   if (input) {
     input.focus()
   } else if (this.node.dom.expand) {
@@ -382,7 +382,7 @@ treemode._setRoot = function (node) {
  *                                              'value')
  */
 treemode.search = function (text) {
-  var results
+  let results
   if (this.node) {
     this.content.removeChild(this.table) // Take the table offline
     results = this.node.search(text)
@@ -457,7 +457,7 @@ treemode._onChange = function () {
   this._debouncedValidate()
 
   if (this.treePath) {
-    var selectedNode = (this.node && this.selection)
+    const selectedNode = (this.node && this.selection)
       ? this.node.findNodeByInternalPath(this.selection.path)
       : this.multiselection
         ? this.multiselection.nodes[0]
@@ -517,23 +517,21 @@ treemode._onChange = function () {
  * Throws an exception when no JSON schema is configured
  */
 treemode.validate = function () {
-  var root = this.node
+  const root = this.node
   if (!root) { // TODO: this should be redundant but is needed on mode switch
     return
   }
 
-  var json = root.getValue()
+  const json = root.getValue()
 
   // execute JSON schema validation
-  var schemaErrors = []
+  let schemaErrors = []
   if (this.validateSchema) {
-    var valid = this.validateSchema(json)
+    const valid = this.validateSchema(json)
     if (!valid) {
       // apply all new errors
       schemaErrors = this.validateSchema.errors
-        .map(function (error) {
+        .map(error => util.improveSchemaError(error))
-          return util.improveSchemaError(error)
-        })
         .map(function findNode (error) {
           return {
             node: root.findNode(error.dataPath),
@@ -549,17 +547,17 @@ treemode.validate = function () {
   // execute custom validation and after than merge and render all errors
   try {
     this.validationSequence++
-    var me = this
+    const me = this
-    var seq = this.validationSequence
+    const seq = this.validationSequence
     this._validateCustom(json)
-      .then(function (customValidationErrors) {
+      .then(customValidationErrors => {
         // only apply when there was no other validation started whilst resolving async results
         if (seq === me.validationSequence) {
-          var errorNodes = [].concat(schemaErrors, customValidationErrors || [])
+          const errorNodes = [].concat(schemaErrors, customValidationErrors || [])
           me._renderValidationErrors(errorNodes)
         }
       })
-      .catch(function (err) {
+      .catch(err => {
         console.error(err)
       })
   } catch (err) {
@@ -570,39 +568,30 @@ treemode.validate = function () {
 treemode._renderValidationErrors = function (errorNodes) {
   // clear all current errors
   if (this.errorNodes) {
-    this.errorNodes.forEach(function (node) {
+    this.errorNodes.forEach(node => {
       node.setError(null)
     })
   }
 
   // render the new errors
-  var parentPairs = errorNodes
+  const parentPairs = errorNodes
-    .reduce(function (all, entry) {
+    .reduce((all, entry) => entry.node
-      return entry.node
+      .findParents()
-        .findParents()
+      .filter(parent => !all.some(pair => pair[0] === parent))
-        .filter(function (parent) {
+      .map(parent => [parent, entry.node])
-          return !all.some(function (pair) {
+      .concat(all), [])
-            return pair[0] === parent
-          })
-        })
-        .map(function (parent) {
-          return [parent, entry.node]
-        })
-        .concat(all)
-    }, [])
 
   this.errorNodes = parentPairs
-    .map(function (pair) {
+    .map(pair => ({
-      return {
+      node: pair[0],
-        node: pair[0],
+      child: pair[1],
-        child: pair[1],
+
-        error: {
+      error: {
-          message: pair[0].type === 'object'
+        message: pair[0].type === 'object'
-            ? 'Contains invalid properties' // object
+          ? 'Contains invalid properties' // object
-            : 'Contains invalid items' // array
+          : 'Contains invalid items' // array
-        }
       }
-    })
+    }))
     .concat(errorNodes)
     .map(function setError (entry) {
       entry.node.setError(entry.error, entry.child)
@@ -618,18 +607,18 @@ treemode._renderValidationErrors = function (errorNodes) {
 treemode._validateCustom = function (json) {
   try {
     if (this.options.onValidate) {
-      var root = this.node
+      const root = this.node
-      var customValidateResults = this.options.onValidate(json)
+      const customValidateResults = this.options.onValidate(json)
 
-      var resultPromise = util.isPromise(customValidateResults)
+      const resultPromise = util.isPromise(customValidateResults)
         ? customValidateResults
         : Promise.resolve(customValidateResults)
 
-      return resultPromise.then(function (customValidationPathErrors) {
+      return resultPromise.then(customValidationPathErrors => {
         if (Array.isArray(customValidationPathErrors)) {
           return customValidationPathErrors
-            .filter(function (error) {
+            .filter(error => {
-              var valid = util.isValidValidationError(error)
+              const valid = util.isValidValidationError(error)
 
               if (!valid) {
                 console.warn('Ignoring a custom validation error with invalid structure. ' +
@@ -639,8 +628,8 @@ treemode._validateCustom = function (json) {
 
               return valid
             })
-            .map(function (error) {
+            .map(error => {
-              var node
+              let node
               try {
                 node = (error && error.path) ? root.findNodeByPath(error.path) : null
               } catch (err) {
@@ -655,9 +644,7 @@ treemode._validateCustom = function (json) {
                 error: error
               }
             })
-            .filter(function (entry) {
+            .filter(entry => entry && entry.node && entry.error && entry.error.message)
-              return entry && entry.node && entry.error && entry.error.message
-            })
         } else {
           return null
         }
@@ -685,13 +672,13 @@ treemode.refresh = function () {
  * @param {Number} mouseY  Absolute mouse position in pixels
  */
 treemode.startAutoScroll = function (mouseY) {
-  var me = this
+  const me = this
-  var content = this.scrollableContent
+  const content = this.scrollableContent
-  var top = util.getAbsoluteTop(content)
+  const top = util.getAbsoluteTop(content)
-  var height = content.clientHeight
+  const height = content.clientHeight
-  var bottom = top + height
+  const bottom = top + height
-  var margin = 24
+  const margin = 24
-  var interval = 50 // ms
+  const interval = 50 // ms
 
   if ((mouseY < top + margin) && content.scrollTop > 0) {
     this.autoScrollStep = ((top + margin) - mouseY) / 3
@@ -704,7 +691,7 @@ treemode.startAutoScroll = function (mouseY) {
 
   if (this.autoScrollStep) {
     if (!this.autoScrollTimer) {
-      this.autoScrollTimer = setInterval(function () {
+      this.autoScrollTimer = setInterval(() => {
         if (me.autoScrollStep) {
           content.scrollTop -= me.autoScrollStep
         } else {
@@ -751,22 +738,20 @@ treemode.setDomSelection = function (selection) {
   }
   if (selection.paths) {
     // multi-select
-    var me = this
+    const me = this
-    var nodes = selection.paths.map(function (path) {
+    const nodes = selection.paths.map(path => me.node.findNodeByInternalPath(path))
-      return me.node.findNodeByInternalPath(path)
-    })
 
     this.select(nodes)
   } else {
     // find the actual DOM element where to apply the focus
-    var node = selection.path
+    const node = selection.path
       ? this.node.findNodeByInternalPath(selection.path)
       : null
-    var container = (node && selection.domName)
+    const container = (node && selection.domName)
       ? node.dom[selection.domName]
       : null
     if (selection.range && container) {
-      var range = Object.assign({}, selection.range, { container: container })
+      const range = Object.assign({}, selection.range, { container: container })
       util.setSelectionOffset(range)
     } else if (node) { // just a fallback
       node.focus()
@@ -787,15 +772,13 @@ treemode.getDomSelection = function () {
   // find the node and field name of the current target,
   // so we can store the current selection in a serializable
   // way (internal node path and domName)
-  var node = Node.getNodeFromTarget(this.focusTarget)
+  const node = Node.getNodeFromTarget(this.focusTarget)
-  var focusTarget = this.focusTarget
+  const focusTarget = this.focusTarget
-  var domName = node
+  const domName = node
-    ? Object.keys(node.dom).find(function (domName) {
+    ? Object.keys(node.dom).find(domName => node.dom[domName] === focusTarget)
-      return node.dom[domName] === focusTarget
-    })
     : null
 
-  var range = util.getSelectionOffset()
+  let range = util.getSelectionOffset()
   if (range && range.container.nodeName !== 'DIV') { // filter on (editable) divs)
     range = null
   }
@@ -814,9 +797,7 @@ treemode.getDomSelection = function () {
     domName: domName,
     range: range,
     paths: this.multiselection.length > 0
-      ? this.multiselection.nodes.map(function (node) {
+      ? this.multiselection.nodes.map(node => node.getInternalPath())
-        return node.getInternalPath()
-      })
       : null,
     scrollTop: this.scrollableContent ? this.scrollableContent.scrollTop : 0
   }
@@ -832,9 +813,9 @@ treemode.getDomSelection = function () {
  *                                              when not.
  */
 treemode.scrollTo = function (top, animateCallback) {
-  var content = this.scrollableContent
+  const content = this.scrollableContent
   if (content) {
-    var editor = this
+    const editor = this
     // cancel any running animation
     if (editor.animateTimeout) {
       clearTimeout(editor.animateTimeout)
@@ -846,14 +827,14 @@ treemode.scrollTo = function (top, animateCallback) {
     }
 
     // calculate final scroll position
-    var height = content.clientHeight
+    const height = content.clientHeight
-    var bottom = content.scrollHeight - height
+    const bottom = content.scrollHeight - height
-    var finalScrollTop = Math.min(Math.max(top - height / 4, 0), bottom)
+    const finalScrollTop = Math.min(Math.max(top - height / 4, 0), bottom)
 
     // animate towards the new scroll position
-    var animate = function () {
+    const animate = () => {
-      var scrollTop = content.scrollTop
+      const scrollTop = content.scrollTop
-      var diff = (finalScrollTop - scrollTop)
+      const diff = (finalScrollTop - scrollTop)
       if (Math.abs(diff) > 3) {
         content.scrollTop += diff / 3
         editor.animateCallback = animateCallback
@@ -890,7 +871,7 @@ treemode._createFrame = function () {
   this.contentOuter.className = 'jsoneditor-outer'
 
   // create one global event listener to handle all events from all nodes
-  var editor = this
+  const editor = this
   function onEvent (event) {
     // when switching to mode "code" or "text" via the menu, some events
     // are still fired whilst the _onEvent methods is already removed.
@@ -898,8 +879,8 @@ treemode._createFrame = function () {
       editor._onEvent(event)
     }
   }
-  this.frame.onclick = function (event) {
+  this.frame.onclick = event => {
-    var target = event.target// || event.srcElement;
+    const target = event.target// || event.srcElement;
 
     onEvent(event)
 
@@ -936,32 +917,32 @@ treemode._createFrame = function () {
     this.frame.appendChild(this.menu)
 
     // create expand all button
-    var expandAll = document.createElement('button')
+    const expandAll = document.createElement('button')
     expandAll.type = 'button'
     expandAll.className = 'jsoneditor-expand-all'
     expandAll.title = translate('expandAll')
-    expandAll.onclick = function () {
+    expandAll.onclick = () => {
       editor.expandAll()
     }
     this.menu.appendChild(expandAll)
 
     // create collapse all button
-    var collapseAll = document.createElement('button')
+    const collapseAll = document.createElement('button')
     collapseAll.type = 'button'
     collapseAll.title = translate('collapseAll')
     collapseAll.className = 'jsoneditor-collapse-all'
-    collapseAll.onclick = function () {
+    collapseAll.onclick = () => {
       editor.collapseAll()
     }
     this.menu.appendChild(collapseAll)
 
     // create sort button
     if (this.options.enableSort) {
-      var sort = document.createElement('button')
+      const sort = document.createElement('button')
       sort.type = 'button'
       sort.className = 'jsoneditor-sort'
       sort.title = translate('sortTitleShort')
-      sort.onclick = function () {
+      sort.onclick = () => {
         editor.node.showSortModal()
       }
       this.menu.appendChild(sort)
@@ -969,11 +950,11 @@ treemode._createFrame = function () {
 
     // create transform button
     if (this.options.enableTransform) {
-      var transform = document.createElement('button')
+      const transform = document.createElement('button')
       transform.type = 'button'
       transform.title = translate('transformTitleShort')
       transform.className = 'jsoneditor-transform'
-      transform.onclick = function () {
+      transform.onclick = () => {
         editor.node.showTransformModal()
       }
       this.menu.appendChild(transform)
@@ -982,29 +963,29 @@ treemode._createFrame = function () {
     // create undo/redo buttons
     if (this.history) {
       // create undo button
-      var undo = document.createElement('button')
+      const undo = document.createElement('button')
       undo.type = 'button'
       undo.className = 'jsoneditor-undo jsoneditor-separator'
       undo.title = translate('undo')
-      undo.onclick = function () {
+      undo.onclick = () => {
         editor._onUndo()
       }
       this.menu.appendChild(undo)
       this.dom.undo = undo
 
       // create redo button
-      var redo = document.createElement('button')
+      const redo = document.createElement('button')
       redo.type = 'button'
       redo.className = 'jsoneditor-redo'
       redo.title = translate('redo')
-      redo.onclick = function () {
+      redo.onclick = () => {
         editor._onRedo()
       }
       this.menu.appendChild(redo)
       this.dom.redo = redo
 
       // register handler for onchange of history
-      this.history.onChange = function () {
+      this.history.onChange = () => {
         undo.disabled = !editor.history.canUndo()
         redo.disabled = !editor.history.canRedo()
       }
@@ -1013,7 +994,7 @@ treemode._createFrame = function () {
 
     // create mode box
     if (this.options && this.options.modes && this.options.modes.length) {
-      var me = this
+      const me = this
       this.modeSwitcher = new ModeSwitcher(this.menu, this.options.modes, this.options.mode, function onSwitch (mode) {
         // switch mode and restore focus
         me.setMode(mode)
@@ -1078,7 +1059,7 @@ treemode._onEvent = function (event) {
     return
   }
 
-  var node = Node.getNodeFromTarget(event.target)
+  const node = Node.getNodeFromTarget(event.target)
 
   if (event.type === 'keydown') {
     this._onKeyDown(event)
@@ -1100,8 +1081,8 @@ treemode._onEvent = function (event) {
 
   if (node && this.options && this.options.navigationBar && node && (event.type === 'keydown' || event.type === 'mousedown')) {
     // apply on next tick, right after the new key press is applied
-    var me = this
+    const me = this
-    setTimeout(function () {
+    setTimeout(() => {
       me._updateTreePath(node.getNodePath())
     })
   }
@@ -1154,15 +1135,15 @@ treemode._updateTreePath = function (pathNodes) {
   if (pathNodes && pathNodes.length) {
     util.removeClassName(this.navBar, 'nav-bar-empty')
 
-    var pathObjs = []
+    const pathObjs = []
-    pathNodes.forEach(function (node) {
+    pathNodes.forEach(node => {
-      var pathObj = {
+      const pathObj = {
         name: getName(node),
         node: node,
         children: []
       }
       if (node.childs && node.childs.length) {
-        node.childs.forEach(function (childNode) {
+        node.childs.forEach(childNode => {
           pathObj.children.push({
             name: getName(childNode),
             node: childNode
@@ -1188,7 +1169,7 @@ treemode._updateTreePath = function (pathNodes) {
  * @param {Object} pathObj path object that was represents the selected section node
  * @private
  */
-treemode._onTreePathSectionSelected = function (pathObj) {
+treemode._onTreePathSectionSelected = pathObj => {
   if (pathObj && pathObj.node) {
     pathObj.node.expandTo()
     pathObj.node.focus()
@@ -1203,9 +1184,7 @@ treemode._onTreePathSectionSelected = function (pathObj) {
  */
 treemode._onTreePathMenuItemSelected = function (pathObj, selection) {
   if (pathObj && pathObj.children.length) {
-    var selectionObj = pathObj.children.find(function (obj) {
+    const selectionObj = pathObj.children.find(obj => obj.name === selection)
-      return obj.name === selection
-    })
     if (selectionObj && selectionObj.node) {
       this._updateTreePath(selectionObj.node.getNodePath())
       selectionObj.node.expandTo()
@@ -1229,8 +1208,8 @@ treemode._updateDragDistance = function (event) {
     this._startDragDistance(event)
   }
 
-  var diffX = event.pageX - this.dragDistanceEvent.initialPageX
+  const diffX = event.pageX - this.dragDistanceEvent.initialPageX
-  var diffY = event.pageY - this.dragDistanceEvent.initialPageY
+  const diffY = event.pageY - this.dragDistanceEvent.initialPageY
 
   this.dragDistanceEvent.dragDistance = Math.sqrt(diffX * diffX + diffY * diffY)
   this.dragDistanceEvent.hasMoved =
@@ -1248,7 +1227,7 @@ treemode._updateDragDistance = function (event) {
  * @private
  */
 treemode._onMultiSelectStart = function (event) {
-  var node = Node.getNodeFromTarget(event.target)
+  const node = Node.getNodeFromTarget(event.target)
 
   if (this.options.mode !== 'tree' || this.options.onEditable !== undefined) {
     // dragging not allowed in modes 'view' and 'form'
@@ -1264,14 +1243,14 @@ treemode._onMultiSelectStart = function (event) {
 
   this._startDragDistance(event)
 
-  var editor = this
+  const editor = this
   if (!this.mousemove) {
-    this.mousemove = util.addEventListener(window, 'mousemove', function (event) {
+    this.mousemove = util.addEventListener(window, 'mousemove', event => {
       editor._onMultiSelect(event)
     })
   }
   if (!this.mouseup) {
-    this.mouseup = util.addEventListener(window, 'mouseup', function (event) {
+    this.mouseup = util.addEventListener(window, 'mouseup', event => {
       editor._onMultiSelectEnd(event)
     })
   }
@@ -1292,7 +1271,7 @@ treemode._onMultiSelect = function (event) {
     return
   }
 
-  var node = Node.getNodeFromTarget(event.target)
+  const node = Node.getNodeFromTarget(event.target)
 
   if (node) {
     if (this.multiselection.start == null) {
@@ -1305,13 +1284,13 @@ treemode._onMultiSelect = function (event) {
   this.deselect()
 
   // find the selected nodes in the range from first to last
-  var start = this.multiselection.start
+  const start = this.multiselection.start
-  var end = this.multiselection.end || this.multiselection.start
+  const end = this.multiselection.end || this.multiselection.start
   if (start && end) {
     // find the top level childs, all having the same parent
     this.multiselection.nodes = this._findTopLevelNodes(start, end)
     if (this.multiselection.nodes && this.multiselection.nodes.length) {
-      var firstNode = this.multiselection.nodes[0]
+      const firstNode = this.multiselection.nodes[0]
       if (this.multiselection.start === firstNode || this.multiselection.start.isDescendantOf(firstNode)) {
         this.multiselection.direction = 'down'
       } else {
@@ -1352,8 +1331,8 @@ treemode._onMultiSelectEnd = function () {
  *                                            state is cleared too.
  */
 treemode.deselect = function (clearStartAndEnd) {
-  var selectionChanged = !!this.multiselection.nodes.length
+  const selectionChanged = !!this.multiselection.nodes.length
-  this.multiselection.nodes.forEach(function (node) {
+  this.multiselection.nodes.forEach(node => {
     node.setSelected(false)
   })
   this.multiselection.nodes = []
@@ -1384,14 +1363,14 @@ treemode.select = function (nodes) {
 
     this.multiselection.nodes = nodes.slice(0)
 
-    var first = nodes[0]
+    const first = nodes[0]
-    nodes.forEach(function (node) {
+    nodes.forEach(node => {
       node.expandPathToNode()
       node.setSelected(true, node === first)
     })
 
     if (this._selectionChangedHandler) {
-      var selection = this.getSelection()
+      const selection = this.getSelection()
       this._selectionChangedHandler(selection.start, selection.end)
     }
   }
@@ -1406,16 +1385,16 @@ treemode.select = function (nodes) {
  * @return {Array.<Node>} Returns an ordered list with child nodes
  * @private
  */
-treemode._findTopLevelNodes = function (start, end) {
+treemode._findTopLevelNodes = (start, end) => {
-  var startPath = start.getNodePath()
+  const startPath = start.getNodePath()
-  var endPath = end.getNodePath()
+  const endPath = end.getNodePath()
-  var i = 0
+  let i = 0
   while (i < startPath.length && startPath[i] === endPath[i]) {
     i++
   }
-  var root = startPath[i - 1]
+  let root = startPath[i - 1]
-  var startChild = startPath[i]
+  let startChild = startPath[i]
-  var endChild = endPath[i]
+  let endChild = endPath[i]
 
   if (!startChild || !endChild) {
     if (root.parent) {
@@ -1431,10 +1410,10 @@ treemode._findTopLevelNodes = function (start, end) {
   }
 
   if (root && startChild && endChild) {
-    var startIndex = root.childs.indexOf(startChild)
+    const startIndex = root.childs.indexOf(startChild)
-    var endIndex = root.childs.indexOf(endChild)
+    const endIndex = root.childs.indexOf(endChild)
-    var firstIndex = Math.min(startIndex, endIndex)
+    const firstIndex = Math.min(startIndex, endIndex)
-    var lastIndex = Math.max(startIndex, endIndex)
+    const lastIndex = Math.max(startIndex, endIndex)
 
     return root.childs.slice(firstIndex, lastIndex + 1)
   } else {
@@ -1448,23 +1427,23 @@ treemode._findTopLevelNodes = function (start, end) {
  * @private
  */
 treemode._showAutoComplete = function (element) {
-  var node = Node.getNodeFromTarget(element)
+  const node = Node.getNodeFromTarget(element)
 
-  var jsonElementType = ''
+  let jsonElementType = ''
   if (element.className.indexOf('jsoneditor-value') >= 0) jsonElementType = 'value'
   if (element.className.indexOf('jsoneditor-field') >= 0) jsonElementType = 'field'
 
-  var self = this
+  const self = this
 
-  setTimeout(function () {
+  setTimeout(() => {
     if (node && (self.options.autocomplete.trigger === 'focus' || element.innerText.length > 0)) {
-      var result = self.options.autocomplete.getOptions(element.innerText, node.getPath(), jsonElementType, node.editor)
+      const result = self.options.autocomplete.getOptions(element.innerText, node.getPath(), jsonElementType, node.editor)
       if (result === null) {
         self.autocomplete.hideDropDown()
       } else if (typeof result.then === 'function') {
         // probably a promise
         result
-          .then(function (obj) {
+          .then(obj => {
             if (obj === null) {
               self.autocomplete.hideDropDown()
             } else if (obj.options) {
@@ -1473,7 +1452,7 @@ treemode._showAutoComplete = function (element) {
               self.autocomplete.show(element, 0, obj)
             }
           })
-          .catch(function (err) {
+          .catch(err => {
             console.error(err)
           })
       } else {
@@ -1490,16 +1469,16 @@ treemode._showAutoComplete = function (element) {
  * @private
  */
 treemode._onKeyDown = function (event) {
-  var keynum = event.which || event.keyCode
+  const keynum = event.which || event.keyCode
-  var altKey = event.altKey
+  const altKey = event.altKey
-  var ctrlKey = event.ctrlKey
+  const ctrlKey = event.ctrlKey
-  var metaKey = event.metaKey
+  const metaKey = event.metaKey
-  var shiftKey = event.shiftKey
+  const shiftKey = event.shiftKey
-  var handled = false
+  let handled = false
 
   if (keynum === 9) { // Tab or Shift+Tab
-    var me = this
+    const me = this
-    setTimeout(function () {
+    setTimeout(() => {
       // select all text when moving focus to an editable div
       util.selectContentEditable(me.focusTarget)
     }, 0)
@@ -1511,7 +1490,7 @@ treemode._onKeyDown = function (event) {
       this.searchBox.dom.search.select()
       handled = true
     } else if (keynum === 114 || (ctrlKey && keynum === 71)) { // F3 or Ctrl+G
-      var focus = true
+      const focus = true
       if (!shiftKey) {
         // select next search result (F3 or Ctrl+G)
         this.searchBox.next(focus)
@@ -1578,7 +1557,7 @@ treemode._createTable = function () {
 
   // create colgroup where the first two columns don't have a fixed
   // width, and the edit columns do have a fixed width
-  var col
+  let col
   this.colgroupContent = document.createElement('colgroup')
   if (this.options.mode === 'tree') {
     col = document.createElement('col')
@@ -1606,8 +1585,8 @@ treemode._createTable = function () {
  *                               is being closed.
  */
 treemode.showContextMenu = function (anchor, onClose) {
-  var items = []
+  let items = []
-  var selectedNodes = this.multiselection.nodes.slice()
+  const selectedNodes = this.multiselection.nodes.slice()
 
   // create duplicate button
   items.push({
@@ -1630,9 +1609,7 @@ treemode.showContextMenu = function (anchor, onClose) {
   })
 
   if (this.options.onCreateMenu) {
-    var paths = selectedNodes.map(function (node) {
+    const paths = selectedNodes.map(node => node.getPath())
-      return node.getPath()
-    })
 
     items = this.options.onCreateMenu(items, {
       type: 'multiple',
@@ -1641,7 +1618,7 @@ treemode.showContextMenu = function (anchor, onClose) {
     })
   }
 
-  var menu = new ContextMenu(items, { close: onClose })
+  const menu = new ContextMenu(items, { close: onClose })
   menu.show(anchor, this.frame)
 }
 
@@ -1650,14 +1627,14 @@ treemode.showContextMenu = function (anchor, onClose) {
  * @return {{start:SerializableNode, end: SerializableNode}}
  */
 treemode.getSelection = function () {
-  var selection = {
+  const selection = {
     start: null,
     end: null
   }
   if (this.multiselection.nodes && this.multiselection.nodes.length) {
     if (this.multiselection.nodes.length) {
-      var selection1 = this.multiselection.nodes[0]
+      const selection1 = this.multiselection.nodes[0]
-      var selection2 = this.multiselection.nodes[this.multiselection.nodes.length - 1]
+      const selection2 = this.multiselection.nodes[this.multiselection.nodes.length - 1]
       if (this.multiselection.direction === 'down') {
         selection.start = selection1.serialize()
         selection.end = selection2.serialize()
@@ -1697,9 +1674,9 @@ treemode.setSelection = function (start, end) {
     this.setDomSelection(start)
   }
 
-  var nodes = this._getNodeInstancesByRange(start, end)
+  const nodes = this._getNodeInstancesByRange(start, end)
 
-  nodes.forEach(function (node) {
+  nodes.forEach(node => {
     node.expandTo()
   })
   this.select(nodes)
@@ -1713,7 +1690,7 @@ treemode.setSelection = function (start, end) {
  * @private
  */
 treemode._getNodeInstancesByRange = function (start, end) {
-  var startNode, endNode
+  let startNode, endNode
 
   if (start && start.path) {
     startNode = this.node.findNodeByPath(start.path)
@@ -1722,7 +1699,7 @@ treemode._getNodeInstancesByRange = function (start, end) {
     }
   }
 
-  var nodes = []
+  let nodes = []
   if (startNode instanceof Node) {
     if (endNode instanceof Node && endNode !== startNode) {
       if (startNode.parent === endNode.parent) {
@@ -1733,7 +1710,7 @@ treemode._getNodeInstancesByRange = function (start, end) {
           start = endNode
           end = startNode
         }
-        var current = start
+        let current = start
         nodes.push(current)
         do {
           current = current.nextSibling()
@@ -1751,10 +1728,10 @@ treemode._getNodeInstancesByRange = function (start, end) {
 }
 
 treemode.getNodesByRange = function (start, end) {
-  var nodes = this._getNodeInstancesByRange(start, end)
+  const nodes = this._getNodeInstancesByRange(start, end)
-  var serializableNodes = []
+  const serializableNodes = []
 
-  nodes.forEach(function (node) {
+  nodes.forEach(node => {
     serializableNodes.push(node.serialize())
   })
 

src/js/util.js

@@ -1,12 +1,12 @@
 'use strict'
 
 require('./polyfills')
-var naturalSort = require('javascript-natural-sort')
+const naturalSort = require('javascript-natural-sort')
-var jsonlint = require('./assets/jsonlint/jsonlint')
+const jsonlint = require('./assets/jsonlint/jsonlint')
-var jsonMap = require('json-source-map')
+const jsonMap = require('json-source-map')
-var translate = require('./i18n').translate
+const translate = require('./i18n').translate
 
-var MAX_ITEMS_FIELDS_COLLECTION = 10000
+const MAX_ITEMS_FIELDS_COLLECTION = 10000
 
 /**
  * Parse JSON using the parser built-in in the browser.
@@ -34,22 +34,22 @@ exports.parse = function parse (jsonString) {
  * @param {string} jsString
  * @returns {string} json
  */
-exports.repair = function (jsString) {
+exports.repair = jsString => {
   // TODO: refactor this function, it's too large and complicated now
 
   // escape all single and double quotes inside strings
-  var chars = []
+  const chars = []
-  var i = 0
+  let i = 0
 
   // If JSON starts with a function (characters/digits/"_-"), remove this function.
   // This is useful for "stripping" JSONP objects to become JSON
   // For example: /* some comment */ function_12321321 ( [{"a":"b"}] ); => [{"a":"b"}]
-  var match = jsString.match(/^\s*(\/\*(.|[\r\n])*?\*\/)?\s*[\da-zA-Z_$]+\s*\(([\s\S]*)\)\s*;?\s*$/)
+  const match = jsString.match(/^\s*(\/\*(.|[\r\n])*?\*\/)?\s*[\da-zA-Z_$]+\s*\(([\s\S]*)\)\s*;?\s*$/)
   if (match) {
     jsString = match[3]
   }
 
-  var controlChars = {
+  const controlChars = {
     '\b': '\\b',
     '\f': '\\f',
     '\n': '\\n',
@@ -57,14 +57,14 @@ exports.repair = function (jsString) {
     '\t': '\\t'
   }
 
-  var quote = '\''
+  const quote = '\''
-  var quoteDbl = '"'
+  const quoteDbl = '"'
-  var quoteLeft = '\u2018'
+  const quoteLeft = '\u2018'
-  var quoteRight = '\u2019'
+  const quoteRight = '\u2019'
-  var quoteDblLeft = '\u201C'
+  const quoteDblLeft = '\u201C'
-  var quoteDblRight = '\u201D'
+  const quoteDblRight = '\u201D'
-  var graveAccent = '\u0060'
+  const graveAccent = '\u0060'
-  var acuteAccent = '\u00B4'
+  const acuteAccent = '\u00B4'
 
   // helper functions to get the current/prev/next character
   function curr () { return jsString.charAt(i) }
@@ -77,10 +77,10 @@ exports.repair = function (jsString) {
 
   // get the last parsed non-whitespace character
   function lastNonWhitespace () {
-    var p = chars.length - 1
+    let p = chars.length - 1
 
     while (p >= 0) {
-      var pp = chars[p]
+      const pp = chars[p]
       if (!isWhiteSpace(pp)) {
         return pp
       }
@@ -92,7 +92,7 @@ exports.repair = function (jsString) {
 
   // get at the first next non-white space character
   function nextNonWhiteSpace () {
-    var iNext = i + 1
+    let iNext = i + 1
     while (iNext < jsString.length && isWhiteSpace(jsString[iNext])) {
       iNext++
     }
@@ -123,11 +123,11 @@ exports.repair = function (jsString) {
    * @return {string}
    */
   function parseString (endQuote) {
-    var string = ''
+    let string = ''
 
     string += '"'
     i++
-    var c = curr()
+    let c = curr()
     while (i < jsString.length && c !== endQuote) {
       if (c === '"' && prev() !== '\\') {
         // unescaped double quote, escape it
@@ -161,11 +161,11 @@ exports.repair = function (jsString) {
 
   // parse an unquoted key
   function parseKey () {
-    var specialValues = ['null', 'true', 'false']
+    const specialValues = ['null', 'true', 'false']
-    var key = ''
+    let key = ''
-    var c = curr()
+    let c = curr()
 
-    var regexp = /[a-zA-Z_$\d]/ // letter, number, underscore, dollar character
+    const regexp = /[a-zA-Z_$\d]/ // letter, number, underscore, dollar character
     while (regexp.test(c)) {
       key += c
       i++
@@ -180,9 +180,9 @@ exports.repair = function (jsString) {
   }
 
   function parseMongoDataType () {
-    var c = curr()
+    let c = curr()
-    var value
+    let value
-    var dataType = ''
+    let dataType = ''
     while (/[a-zA-Z_$]/.test(c)) {
       dataType += c
       i++
@@ -233,7 +233,7 @@ exports.repair = function (jsString) {
   }
 
   while (i < jsString.length) {
-    var c = curr()
+    const c = curr()
 
     if (c === '/' && next() === '*') {
       skipBlockComment()
@@ -278,14 +278,13 @@ exports.repair = function (jsString) {
  * @param {string} text
  * @return {string}
  */
-exports.escapeUnicodeChars = function (text) {
+exports.escapeUnicodeChars = text => // see https://www.wikiwand.com/en/UTF-16
-  // see https://www.wikiwand.com/en/UTF-16
+// note: we leave surrogate pairs as two individual chars,
-  // note: we leave surrogate pairs as two individual chars,
+// as JSON doesn't interpret them as a single unicode char.
-  // as JSON doesn't interpret them as a single unicode char.
+  text.replace(
-  return text.replace(/[\u007F-\uFFFF]/g, function (c) {
+    /[\u007F-\uFFFF]/g,
-    return '\\u' + ('0000' + c.charCodeAt(0).toString(16)).slice(-4)
+    c => '\\u' + ('0000' + c.charCodeAt(0).toString(16)).slice(-4)
-  })
+  )
-}
 
 /**
  * Validate a string containing a JSON object
@@ -309,7 +308,7 @@ exports.validate = function validate (jsonString) {
  * @return {Object} a
  */
 exports.extend = function extend (a, b) {
-  for (var prop in b) {
+  for (const prop in b) {
     if (hasOwnProperty(b, prop)) {
       a[prop] = b[prop]
     }
@@ -323,7 +322,7 @@ exports.extend = function extend (a, b) {
  * @return {Object} a
  */
 exports.clear = function clear (a) {
-  for (var prop in a) {
+  for (const prop in a) {
     if (hasOwnProperty(a, prop)) {
       delete a[prop]
     }
@@ -367,7 +366,7 @@ exports.type = function type (object) {
  * with 'http://*' or 'https://*' and has no whitespace characters)
  * @param {String} text
  */
-var isUrlRegex = /^https?:\/\/\S+$/
+const isUrlRegex = /^https?:\/\/\S+$/
 exports.isUrl = function isUrl (text) {
   return (typeof text === 'string' || text instanceof String) &&
       isUrlRegex.test(text)
@@ -378,9 +377,7 @@ exports.isUrl = function isUrl (text) {
  * @param {*} obj
  * @returns {boolean} returns true when obj is an array
  */
-exports.isArray = function (obj) {
+exports.isArray = obj => Object.prototype.toString.call(obj) === '[object Array]'
-  return Object.prototype.toString.call(obj) === '[object Array]'
-}
 
 /**
  * Retrieve the absolute left value of a DOM element
@@ -389,7 +386,7 @@ exports.isArray = function (obj) {
  *                          in the browser page.
  */
 exports.getAbsoluteLeft = function getAbsoluteLeft (elem) {
-  var rect = elem.getBoundingClientRect()
+  const rect = elem.getBoundingClientRect()
   return rect.left + window.pageXOffset || document.scrollLeft || 0
 }
 
@@ -400,7 +397,7 @@ exports.getAbsoluteLeft = function getAbsoluteLeft (elem) {
  *                          in the browser page.
  */
 exports.getAbsoluteTop = function getAbsoluteTop (elem) {
-  var rect = elem.getBoundingClientRect()
+  const rect = elem.getBoundingClientRect()
   return rect.top + window.pageYOffset || document.scrollTop || 0
 }
 
@@ -410,7 +407,7 @@ exports.getAbsoluteTop = function getAbsoluteTop (elem) {
  * @param {String} className
  */
 exports.addClassName = function addClassName (elem, className) {
-  var classes = elem.className.split(' ')
+  const classes = elem.className.split(' ')
   if (classes.indexOf(className) === -1) {
     classes.push(className) // add the class to the array
     elem.className = classes.join(' ')
@@ -431,8 +428,8 @@ exports.removeAllClassNames = function removeAllClassNames (elem) {
  * @param {String} className
  */
 exports.removeClassName = function removeClassName (elem, className) {
-  var classes = elem.className.split(' ')
+  const classes = elem.className.split(' ')
-  var index = classes.indexOf(className)
+  const index = classes.indexOf(className)
   if (index !== -1) {
     classes.splice(index, 1) // remove the class from the array
     elem.className = classes.join(' ')
@@ -445,9 +442,9 @@ exports.removeClassName = function removeClassName (elem, className) {
  * @param {Element} divElement
  */
 exports.stripFormatting = function stripFormatting (divElement) {
-  var childs = divElement.childNodes
+  const childs = divElement.childNodes
-  for (var i = 0, iMax = childs.length; i < iMax; i++) {
+  for (let i = 0, iMax = childs.length; i < iMax; i++) {
-    var child = childs[i]
+    const child = childs[i]
 
     // remove the style
     if (child.style) {
@@ -456,10 +453,10 @@ exports.stripFormatting = function stripFormatting (divElement) {
     }
 
     // remove all attributes
-    var attributes = child.attributes
+    const attributes = child.attributes
     if (attributes) {
-      for (var j = attributes.length - 1; j >= 0; j--) {
+      for (let j = attributes.length - 1; j >= 0; j--) {
-        var attribute = attributes[j]
+        const attribute = attributes[j]
         if (attribute.specified === true) {
           child.removeAttribute(attribute.name)
         }
@@ -479,7 +476,7 @@ exports.stripFormatting = function stripFormatting (divElement) {
  * @param {Element} contentEditableElement   A content editable div
  */
 exports.setEndOfContentEditable = function setEndOfContentEditable (contentEditableElement) {
-  var range, selection
+  let range, selection
   if (document.createRange) {
     range = document.createRange()// Create a range (a range is a like the selection but invisible)
     range.selectNodeContents(contentEditableElement)// Select the entire contents of the element with the range
@@ -500,7 +497,7 @@ exports.selectContentEditable = function selectContentEditable (contentEditableE
     return
   }
 
-  var sel, range
+  let sel, range
   if (window.getSelection && document.createRange) {
     range = document.createRange()
     range.selectNodeContents(contentEditableElement)
@@ -517,7 +514,7 @@ exports.selectContentEditable = function selectContentEditable (contentEditableE
  */
 exports.getSelection = function getSelection () {
   if (window.getSelection) {
-    var sel = window.getSelection()
+    const sel = window.getSelection()
     if (sel.getRangeAt && sel.rangeCount) {
       return sel.getRangeAt(0)
     }
@@ -533,7 +530,7 @@ exports.getSelection = function getSelection () {
 exports.setSelection = function setSelection (range) {
   if (range) {
     if (window.getSelection) {
-      var sel = window.getSelection()
+      const sel = window.getSelection()
       sel.removeAllRanges()
       sel.addRange(range)
     }
@@ -550,7 +547,7 @@ exports.setSelection = function setSelection (range) {
  *                          Returns null if no text selection is found
  */
 exports.getSelectionOffset = function getSelectionOffset () {
-  var range = exports.getSelection()
+  const range = exports.getSelection()
 
   if (range && 'startOffset' in range && 'endOffset' in range &&
       range.startContainer && (range.startContainer === range.endContainer)) {
@@ -573,9 +570,9 @@ exports.getSelectionOffset = function getSelectionOffset () {
  */
 exports.setSelectionOffset = function setSelectionOffset (params) {
   if (document.createRange && window.getSelection) {
-    var selection = window.getSelection()
+    const selection = window.getSelection()
     if (selection) {
-      var range = document.createRange()
+      const range = document.createRange()
 
       if (!params.container.firstChild) {
         params.container.appendChild(document.createTextNode(''))
@@ -598,12 +595,12 @@ exports.setSelectionOffset = function setSelectionOffset (params) {
  * @return {String} innerText
  */
 exports.getInnerText = function getInnerText (element, buffer) {
-  var first = (buffer === undefined)
+  const first = (buffer === undefined)
   if (first) {
     buffer = {
       text: '',
       flush: function () {
-        var text = this.text
+        const text = this.text
         this.text = ''
         return text
       },
@@ -620,15 +617,15 @@ exports.getInnerText = function getInnerText (element, buffer) {
 
   // divs or other HTML elements
   if (element.hasChildNodes()) {
-    var childNodes = element.childNodes
+    const childNodes = element.childNodes
-    var innerText = ''
+    let innerText = ''
 
-    for (var i = 0, iMax = childNodes.length; i < iMax; i++) {
+    for (let i = 0, iMax = childNodes.length; i < iMax; i++) {
-      var child = childNodes[i]
+      const child = childNodes[i]
 
       if (child.nodeName === 'DIV' || child.nodeName === 'P') {
-        var prevChild = childNodes[i - 1]
+        const prevChild = childNodes[i - 1]
-        var prevName = prevChild ? prevChild.nodeName : undefined
+        const prevName = prevChild ? prevChild.nodeName : undefined
         if (prevName && prevName !== 'DIV' && prevName !== 'P' && prevName !== 'BR') {
           innerText += '\n'
           buffer.flush()
@@ -665,8 +662,8 @@ exports.getInnerText = function getInnerText (element, buffer) {
  * @param {Element} parent
  * @return {boolean}
  */
-exports.hasParentNode = function (elem, parent) {
+exports.hasParentNode = (elem, parent) => {
-  var e = elem ? elem.parentNode : undefined
+  let e = elem ? elem.parentNode : undefined
 
   while (e) {
     if (e === parent) {
@@ -686,10 +683,10 @@ exports.hasParentNode = function (elem, parent) {
  */
 exports.getInternetExplorerVersion = function getInternetExplorerVersion () {
   if (_ieVersion === -1) {
-    var rv = -1 // Return value assumes failure.
+    let rv = -1 // Return value assumes failure.
     if (typeof navigator !== 'undefined' && navigator.appName === 'Microsoft Internet Explorer') {
-      var ua = navigator.userAgent
+      const ua = navigator.userAgent
-      var re = new RegExp('MSIE ([0-9]+[.0-9]+)')
+      const re = new RegExp('MSIE ([0-9]+[.0-9]+)')
       if (re.exec(ua) != null) {
         rv = parseFloat(RegExp.$1)
       }
@@ -737,9 +734,7 @@ exports.addEventListener = function addEventListener (element, action, listener,
     return listener
   } else if (element.attachEvent) {
     // Old IE browsers
-    var f = function () {
+    const f = () => listener.call(element, window.event)
-      return listener.call(element, window.event)
-    }
     element.attachEvent('on' + action, f)
     return f
   }
@@ -773,8 +768,8 @@ exports.removeEventListener = function removeEventListener (element, action, lis
  * @param {Element} parent
  * @return {boolean} returns true if elem is a child of the parent
  */
-exports.isChildOf = function (elem, parent) {
+exports.isChildOf = (elem, parent) => {
-  var e = elem.parentNode
+  let e = elem.parentNode
   while (e) {
     if (e === parent) {
       return true
@@ -791,11 +786,11 @@ exports.isChildOf = function (elem, parent) {
  * @return {Array}
  */
 exports.parsePath = function parsePath (jsonPath) {
-  var path = []
+  const path = []
-  var i = 0
+  let i = 0
 
   function parseProperty () {
-    var prop = ''
+    let prop = ''
     while (jsonPath[i] !== undefined && /[\w$]/.test(jsonPath[i])) {
       prop += jsonPath[i]
       i++
@@ -809,7 +804,7 @@ exports.parsePath = function parsePath (jsonPath) {
   }
 
   function parseIndex (end) {
-    var name = ''
+    let name = ''
     while (jsonPath[i] !== undefined && jsonPath[i] !== end) {
       name += jsonPath[i]
       i++
@@ -830,7 +825,7 @@ exports.parsePath = function parsePath (jsonPath) {
       i++
 
       if (jsonPath[i] === '\'' || jsonPath[i] === '"') {
-        var end = jsonPath[i]
+        const end = jsonPath[i]
         i++
 
         path.push(parseIndex(end))
@@ -840,7 +835,7 @@ exports.parsePath = function parsePath (jsonPath) {
         }
         i++
       } else {
-        var index = parseIndex(']').trim()
+        let index = parseIndex(']').trim()
         if (index.length === 0) {
           throw new Error('Invalid JSON path: array value expected at index ' + i)
         }
@@ -868,7 +863,7 @@ exports.parsePath = function parsePath (jsonPath) {
  */
 exports.stringifyPath = function stringifyPath (path) {
   return path
-    .map(function (p) {
+    .map(p => {
       if (typeof p === 'number') {
         return ('[' + p + ']')
       } else if (typeof p === 'string' && p.match(/^[A-Za-z0-9_$]+$/)) {
@@ -885,16 +880,14 @@ exports.stringifyPath = function stringifyPath (path) {
  * @param {Object} error
  * @return {Object} The error
  */
-exports.improveSchemaError = function (error) {
+exports.improveSchemaError = error => {
   if (error.keyword === 'enum' && Array.isArray(error.schema)) {
-    var enums = error.schema
+    let enums = error.schema
     if (enums) {
-      enums = enums.map(function (value) {
+      enums = enums.map(value => JSON.stringify(value))
-        return JSON.stringify(value)
-      })
 
       if (enums.length > 5) {
-        var more = ['(' + (enums.length - 5) + ' more...)']
+        const more = ['(' + (enums.length - 5) + ' more...)']
         enums = enums.slice(0, 5)
         enums.push(more)
       }
@@ -914,20 +907,16 @@ exports.improveSchemaError = function (error) {
  * @param {*} object
  * @returns {boolean} Returns true when object is a promise, false otherwise
  */
-exports.isPromise = function (object) {
+exports.isPromise = object => object && typeof object.then === 'function' && typeof object.catch === 'function'
-  return object && typeof object.then === 'function' && typeof object.catch === 'function'
-}
 
 /**
  * Test whether a custom validation error has the correct structure
  * @param {*} validationError The error to be checked.
  * @returns {boolean} Returns true if the structure is ok, false otherwise
  */
-exports.isValidValidationError = function (validationError) {
+exports.isValidValidationError = validationError => typeof validationError === 'object' &&
-  return typeof validationError === 'object' &&
+    Array.isArray(validationError.path) &&
-      Array.isArray(validationError.path) &&
+    typeof validationError.message === 'string'
-      typeof validationError.message === 'string'
-}
 
 /**
  * Test whether the child rect fits completely inside the parent rect.
@@ -935,8 +924,8 @@ exports.isValidValidationError = function (validationError) {
  * @param {ClientRect} child
  * @param {number} margin
  */
-exports.insideRect = function (parent, child, margin) {
+exports.insideRect = (parent, child, margin) => {
-  var _margin = margin !== undefined ? margin : 0
+  const _margin = margin !== undefined ? margin : 0
   return child.left - _margin >= parent.left &&
       child.right + _margin <= parent.right &&
       child.top - _margin >= parent.top &&
@@ -958,14 +947,14 @@ exports.insideRect = function (parent, child, margin) {
  * @return {function} Return the debounced function
  */
 exports.debounce = function debounce (func, wait, immediate) {
-  var timeout
+  let timeout
   return function () {
-    var context = this; var args = arguments
+    const context = this; const args = arguments
-    var later = function () {
+    const later = () => {
       timeout = null
       if (!immediate) func.apply(context, args)
     }
-    var callNow = immediate && !timeout
+    const callNow = immediate && !timeout
     clearTimeout(timeout)
     timeout = setTimeout(later, wait)
     if (callNow) func.apply(context, args)
@@ -981,10 +970,10 @@ exports.debounce = function debounce (func, wait, immediate) {
  *                                        of the changed part in newText.
  */
 exports.textDiff = function textDiff (oldText, newText) {
-  var len = newText.length
+  const len = newText.length
-  var start = 0
+  let start = 0
-  var oldEnd = oldText.length
+  let oldEnd = oldText.length
-  var newEnd = newText.length
+  let newEnd = newText.length
 
   while (newText.charAt(start) === oldText.charAt(start) &&
   start < len) {
@@ -1007,8 +996,8 @@ exports.textDiff = function textDiff (oldText, newText) {
  * @param {DOMElement} el A dom element of a textarea or input text.
  * @return {Object} reference Object with 2 properties (start and end) with the identifier of the location of the cursor and selected text.
  **/
-exports.getInputSelection = function (el) {
+exports.getInputSelection = el => {
-  var startIndex = 0; var endIndex = 0; var normalizedValue; var range; var textInputRange; var len; var endRange
+  let startIndex = 0; let endIndex = 0; let normalizedValue; let range; let textInputRange; let len; let endRange
 
   if (typeof el.selectionStart === 'number' && typeof el.selectionEnd === 'number') {
     startIndex = el.selectionStart
@@ -1059,9 +1048,9 @@ exports.getInputSelection = function (el) {
    * @returns {{row: Number, column: Number}}
    */
   function _positionForIndex (index) {
-    var textTillIndex = el.value.substring(0, index)
+    const textTillIndex = el.value.substring(0, index)
-    var row = (textTillIndex.match(/\n/g) || []).length + 1
+    const row = (textTillIndex.match(/\n/g) || []).length + 1
-    var col = textTillIndex.length - textTillIndex.lastIndexOf('\n')
+    const col = textTillIndex.length - textTillIndex.lastIndexOf('\n')
 
     return {
       row: row,
@@ -1077,13 +1066,13 @@ exports.getInputSelection = function (el) {
  * @param {Number} column column value, > 0, if exceeds column length - end of column will be returned
  * @returns {Number} index of position in text, -1 if not found
  */
-exports.getIndexForPosition = function (el, row, column) {
+exports.getIndexForPosition = (el, row, column) => {
-  var text = el.value || ''
+  const text = el.value || ''
   if (row > 0 && column > 0) {
-    var rows = text.split('\n', row)
+    const rows = text.split('\n', row)
     row = Math.min(rows.length, row)
     column = Math.min(rows[row - 1].length, column - 1)
-    var columnCount = (row === 1 ? column : column + 1) // count new line on multiple rows
+    const columnCount = (row === 1 ? column : column + 1) // count new line on multiple rows
     return rows.slice(0, row - 1).join('\n').length + columnCount
   }
   return -1
@@ -1109,7 +1098,7 @@ exports.getPositionForPath = function (text, paths) {
     return result
   }
 
-  paths.forEach(function (path) {
+  paths.forEach(path => {
     const pathArr = me.parsePath(path)
     const pointerName = exports.compileJSONPointer(pathArr)
     const pointer = jsmap.pointers[pointerName]
@@ -1131,14 +1120,12 @@ exports.getPositionForPath = function (text, paths) {
  * @param {Array.<string | number>} path
  * @return {string}
  */
-exports.compileJSONPointer = function (path) {
+exports.compileJSONPointer = path => path
-  return path
+  .map(p => ('/' + String(p)
-    .map(p => ('/' + String(p)
+    .replace(/~/g, '~0')
-      .replace(/~/g, '~0')
+    .replace(/\//g, '~1')
-      .replace(/\//g, '~1')
+  ))
-    ))
+  .join('')
-    .join('')
-}
 
 /**
  * Get the applied color given a color name or code
@@ -1148,8 +1135,8 @@ exports.compileJSONPointer = function (path) {
  *                   color, and returns null otherwise. Example output:
  *                   'rgba(255,0,0,0.7)' or 'rgb(255,0,0)'
  */
-exports.getColorCSS = function (color) {
+exports.getColorCSS = color => {
-  var ele = document.createElement('div')
+  const ele = document.createElement('div')
   ele.style.color = color
   return ele.style.color.split(/\s+/).join('').toLowerCase() || null
 }
@@ -1159,9 +1146,7 @@ exports.getColorCSS = function (color) {
  * @param {string} color
  * @returns {boolean} returns true if a valid color, false otherwise
  */
-exports.isValidColor = function (color) {
+exports.isValidColor = color => !!exports.getColorCSS(color)
-  return !!exports.getColorCSS(color)
-}
 
 /**
  * Make a tooltip for a field based on the field's schema.
@@ -1169,12 +1154,12 @@ exports.isValidColor = function (color) {
  * @param {string} [locale] Locale code (for example, zh-CN)
  * @returns {string} Field tooltip, may be empty string if all relevant schema properties are missing
  */
-exports.makeFieldTooltip = function (schema, locale) {
+exports.makeFieldTooltip = (schema, locale) => {
   if (!schema) {
     return ''
   }
 
-  var tooltip = ''
+  let tooltip = ''
   if (schema.title) {
     tooltip += schema.title
   }
@@ -1199,7 +1184,7 @@ exports.makeFieldTooltip = function (schema, locale) {
       tooltip += '\n\n'
     }
     tooltip += translate('examples', undefined, locale) + '\n'
-    schema.examples.forEach(function (example, index) {
+    schema.examples.forEach((example, index) => {
       tooltip += JSON.stringify(example, null, 2)
       if (index !== schema.examples.length - 1) {
         tooltip += '\n'
@@ -1217,10 +1202,10 @@ exports.makeFieldTooltip = function (schema, locale) {
  * @param {string[]} path
  * @return {*}
  */
-exports.get = function (object, path) {
+exports.get = (object, path) => {
-  var value = object
+  let value = object
 
-  for (var i = 0; i < path.length && value !== undefined && value !== null; i++) {
+  for (let i = 0; i < path.length && value !== undefined && value !== null; i++) {
     value = value[path[i]]
   }
 
@@ -1233,13 +1218,13 @@ exports.get = function (object, path) {
  * @param {string} name
  * @param {Array} existingPropNames    Array with existing prop names
  */
-exports.findUniqueName = function (name, existingPropNames) {
+exports.findUniqueName = (name, existingPropNames) => {
-  var strippedName = name.replace(/ \(copy( \d+)?\)$/, '')
+  const strippedName = name.replace(/ \(copy( \d+)?\)$/, '')
-  var validName = strippedName
+  let validName = strippedName
-  var i = 1
+  let i = 1
 
   while (existingPropNames.indexOf(validName) !== -1) {
-    var copy = 'copy' + (i > 1 ? (' ' + i) : '')
+    const copy = 'copy' + (i > 1 ? (' ' + i) : '')
     validName = strippedName + ' (' + copy + ')'
     i++
   }
@@ -1253,27 +1238,27 @@ exports.findUniqueName = function (name, existingPropNames) {
  * @param {boolean} [includeObjects=false] If true, object and array paths are returned as well
  * @return {string[]}
  */
-exports.getChildPaths = function (json, includeObjects) {
+exports.getChildPaths = (json, includeObjects) => {
-  var pathsMap = {}
+  const pathsMap = {}
 
   function getObjectChildPaths (json, pathsMap, rootPath, includeObjects) {
-    var isValue = !Array.isArray(json) && !exports.isObject(json)
+    const isValue = !Array.isArray(json) && !exports.isObject(json)
 
     if (isValue || includeObjects) {
       pathsMap[rootPath || ''] = true
     }
 
     if (exports.isObject(json)) {
-      Object.keys(json).forEach(function (field) {
+      Object.keys(json).forEach(field => {
         getObjectChildPaths(json[field], pathsMap, rootPath + '.' + field, includeObjects)
       })
     }
   }
 
   if (Array.isArray(json)) {
-    var max = Math.min(json.length, MAX_ITEMS_FIELDS_COLLECTION)
+    const max = Math.min(json.length, MAX_ITEMS_FIELDS_COLLECTION)
-    for (var i = 0; i < max; i++) {
+    for (let i = 0; i < max; i++) {
-      var item = json[i]
+      const item = json[i]
       getObjectChildPaths(item, pathsMap, '', includeObjects)
     }
   } else {
@@ -1289,14 +1274,14 @@ exports.getChildPaths = function (json, includeObjects) {
  * @param {String} [path] JSON pointer
  * @param {'asc' | 'desc'} [direction]
  */
-exports.sort = function (array, path, direction) {
+exports.sort = (array, path, direction) => {
-  var parsedPath = path && path !== '.' ? exports.parsePath(path) : []
+  const parsedPath = path && path !== '.' ? exports.parsePath(path) : []
-  var sign = direction === 'desc' ? -1 : 1
+  const sign = direction === 'desc' ? -1 : 1
 
-  var sortedArray = array.slice()
+  const sortedArray = array.slice()
-  sortedArray.sort(function (a, b) {
+  sortedArray.sort((a, b) => {
-    var aValue = exports.get(a, parsedPath)
+    const aValue = exports.get(a, parsedPath)
-    var bValue = exports.get(b, parsedPath)
+    const bValue = exports.get(b, parsedPath)
 
     return sign * (aValue > bValue ? 1 : aValue < bValue ? -1 : 0)
   })
@@ -1309,14 +1294,12 @@ exports.sort = function (array, path, direction) {
  * @param {Object} object
  * @param {'asc' | 'desc'} [direction]
  */
-exports.sortObjectKeys = function (object, direction) {
+exports.sortObjectKeys = (object, direction) => {
-  var sign = (direction === 'desc') ? -1 : 1
+  const sign = (direction === 'desc') ? -1 : 1
-  var sortedFields = Object.keys(object).sort(function (a, b) {
+  const sortedFields = Object.keys(object).sort((a, b) => sign * naturalSort(a, b))
-    return sign * naturalSort(a, b)
-  })
 
-  var sortedObject = {}
+  const sortedObject = {}
-  sortedFields.forEach(function (field) {
+  sortedFields.forEach(field => {
     sortedObject[field] = object[field]
   })
 
@@ -1330,10 +1313,10 @@ exports.sortObjectKeys = function (object, direction) {
  * @return {*} castedStr
  * @private
  */
-exports.parseString = function (str) {
+exports.parseString = str => {
-  var lower = str.toLowerCase()
+  const lower = str.toLowerCase()
-  var num = Number(str) // will nicely fail with '123ab'
+  const num = Number(str) // will nicely fail with '123ab'
-  var numFloat = parseFloat(str) // will nicely fail with '  '
+  const numFloat = parseFloat(str) // will nicely fail with '  '
 
   if (str === '') {
     return ''
@@ -1356,27 +1339,27 @@ exports.parseString = function (str) {
  * @param {number} size
  * @return {string} Returns a human readable size
  */
-exports.formatSize = function (size) {
+exports.formatSize = size => {
   if (size < 900) {
     return size.toFixed() + ' B'
   }
 
-  var KiB = size / 1024
+  const KiB = size / 1024
   if (KiB < 900) {
     return KiB.toFixed(1) + ' KiB'
   }
 
-  var MiB = KiB / 1024
+  const MiB = KiB / 1024
   if (MiB < 900) {
     return MiB.toFixed(1) + ' MiB'
   }
 
-  var GiB = MiB / 1024
+  const GiB = MiB / 1024
   if (GiB < 900) {
     return GiB.toFixed(1) + ' GiB'
   }
 
-  var TiB = GiB / 1024
+  const TiB = GiB / 1024
   return TiB.toFixed(1) + ' TiB'
 }
 
@@ -1387,7 +1370,7 @@ exports.formatSize = function (size) {
  * @return {string} Returns the limited text,
  *                  ending with '...' if the max was exceeded
  */
-exports.limitCharacters = function (text, maxCharacterCount) {
+exports.limitCharacters = (text, maxCharacterCount) => {
   if (text.length <= maxCharacterCount) {
     return text
   }
@@ -1400,9 +1383,7 @@ exports.limitCharacters = function (text, maxCharacterCount) {
  * @param {*} value
  * @return {boolean}
  */
-exports.isObject = function (value) {
+exports.isObject = value => typeof value === 'object' && value !== null && !Array.isArray(value)
-  return typeof value === 'object' && value !== null && !Array.isArray(value)
-}
 
 /**
  * Helper function to test whether an array contains an item
@@ -1410,9 +1391,7 @@ exports.isObject = function (value) {
  * @param {*} item
  * @return {boolean} Returns true if `item` is in `array`, returns false otherwise.
  */
-exports.contains = function (array, item) {
+exports.contains = (array, item) => array.indexOf(item) !== -1
-  return array.indexOf(item) !== -1
-}
 
 function hasOwnProperty (object, key) {
   return Object.prototype.hasOwnProperty.call(object, key)

src/js/validationUtils.js

@@ -1,6 +1,6 @@
-var isPromise = require('./util').isPromise
+const isPromise = require('./util').isPromise
-var isValidValidationError = require('./util').isValidValidationError
+const isValidValidationError = require('./util').isValidValidationError
-var stringifyPath = require('./util').stringifyPath
+const stringifyPath = require('./util').stringifyPath
 
 /**
  * Execute custom validation if configured.
@@ -13,17 +13,17 @@ function validateCustom (json, onValidate) {
   }
 
   try {
-    var customValidateResults = onValidate(json)
+    const customValidateResults = onValidate(json)
 
-    var resultPromise = isPromise(customValidateResults)
+    const resultPromise = isPromise(customValidateResults)
       ? customValidateResults
       : Promise.resolve(customValidateResults)
 
-    return resultPromise.then(function (customValidationPathErrors) {
+    return resultPromise.then(customValidationPathErrors => {
       if (Array.isArray(customValidationPathErrors)) {
         return customValidationPathErrors
-          .filter(function (error) {
+          .filter(error => {
-            var valid = isValidValidationError(error)
+            const valid = isValidValidationError(error)
 
             if (!valid) {
               console.warn('Ignoring a custom validation error with invalid structure. ' +
@@ -33,13 +33,11 @@ function validateCustom (json, onValidate) {
 
             return valid
           })
-          .map(function (error) {
+          .map(error => // change data structure into the structure matching the JSON schema errors
-            // change data structure into the structure matching the JSON schema errors
+            ({
-            return {
               dataPath: stringifyPath(error.path),
               message: error.message
-            }
+            }))
-          })
       } else {
         return []
       }

src/js/vanilla-picker/index.js

@@ -1,4 +1,4 @@
-var VanillaPicker
+let VanillaPicker
 
 if (window.Picker) {
   // use the already loaded instance of VanillaPicker