Style: no more var

.travis.yml

@@ -1,4 +1,4 @@
 language: node_js
 node_js:
   - 'node'
-install: npm install standard depcheck
+install: npm install standard depcheck walk-sync

bin/extra-lint.js

@@ -30,10 +30,9 @@ files.forEach(function (file) {
       error = 'Line >100 chars'
     }
 
-    // TODO: No vars
+    if (line.match(/^var /) || line.match(/ var /)) {
-    // if (line.match(/^var /) || line.match(/ var /)) {
+      error = 'Use const or let'
-    //   error = 'Use const or let'
+    }
-    // }
 
     if (error) {
       let name = path.basename(file)

src/config.js

@@ -1,12 +1,12 @@
-var appConfig = require('application-config')('WebTorrent')
+const appConfig = require('application-config')('WebTorrent')
-var fs = require('fs')
+const fs = require('fs')
-var path = require('path')
+const path = require('path')
 
-var APP_NAME = 'WebTorrent'
+const APP_NAME = 'WebTorrent'
-var APP_TEAM = 'WebTorrent, LLC'
+const APP_TEAM = 'WebTorrent, LLC'
-var APP_VERSION = require('../package.json').version
+const APP_VERSION = require('../package.json').version
 
-var PORTABLE_PATH = path.join(path.dirname(process.execPath), 'Portable Settings')
+const PORTABLE_PATH = path.join(path.dirname(process.execPath), 'Portable Settings')
 
 module.exports = {
   ANNOUNCEMENT_URL: 'https://webtorrent.io/desktop/announcement',
@@ -95,7 +95,7 @@ function getDefaultDownloadPath () {
     return path.join(getConfigPath(), 'Downloads')
   }
 
-  var electron = require('electron')
+  const electron = require('electron')
 
   return process.type === 'renderer'
     ? electron.remote.app.getPath('downloads')

src/crash-reporter.js

@@ -2,8 +2,8 @@ module.exports = {
   init
 }
 
-var config = require('./config')
+const config = require('./config')
-var electron = require('electron')
+const electron = require('electron')
 
 function init () {
   electron.crashReporter.start({

src/main/announcement.js

@@ -2,12 +2,12 @@ module.exports = {
   init
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var config = require('../config')
+const config = require('../config')
-var log = require('./log')
+const log = require('./log')
 
-var ANNOUNCEMENT_URL = config.ANNOUNCEMENT_URL +
+const ANNOUNCEMENT_URL = config.ANNOUNCEMENT_URL +
   '?version=' + config.APP_VERSION +
   '&platform=' + process.platform
 
@@ -26,7 +26,7 @@ var ANNOUNCEMENT_URL = config.ANNOUNCEMENT_URL +
  *   }
  */
 function init () {
-  var get = require('simple-get')
+  const get = require('simple-get')
   get.concat(ANNOUNCEMENT_URL, onResponse)
 }
 

src/main/dialog.js

@@ -6,10 +6,10 @@ module.exports = {
   openFiles
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var log = require('./log')
+const log = require('./log')
-var windows = require('./windows')
+const windows = require('./windows')
 
 /**
  * Show open dialog to create a single-file torrent.
@@ -17,7 +17,7 @@ var windows = require('./windows')
 function openSeedFile () {
   if (!windows.main.win) return
   log('openSeedFile')
-  var opts = {
+  const opts = {
     title: 'Select a file for the torrent.',
     properties: [ 'openFile' ]
   }
@@ -37,7 +37,7 @@ function openSeedFile () {
 function openSeedDirectory () {
   if (!windows.main.win) return
   log('openSeedDirectory')
-  var opts = process.platform === 'darwin'
+  const opts = process.platform === 'darwin'
     ? {
       title: 'Select a file or folder for the torrent.',
       properties: [ 'openFile', 'openDirectory' ]
@@ -61,7 +61,7 @@ function openSeedDirectory () {
 function openFiles () {
   if (!windows.main.win) return
   log('openFiles')
-  var opts = process.platform === 'darwin'
+  const opts = process.platform === 'darwin'
     ? {
       title: 'Select a file or folder to add.',
       properties: [ 'openFile', 'openDirectory' ]
@@ -84,7 +84,7 @@ function openFiles () {
 function openTorrentFile () {
   if (!windows.main.win) return
   log('openTorrentFile')
-  var opts = {
+  const opts = {
     title: 'Select a .torrent file.',
     filters: [{ name: 'Torrent Files', extensions: ['torrent'] }],
     properties: [ 'openFile', 'multiSelections' ]

src/main/dock.js

@@ -4,17 +4,17 @@ module.exports = {
   setBadge
 }
 
-var {app, Menu} = require('electron')
+const {app, Menu} = require('electron')
 
-var dialog = require('./dialog')
+const dialog = require('./dialog')
-var log = require('./log')
+const log = require('./log')
 
 /**
  * Add a right-click menu to the dock icon. (Mac)
  */
 function init () {
   if (!app.dock) return
-  var menu = Menu.buildFromTemplate(getMenuTemplate())
+  const menu = Menu.buildFromTemplate(getMenuTemplate())
   app.dock.setMenu(menu)
 }
 

src/main/external-player.js

@@ -4,14 +4,14 @@ module.exports = {
   checkInstall
 }
 
-var cp = require('child_process')
+const cp = require('child_process')
-var vlcCommand = require('vlc-command')
+const vlcCommand = require('vlc-command')
 
-var log = require('./log')
+const log = require('./log')
-var windows = require('./windows')
+const windows = require('./windows')
 
 // holds a ChildProcess while we're playing a video in an external player, null otherwise
-var proc
+let proc = null
 
 function checkInstall (path, cb) {
   // check for VLC if external player has not been specified by the user
@@ -26,7 +26,7 @@ function spawn (path, url, title) {
   // Try to find and use VLC if external player is not specified
   vlcCommand(function (err, vlcPath) {
     if (err) return windows.main.dispatch('externalPlayerNotFound')
-    var args = [
+    const args = [
       '--play-and-exit',
       '--video-on-top',
       '--quiet',
@@ -50,7 +50,7 @@ function spawnExternal (path, args) {
   proc = cp.spawn(path, args, {stdio: 'ignore'})
 
   // If it works, close the modal after a second
-  var closeModalTimeout = setTimeout(() =>
+  const closeModalTimeout = setTimeout(() =>
     windows.main.dispatch('exitModal'), 1000)
 
   proc.on('close', function (code) {

src/main/handlers.js

@@ -3,8 +3,8 @@ module.exports = {
   uninstall
 }
 
-var config = require('../config')
+const config = require('../config')
-var path = require('path')
+const path = require('path')
 
 function install () {
   if (process.platform === 'darwin') {
@@ -31,8 +31,8 @@ function uninstall () {
 }
 
 function installDarwin () {
-  var electron = require('electron')
+  const electron = require('electron')
-  var app = electron.app
+  const app = electron.app
 
   // On Mac, only protocols that are listed in `Info.plist` can be set as the
   // default handler at runtime.
@@ -44,18 +44,18 @@ function installDarwin () {
 
 function uninstallDarwin () {}
 
-var EXEC_COMMAND = [ process.execPath ]
+const EXEC_COMMAND = [ process.execPath ]
 
 if (!config.IS_PRODUCTION) {
   EXEC_COMMAND.push(config.ROOT_PATH)
 }
 
 function installWin32 () {
-  var Registry = require('winreg')
+  const Registry = require('winreg')
 
-  var log = require('./log')
+  const log = require('./log')
 
-  var iconPath = path.join(
+  const iconPath = path.join(
     process.resourcesPath, 'app.asar.unpacked', 'static', 'WebTorrentFile.ico'
   )
   registerProtocolHandlerWin32(
@@ -100,7 +100,7 @@ function installWin32 () {
    */
 
   function registerProtocolHandlerWin32 (protocol, name, icon, command) {
-    var protocolKey = new Registry({
+    const protocolKey = new Registry({
       hive: Registry.HKCU, // HKEY_CURRENT_USER
       key: '\\Software\\Classes\\' + protocol
     })
@@ -120,7 +120,7 @@ function installWin32 () {
     function setIcon (err) {
       if (err) log.error(err.message)
 
-      var iconKey = new Registry({
+      const iconKey = new Registry({
         hive: Registry.HKCU,
         key: '\\Software\\Classes\\' + protocol + '\\DefaultIcon'
       })
@@ -130,7 +130,7 @@ function installWin32 () {
     function setCommand (err) {
       if (err) log.error(err.message)
 
-      var commandKey = new Registry({
+      const commandKey = new Registry({
         hive: Registry.HKCU,
         key: '\\Software\\Classes\\' + protocol + '\\shell\\open\\command'
       })
@@ -161,7 +161,7 @@ function installWin32 () {
     setExt()
 
     function setExt () {
-      var extKey = new Registry({
+      const extKey = new Registry({
         hive: Registry.HKCU, // HKEY_CURRENT_USER
         key: '\\Software\\Classes\\' + ext
       })
@@ -171,7 +171,7 @@ function installWin32 () {
     function setId (err) {
       if (err) log.error(err.message)
 
-      var idKey = new Registry({
+      const idKey = new Registry({
         hive: Registry.HKCU,
         key: '\\Software\\Classes\\' + id
       })
@@ -181,7 +181,7 @@ function installWin32 () {
     function setIcon (err) {
       if (err) log.error(err.message)
 
-      var iconKey = new Registry({
+      const iconKey = new Registry({
         hive: Registry.HKCU,
         key: '\\Software\\Classes\\' + id + '\\DefaultIcon'
       })
@@ -191,7 +191,7 @@ function installWin32 () {
     function setCommand (err) {
       if (err) log.error(err.message)
 
-      var commandKey = new Registry({
+      const commandKey = new Registry({
         hive: Registry.HKCU,
         key: '\\Software\\Classes\\' + id + '\\shell\\open\\command'
       })
@@ -205,7 +205,7 @@ function installWin32 () {
 }
 
 function uninstallWin32 () {
-  var Registry = require('winreg')
+  const Registry = require('winreg')
 
   unregisterProtocolHandlerWin32('magnet', EXEC_COMMAND)
   unregisterProtocolHandlerWin32('stream-magnet', EXEC_COMMAND)
@@ -215,7 +215,7 @@ function uninstallWin32 () {
     getCommand()
 
     function getCommand () {
-      var commandKey = new Registry({
+      const commandKey = new Registry({
         hive: Registry.HKCU, // HKEY_CURRENT_USER
         key: '\\Software\\Classes\\' + protocol + '\\shell\\open\\command'
       })
@@ -227,7 +227,7 @@ function uninstallWin32 () {
     }
 
     function destroyProtocol () {
-      var protocolKey = new Registry({
+      const protocolKey = new Registry({
         hive: Registry.HKCU,
         key: '\\Software\\Classes\\' + protocol
       })
@@ -239,7 +239,7 @@ function uninstallWin32 () {
     eraseId()
 
     function eraseId () {
-      var idKey = new Registry({
+      const idKey = new Registry({
         hive: Registry.HKCU, // HKEY_CURRENT_USER
         key: '\\Software\\Classes\\' + id
       })
@@ -247,7 +247,7 @@ function uninstallWin32 () {
     }
 
     function getExt () {
-      var extKey = new Registry({
+      const extKey = new Registry({
         hive: Registry.HKCU,
         key: '\\Software\\Classes\\' + ext
       })
@@ -259,7 +259,7 @@ function uninstallWin32 () {
     }
 
     function destroyExt () {
-      var extKey = new Registry({
+      const extKey = new Registry({
         hive: Registry.HKCU, // HKEY_CURRENT_USER
         key: '\\Software\\Classes\\' + ext
       })
@@ -273,12 +273,12 @@ function commandToArgs (command) {
 }
 
 function installLinux () {
-  var fs = require('fs-extra')
+  const fs = require('fs-extra')
-  var os = require('os')
+  const os = require('os')
-  var path = require('path')
+  const path = require('path')
 
-  var config = require('../config')
+  const config = require('../config')
-  var log = require('./log')
+  const log = require('./log')
 
   // Do not install in user dir if running on system
   if (/^\/opt/.test(process.execPath)) return
@@ -287,7 +287,7 @@ function installLinux () {
   installIconFile()
 
   function installDesktopFile () {
-    var templatePath = path.join(
+    const templatePath = path.join(
       config.STATIC_PATH, 'linux', 'webtorrent-desktop.desktop'
     )
     fs.readFile(templatePath, 'utf8', writeDesktopFile)
@@ -296,7 +296,7 @@ function installLinux () {
   function writeDesktopFile (err, desktopFile) {
     if (err) return log.error(err.message)
 
-    var appPath = config.IS_PRODUCTION
+    const appPath = config.IS_PRODUCTION
       ? path.dirname(process.execPath)
       : config.ROOT_PATH
 
@@ -305,7 +305,7 @@ function installLinux () {
     desktopFile = desktopFile.replace(/\$EXEC_PATH/g, EXEC_COMMAND.join(' '))
     desktopFile = desktopFile.replace(/\$TRY_EXEC_PATH/g, process.execPath)
 
-    var desktopFilePath = path.join(
+    const desktopFilePath = path.join(
       os.homedir(),
       '.local',
       'share',
@@ -319,14 +319,14 @@ function installLinux () {
   }
 
   function installIconFile () {
-    var iconStaticPath = path.join(config.STATIC_PATH, 'WebTorrent.png')
+    const iconStaticPath = path.join(config.STATIC_PATH, 'WebTorrent.png')
     fs.readFile(iconStaticPath, writeIconFile)
   }
 
   function writeIconFile (err, iconFile) {
     if (err) return log.error(err.message)
 
-    var iconFilePath = path.join(
+    const iconFilePath = path.join(
       os.homedir(),
       '.local',
       'share',
@@ -341,11 +341,11 @@ function installLinux () {
 }
 
 function uninstallLinux () {
-  var os = require('os')
+  const os = require('os')
-  var path = require('path')
+  const path = require('path')
-  var fs = require('fs-extra')
+  const fs = require('fs-extra')
 
-  var desktopFilePath = path.join(
+  const desktopFilePath = path.join(
     os.homedir(),
     '.local',
     'share',
@@ -354,7 +354,7 @@ function uninstallLinux () {
   )
   fs.removeSync(desktopFilePath)
 
-  var iconFilePath = path.join(
+  const iconFilePath = path.join(
     os.homedir(),
     '.local',
     'share',

src/main/index.js

@@ -1,26 +1,26 @@
 console.time('init')
 
-var electron = require('electron')
+const electron = require('electron')
 
-var app = electron.app
+const app = electron.app
-var ipcMain = electron.ipcMain
+const ipcMain = electron.ipcMain
 
-var announcement = require('./announcement')
+const announcement = require('./announcement')
-var config = require('../config')
+const config = require('../config')
-var crashReporter = require('../crash-reporter')
+const crashReporter = require('../crash-reporter')
-var dialog = require('./dialog')
+const dialog = require('./dialog')
-var dock = require('./dock')
+const dock = require('./dock')
-var ipc = require('./ipc')
+const ipc = require('./ipc')
-var log = require('./log')
+const log = require('./log')
-var menu = require('./menu')
+const menu = require('./menu')
-var squirrelWin32 = require('./squirrel-win32')
+const squirrelWin32 = require('./squirrel-win32')
-var tray = require('./tray')
+const tray = require('./tray')
-var updater = require('./updater')
+const updater = require('./updater')
-var userTasks = require('./user-tasks')
+const userTasks = require('./user-tasks')
-var windows = require('./windows')
+const windows = require('./windows')
 
-var shouldQuit = false
+let shouldQuit = false
-var argv = sliceArgv(process.argv)
+let argv = sliceArgv(process.argv)
 
 if (config.IS_PRODUCTION) {
   // When Electron is running in production mode (packaged app), then run React
@@ -51,7 +51,7 @@ function init () {
     app.setPath('userData', config.CONFIG_PATH)
   }
 
-  var isReady = false // app ready, windows can be created
+  let isReady = false // app ready, windows can be created
   app.ipcReady = false // main window has finished loading and IPC is ready
   app.isQuitting = false
 
@@ -78,7 +78,7 @@ function init () {
     // Report uncaught exceptions
     process.on('uncaughtException', (err) => {
       console.error(err)
-      var error = {message: err.message, stack: err.stack}
+      const error = {message: err.message, stack: err.stack}
       windows.main.dispatch('uncaughtError', 'main', error)
     })
   })
@@ -148,7 +148,7 @@ function sliceArgv (argv) {
 }
 
 function processArgv (argv) {
-  var torrentIds = []
+  let torrentIds = []
   argv.forEach(function (arg) {
     if (arg === '-n') {
       dialog.openSeedDirectory()

src/main/ipc.js

@@ -2,27 +2,27 @@ module.exports = {
   init
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var app = electron.app
+const app = electron.app
 
-var dialog = require('./dialog')
+const dialog = require('./dialog')
-var dock = require('./dock')
+const dock = require('./dock')
-var handlers = require('./handlers')
+const handlers = require('./handlers')
-var log = require('./log')
+const log = require('./log')
-var menu = require('./menu')
+const menu = require('./menu')
-var powerSaveBlocker = require('./power-save-blocker')
+const powerSaveBlocker = require('./power-save-blocker')
-var shell = require('./shell')
+const shell = require('./shell')
-var shortcuts = require('./shortcuts')
+const shortcuts = require('./shortcuts')
-var externalPlayer = require('./external-player')
+const externalPlayer = require('./external-player')
-var windows = require('./windows')
+const windows = require('./windows')
-var thumbar = require('./thumbar')
+const thumbar = require('./thumbar')
 
 // Messages from the main process, to be sent once the WebTorrent process starts
-var messageQueueMainToWebTorrent = []
+const messageQueueMainToWebTorrent = []
 
 function init () {
-  var ipc = electron.ipcMain
+  const ipc = electron.ipcMain
 
   ipc.once('ipcReady', function (e) {
     app.ipcReady = true
@@ -106,7 +106,7 @@ function init () {
    * Windows: Main
    */
 
-  var main = windows.main
+  const main = windows.main
 
   ipc.on('setAspectRatio', (e, ...args) => main.setAspectRatio(...args))
   ipc.on('setBounds', (e, ...args) => main.setBounds(...args))
@@ -130,7 +130,7 @@ function init () {
   ipc.on('quitExternalPlayer', () => externalPlayer.kill())
 
   // Capture all events
-  var oldEmit = ipc.emit
+  const oldEmit = ipc.emit
   ipc.emit = function (name, e, ...args) {
     // Relay messages between the main window and the WebTorrent hidden window
     if (name.startsWith('wt-') && !app.isQuitting) {

src/main/log.js

@@ -8,10 +8,10 @@ module.exports.error = error
  * where they can be viewed in Developer Tools.
  */
 
-var electron = require('electron')
+const electron = require('electron')
-var windows = require('./windows')
+const windows = require('./windows')
 
-var app = electron.app
+const app = electron.app
 
 function log (...args) {
   if (app.ipcReady) {

src/main/menu.js

@@ -8,16 +8,16 @@ module.exports = {
   onToggleFullScreen
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var app = electron.app
+const app = electron.app
 
-var config = require('../config')
+const config = require('../config')
-var dialog = require('./dialog')
+const dialog = require('./dialog')
-var shell = require('./shell')
+const shell = require('./shell')
-var windows = require('./windows')
+const windows = require('./windows')
 
-var menu
+let menu = null
 
 function init () {
   menu = electron.Menu.buildFromTemplate(getMenuTemplate())
@@ -72,8 +72,8 @@ function onToggleFullScreen (flag) {
 }
 
 function getMenuItem (label) {
-  for (var i = 0; i < menu.items.length; i++) {
+  for (let i = 0; i < menu.items.length; i++) {
-    var menuItem = menu.items[i].submenu.items.find(function (item) {
+    const menuItem = menu.items[i].submenu.items.find(function (item) {
       return item.label === label
     })
     if (menuItem) return menuItem
@@ -81,7 +81,7 @@ function getMenuItem (label) {
 }
 
 function getMenuTemplate () {
-  var template = [
+  const template = [
     {
       label: 'File',
       submenu: [

src/main/power-save-blocker.js

@@ -3,10 +3,10 @@ module.exports = {
   disable
 }
 
-var electron = require('electron')
+const electron = require('electron')
-var log = require('./log')
+const log = require('./log')
 
-var blockId = 0
+let blockId = 0
 
 /**
  * Block the system from entering low-power (sleep) mode or turning off the

src/main/shell.js

@@ -5,8 +5,8 @@ module.exports = {
   moveItemToTrash
 }
 
-var electron = require('electron')
+const electron = require('electron')
-var log = require('./log')
+const log = require('./log')
 
 /**
  * Open the given external protocol URL in the desktop’s default manner.

src/main/shortcuts.js

@@ -3,8 +3,8 @@ module.exports = {
   enable
 }
 
-var electron = require('electron')
+const electron = require('electron')
-var windows = require('./windows')
+const windows = require('./windows')
 
 function enable () {
   // Register play/pause media key, available on some keyboards.

src/main/squirrel-win32.js

@@ -2,18 +2,18 @@ module.exports = {
   handleEvent
 }
 
-var cp = require('child_process')
+const cp = require('child_process')
-var electron = require('electron')
+const electron = require('electron')
-var fs = require('fs')
+const fs = require('fs')
-var os = require('os')
+const os = require('os')
-var path = require('path')
+const path = require('path')
 
-var app = electron.app
+const app = electron.app
 
-var handlers = require('./handlers')
+const handlers = require('./handlers')
 
-var EXE_NAME = path.basename(process.execPath)
+const EXE_NAME = path.basename(process.execPath)
-var UPDATE_EXE = path.join(process.execPath, '..', '..', 'Update.exe')
+const UPDATE_EXE = path.join(process.execPath, '..', '..', 'Update.exe')
 
 function handleEvent (cmd) {
   if (cmd === '--squirrel-install') {
@@ -73,9 +73,9 @@ function handleEvent (cmd) {
  * the output from standard out.
  */
 function spawn (command, args, cb) {
-  var stdout = ''
+  let stdout = ''
-
+  let error = null
-  var child
+  let child = null
   try {
     child = cp.spawn(command, args)
   } catch (err) {
@@ -90,10 +90,10 @@ function spawn (command, args, cb) {
     stdout += data
   })
 
-  var error = null
   child.on('error', function (processError) {
     error = processError
   })
+
   child.on('close', function (code, signal) {
     if (code !== 0 && !error) error = new Error('Command failed: #{signal || code}')
     if (error) error.stdout = stdout
@@ -122,12 +122,12 @@ function createShortcuts (cb) {
  * command.
  */
 function updateShortcuts (cb) {
-  var homeDir = os.homedir()
+  const homeDir = os.homedir()
   if (homeDir) {
-    var desktopShortcutPath = path.join(homeDir, 'Desktop', 'WebTorrent.lnk')
+    const desktopShortcutPath = path.join(homeDir, 'Desktop', 'WebTorrent.lnk')
     // If the desktop shortcut was deleted by the user, then keep it deleted.
     fs.access(desktopShortcutPath, function (err) {
-      var desktopShortcutExists = !err
+      const desktopShortcutExists = !err
       createShortcuts(function () {
         if (desktopShortcutExists) {
           cb()

src/main/thumbar.js

@@ -12,10 +12,10 @@ module.exports = {
  * or activating the window.
  */
 
-var path = require('path')
+const path = require('path')
-var config = require('../config')
+const config = require('../config')
 
-var windows = require('./windows')
+const windows = require('./windows')
 
 const PREV_ICON = path.join(config.STATIC_PATH, 'PreviousTrackThumbnailBarButton.png')
 const PLAY_ICON = path.join(config.STATIC_PATH, 'PlayThumbnailBarButton.png')
@@ -27,7 +27,7 @@ const PREV = 0
 const PLAY_PAUSE = 1
 const NEXT = 2
 
-var buttons = []
+let buttons = []
 
 /**
  * Show the Windows thumbnail toolbar buttons.

src/main/tray.js

@@ -4,14 +4,14 @@ module.exports = {
   setWindowFocus
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var app = electron.app
+const app = electron.app
 
-var config = require('../config')
+const config = require('../config')
-var windows = require('./windows')
+const windows = require('./windows')
 
-var tray
+let tray
 
 function init () {
   if (process.platform === 'linux') {
@@ -49,7 +49,7 @@ function initWin32 () {
  * Check for libappindicator1 support before creating tray icon
  */
 function checkLinuxTraySupport (cb) {
-  var cp = require('child_process')
+  const cp = require('child_process')
 
   // Check that we're on Ubuntu (or another debian system) and that we have
   // libappindicator1. If WebTorrent was installed from the deb file, we should
@@ -74,7 +74,7 @@ function createTray () {
 }
 
 function updateTrayMenu () {
-  var contextMenu = electron.Menu.buildFromTemplate(getMenuTemplate())
+  const contextMenu = electron.Menu.buildFromTemplate(getMenuTemplate())
   tray.setContextMenu(contextMenu)
 }
 

src/main/updater.js

@@ -2,14 +2,14 @@ module.exports = {
   init
 }
 
-var electron = require('electron')
+const electron = require('electron')
-var get = require('simple-get')
+const get = require('simple-get')
 
-var config = require('../config')
+const config = require('../config')
-var log = require('./log')
+const log = require('./log')
-var windows = require('./windows')
+const windows = require('./windows')
 
-var AUTO_UPDATE_URL = config.AUTO_UPDATE_URL +
+const AUTO_UPDATE_URL = config.AUTO_UPDATE_URL +
   '?version=' + config.APP_VERSION +
   '&platform=' + process.platform
 

src/main/user-tasks.js

@@ -2,9 +2,9 @@ module.exports = {
   init
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var app = electron.app
+const app = electron.app
 
 /**
  * Add a user task menu to the app icon on right-click. (Windows)

src/main/windows/about.js

@@ -1,17 +1,17 @@
-var about = module.exports = {
+const about = module.exports = {
   init,
   win: null
 }
 
-var config = require('../../config')
+const config = require('../../config')
-var electron = require('electron')
+const electron = require('electron')
 
 function init () {
   if (about.win) {
     return about.win.show()
   }
 
-  var win = about.win = new electron.BrowserWindow({
+  const win = about.win = new electron.BrowserWindow({
     backgroundColor: '#ECECEC',
     center: true,
     fullscreen: false,

src/main/windows/main.js

@@ -1,4 +1,4 @@
-var main = module.exports = {
+const main = module.exports = {
   dispatch,
   hide,
   init,
@@ -14,23 +14,23 @@ var main = module.exports = {
   win: null
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var app = electron.app
+const app = electron.app
 
-var config = require('../../config')
+const config = require('../../config')
-var log = require('../log')
+const log = require('../log')
-var menu = require('../menu')
+const menu = require('../menu')
-var tray = require('../tray')
+const tray = require('../tray')
 
-var HEADER_HEIGHT = 38
+const HEADER_HEIGHT = 38
-var TORRENT_HEIGHT = 100
+const TORRENT_HEIGHT = 100
 
 function init () {
   if (main.win) {
     return main.win.show()
   }
-  var win = main.win = new electron.BrowserWindow({
+  const win = main.win = new electron.BrowserWindow({
     backgroundColor: '#282828',
     darkTheme: true, // Forces dark theme (GTK+3)
     icon: getIconPath(), // Window icon (Windows, Linux)
@@ -114,7 +114,7 @@ function setBounds (bounds, maximize) {
   }
 
   // Maximize or minimize, if the second argument is present
-  var willBeMaximized
+  let willBeMaximized
   if (maximize === true) {
     if (!main.win.isMaximized()) {
       log('setBounds: maximizing')
@@ -136,7 +136,7 @@ function setBounds (bounds, maximize) {
     log('setBounds: setting bounds to ' + JSON.stringify(bounds))
     if (bounds.x === null && bounds.y === null) {
       // X and Y not specified? By default, center on current screen
-      var scr = electron.screen.getDisplayMatching(main.win.getBounds())
+      const scr = electron.screen.getDisplayMatching(main.win.getBounds())
       bounds.x = Math.round(scr.bounds.x + scr.bounds.width / 2 - bounds.width / 2)
       bounds.y = Math.round(scr.bounds.y + scr.bounds.height / 2 - bounds.height / 2)
       log('setBounds: centered to ' + JSON.stringify(bounds))

src/main/windows/webtorrent.js

@@ -1,4 +1,4 @@
-var webtorrent = module.exports = {
+const webtorrent = module.exports = {
   init,
   send,
   show,
@@ -6,13 +6,13 @@ var webtorrent = module.exports = {
   win: null
 }
 
-var electron = require('electron')
+const electron = require('electron')
 
-var config = require('../../config')
+const config = require('../../config')
-var log = require('../log')
+const log = require('../log')
 
 function init () {
-  var win = webtorrent.win = new electron.BrowserWindow({
+  const win = webtorrent.win = new electron.BrowserWindow({
     backgroundColor: '#1E1E1E',
     center: true,
     fullscreen: false,

src/renderer/components/header.js

@@ -4,7 +4,7 @@ const {dispatcher} = require('../lib/dispatcher')
 
 class Header extends React.Component {
   render () {
-    var loc = this.props.state.location
+    const loc = this.props.state.location
     return (
       <div className='header'>
         {this.getTitle()}
@@ -31,12 +31,12 @@ class Header extends React.Component {
 
   getTitle () {
     if (process.platform !== 'darwin') return null
-    var state = this.props.state
+    const state = this.props.state
     return (<div className='title ellipsis'>{state.window.title}</div>)
   }
 
   getAddButton () {
-    var state = this.props.state
+    const state = this.props.state
     if (state.location.url() !== 'home') return null
     return (
       <i

src/renderer/components/path-selector.js

@@ -29,7 +29,7 @@ class PathSelector extends React.Component {
   }
 
   handleClick () {
-    var opts = Object.assign({
+    const opts = Object.assign({
       defaultPath: this.props.value,
       properties: [ 'openFile', 'openDirectory' ]
     }, this.props.dialog)

src/renderer/components/remove-torrent-modal.js

@@ -4,11 +4,11 @@ const {dispatch, dispatcher} = require('../lib/dispatcher')
 
 module.exports = class RemoveTorrentModal extends React.Component {
   render () {
-    var state = this.props.state
+    const state = this.props.state
-    var message = state.modal.deleteData
+    const message = state.modal.deleteData
       ? 'Are you sure you want to remove this torrent from the list and delete the data file?'
       : 'Are you sure you want to remove this torrent from the list?'
-    var buttonText = state.modal.deleteData ? 'Remove Data' : 'Remove'
+    const buttonText = state.modal.deleteData ? 'Remove Data' : 'Remove'
 
     return (
       <div>

src/renderer/components/unsupported-media-modal.js

@@ -6,20 +6,20 @@ const {dispatcher} = require('../lib/dispatcher')
 
 module.exports = class UnsupportedMediaModal extends React.Component {
   render () {
-    var state = this.props.state
+    const state = this.props.state
-    var err = state.modal.error
+    const err = state.modal.error
-    var message = (err && err.getMessage)
+    const message = (err && err.getMessage)
       ? err.getMessage()
       : err
-    var playerPath = state.saved.prefs.externalPlayerPath
+    const playerPath = state.saved.prefs.externalPlayerPath
-    var playerName = playerPath
+    const playerName = playerPath
       ? path.basename(playerPath).split('.')[0]
       : 'VLC'
-    var onPlay = dispatcher('openExternalPlayer')
+    const onPlay = dispatcher('openExternalPlayer')
-    var actionButton = state.modal.externalPlayerInstalled
+    const actionButton = state.modal.externalPlayerInstalled
       ? (<button className='button-raised' onClick={onPlay}>Play in {playerName}</button>)
       : (<button className='button-raised' onClick={() => this.onInstall()}>Install VLC</button>)
-    var playerMessage = state.modal.externalPlayerNotFound
+    const playerMessage = state.modal.externalPlayerNotFound
       ? 'Couldn\'t run external player. Please make sure it\'s installed.'
       : ''
     return (
@@ -39,7 +39,7 @@ module.exports = class UnsupportedMediaModal extends React.Component {
     electron.shell.openExternal('http://www.videolan.org/vlc/')
 
     // TODO: dcposch send a dispatch rather than modifying state directly
-    var state = this.props.state
+    const state = this.props.state
     state.modal.externalPlayerInstalled = true // Assume they'll install it successfully
   }
 }

src/renderer/components/update-available-modal.js

@@ -5,7 +5,7 @@ const {dispatch} = require('../lib/dispatcher')
 
 module.exports = class UpdateAvailableModal extends React.Component {
   render () {
-    var state = this.props.state
+    const state = this.props.state
     return (
       <div className='update-available-modal'>
         <p><strong>A new version of WebTorrent is available: v{state.modal.version}</strong></p>

src/renderer/controllers/media-controller.js

@@ -20,7 +20,7 @@ module.exports = class MediaController {
   }
 
   mediaError (error) {
-    var state = this.state
+    const state = this.state
     if (state.location.url() === 'player') {
       state.playing.result = 'error'
       state.playing.location = 'error'
@@ -45,8 +45,8 @@ module.exports = class MediaController {
   }
 
   openExternalPlayer () {
-    var state = this.state
+    const state = this.state
-    var mediaURL = Playlist.getCurrentLocalURL(this.state)
+    const mediaURL = Playlist.getCurrentLocalURL(this.state)
     ipcRenderer.send('openExternalPlayer',
       state.saved.prefs.externalPlayerPath,
       mediaURL,
@@ -55,7 +55,7 @@ module.exports = class MediaController {
   }
 
   externalPlayerNotFound () {
-    var modal = this.state.modal
+    const modal = this.state.modal
     if (modal && modal.id === 'unsupported-media-modal') {
       modal.externalPlayerNotFound = true
     }

src/renderer/controllers/playback-controller.js

@@ -27,7 +27,7 @@ module.exports = class PlaybackController {
   // * Stream, if not already fully downloaded
   // * If no file index is provided, restore the most recently viewed file or autoplay the first
   playFile (infoHash, index /* optional */) {
-    var state = this.state
+    const state = this.state
     if (state.location.url() === 'player') {
       this.updatePlayer(infoHash, index, false, (err) => {
         if (err) dispatch('error', err)
@@ -52,8 +52,8 @@ module.exports = class PlaybackController {
 
   // Open a file in OS default app.
   openItem (infoHash, index) {
-    var torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
+    const torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
-    var filePath = path.join(
+    const filePath = path.join(
       torrentSummary.path,
       torrentSummary.files[index].path)
     ipcRenderer.send('openItem', filePath)
@@ -61,12 +61,12 @@ module.exports = class PlaybackController {
 
   // Toggle (play or pause) the currently playing media
   playPause () {
-    var state = this.state
+    const state = this.state
     if (state.location.url() !== 'player') return
 
     // force rerendering if window is hidden,
     // in order to bypass `raf` and play/pause media immediately
-    var mediaTag = document.querySelector('video,audio')
+    const mediaTag = document.querySelector('video,audio')
     if (!state.window.isVisible && mediaTag) {
       if (state.playing.isPaused) mediaTag.play()
       else mediaTag.pause()
@@ -78,7 +78,7 @@ module.exports = class PlaybackController {
 
   // Play next file in list (if any)
   nextTrack () {
-    var state = this.state
+    const state = this.state
     if (Playlist.hasNext(state)) {
       this.updatePlayer(
           state.playing.infoHash, Playlist.getNextIndex(state), false, (err) => {
@@ -90,7 +90,7 @@ module.exports = class PlaybackController {
 
   // Play previous track in list (if any)
   previousTrack () {
-    var state = this.state
+    const state = this.state
     if (Playlist.hasPrevious(state)) {
       this.updatePlayer(
         state.playing.infoHash, Playlist.getPreviousIndex(state), false, (err) => {
@@ -102,7 +102,7 @@ module.exports = class PlaybackController {
 
   // Play (unpause) the current media
   play () {
-    var state = this.state
+    const state = this.state
     if (!state.playing.isPaused) return
     state.playing.isPaused = false
     if (isCasting(state)) {
@@ -113,7 +113,7 @@ module.exports = class PlaybackController {
 
   // Pause the currently playing media
   pause () {
-    var state = this.state
+    const state = this.state
     if (state.playing.isPaused) return
     state.playing.isPaused = true
     if (isCasting(state)) {
@@ -142,8 +142,8 @@ module.exports = class PlaybackController {
   // to 0.25 (quarter-speed playback), then goes to -0.25, -0.5, -1, -2, etc
   // until -16 (fast rewind)
   changePlaybackRate (direction) {
-    var state = this.state
+    const state = this.state
-    var rate = state.playing.playbackRate
+    let rate = state.playing.playbackRate
     if (direction > 0 && rate >= 0.25 && rate < 2) {
       rate += 0.25
     } else if (direction < 0 && rate > 0.25 && rate <= 2) {
@@ -178,7 +178,7 @@ module.exports = class PlaybackController {
     // check if its in [0.0 - 1.0] range
     volume = Math.max(0, Math.min(1, volume))
 
-    var state = this.state
+    const state = this.state
     if (isCasting(state)) {
       Cast.setVolume(volume)
     } else {
@@ -192,8 +192,8 @@ module.exports = class PlaybackController {
   // * The video is paused
   // * The video is playing remotely on Chromecast or Airplay
   showOrHidePlayerControls () {
-    var state = this.state
+    const state = this.state
-    var hideControls = state.location.url() === 'player' &&
+    const hideControls = state.location.url() === 'player' &&
       state.playing.mouseStationarySince !== 0 &&
       new Date().getTime() - state.playing.mouseStationarySince > 2000 &&
       !state.playing.isPaused &&
@@ -208,9 +208,8 @@ module.exports = class PlaybackController {
 
   // Opens the video player to a specific torrent
   openPlayer (infoHash, index, cb) {
-    var state = this.state
+    const state = this.state
-
+    const torrentSummary = TorrentSummary.getByKey(state, infoHash)
-    var torrentSummary = TorrentSummary.getByKey(state, infoHash)
 
     if (index === undefined) index = torrentSummary.mostRecentFileIndex
     if (index === undefined) index = torrentSummary.files.findIndex(TorrentPlayer.isPlayable)
@@ -224,7 +223,7 @@ module.exports = class PlaybackController {
     torrentSummary.playStatus = 'requested'
     this.update()
 
-    var timeout = setTimeout(() => {
+    const timeout = setTimeout(() => {
       telemetry.logPlayAttempt('timeout')
       // TODO: remove torrentSummary.playStatus
       torrentSummary.playStatus = 'timeout' /* no seeders available? */
@@ -237,7 +236,7 @@ module.exports = class PlaybackController {
       clearTimeout(timeout)
 
       // if we timed out (user clicked play a long time ago), don't autoplay
-      var timedOut = torrentSummary.playStatus === 'timeout'
+      const timedOut = torrentSummary.playStatus === 'timeout'
       delete torrentSummary.playStatus
       if (timedOut) {
         ipcRenderer.send('wt-stop-server')
@@ -267,10 +266,10 @@ module.exports = class PlaybackController {
 
   // Called each time the current file changes
   updatePlayer (infoHash, index, resume, cb) {
-    var state = this.state
+    const state = this.state
 
-    var torrentSummary = TorrentSummary.getByKey(state, infoHash)
+    const torrentSummary = TorrentSummary.getByKey(state, infoHash)
-    var fileSummary = torrentSummary.files[index]
+    const fileSummary = torrentSummary.files[index]
 
     if (!TorrentPlayer.isPlayable(fileSummary)) {
       torrentSummary.mostRecentFileIndex = undefined
@@ -280,16 +279,17 @@ module.exports = class PlaybackController {
     torrentSummary.mostRecentFileIndex = index
 
     // update state
+    state.playing.infoHash = infoHash
     state.playing.fileIndex = index
     state.playing.type = TorrentPlayer.isVideo(fileSummary) ? 'video'
       : TorrentPlayer.isAudio(fileSummary) ? 'audio'
       : 'other'
 
     // pick up where we left off
-    var jumpToTime = 0
+    let jumpToTime = 0
     if (resume && fileSummary.currentTime) {
-      var fraction = fileSummary.currentTime / fileSummary.duration
+      const fraction = fileSummary.currentTime / fileSummary.duration
-      var secondsLeft = fileSummary.duration - fileSummary.currentTime
+      const secondsLeft = fileSummary.duration - fileSummary.currentTime
       if (fraction < 0.9 && secondsLeft > 10) {
         jumpToTime = fileSummary.currentTime
       }
@@ -330,7 +330,7 @@ module.exports = class PlaybackController {
     console.log('closePlayer')
 
     // Quit any external players, like Chromecast/Airplay/etc or VLC
-    var state = this.state
+    const state = this.state
     if (isCasting(state)) {
       Cast.stop()
     }
@@ -342,7 +342,7 @@ module.exports = class PlaybackController {
     state.previousVolume = state.playing.volume
 
     // Telemetry: track what happens after the user clicks play
-    var result = state.playing.result // 'success' or 'error'
+    const result = state.playing.result // 'success' or 'error'
     if (result === 'success') telemetry.logPlayAttempt('success') // first frame displayed
     else if (result === 'error') telemetry.logPlayAttempt('error') // codec missing, etc
     else if (result === undefined) telemetry.logPlayAttempt('abandoned') // user gave up waiting

src/renderer/controllers/prefs-controller.js

@@ -11,7 +11,7 @@ module.exports = class PrefsController {
 
   // Goes to the Preferences screen
   show () {
-    var state = this.state
+    const state = this.state
     state.location.go({
       url: 'preferences',
       setup: function (cb) {
@@ -32,20 +32,21 @@ module.exports = class PrefsController {
   // For example: updatePreferences('foo.bar', 'baz')
   // Call save() to save to config.json
   update (property, value) {
-    var path = property.split('.')
+    const path = property.split('.')
-    var key = this.state.unsaved.prefs
+    let obj = this.state.unsaved.prefs
-    for (var i = 0; i < path.length - 1; i++) {
+    let i
-      if (typeof key[path[i]] === 'undefined') {
+    for (i = 0; i < path.length - 1; i++) {
-        key[path[i]] = {}
+      if (typeof obj[path[i]] === 'undefined') {
+        obj[path[i]] = {}
       }
-      key = key[path[i]]
+      obj = obj[path[i]]
     }
-    key[path[i]] = value
+    obj[path[i]] = value
   }
 
   // All unsaved prefs take effect atomically, and are saved to config.json
   save () {
-    var state = this.state
+    const state = this.state
     if (state.unsaved.prefs.isFileHandler !== state.saved.prefs.isFileHandler) {
       ipcRenderer.send('setDefaultFileHandler', state.unsaved.prefs.isFileHandler)
     }

src/renderer/controllers/subtitles-controller.js

@@ -28,26 +28,26 @@ module.exports = class SubtitlesController {
   }
 
   toggleSubtitlesMenu () {
-    var subtitles = this.state.playing.subtitles
+    const subtitles = this.state.playing.subtitles
     subtitles.showMenu = !subtitles.showMenu
   }
 
   addSubtitles (files, autoSelect) {
-    var state = this.state
+    const state = this.state
     // Subtitles are only supported when playing video files
     if (state.playing.type !== 'video') return
     if (files.length === 0) return
-    var subtitles = state.playing.subtitles
+    const subtitles = state.playing.subtitles
 
     // Read the files concurrently, then add all resulting subtitle tracks
-    var tasks = files.map((file) => (cb) => loadSubtitle(file, cb))
+    const tasks = files.map((file) => (cb) => loadSubtitle(file, cb))
     parallel(tasks, function (err, tracks) {
       if (err) return dispatch('error', err)
 
-      for (var i = 0; i < tracks.length; i++) {
+      for (let i = 0; i < tracks.length; i++) {
         // No dupes allowed
-        var track = tracks[i]
+        const track = tracks[i]
-        var trackIndex = state.playing.subtitles.tracks
+        let trackIndex = state.playing.subtitles.tracks
           .findIndex((t) => track.filePath === t.filePath)
 
         // Add the track
@@ -68,46 +68,46 @@ module.exports = class SubtitlesController {
 
   checkForSubtitles () {
     if (this.state.playing.type !== 'video') return
-    var torrentSummary = this.state.getPlayingTorrentSummary()
+    const torrentSummary = this.state.getPlayingTorrentSummary()
     if (!torrentSummary || !torrentSummary.progress) return
 
     torrentSummary.progress.files.forEach((fp, ix) => {
       if (fp.numPieces !== fp.numPiecesPresent) return // ignore incomplete files
-      var file = torrentSummary.files[ix]
+      const file = torrentSummary.files[ix]
       if (!this.isSubtitle(file.name)) return
-      var filePath = path.join(torrentSummary.path, file.path)
+      const filePath = path.join(torrentSummary.path, file.path)
       this.addSubtitles([filePath], false)
     })
   }
 
   isSubtitle (file) {
-    var name = typeof file === 'string' ? file : file.name
+    const name = typeof file === 'string' ? file : file.name
-    var ext = path.extname(name).toLowerCase()
+    const ext = path.extname(name).toLowerCase()
     return ext === '.srt' || ext === '.vtt'
   }
 }
 
 function loadSubtitle (file, cb) {
   // Lazy load to keep startup fast
-  var concat = require('simple-concat')
+  const concat = require('simple-concat')
-  var LanguageDetect = require('languagedetect')
+  const LanguageDetect = require('languagedetect')
-  var srtToVtt = require('srt-to-vtt')
+  const srtToVtt = require('srt-to-vtt')
 
   // Read the .SRT or .VTT file, parse it, add subtitle track
-  var filePath = file.path || file
+  const filePath = file.path || file
 
-  var vttStream = fs.createReadStream(filePath).pipe(srtToVtt())
+  const vttStream = fs.createReadStream(filePath).pipe(srtToVtt())
 
   concat(vttStream, function (err, buf) {
     if (err) return dispatch('error', 'Can\'t parse subtitles file.')
 
     // Detect what language the subtitles are in
-    var vttContents = buf.toString().replace(/(.*-->.*)/g, '')
+    const vttContents = buf.toString().replace(/(.*-->.*)/g, '')
-    var langDetected = (new LanguageDetect()).detect(vttContents, 2)
+    let langDetected = (new LanguageDetect()).detect(vttContents, 2)
     langDetected = langDetected.length ? langDetected[0][0] : 'subtitle'
     langDetected = langDetected.slice(0, 1).toUpperCase() + langDetected.slice(1)
 
-    var track = {
+    const track = {
       buffer: 'data:text/vtt;base64,' + buf.toString('base64'),
       language: langDetected,
       label: langDetected,
@@ -121,18 +121,18 @@ function loadSubtitle (file, cb) {
 // Checks whether a language name like 'English' or 'German' matches the system
 // language, aka the current locale
 function isSystemLanguage (language) {
-  var iso639 = require('iso-639-1')
+  const iso639 = require('iso-639-1')
-  var osLangISO = window.navigator.language.split('-')[0] // eg 'en'
+  const osLangISO = window.navigator.language.split('-')[0] // eg 'en'
-  var langIso = iso639.getCode(language) // eg 'de' if language is 'German'
+  const langIso = iso639.getCode(language) // eg 'de' if language is 'German'
   return langIso === osLangISO
 }
 
 // Make sure we don't have two subtitle tracks with the same label
 // Labels each track by language, eg 'German', 'English', 'English 2', ...
 function relabelSubtitles (subtitles) {
-  var counts = {}
+  const counts = {}
   subtitles.tracks.forEach(function (track) {
-    var lang = track.language
+    const lang = track.language
     counts[lang] = (counts[lang] || 0) + 1
     track.label = counts[lang] > 1 ? (lang + ' ' + counts[lang]) : lang
   })

src/renderer/controllers/torrent-controller.js

@@ -11,12 +11,12 @@ module.exports = class TorrentController {
   }
 
   torrentInfoHash (torrentKey, infoHash) {
-    var torrentSummary = this.getTorrentSummary(torrentKey)
+    let torrentSummary = this.getTorrentSummary(torrentKey)
     console.log('got infohash for %s torrent %s',
       torrentSummary ? 'existing' : 'new', torrentKey)
 
     if (!torrentSummary) {
-      var torrents = this.state.saved.torrents
+      const torrents = this.state.saved.torrents
 
       // Check if an existing (non-active) torrent has the same info hash
       if (torrents.find((t) => t.infoHash === infoHash)) {
@@ -48,7 +48,7 @@ module.exports = class TorrentController {
     }
     dispatch('error', message)
 
-    var torrentSummary = this.getTorrentSummary(torrentKey)
+    const torrentSummary = this.getTorrentSummary(torrentKey)
     if (torrentSummary) {
       console.log('Pausing torrent %s due to error: %s', torrentSummary.infoHash, message)
       torrentSummary.status = 'paused'
@@ -58,14 +58,14 @@ module.exports = class TorrentController {
 
   torrentMetadata (torrentKey, torrentInfo) {
     // Summarize torrent
-    var torrentSummary = this.getTorrentSummary(torrentKey)
+    const torrentSummary = this.getTorrentSummary(torrentKey)
     torrentSummary.status = 'downloading'
     torrentSummary.name = torrentSummary.displayName || torrentInfo.name
     torrentSummary.path = torrentInfo.path
     torrentSummary.magnetURI = torrentInfo.magnetURI
     // TODO: make torrentInfo immutable, save separately as torrentSummary.info
     // For now, check whether torrentSummary.files has already been set:
-    var hasDetailedFileInfo = torrentSummary.files && torrentSummary.files[0].path
+    const hasDetailedFileInfo = torrentSummary.files && torrentSummary.files[0].path
     if (!hasDetailedFileInfo) {
       torrentSummary.files = torrentInfo.files
     }
@@ -83,7 +83,7 @@ module.exports = class TorrentController {
 
   torrentDone (torrentKey, torrentInfo) {
     // Update the torrent summary
-    var torrentSummary = this.getTorrentSummary(torrentKey)
+    const torrentSummary = this.getTorrentSummary(torrentKey)
     torrentSummary.status = 'seeding'
 
     // Notify the user that a torrent finished, but only if we actually DL'd at least part of it.
@@ -100,22 +100,18 @@ module.exports = class TorrentController {
   }
 
   torrentProgress (progressInfo) {
-    // Overall progress across all active torrents, 0 to 1
+    // Overall progress across all active torrents, 0 to 1, or -1 to hide the progress bar
-    var progress = progressInfo.progress
-    var hasActiveTorrents = progressInfo.hasActiveTorrents
-
     // Hide progress bar when client has no torrents, or progress is 100%
-    // TODO: isn't this equivalent to: if (progress === 1) ?
+    const progress = (!progressInfo.hasActiveTorrents || progressInfo.progress === 1)
-    if (!hasActiveTorrents || progress === 1) {
+      ? -1
-      progress = -1
+      : progressInfo.progress
-    }
 
     // Show progress bar under the WebTorrent taskbar icon, on OSX
     this.state.dock.progress = progress
 
     // Update progress for each individual torrent
     progressInfo.torrents.forEach((p) => {
-      var torrentSummary = this.getTorrentSummary(p.torrentKey)
+      const torrentSummary = this.getTorrentSummary(p.torrentKey)
       if (!torrentSummary) {
         console.log('warning: got progress for missing torrent %s', p.torrentKey)
         return
@@ -130,27 +126,27 @@ module.exports = class TorrentController {
   }
 
   torrentFileModtimes (torrentKey, fileModtimes) {
-    var torrentSummary = this.getTorrentSummary(torrentKey)
+    const torrentSummary = this.getTorrentSummary(torrentKey)
     torrentSummary.fileModtimes = fileModtimes
     dispatch('saveStateThrottled')
   }
 
   torrentFileSaved (torrentKey, torrentFileName) {
     console.log('torrent file saved %s: %s', torrentKey, torrentFileName)
-    var torrentSummary = this.getTorrentSummary(torrentKey)
+    const torrentSummary = this.getTorrentSummary(torrentKey)
     torrentSummary.torrentFileName = torrentFileName
     dispatch('saveStateThrottled')
   }
 
   torrentPosterSaved (torrentKey, posterFileName) {
-    var torrentSummary = this.getTorrentSummary(torrentKey)
+    const torrentSummary = this.getTorrentSummary(torrentKey)
     torrentSummary.posterFileName = posterFileName
     dispatch('saveStateThrottled')
   }
 
   torrentAudioMetadata (infoHash, index, info) {
-    var torrentSummary = this.getTorrentSummary(infoHash)
+    const torrentSummary = this.getTorrentSummary(infoHash)
-    var fileSummary = torrentSummary.files[index]
+    const fileSummary = torrentSummary.files[index]
     fileSummary.audioInfo = info
     dispatch('update')
   }
@@ -167,7 +163,7 @@ module.exports = class TorrentController {
 }
 
 function getTorrentPath (torrentSummary) {
-  var itemPath = TorrentSummary.getFileOrFolder(torrentSummary)
+  let itemPath = TorrentSummary.getFileOrFolder(torrentSummary)
   if (torrentSummary.files.length > 1) {
     itemPath = path.dirname(itemPath)
   }
@@ -175,7 +171,7 @@ function getTorrentPath (torrentSummary) {
 }
 
 function showDoneNotification (torrent) {
-  var notif = new window.Notification('Download Complete', {
+  const notif = new window.Notification('Download Complete', {
     body: torrent.name,
     silent: true
   })

src/renderer/controllers/torrent-list-controller.js

@@ -30,8 +30,8 @@ module.exports = class TorrentListController {
       torrentId = torrentId.slice(torrentId.indexOf('#') + 1)
     }
 
-    var torrentKey = this.state.nextTorrentKey++
+    const torrentKey = this.state.nextTorrentKey++
-    var path = this.state.saved.prefs.downloadPath
+    const path = this.state.saved.prefs.downloadPath
 
     ipcRenderer.send('wt-start-torrenting', torrentKey, torrentId, path)
 
@@ -66,15 +66,15 @@ module.exports = class TorrentListController {
 
   // Creates a new torrent and start seeeding
   createTorrent (options) {
-    var state = this.state
+    const state = this.state
-    var torrentKey = state.nextTorrentKey++
+    const torrentKey = state.nextTorrentKey++
     ipcRenderer.send('wt-create-torrent', torrentKey, options)
     state.location.cancel()
   }
 
   // Starts downloading and/or seeding a given torrentSummary.
   startTorrentingSummary (torrentKey) {
-    var s = TorrentSummary.getByKey(this.state, torrentKey)
+    const s = TorrentSummary.getByKey(this.state, torrentKey)
     if (!s) throw new Error('Missing key: ' + torrentKey)
 
     // New torrent: give it a path
@@ -84,7 +84,7 @@ module.exports = class TorrentListController {
       return start()
     }
 
-    var fileOrFolder = TorrentSummary.getFileOrFolder(s)
+    const fileOrFolder = TorrentSummary.getFileOrFolder(s)
 
     // New torrent: metadata not yet received
     if (!fileOrFolder) return start()
@@ -110,7 +110,7 @@ module.exports = class TorrentListController {
 
   // TODO: use torrentKey, not infoHash
   toggleTorrent (infoHash) {
-    var torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
+    const torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
     if (torrentSummary.status === 'paused') {
       torrentSummary.status = 'new'
       this.startTorrentingSummary(torrentSummary.torrentKey)
@@ -123,7 +123,7 @@ module.exports = class TorrentListController {
   }
 
   toggleTorrentFile (infoHash, index) {
-    var torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
+    const torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
     torrentSummary.selections[index] = !torrentSummary.selections[index]
 
     // Let the WebTorrent process know to start or stop fetching that file
@@ -142,10 +142,10 @@ module.exports = class TorrentListController {
   deleteTorrent (infoHash, deleteData) {
     ipcRenderer.send('wt-stop-torrenting', infoHash)
 
-    var index = this.state.saved.torrents.findIndex((x) => x.infoHash === infoHash)
+    const index = this.state.saved.torrents.findIndex((x) => x.infoHash === infoHash)
 
     if (index > -1) {
-      var summary = this.state.saved.torrents[index]
+      const summary = this.state.saved.torrents[index]
 
       // remove torrent and poster file
       deleteFile(TorrentSummary.getTorrentPath(summary))
@@ -173,8 +173,8 @@ module.exports = class TorrentListController {
   }
 
   openTorrentContextMenu (infoHash) {
-    var torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
+    const torrentSummary = TorrentSummary.getByKey(this.state, infoHash)
-    var menu = new electron.remote.Menu()
+    const menu = new electron.remote.Menu()
 
     menu.append(new electron.remote.MenuItem({
       label: 'Remove From List',
@@ -223,11 +223,11 @@ module.exports = class TorrentListController {
 // Calls `cb` on success, calls `onError` on failure
 function findFilesRecursive (paths, cb) {
   if (paths.length > 1) {
-    var numComplete = 0
+    let numComplete = 0
-    var ret = []
+    let ret = []
     paths.forEach(function (path) {
       findFilesRecursive([path], function (fileObjs) {
-        ret = ret.concat(fileObjs)
+        ret.push(...fileObjs)
         if (++numComplete === paths.length) {
           ret.sort((a, b) => a.path < b.path ? -1 : a.path > b.path)
           cb(ret)
@@ -237,13 +237,13 @@ function findFilesRecursive (paths, cb) {
     return
   }
 
-  var fileOrFolder = paths[0]
+  const fileOrFolder = paths[0]
   fs.stat(fileOrFolder, function (err, stat) {
     if (err) return dispatch('error', err)
 
     // Files: return name, path, and size
     if (!stat.isDirectory()) {
-      var filePath = fileOrFolder
+      const filePath = fileOrFolder
       return cb([{
         name: path.basename(filePath),
         path: filePath,
@@ -252,10 +252,10 @@ function findFilesRecursive (paths, cb) {
     }
 
     // Folders: recurse, make a list of all the files
-    var folderPath = fileOrFolder
+    const folderPath = fileOrFolder
     fs.readdir(folderPath, function (err, fileNames) {
       if (err) return dispatch('error', err)
-      var paths = fileNames.map((fileName) => path.join(folderPath, fileName))
+      const paths = fileNames.map((fileName) => path.join(folderPath, fileName))
       findFilesRecursive(paths, cb)
     })
   })
@@ -270,7 +270,7 @@ function deleteFile (path) {
 
 // Delete all files in a torrent
 function moveItemToTrash (torrentSummary) {
-  var filePath = TorrentSummary.getFileOrFolder(torrentSummary)
+  const filePath = TorrentSummary.getFileOrFolder(torrentSummary)
   if (filePath) ipcRenderer.send('moveItemToTrash', filePath)
 }
 
@@ -279,9 +279,9 @@ function showItemInFolder (torrentSummary) {
 }
 
 function saveTorrentFileAs (torrentSummary) {
-  var downloadPath = this.state.saved.prefs.downloadPath
+  const downloadPath = this.state.saved.prefs.downloadPath
-  var newFileName = path.parse(torrentSummary.name).name + '.torrent'
+  const newFileName = path.parse(torrentSummary.name).name + '.torrent'
-  var opts = {
+  const opts = {
     title: 'Save Torrent File',
     defaultPath: path.join(downloadPath, newFileName),
     filters: [
@@ -289,10 +289,10 @@ function saveTorrentFileAs (torrentSummary) {
       { name: 'All Files', extensions: ['*'] }
     ]
   }
-  var win = electron.remote.getCurrentWindow()
+  const win = electron.remote.getCurrentWindow()
   electron.remote.dialog.showSaveDialog(win, opts, function (savePath) {
     if (!savePath) return // They clicked Cancel
-    var torrentPath = TorrentSummary.getTorrentPath(torrentSummary)
+    const torrentPath = TorrentSummary.getTorrentPath(torrentSummary)
     fs.readFile(torrentPath, function (err, torrentFile) {
       if (err) return dispatch('error', err)
       fs.writeFile(savePath, torrentFile, function (err) {

src/renderer/controllers/update-controller.js

@@ -8,7 +8,7 @@ module.exports = class UpdateController {
 
   // Shows a modal saying that we have an update
   updateAvailable (version) {
-    var skipped = this.state.saved.skippedVersions
+    const skipped = this.state.saved.skippedVersions
     if (skipped && skipped.includes(version)) {
       console.log('new version skipped by user: v' + version)
       return
@@ -18,7 +18,7 @@ module.exports = class UpdateController {
 
   // Don't show the modal again until the next version
   skipVersion (version) {
-    var skipped = this.state.saved.skippedVersions
+    let skipped = this.state.saved.skippedVersions
     if (!skipped) skipped = this.state.saved.skippedVersions = []
     skipped.push(version)
     State.saveThrottled(this.state)

src/renderer/lib/capture-video-frame.js

@@ -17,14 +17,14 @@ function captureVideoFrame (video, format) {
     throw new Error('Second argument must be one of "png", "jpg", or "webp"')
   }
 
-  var canvas = document.createElement('canvas')
+  const canvas = document.createElement('canvas')
   canvas.width = video.videoWidth
   canvas.height = video.videoHeight
 
   canvas.getContext('2d').drawImage(video, 0, 0)
 
-  var dataUri = canvas.toDataURL('image/' + format)
+  const dataUri = canvas.toDataURL('image/' + format)
-  var data = dataUri.split(',')[1]
+  const data = dataUri.split(',')[1]
 
   return new Buffer(data, 'base64')
 }

src/renderer/lib/cast.js

@@ -13,19 +13,19 @@ module.exports = {
   setRate
 }
 
-// Lazy load these for a ~300ms improvement in startup time
+const config = require('../../config')
-var airplayer, chromecasts, dlnacasts
 
-var config = require('../../config')
+// Lazy load these for a ~300ms improvement in startup time
+let airplayer, chromecasts, dlnacasts
 
 // App state. Cast modifies state.playing and state.errors in response to events
-var state
+let state
 
 // Callback to notify module users when state has changed
-var update
+let update
 
 // setInterval() for updating cast status
-var statusInterval = null
+let statusInterval = null
 
 // Start looking for cast devices on the local network
 function init (appState, callback) {
@@ -59,7 +59,7 @@ function init (appState, callback) {
 
 // chromecast player implementation
 function chromecastPlayer () {
-  var ret = {
+  const ret = {
     device: null,
     addDevice,
     getDevices,
@@ -95,7 +95,7 @@ function chromecastPlayer () {
   }
 
   function open () {
-    var torrentSummary = state.saved.torrents.find((x) => x.infoHash === state.playing.infoHash)
+    const torrentSummary = state.saved.torrents.find((x) => x.infoHash === state.playing.infoHash)
     ret.device.play(state.server.networkURL + '/' + state.playing.fileIndex, {
       type: 'video/mp4',
       title: config.APP_NAME + ' - ' + torrentSummary.name
@@ -146,7 +146,7 @@ function chromecastPlayer () {
 
 // airplay player implementation
 function airplayPlayer () {
-  var ret = {
+  const ret = {
     device: null,
     addDevice,
     getDevices,
@@ -238,7 +238,7 @@ function airplayPlayer () {
 
 // DLNA player implementation
 function dlnaPlayer (player) {
-  var ret = {
+  const ret = {
     device: null,
     addDevice,
     getDevices,
@@ -274,7 +274,7 @@ function dlnaPlayer (player) {
   }
 
   function open () {
-    var torrentSummary = state.saved.torrents.find((x) => x.infoHash === state.playing.infoHash)
+    const torrentSummary = state.saved.torrents.find((x) => x.infoHash === state.playing.infoHash)
     ret.device.play(state.server.networkURL + '/' + state.playing.fileIndex, {
       type: 'video/mp4',
       title: config.APP_NAME + ' - ' + torrentSummary.name,
@@ -331,7 +331,7 @@ function dlnaPlayer (player) {
 // Start polling cast device state, whenever we're connected
 function startStatusInterval () {
   statusInterval = setInterval(function () {
-    var player = getPlayer()
+    const player = getPlayer()
     if (player) player.status()
   }, 1000)
 }
@@ -355,8 +355,8 @@ function toggleMenu (location) {
   }
 
   // Find all cast devices of the given type
-  var player = getPlayer(location)
+  const player = getPlayer(location)
-  var devices = player ? player.getDevices() : []
+  const devices = player ? player.getDevices() : []
   if (devices.length === 0) throw new Error('No ' + location + ' devices available')
 
   // Show a menu
@@ -364,10 +364,10 @@ function toggleMenu (location) {
 }
 
 function selectDevice (index) {
-  var {location, devices} = state.devices.castMenu
+  const {location, devices} = state.devices.castMenu
 
   // Start casting
-  var player = getPlayer(location)
+  const player = getPlayer(location)
   player.device = devices[index]
   player.open()
 
@@ -383,7 +383,7 @@ function selectDevice (index) {
 
 // Stops casting, move video back to local screen
 function stop () {
-  var player = getPlayer()
+  const player = getPlayer()
   if (player) {
     player.stop(function () {
       player.device = null
@@ -418,18 +418,18 @@ function getPlayer (location) {
 }
 
 function play () {
-  var player = getPlayer()
+  const player = getPlayer()
   if (player) player.play(castCallback)
 }
 
 function pause () {
-  var player = getPlayer()
+  const player = getPlayer()
   if (player) player.pause(castCallback)
 }
 
 function setRate (rate) {
-  var player
+  let player
-  var result = true
+  let result = true
   if (state.playing.location === 'chromecast') {
     // TODO find how to control playback rate on chromecast
     castCallback()
@@ -444,12 +444,12 @@ function setRate (rate) {
 }
 
 function seek (time) {
-  var player = getPlayer()
+  const player = getPlayer()
   if (player) player.seek(time, castCallback)
 }
 
 function setVolume (volume) {
-  var player = getPlayer()
+  const player = getPlayer()
   if (player) player.volume(volume, castCallback)
 }
 

src/renderer/lib/dispatcher.js

@@ -4,8 +4,8 @@ module.exports = {
   setDispatch
 }
 
-var dispatchers = {}
+const dispatchers = {}
-var _dispatch = function () {}
+let _dispatch = function () {}
 
 function setDispatch (dispatch) {
   _dispatch = dispatch
@@ -20,8 +20,8 @@ function dispatch (...args) {
 // function. This prevents React from updating the listener functions on
 // each update().
 function dispatcher (...args) {
-  var str = JSON.stringify(args)
+  const str = JSON.stringify(args)
-  var handler = dispatchers[str]
+  let handler = dispatchers[str]
   if (!handler) {
     handler = dispatchers[str] = function (e) {
       // Do not propagate click to elements below the button

src/renderer/lib/migrations.js

@@ -17,7 +17,7 @@ function run (state) {
     state.saved.version = '0.0.0' // Pre-0.7.0 version, so run all migrations
   }
 
-  var version = state.saved.version
+  const version = state.saved.version
 
   if (semver.lt(version, '0.7.0')) {
     migrate_0_7_0(state.saved)
@@ -40,11 +40,11 @@ function run (state) {
 }
 
 function migrate_0_7_0 (saved) {
-  var fs = require('fs-extra')
+  const fs = require('fs-extra')
-  var path = require('path')
+  const path = require('path')
 
   saved.torrents.forEach(function (ts) {
-    var infoHash = ts.infoHash
+    const infoHash = ts.infoHash
 
     // Replace torrentPath with torrentFileName
     // There are a number of cases to handle here:
@@ -52,7 +52,7 @@ function migrate_0_7_0 (saved) {
     // * Then, relative paths for the default torrents, eg '../static/sintel.torrent'
     // * Then, paths computed at runtime for default torrents, eg 'sintel.torrent'
     // * Finally, now we're getting rid of torrentPath altogether
-    var src, dst
+    let src, dst
     if (ts.torrentPath) {
       if (path.isAbsolute(ts.torrentPath) || ts.torrentPath.startsWith('..')) {
         src = ts.torrentPath
@@ -70,7 +70,7 @@ function migrate_0_7_0 (saved) {
 
     // Replace posterURL with posterFileName
     if (ts.posterURL) {
-      var extension = path.extname(ts.posterURL)
+      const extension = path.extname(ts.posterURL)
       src = path.isAbsolute(ts.posterURL)
         ? ts.posterURL
         : path.join(config.STATIC_PATH, ts.posterURL)
@@ -116,7 +116,7 @@ function migrate_0_12_0 (saved) {
   // Undo a terrible bug where clicking Play on a default torrent on a fresh
   // install results in a "path missing" error
   // See https://github.com/feross/webtorrent-desktop/pull/806
-  var defaultTorrentFiles = [
+  const defaultTorrentFiles = [
     '6a9759bffd5c0af65319979fb7832189f4f3c35d.torrent',
     '88594aaacbde40ef3e2510c47374ec0aa396c08e.torrent',
     '6a02592d2bbc069628cd5ed8a54f88ee06ac0ba5.torrent',
@@ -125,7 +125,7 @@ function migrate_0_12_0 (saved) {
   ]
   saved.torrents.forEach(function (torrentSummary) {
     if (!defaultTorrentFiles.includes(torrentSummary.torrentFileName)) return
-    var fileOrFolder = TorrentSummary.getFileOrFolder(torrentSummary)
+    const fileOrFolder = TorrentSummary.getFileOrFolder(torrentSummary)
     if (!fileOrFolder) return
     try {
       fs.statSync(fileOrFolder)

src/renderer/lib/playlist.js

@@ -9,7 +9,7 @@ module.exports = {
 const TorrentSummary = require('./torrent-summary')
 const TorrentPlayer = require('./torrent-player')
 
-var cache = {
+const cache = {
   infoHash: null,
   previousIndex: null,
   currentIndex: null,
@@ -41,8 +41,8 @@ function getCurrentLocalURL (state) {
 }
 
 function updateCache (state) {
-  var infoHash = state.playing.infoHash
+  const infoHash = state.playing.infoHash
-  var fileIndex = state.playing.fileIndex
+  const fileIndex = state.playing.fileIndex
 
   if (infoHash === cache.infoHash) {
     switch (fileIndex) {
@@ -69,7 +69,7 @@ function updateCache (state) {
 }
 
 function findPreviousIndex (state) {
-  var files = TorrentSummary.getByKey(state, state.playing.infoHash).files
+  const files = TorrentSummary.getByKey(state, state.playing.infoHash).files
   for (var i = state.playing.fileIndex - 1; i >= 0; i--) {
     if (TorrentPlayer.isPlayable(files[i])) return i
   }
@@ -77,7 +77,7 @@ function findPreviousIndex (state) {
 }
 
 function findNextIndex (state) {
-  var files = TorrentSummary.getByKey(state, state.playing.infoHash).files
+  const files = TorrentSummary.getByKey(state, state.playing.infoHash).files
   for (var i = state.playing.fileIndex + 1; i < files.length; i++) {
     if (TorrentPlayer.isPlayable(files[i])) return i
   }

src/renderer/lib/sound.js

@@ -3,15 +3,15 @@ module.exports = {
   play
 }
 
-var config = require('../../config')
+const config = require('../../config')
-var path = require('path')
+const path = require('path')
 
-var VOLUME = 0.15
+const VOLUME = 0.15
 
 /* Cache of Audio elements, for instant playback */
-var cache = {}
+const cache = {}
 
-var sounds = {
+const sounds = {
   ADD: {
     url: 'file://' + path.join(config.STATIC_PATH, 'sound', 'add.wav'),
     volume: VOLUME
@@ -47,10 +47,10 @@ var sounds = {
 }
 
 function preload () {
-  for (var name in sounds) {
+  for (let name in sounds) {
     if (!cache[name]) {
-      var sound = sounds[name]
+      const sound = sounds[name]
-      var audio = cache[name] = new window.Audio()
+      const audio = cache[name] = new window.Audio()
       audio.volume = sound.volume
       audio.src = sound.url
     }
@@ -58,9 +58,9 @@ function preload () {
 }
 
 function play (name) {
-  var audio = cache[name]
+  let audio = cache[name]
   if (!audio) {
-    var sound = sounds[name]
+    const sound = sounds[name]
     if (!sound) {
       throw new Error('Invalid sound name')
     }

src/renderer/lib/state.js

@@ -1,11 +1,11 @@
-var appConfig = require('application-config')('WebTorrent')
+const appConfig = require('application-config')('WebTorrent')
-var path = require('path')
+const path = require('path')
-var {EventEmitter} = require('events')
+const {EventEmitter} = require('events')
 
-var config = require('../../config')
+const config = require('../../config')
-var migrations = require('./migrations')
+const migrations = require('./migrations')
 
-var State = module.exports = Object.assign(new EventEmitter(), {
+const State = module.exports = Object.assign(new EventEmitter(), {
   getDefaultPlayState,
   load,
   save,
@@ -15,7 +15,7 @@ var State = module.exports = Object.assign(new EventEmitter(), {
 appConfig.filePath = path.join(config.CONFIG_PATH, 'config.json')
 
 function getDefaultState () {
-  var LocationHistory = require('location-history')
+  const LocationHistory = require('location-history')
 
   return {
     /*
@@ -98,11 +98,11 @@ function getDefaultPlayState () {
 
 /* If the saved state file doesn't exist yet, here's what we use instead */
 function setupSavedState (cb) {
-  var fs = require('fs-extra')
+  const fs = require('fs-extra')
-  var parseTorrent = require('parse-torrent')
+  const parseTorrent = require('parse-torrent')
-  var parallel = require('run-parallel')
+  const parallel = require('run-parallel')
 
-  var saved = {
+  const saved = {
     prefs: {
       downloadPath: config.DEFAULT_DOWNLOAD_PATH,
       isFileHandler: false,
@@ -113,10 +113,10 @@ function setupSavedState (cb) {
     version: config.APP_VERSION /* make sure we can upgrade gracefully later */
   }
 
-  var tasks = []
+  const tasks = []
 
   config.DEFAULT_TORRENTS.map(function (t, i) {
-    var infoHash = saved.torrents[i].infoHash
+    const infoHash = saved.torrents[i].infoHash
     tasks.push(function (cb) {
       fs.copy(
         path.join(config.STATIC_PATH, t.posterFileName),
@@ -139,8 +139,8 @@ function setupSavedState (cb) {
   })
 
   function createTorrentObject (t) {
-    var torrent = fs.readFileSync(path.join(config.STATIC_PATH, t.torrentFileName))
+    const torrent = fs.readFileSync(path.join(config.STATIC_PATH, t.torrentFileName))
-    var parsedTorrent = parseTorrent(torrent)
+    const parsedTorrent = parseTorrent(torrent)
 
     return {
       status: 'paused',
@@ -157,18 +157,18 @@ function setupSavedState (cb) {
 }
 
 function getPlayingTorrentSummary () {
-  var infoHash = this.playing.infoHash
+  const infoHash = this.playing.infoHash
   return this.saved.torrents.find((x) => x.infoHash === infoHash)
 }
 
 function getPlayingFileSummary () {
-  var torrentSummary = this.getPlayingTorrentSummary()
+  const torrentSummary = this.getPlayingTorrentSummary()
   if (!torrentSummary) return null
   return torrentSummary.files[this.playing.fileIndex]
 }
 
 function load (cb) {
-  var state = getDefaultState()
+  const state = getDefaultState()
 
   appConfig.read(function (err, saved) {
     if (err || !saved.version) {
@@ -193,14 +193,14 @@ function save (state, cb) {
   delete state.saveStateTimeout
 
   // Clean up, so that we're not saving any pending state
-  var copy = Object.assign({}, state.saved)
+  const copy = Object.assign({}, state.saved)
   // Remove torrents pending addition to the list, where we haven't finished
   // reading the torrent file or file(s) to seed & don't have an infohash
   copy.torrents = copy.torrents
     .filter((x) => x.infoHash)
     .map(function (x) {
-      var torrent = {}
+      const torrent = {}
-      for (var key in x) {
+      for (let key in x) {
         if (key === 'progress' || key === 'torrentKey') {
           continue // Don't save progress info or key for the webtorrent process
         }

src/renderer/lib/telemetry.js

@@ -14,7 +14,7 @@ const url = require('url')
 
 const config = require('../../config')
 
-var telemetry
+let telemetry
 
 function init (state) {
   telemetry = state.saved.telemetry
@@ -23,7 +23,7 @@ function init (state) {
     reset()
   }
 
-  var now = new Date()
+  const now = new Date()
   telemetry.version = config.APP_VERSION
   telemetry.timestamp = now.toISOString()
   telemetry.localTime = now.toTimeString()
@@ -56,17 +56,17 @@ function reset () {
 
 function postToServer () {
   // Serialize the telemetry summary
-  var payload = new Buffer(JSON.stringify(telemetry), 'utf8')
+  const payload = new Buffer(JSON.stringify(telemetry), 'utf8')
 
   // POST to our server
-  var options = url.parse(config.TELEMETRY_URL)
+  const options = url.parse(config.TELEMETRY_URL)
   options.method = 'POST'
   options.headers = {
     'Content-Type': 'application/json',
     'Content-Length': payload.length
   }
 
-  var req = https.request(options, function (res) {
+  const req = https.request(options, function (res) {
     if (res.statusCode === 200) {
       console.log('Successfully posted telemetry summary')
       reset()
@@ -85,7 +85,7 @@ function postToServer () {
 // collects screen resolution, etc
 function createSummary () {
   // Make a 256-bit random unique ID
-  var userID = crypto.randomBytes(32).toString('hex')
+  const userID = crypto.randomBytes(32).toString('hex')
   return { userID }
 }
 
@@ -111,10 +111,10 @@ function getSystemInfo () {
 
 // Get the number of torrents, rounded to the nearest power of two
 function getApproxNumTorrents (state) {
-  var exactNum = state.saved.torrents.length
+  const exactNum = state.saved.torrents.length
   if (exactNum === 0) return 0
   // Otherwise, return 1, 2, 4, 8, etc by rounding in log space
-  var log2 = Math.log(exactNum) / Math.log(2)
+  const log2 = Math.log(exactNum) / Math.log(2)
   return 1 << Math.round(log2)
 }
 
@@ -124,8 +124,8 @@ function logUncaughtError (procName, e) {
   // Hopefully uncaught errors immediately on startup are fixed in dev
   if (!telemetry) return
 
-  var message
+  let message
-  var stack = ''
+  let stack = ''
   if (e == null) {
     message = 'Unexpected undefined error'
   } else if (e.error) {
@@ -165,14 +165,14 @@ function logUncaughtError (procName, e) {
   if (stack.length > 1000) stack = stack.substring(0, 1000)
 
   // Log the app version *at the time of the error*
-  var version = config.APP_VERSION
+  const version = config.APP_VERSION
 
   telemetry.uncaughtErrors.push({process: procName, message, stack, version})
 }
 
 // Turns a DOM element into a string, eg "DIV.my-class.visible"
 function getElemString (elem) {
-  var ret = elem.tagName
+  let ret = elem.tagName
   try {
     ret += '.' + Array.from(elem.classList).join('.')
   } catch (e) {}
@@ -186,7 +186,7 @@ function logPlayAttempt (result) {
     return console.error('Unknown play attempt result', result)
   }
 
-  var attempts = telemetry.playAttempts
+  const attempts = telemetry.playAttempts
   attempts.total = (attempts.total || 0) + 1
   attempts[result] = (attempts[result] || 0) + 1
 }

src/renderer/lib/torrent-player.js

@@ -6,7 +6,7 @@ module.exports = {
   isPlayableTorrentSummary
 }
 
-var path = require('path')
+const path = require('path')
 
 // Checks whether a fileSummary or file path is audio/video that we can play,
 // based on the file extension
@@ -46,13 +46,13 @@ function isAudio (file) {
 // - a file object where obj.name is ends in .torrent
 // - a string that's a magnet link (magnet://...)
 function isTorrent (file) {
-  var isTorrentFile = getFileExtension(file) === '.torrent'
+  const isTorrentFile = getFileExtension(file) === '.torrent'
-  var isMagnet = typeof file === 'string' && /^(stream-)?magnet:/.test(file)
+  const isMagnet = typeof file === 'string' && /^(stream-)?magnet:/.test(file)
   return isTorrentFile || isMagnet
 }
 
 function getFileExtension (file) {
-  var name = typeof file === 'string' ? file : file.name
+  const name = typeof file === 'string' ? file : file.name
   return path.extname(name).toLowerCase()
 }
 

src/renderer/lib/torrent-poster.js

@@ -1,22 +1,22 @@
 module.exports = torrentPoster
 
-var captureVideoFrame = require('./capture-video-frame')
+const captureVideoFrame = require('./capture-video-frame')
-var path = require('path')
+const path = require('path')
 
 function torrentPoster (torrent, cb) {
   // First, try to use a poster image if available
-  var posterFile = torrent.files.filter(function (file) {
+  const posterFile = torrent.files.filter(function (file) {
     return /^poster\.(jpg|png|gif)$/.test(file.name)
   })[0]
   if (posterFile) return torrentPosterFromImage(posterFile, torrent, cb)
 
   // Second, try to use the largest video file
   // Filter out file formats that the <video> tag definitely can't play
-  var videoFile = getLargestFileByExtension(torrent, ['.mp4', '.m4v', '.webm', '.mov', '.mkv'])
+  const videoFile = getLargestFileByExtension(torrent, ['.mp4', '.m4v', '.webm', '.mov', '.mkv'])
   if (videoFile) return torrentPosterFromVideo(videoFile, torrent, cb)
 
   // Third, try to use the largest image file
-  var imgFile = getLargestFileByExtension(torrent, ['.gif', '.jpg', '.jpeg', '.png'])
+  const imgFile = getLargestFileByExtension(torrent, ['.gif', '.jpg', '.jpeg', '.png'])
   if (imgFile) return torrentPosterFromImage(imgFile, torrent, cb)
 
   // TODO: generate a waveform from the largest sound file
@@ -25,8 +25,8 @@ function torrentPoster (torrent, cb) {
 }
 
 function getLargestFileByExtension (torrent, extensions) {
-  var files = torrent.files.filter(function (file) {
+  const files = torrent.files.filter(function (file) {
-    var extname = path.extname(file.name).toLowerCase()
+    const extname = path.extname(file.name).toLowerCase()
     return extensions.indexOf(extname) !== -1
   })
   if (files.length === 0) return undefined
@@ -36,15 +36,15 @@ function getLargestFileByExtension (torrent, extensions) {
 }
 
 function torrentPosterFromVideo (file, torrent, cb) {
-  var index = torrent.files.indexOf(file)
+  const index = torrent.files.indexOf(file)
 
-  var server = torrent.createServer(0)
+  const server = torrent.createServer(0)
   server.listen(0, onListening)
 
   function onListening () {
-    var port = server.address().port
+    const port = server.address().port
-    var url = 'http://localhost:' + port + '/' + index
+    const url = 'http://localhost:' + port + '/' + index
-    var video = document.createElement('video')
+    const video = document.createElement('video')
     video.addEventListener('canplay', onCanPlay)
 
     video.volume = 0
@@ -61,7 +61,7 @@ function torrentPosterFromVideo (file, torrent, cb) {
     function onSeeked () {
       video.removeEventListener('seeked', onSeeked)
 
-      var buf = captureVideoFrame(video)
+      const buf = captureVideoFrame(video)
 
       // unload video element
       video.pause()
@@ -78,6 +78,6 @@ function torrentPosterFromVideo (file, torrent, cb) {
 }
 
 function torrentPosterFromImage (file, torrent, cb) {
-  var extname = path.extname(file.name)
+  const extname = path.extname(file.name)
   file.getBuffer((err, buf) => cb(err, buf, extname))
 }

src/renderer/lib/torrent-summary.js

@@ -6,8 +6,8 @@ module.exports = {
   getFileOrFolder
 }
 
-var path = require('path')
+const path = require('path')
-var config = require('../../config')
+const config = require('../../config')
 
 // Expects a torrentSummary
 // Returns an absolute path to the torrent file, or null if unavailable
@@ -20,7 +20,7 @@ function getTorrentPath (torrentSummary) {
 // Returns an absolute path to the poster image, or null if unavailable
 function getPosterPath (torrentSummary) {
   if (!torrentSummary || !torrentSummary.posterFileName) return null
-  var posterPath = path.join(config.POSTER_PATH, torrentSummary.posterFileName)
+  const posterPath = path.join(config.POSTER_PATH, torrentSummary.posterFileName)
   // Work around a Chrome bug (reproduced in vanilla Chrome, not just Electron):
   // Backslashes in URLS in CSS cause bizarre string encoding issues
   return posterPath.replace(/\\/g, '/')
@@ -29,7 +29,7 @@ function getPosterPath (torrentSummary) {
 // Expects a torrentSummary
 // Returns a torrentID: filename, magnet URI, or infohash
 function getTorrentID (torrentSummary) {
-  var s = torrentSummary
+  const s = torrentSummary
   if (s.torrentFileName) { // Load torrent file from disk
     return getTorrentPath(s)
   } else { // Load torrent from DHT
@@ -51,7 +51,7 @@ function getByKey (state, torrentKey) {
 // TODO: make this assumption explicit, enforce it in the `create-torrent`
 // module. Store root folder explicitly to avoid hacky path processing below.
 function getFileOrFolder (torrentSummary) {
-  var ts = torrentSummary
+  const ts = torrentSummary
   if (!ts.path || !ts.files || ts.files.length === 0) return null
   return path.join(ts.path, ts.files[0].path.split('/')[0])
 }

src/renderer/main.js

@@ -28,27 +28,27 @@ const SubtitlesController = require('./controllers/subtitles-controller')
 const TorrentListController = require('./controllers/torrent-list-controller')
 const TorrentController = require('./controllers/torrent-controller')
 
+// Electron apps have two processes: a main process (node) runs first and starts
+// a renderer process (essentially a Chrome window). We're in the renderer process,
+// and this IPC channel receives from and sends messages to the main process
+const ipcRenderer = electron.ipcRenderer
+
 // Yo-yo pattern: state object lives here and percolates down thru all the views.
 // Events come back up from the views via dispatch(...)
 require('./lib/dispatcher').setDispatch(dispatch)
 
 // From dispatch(...), events are sent to one of the controllers
-var controllers = null
+let controllers = null
 
 // This dependency is the slowest-loading, so we lazy load it
-var Cast = null
+let Cast = null
-
-// Electron apps have two processes: a main process (node) runs first and starts
-// a renderer process (essentially a Chrome window). We're in the renderer process,
-// and this IPC channel receives from and sends messages to the main process
-var ipcRenderer = electron.ipcRenderer
 
 // All state lives in state.js. `state.saved` is read from and written to a file.
 // All other state is ephemeral. First we load state.saved then initialize the app.
-var state
+let state
 
 // Root React component
-var app
+let app
 
 State.load(onState)
 
@@ -264,7 +264,7 @@ function dispatch (action, ...args) {
     console.log('dispatch: %s %o', action, args)
   }
 
-  var handler = dispatchHandlers[action]
+  const handler = dispatchHandlers[action]
   if (handler) handler(...args)
   else console.error('Missing dispatch handler: ' + action)
 
@@ -284,7 +284,7 @@ function setupIpc () {
 
   ipcRenderer.on('fullscreenChanged', onFullscreenChanged)
 
-  var tc = controllers.torrent
+  const tc = controllers.torrent
   ipcRenderer.on('wt-infohash', (e, ...args) => tc.torrentInfoHash(...args))
   ipcRenderer.on('wt-metadata', (e, ...args) => tc.torrentMetadata(...args))
   ipcRenderer.on('wt-done', (e, ...args) => tc.torrentDone(...args))
@@ -311,7 +311,7 @@ function backToList () {
   state.modal = null
   state.location.backToFirst(function () {
     // If we were already on the torrent list, scroll to the top
-    var contentTag = document.querySelector('.content')
+    const contentTag = document.querySelector('.content')
     if (contentTag) contentTag.scrollTop = 0
   })
 }
@@ -358,18 +358,18 @@ function setDimensions (dimensions) {
   state.window.wasMaximized = electron.remote.getCurrentWindow().isMaximized
 
   // Limit window size to screen size
-  var screenWidth = window.screen.width
+  const screenWidth = window.screen.width
-  var screenHeight = window.screen.height
+  const screenHeight = window.screen.height
-  var aspectRatio = dimensions.width / dimensions.height
+  const aspectRatio = dimensions.width / dimensions.height
-  var scaleFactor = Math.min(
+  const scaleFactor = Math.min(
     Math.min(screenWidth / dimensions.width, 1),
     Math.min(screenHeight / dimensions.height, 1)
   )
-  var width = Math.max(
+  const width = Math.max(
     Math.floor(dimensions.width * scaleFactor),
     config.WINDOW_MIN_WIDTH
   )
-  var height = Math.max(
+  const height = Math.max(
     Math.floor(dimensions.height * scaleFactor),
     config.WINDOW_MIN_HEIGHT
   )
@@ -384,9 +384,9 @@ function setDimensions (dimensions) {
 function onOpen (files) {
   if (!Array.isArray(files)) files = [ files ]
 
-  var url = state.location.url()
+  const url = state.location.url()
-  var allTorrents = files.every(TorrentPlayer.isTorrent)
+  const allTorrents = files.every(TorrentPlayer.isTorrent)
-  var allSubtitles = files.every(controllers.subtitles.isSubtitle)
+  const allSubtitles = files.every(controllers.subtitles.isSubtitle)
 
   if (allTorrents) {
     // Drop torrents onto the app: go to home screen, add torrents, no matter what
@@ -422,7 +422,7 @@ function onError (err) {
 function onPaste (e) {
   if (e.target.tagName.toLowerCase() === 'input') return
 
-  var torrentIds = electron.clipboard.readText().split('\n')
+  const torrentIds = electron.clipboard.readText().split('\n')
   torrentIds.forEach(function (torrentId) {
     torrentId = torrentId.trim()
     if (torrentId.length === 0) return

src/renderer/pages/App.js

@@ -33,21 +33,21 @@ darkBaseTheme.palette.accent3Color = colors.redA100
 
 class App extends React.Component {
   render () {
-    var state = this.props.state
+    const state = this.props.state
 
     // Hide player controls while playing video, if the mouse stays still for a while
     // Never hide the controls when:
     // * The mouse is over the controls or we're scrubbing (see CSS)
     // * The video is paused
     // * The video is playing remotely on Chromecast or Airplay
-    var hideControls = state.location.url() === 'player' &&
+    const hideControls = state.location.url() === 'player' &&
       state.playing.mouseStationarySince !== 0 &&
       new Date().getTime() - state.playing.mouseStationarySince > 2000 &&
       !state.playing.isPaused &&
       state.playing.location === 'local' &&
       state.playing.playbackRate === 1
 
-    var cls = [
+    const cls = [
       'view-' + state.location.url(), /* e.g. view-home, view-player */
       'is-' + process.platform /* e.g. is-darwin, is-win32, is-linux */
     ]
@@ -55,7 +55,7 @@ class App extends React.Component {
     if (state.window.isFocused) cls.push('is-focused')
     if (hideControls) cls.push('hide-video-controls')
 
-    var vdom = (
+    const vdom = (
       <MuiThemeProvider muiTheme={getMuiTheme(darkBaseTheme)}>
         <div className={'app ' + cls.join(' ')}>
           <Header state={state} />
@@ -70,12 +70,12 @@ class App extends React.Component {
   }
 
   getErrorPopover () {
-    var state = this.props.state
+    const state = this.props.state
-    var now = new Date().getTime()
+    const now = new Date().getTime()
-    var recentErrors = state.errors.filter((x) => now - x.time < 5000)
+    const recentErrors = state.errors.filter((x) => now - x.time < 5000)
-    var hasErrors = recentErrors.length > 0
+    const hasErrors = recentErrors.length > 0
 
-    var errorElems = recentErrors.map(function (error, i) {
+    const errorElems = recentErrors.map(function (error, i) {
       return (<div key={i} className='error'>{error.message}</div>)
     })
     return (
@@ -88,9 +88,9 @@ class App extends React.Component {
   }
 
   getModal () {
-    var state = this.props.state
+    const state = this.props.state
     if (!state.modal) return
-    var ModalContents = Modals[state.modal.id]
+    const ModalContents = Modals[state.modal.id]
     return (
       <div key='modal' className='modal'>
         <div key='modal-background' className='modal-background' />
@@ -102,8 +102,8 @@ class App extends React.Component {
   }
 
   getView () {
-    var state = this.props.state
+    const state = this.props.state
-    var View = Views[state.location.url()]
+    const View = Views[state.location.url()]
     return (<View state={state} />)
   }
 }

src/renderer/pages/create-torrent-page.js

@@ -20,11 +20,11 @@ class CreateTorrentPage extends React.Component {
   constructor (props) {
     super(props)
 
-    var state = this.props.state
+    const state = this.props.state
-    var info = state.location.current()
+    const info = state.location.current()
 
     // First, extract the base folder that the files are all in
-    var pathPrefix = info.folderPath
+    let pathPrefix = info.folderPath
     if (!pathPrefix) {
       pathPrefix = info.files.map((x) => x.path).reduce(findCommonPrefix)
       if (!pathPrefix.endsWith('/') && !pathPrefix.endsWith('\\')) {
@@ -33,14 +33,14 @@ class CreateTorrentPage extends React.Component {
     }
 
     // Then, exclude .DS_Store and other dotfiles
-    var files = info.files
+    const files = info.files
       .filter((f) => !containsDots(f.path, pathPrefix))
       .map((f) => ({name: f.name, path: f.path, size: f.size}))
     if (files.length === 0) return (<CreateTorrentErrorPage state={state} />)
 
     // Then, use the name of the base folder (or sole file, for a single file torrent)
     // as the default name. Show all files relative to the base folder.
-    var defaultName, basePath
+    let defaultName, basePath
     if (files.length === 1) {
       // Single file torrent: /a/b/foo.jpg -> torrent name 'foo.jpg', path '/a/b'
       defaultName = files[0].name
@@ -52,7 +52,7 @@ class CreateTorrentPage extends React.Component {
     }
 
     // Default trackers
-    var trackers = createTorrent.announceList.join('\n')
+    const trackers = createTorrent.announceList.join('\n')
 
     this.state = {
       comment: '',
@@ -72,14 +72,14 @@ class CreateTorrentPage extends React.Component {
   }
 
   render () {
-    var files = this.state.files
+    const files = this.state.files
 
     // Sanity check: show the number of files and total size
-    var numFiles = files.length
+    const numFiles = files.length
-    var totalBytes = files
+    const totalBytes = files
       .map((f) => f.size)
       .reduce((a, b) => a + b, 0)
-    var torrentInfo = `${numFiles} files, ${prettyBytes(totalBytes)}`
+    const torrentInfo = `${numFiles} files, ${prettyBytes(totalBytes)}`
 
     return (
       <div className='create-torrent'>
@@ -119,10 +119,10 @@ class CreateTorrentPage extends React.Component {
   // * Comment
   renderAdvanced () {
     // Create file list
-    var maxFileElems = 100
+    const maxFileElems = 100
-    var files = this.state.files
+    const files = this.state.files
-    var fileElems = files.slice(0, maxFileElems).map((file, i) => {
+    const fileElems = files.slice(0, maxFileElems).map((file, i) => {
-      var relativePath = path.relative(this.state.pathPrefix, file.path)
+      const relativePath = path.relative(this.state.pathPrefix, file.path)
       return (<div key={i}>{relativePath}</div>)
     })
     if (files.length > maxFileElems) {
@@ -130,8 +130,8 @@ class CreateTorrentPage extends React.Component {
     }
 
     // Align the text fields
-    var textFieldStyle = { width: '' }
+    const textFieldStyle = { width: '' }
-    var textareaStyle = { margin: 0 }
+    const textareaStyle = { margin: 0 }
 
     return (
       <div key='advanced' className='create-torrent-advanced'>
@@ -178,11 +178,11 @@ class CreateTorrentPage extends React.Component {
 }
 
 function handleSubmit () {
-  var announceList = this.state.trackers
+  const announceList = this.state.trackers
     .split('\n')
     .map((s) => s.trim())
     .filter((s) => s !== '')
-  var options = {
+  const options = {
     // We can't let the user choose their own name if we want WebTorrent
     // to use the files in place rather than creating a new folder.
     name: this.state.defaultName,
@@ -197,7 +197,8 @@ function handleSubmit () {
 
 // Finds the longest common prefix
 function findCommonPrefix (a, b) {
-  for (var i = 0; i < a.length && i < b.length; i++) {
+  let i
+  for (i = 0; i < a.length && i < b.length; i++) {
     if (a.charCodeAt(i) !== b.charCodeAt(i)) break
   }
   if (i === a.length) return a
@@ -206,7 +207,7 @@ function findCommonPrefix (a, b) {
 }
 
 function containsDots (path, pathPrefix) {
-  var suffix = path.substring(pathPrefix.length).replace(/\\/g, '/')
+  const suffix = path.substring(pathPrefix.length).replace(/\\/g, '/')
   return ('/' + suffix).includes('/.')
 }
 

src/renderer/pages/player-page.js

@@ -13,9 +13,9 @@ module.exports = class Player extends React.Component {
   render () {
     // Show the video as large as will fit in the window, play immediately
     // If the video is on Chromecast or Airplay, show a title screen instead
-    var state = this.props.state
+    const state = this.props.state
-    var showVideo = state.playing.location === 'local'
+    const showVideo = state.playing.location === 'local'
-    var showControls = state.playing.location !== 'external'
+    const showControls = state.playing.location !== 'external'
     return (
       <div
         className='player'
@@ -39,7 +39,7 @@ function renderMedia (state) {
   // Unfortunately, play/pause can't be done just by modifying HTML.
   // Instead, grab the DOM node and play/pause it if necessary
   // Get the <video> or <audio> tag
-  var mediaElement = document.querySelector(state.playing.type)
+  const mediaElement = document.querySelector(state.playing.type)
   if (mediaElement !== null) {
     if (state.playing.isPaused && !mediaElement.paused) {
       mediaElement.pause()
@@ -67,20 +67,20 @@ function renderMedia (state) {
     }
 
     // Switch to the newly added subtitle track, if available
-    var tracks = mediaElement.textTracks || []
+    const tracks = mediaElement.textTracks || []
-    for (var j = 0; j < tracks.length; j++) {
+    for (let j = 0; j < tracks.length; j++) {
-      var isSelectedTrack = j === state.playing.subtitles.selectedIndex
+      const isSelectedTrack = j === state.playing.subtitles.selectedIndex
       tracks[j].mode = isSelectedTrack ? 'showing' : 'hidden'
     }
 
     // Save video position
-    var file = state.getPlayingFileSummary()
+    const file = state.getPlayingFileSummary()
     file.currentTime = state.playing.currentTime = mediaElement.currentTime
     file.duration = state.playing.duration = mediaElement.duration
 
     // Save selected subtitle
     if (state.playing.subtitles.selectedIndex !== -1) {
-      var index = state.playing.subtitles.selectedIndex
+      const index = state.playing.subtitles.selectedIndex
       file.selectedSubtitle = state.playing.subtitles.tracks[index].filePath
     } else if (file.selectedSubtitle != null) {
       delete file.selectedSubtitle
@@ -90,11 +90,11 @@ function renderMedia (state) {
   }
 
   // Add subtitles to the <video> tag
-  var trackTags = []
+  const trackTags = []
   if (state.playing.subtitles.selectedIndex >= 0) {
-    for (var i = 0; i < state.playing.subtitles.tracks.length; i++) {
+    for (let i = 0; i < state.playing.subtitles.tracks.length; i++) {
-      var track = state.playing.subtitles.tracks[i]
+      const track = state.playing.subtitles.tracks[i]
-      var isSelected = state.playing.subtitles.selectedIndex === i
+      const isSelected = state.playing.subtitles.selectedIndex === i
       trackTags.push(
         <track
           key={i}
@@ -107,8 +107,8 @@ function renderMedia (state) {
   }
 
   // Create the <audio> or <video> tag
-  var MediaTagName = state.playing.type
+  const MediaTagName = state.playing.type
-  var mediaTag = (
+  const mediaTag = (
     <MediaTagName
       src={Playlist.getCurrentLocalURL(state)}
       onDoubleClick={dispatcher('toggleFullScreen')}
@@ -137,8 +137,8 @@ function renderMedia (state) {
   // As soon as we know the video dimensions, resize the window
   function onLoadedMetadata (e) {
     if (state.playing.type !== 'video') return
-    var video = e.target
+    const video = e.target
-    var dimensions = {
+    const dimensions = {
       width: video.videoWidth,
       height: video.videoHeight
     }
@@ -155,7 +155,7 @@ function renderMedia (state) {
   }
 
   function onCanPlay (e) {
-    var elem = e.target
+    const elem = e.target
     if (state.playing.type === 'video' &&
       elem.webkitVideoDecodedByteCount === 0) {
       dispatch('mediaError', 'Video codec unsupported')
@@ -169,15 +169,15 @@ function renderMedia (state) {
 }
 
 function renderOverlay (state) {
-  var elems = []
+  const elems = []
-  var audioMetadataElem = renderAudioMetadata(state)
+  const audioMetadataElem = renderAudioMetadata(state)
-  var spinnerElem = renderLoadingSpinner(state)
+  const spinnerElem = renderLoadingSpinner(state)
   if (audioMetadataElem) elems.push(audioMetadataElem)
   if (spinnerElem) elems.push(spinnerElem)
 
   // Video fills the window, centered with black bars if necessary
   // Audio gets a static poster image and a summary of the file metadata.
-  var style
+  let style
   if (state.playing.type === 'audio') {
     style = { backgroundImage: cssBackgroundImagePoster(state) }
   } else if (elems.length !== 0) {
@@ -195,27 +195,27 @@ function renderOverlay (state) {
 }
 
 function renderAudioMetadata (state) {
-  var fileSummary = state.getPlayingFileSummary()
+  const fileSummary = state.getPlayingFileSummary()
   if (!fileSummary.audioInfo) return
-  var info = fileSummary.audioInfo
+  const info = fileSummary.audioInfo
 
   // Get audio track info
-  var title = info.title
+  let title = info.title
   if (!title) {
     title = fileSummary.name
   }
-  var artist = info.artist && info.artist[0]
+  let artist = info.artist && info.artist[0]
-  var album = info.album
+  let album = info.album
   if (album && info.year && !album.includes(info.year)) {
     album += ' (' + info.year + ')'
   }
-  var track
+  let track
   if (info.track && info.track.no && info.track.of) {
     track = info.track.no + ' of ' + info.track.of
   }
 
   // Show a small info box in the middle of the screen with title/album/etc
-  var elems = []
+  const elems = []
   if (artist) {
     elems.push((
       <div key='artist' className='audio-artist'>
@@ -239,7 +239,7 @@ function renderAudioMetadata (state) {
   }
 
   // Align the title with the other info, if available. Otherwise, center title
-  var emptyLabel = (<label />)
+  const emptyLabel = (<label />)
   elems.unshift((
     <div key='title' className='audio-title'>
       {elems.length ? emptyLabel : undefined}{title}
@@ -251,14 +251,14 @@ function renderAudioMetadata (state) {
 
 function renderLoadingSpinner (state) {
   if (state.playing.isPaused) return
-  var isProbablyStalled = state.playing.isStalled ||
+  const isProbablyStalled = state.playing.isStalled ||
     (new Date().getTime() - state.playing.lastTimeUpdate > 2000)
   if (!isProbablyStalled) return
 
-  var prog = state.getPlayingTorrentSummary().progress || {}
+  const prog = state.getPlayingTorrentSummary().progress || {}
-  var fileProgress = 0
+  let fileProgress = 0
   if (prog.files) {
-    var file = prog.files[state.playing.fileIndex]
+    const file = prog.files[state.playing.fileIndex]
     fileProgress = Math.floor(100 * file.numPiecesPresent / file.numPieces)
   }
 
@@ -275,7 +275,7 @@ function renderLoadingSpinner (state) {
 }
 
 function renderCastScreen (state) {
-  var castIcon, castType, isCast
+  let castIcon, castType, isCast
   if (state.playing.location.startsWith('chromecast')) {
     castIcon = 'cast_connected'
     castType = 'Chromecast'
@@ -290,8 +290,8 @@ function renderCastScreen (state) {
     isCast = true
   } else if (state.playing.location === 'external') {
     // TODO: get the player name in a more reliable way
-    var playerPath = state.saved.prefs.externalPlayerPath
+    const playerPath = state.saved.prefs.externalPlayerPath
-    var playerName = playerPath ? path.basename(playerPath).split('.')[0] : 'VLC'
+    const playerName = playerPath ? path.basename(playerPath).split('.')[0] : 'VLC'
     castIcon = 'tv'
     castType = playerName
     isCast = false
@@ -301,15 +301,15 @@ function renderCastScreen (state) {
     isCast = false
   }
 
-  var isStarting = state.playing.location.endsWith('-pending')
+  const isStarting = state.playing.location.endsWith('-pending')
-  var castName = state.playing.castName
+  const castName = state.playing.castName
-  var castStatus
+  let castStatus
   if (isCast && isStarting) castStatus = 'Connecting to ' + castName + '...'
   else if (isCast && !isStarting) castStatus = 'Connected to ' + castName
   else castStatus = ''
 
   // Show a nice title image, if possible
-  var style = {
+  const style = {
     backgroundImage: cssBackgroundImagePoster(state)
   }
 
@@ -327,12 +327,12 @@ function renderCastScreen (state) {
 function renderCastOptions (state) {
   if (!state.devices.castMenu) return
 
-  var {location, devices} = state.devices.castMenu
+  const {location, devices} = state.devices.castMenu
-  var player = state.devices[location]
+  const player = state.devices[location]
 
-  var items = devices.map(function (device, ix) {
+  const items = devices.map(function (device, ix) {
-    var isSelected = player.device === device
+    const isSelected = player.device === device
-    var name = device.name
+    const name = device.name
     return (
       <li key={ix} onClick={dispatcher('selectCastDevice', ix)}>
         <i className='icon'>{isSelected ? 'radio_button_checked' : 'radio_button_unchecked'}</i>
@@ -349,11 +349,11 @@ function renderCastOptions (state) {
 }
 
 function renderSubtitleOptions (state) {
-  var subtitles = state.playing.subtitles
+  const subtitles = state.playing.subtitles
   if (!subtitles.tracks.length || !subtitles.showMenu) return
 
-  var items = subtitles.tracks.map(function (track, ix) {
+  const items = subtitles.tracks.map(function (track, ix) {
-    var isSelected = state.playing.subtitles.selectedIndex === ix
+    const isSelected = state.playing.subtitles.selectedIndex === ix
     return (
       <li key={ix} onClick={dispatcher('selectSubtitle', ix)}>
         <i className='icon'>{'radio_button_' + (isSelected ? 'checked' : 'unchecked')}</i>
@@ -362,8 +362,8 @@ function renderSubtitleOptions (state) {
     )
   })
 
-  var noneSelected = state.playing.subtitles.selectedIndex === -1
+  const noneSelected = state.playing.subtitles.selectedIndex === -1
-  var noneClass = 'radio_button_' + (noneSelected ? 'checked' : 'unchecked')
+  const noneClass = 'radio_button_' + (noneSelected ? 'checked' : 'unchecked')
   return (
     <ul key='subtitle-options' className='options-list'>
       {items}
@@ -376,17 +376,17 @@ function renderSubtitleOptions (state) {
 }
 
 function renderPlayerControls (state) {
-  var positionPercent = 100 * state.playing.currentTime / state.playing.duration
+  const positionPercent = 100 * state.playing.currentTime / state.playing.duration
-  var playbackCursorStyle = { left: 'calc(' + positionPercent + '% - 3px)' }
+  const playbackCursorStyle = { left: 'calc(' + positionPercent + '% - 3px)' }
-  var captionsClass = state.playing.subtitles.tracks.length === 0
+  const captionsClass = state.playing.subtitles.tracks.length === 0
     ? 'disabled'
     : state.playing.subtitles.selectedIndex >= 0
       ? 'active'
       : ''
-  var prevClass = Playlist.hasPrevious(state) ? '' : 'disabled'
+  const prevClass = Playlist.hasPrevious(state) ? '' : 'disabled'
-  var nextClass = Playlist.hasNext(state) ? '' : 'disabled'
+  const nextClass = Playlist.hasNext(state) ? '' : 'disabled'
 
-  var elements = [
+  const elements = [
     <div key='playback-bar' className='playback-bar'>
       {renderLoadingBar(state)}
       <div
@@ -444,24 +444,24 @@ function renderPlayerControls (state) {
   }
 
   // If we've detected a Chromecast or AppleTV, the user can play video there
-  var castTypes = ['chromecast', 'airplay', 'dlna']
+  const castTypes = ['chromecast', 'airplay', 'dlna']
-  var isCastingAnywhere = castTypes.some(
+  const isCastingAnywhere = castTypes.some(
     (castType) => state.playing.location.startsWith(castType))
 
   // Add the cast buttons. Icons for each cast type, connected/disconnected:
-  var buttonIcons = {
+  const buttonIcons = {
     'chromecast': {true: 'cast_connected', false: 'cast'},
     'airplay': {true: 'airplay', false: 'airplay'},
     'dlna': {true: 'tv', false: 'tv'}
   }
   castTypes.forEach(function (castType) {
     // Do we show this button (eg. the Chromecast button) at all?
-    var isCasting = state.playing.location.startsWith(castType)
+    const isCasting = state.playing.location.startsWith(castType)
-    var player = state.devices[castType]
+    const player = state.devices[castType]
     if ((!player || player.getDevices().length === 0) && !isCasting) return
 
     // Show the button. Three options for eg the Chromecast button:
-    var buttonClass, buttonHandler
+    let buttonClass, buttonHandler
     if (isCasting) {
       // Option 1: we are currently connected to Chromecast. Button stops the cast.
       buttonClass = 'active'
@@ -475,7 +475,7 @@ function renderPlayerControls (state) {
       buttonClass = ''
       buttonHandler = dispatcher('toggleCastMenu', castType)
     }
-    var buttonIcon = buttonIcons[castType][isCasting]
+    const buttonIcon = buttonIcons[castType][isCasting]
 
     elements.push((
       <i
@@ -488,13 +488,13 @@ function renderPlayerControls (state) {
   })
 
   // Render volume slider
-  var volume = state.playing.volume
+  const volume = state.playing.volume
-  var volumeIcon = 'volume_' + (
+  const volumeIcon = 'volume_' + (
     volume === 0 ? 'off'
     : volume < 0.3 ? 'mute'
     : volume < 0.6 ? 'down'
     : 'up')
-  var volumeStyle = {
+  const volumeStyle = {
     background: '-webkit-gradient(linear, left top, right top, ' +
       'color-stop(' + (volume * 100) + '%, #eee), ' +
       'color-stop(' + (volume * 100) + '%, #727272))'
@@ -519,8 +519,8 @@ function renderPlayerControls (state) {
   ))
 
   // Show video playback progress
-  var currentTimeStr = formatTime(state.playing.currentTime)
+  const currentTimeStr = formatTime(state.playing.currentTime)
-  var durationStr = formatTime(state.playing.duration)
+  const durationStr = formatTime(state.playing.duration)
   elements.push((
     <span key='time' className='time float-left'>
       {currentTimeStr} / {durationStr}
@@ -547,7 +547,7 @@ function renderPlayerControls (state) {
   function handleDragStart (e) {
     // Prevent the cursor from changing, eg to a green + icon on Mac
     if (e.dataTransfer) {
-      var dt = e.dataTransfer
+      const dt = e.dataTransfer
       dt.effectAllowed = 'none'
     }
   }
@@ -556,9 +556,9 @@ function renderPlayerControls (state) {
   function handleScrub (e) {
     if (!e.clientX) return
     dispatch('mediaMouseMoved')
-    var windowWidth = document.querySelector('body').clientWidth
+    const windowWidth = document.querySelector('body').clientWidth
-    var fraction = e.clientX / windowWidth
+    const fraction = e.clientX / windowWidth
-    var position = fraction * state.playing.duration /* seconds */
+    const position = fraction * state.playing.duration /* seconds */
     dispatch('skipTo', position)
   }
 
@@ -589,18 +589,18 @@ function renderPlayerControls (state) {
 // Renders the loading bar. Shows which parts of the torrent are loaded, which
 // can be 'spongey' / non-contiguous
 function renderLoadingBar (state) {
-  var torrentSummary = state.getPlayingTorrentSummary()
+  const torrentSummary = state.getPlayingTorrentSummary()
   if (!torrentSummary.progress) {
     return []
   }
 
   // Find all contiguous parts of the torrent which are loaded
-  var prog = torrentSummary.progress
+  const prog = torrentSummary.progress
-  var fileProg = prog.files[state.playing.fileIndex]
+  const fileProg = prog.files[state.playing.fileIndex]
-  var parts = []
+  const parts = []
-  var lastPiecePresent = false
+  let lastPiecePresent = false
-  for (var i = fileProg.startPiece; i <= fileProg.endPiece; i++) {
+  for (let i = fileProg.startPiece; i <= fileProg.endPiece; i++) {
-    var partPresent = Bitfield.prototype.get.call(prog.bitfield, i)
+    const partPresent = Bitfield.prototype.get.call(prog.bitfield, i)
     if (partPresent && !lastPiecePresent) {
       parts.push({start: i - fileProg.startPiece, count: 1})
     } else if (partPresent) {
@@ -610,8 +610,8 @@ function renderLoadingBar (state) {
   }
 
   // Output some bars to show which parts of the file are loaded
-  var loadingBarElems = parts.map(function (part, i) {
+  const loadingBarElems = parts.map(function (part, i) {
-    var style = {
+    const style = {
       left: (100 * part.start / fileProg.numPieces) + '%',
       width: (100 * part.count / fileProg.numPieces) + '%'
     }
@@ -623,8 +623,8 @@ function renderLoadingBar (state) {
 
 // Returns the CSS background-image string for a poster image + dark vignette
 function cssBackgroundImagePoster (state) {
-  var torrentSummary = state.getPlayingTorrentSummary()
+  const torrentSummary = state.getPlayingTorrentSummary()
-  var posterPath = TorrentSummary.getPosterPath(torrentSummary)
+  const posterPath = TorrentSummary.getPosterPath(torrentSummary)
   if (!posterPath) return ''
   return cssBackgroundImageDarkGradient() + `, url('${posterPath}')`
 }
@@ -639,12 +639,12 @@ function formatTime (time) {
     return '0:00'
   }
 
-  var hours = Math.floor(time / 3600)
+  let hours = Math.floor(time / 3600)
-  var minutes = Math.floor(time % 3600 / 60)
+  let minutes = Math.floor(time % 3600 / 60)
   if (hours > 0) {
     minutes = zeroFill(2, minutes)
   }
-  var seconds = zeroFill(2, Math.floor(time % 60))
+  let seconds = zeroFill(2, Math.floor(time % 60))
 
   return (hours > 0 ? hours + ':' : '') + minutes + ':' + seconds
 }

src/renderer/pages/preferences-page.js

@@ -93,7 +93,7 @@ class PreferencesPage extends React.Component {
   }
 
   setDefaultAppButton () {
-    var isFileHandler = this.props.state.unsaved.prefs.isFileHandler
+    const isFileHandler = this.props.state.unsaved.prefs.isFileHandler
     if (isFileHandler) {
       return (
         <Preference>
@@ -117,7 +117,7 @@ class PreferencesPage extends React.Component {
   }
 
   render () {
-    var style = {
+    const style = {
       color: colors.grey400,
       marginLeft: 25,
       marginRight: 25
@@ -147,7 +147,7 @@ class PreferencesSection extends React.Component {
   }
 
   render () {
-    var style = {
+    const style = {
       marginBottom: 25,
       marginTop: 25
     }
@@ -162,7 +162,7 @@ class PreferencesSection extends React.Component {
 
 class Preference extends React.Component {
   render () {
-    var style = { marginBottom: 10 }
+    const style = { marginBottom: 10 }
     return (<div style={style}>{this.props.children}</div>)
   }
 }

src/renderer/pages/torrent-list-page.js

@@ -7,9 +7,9 @@ const {dispatcher} = require('../lib/dispatcher')
 
 module.exports = class TorrentList extends React.Component {
   render () {
-    var state = this.props.state
+    const state = this.props.state
 
-    var contents = []
+    const contents = []
     if (state.downloadPathStatus === 'missing') {
       contents.push(
         <div key='torrent-missing-path'>
@@ -21,7 +21,7 @@ module.exports = class TorrentList extends React.Component {
         </div>
       )
     }
-    var torrentElems = state.saved.torrents.map(
+    const torrentElems = state.saved.torrents.map(
       (torrentSummary) => this.renderTorrent(torrentSummary)
     )
     contents.push(...torrentElems)
@@ -39,23 +39,23 @@ module.exports = class TorrentList extends React.Component {
   }
 
   renderTorrent (torrentSummary) {
-    var state = this.props.state
+    const state = this.props.state
-    var infoHash = torrentSummary.infoHash
+    const infoHash = torrentSummary.infoHash
-    var isSelected = infoHash && state.selectedInfoHash === infoHash
+    const isSelected = infoHash && state.selectedInfoHash === infoHash
 
     // Background image: show some nice visuals, like a frame from the movie, if possible
-    var style = {}
+    const style = {}
     if (torrentSummary.posterFileName) {
-      var gradient = isSelected
+      const gradient = isSelected
         ? 'linear-gradient(to bottom, rgba(0, 0, 0, 0.8) 0%, rgba(0, 0, 0, 0.4) 100%)'
         : 'linear-gradient(to bottom, rgba(0, 0, 0, 0.5) 0%, rgba(0, 0, 0, 0) 100%)'
-      var posterPath = TorrentSummary.getPosterPath(torrentSummary)
+      const posterPath = TorrentSummary.getPosterPath(torrentSummary)
       style.backgroundImage = gradient + `, url('${posterPath}')`
     }
 
     // Foreground: name of the torrent, basic info like size, play button,
     // cast buttons if available, and delete
-    var classes = ['torrent']
+    const classes = ['torrent']
     //  playStatus turns the play button into a loading spinner or error icon
     if (torrentSummary.playStatus) classes.push(torrentSummary.playStatus)
     if (isSelected) classes.push('selected')
@@ -77,13 +77,13 @@ module.exports = class TorrentList extends React.Component {
 
   // Show name, download status, % complete
   renderTorrentMetadata (torrentSummary) {
-    var name = torrentSummary.name || 'Loading torrent...'
+    const name = torrentSummary.name || 'Loading torrent...'
-    var elements = [(
+    const elements = [(
       <div key='name' className='name ellipsis'>{name}</div>
     )]
 
     // If it's downloading/seeding then show progress info
-    var prog = torrentSummary.progress
+    const prog = torrentSummary.progress
     if (torrentSummary.error) {
       elements.push(
         <div key='progress-info' className='ellipsis'>
@@ -107,18 +107,18 @@ module.exports = class TorrentList extends React.Component {
     return (<div key='metadata' className='metadata'>{elements}</div>)
 
     function renderProgressBar () {
-      var progress = Math.floor(100 * prog.progress)
+      const progress = Math.floor(100 * prog.progress)
       return (<progress value={progress} max='100'>{progress}%</progress>)
     }
 
     function renderPercentProgress () {
-      var progress = Math.floor(100 * prog.progress)
+      const progress = Math.floor(100 * prog.progress)
       return (<span key='percent-progress'>{progress}%</span>)
     }
 
     function renderTotalProgress () {
-      var downloaded = prettyBytes(prog.downloaded)
+      const downloaded = prettyBytes(prog.downloaded)
-      var total = prettyBytes(prog.length || 0)
+      const total = prettyBytes(prog.length || 0)
       if (downloaded === total) {
         return (<span key='total-progress'>{downloaded}</span>)
       } else {
@@ -128,7 +128,7 @@ module.exports = class TorrentList extends React.Component {
 
     function renderPeers () {
       if (prog.numPeers === 0) return
-      var count = prog.numPeers === 1 ? 'peer' : 'peers'
+      const count = prog.numPeers === 1 ? 'peer' : 'peers'
       return (<span key='peers'>{prog.numPeers} {count}</span>)
     }
 
@@ -143,22 +143,22 @@ module.exports = class TorrentList extends React.Component {
     }
 
     function renderEta () {
-      var downloaded = prog.downloaded
+      const downloaded = prog.downloaded
-      var total = prog.length || 0
+      const total = prog.length || 0
-      var missing = total - downloaded
+      const missing = total - downloaded
-      var downloadSpeed = prog.downloadSpeed
+      const downloadSpeed = prog.downloadSpeed
       if (downloadSpeed === 0 || missing === 0) return
 
-      var rawEta = missing / downloadSpeed
+      const rawEta = missing / downloadSpeed
-      var hours = Math.floor(rawEta / 3600) % 24
+      const hours = Math.floor(rawEta / 3600) % 24
-      var minutes = Math.floor(rawEta / 60) % 60
+      const minutes = Math.floor(rawEta / 60) % 60
-      var seconds = Math.floor(rawEta % 60)
+      const seconds = Math.floor(rawEta % 60)
 
       // Only display hours and minutes if they are greater than 0 but always
       // display minutes if hours is being displayed
-      var hoursStr = hours ? hours + 'h' : ''
+      const hoursStr = hours ? hours + 'h' : ''
-      var minutesStr = (hours || minutes) ? minutes + 'm' : ''
+      const minutesStr = (hours || minutes) ? minutes + 'm' : ''
-      var secondsStr = seconds + 's'
+      const secondsStr = seconds + 's'
 
       return (<span>ETA: {hoursStr} {minutesStr} {secondsStr}</span>)
     }
@@ -167,9 +167,9 @@ module.exports = class TorrentList extends React.Component {
   // Download button toggles between torrenting (DL/seed) and paused
   // Play button starts streaming the torrent immediately, unpausing if needed
   renderTorrentButtons (torrentSummary) {
-    var infoHash = torrentSummary.infoHash
+    const infoHash = torrentSummary.infoHash
 
-    var playIcon, playTooltip, playClass
+    let playIcon, playTooltip, playClass
     if (torrentSummary.playStatus === 'timeout') {
       playIcon = 'warning'
       playTooltip = 'Playback timed out. No seeds? No internet? Click to try again.'
@@ -178,7 +178,7 @@ module.exports = class TorrentList extends React.Component {
       playTooltip = 'Start streaming'
     }
 
-    var downloadIcon, downloadTooltip
+    let downloadIcon, downloadTooltip
     if (torrentSummary.status === 'seeding') {
       downloadIcon = 'file_upload'
       downloadTooltip = 'Seeding. Click to stop.'
@@ -191,7 +191,7 @@ module.exports = class TorrentList extends React.Component {
     }
 
     // Only show the play/dowload buttons for torrents that contain playable media
-    var playButton, downloadButton, positionElem
+    let playButton, downloadButton, positionElem
     if (!torrentSummary.error) {
       downloadButton = (
         <i
@@ -205,11 +205,11 @@ module.exports = class TorrentList extends React.Component {
 
       // Do we have a saved position? Show it using a radial progress bar on top
       // of the play button, unless already showing a spinner there:
-      var willShowSpinner = torrentSummary.playStatus === 'requested'
+      const willShowSpinner = torrentSummary.playStatus === 'requested'
-      var mostRecentFile = torrentSummary.files &&
+      const mostRecentFile = torrentSummary.files &&
         torrentSummary.files[torrentSummary.mostRecentFileIndex]
       if (mostRecentFile && mostRecentFile.currentTime && !willShowSpinner) {
-        var fraction = mostRecentFile.currentTime / mostRecentFile.duration
+        const fraction = mostRecentFile.currentTime / mostRecentFile.duration
         positionElem = this.renderRadialProgressBar(fraction, 'radial-progress-large')
         playClass = 'resume-position'
       }
@@ -245,9 +245,9 @@ module.exports = class TorrentList extends React.Component {
 
   // Show files, per-file download status and play buttons, and so on
   renderTorrentDetails (torrentSummary) {
-    var filesElement
+    let filesElement
     if (torrentSummary.error || !torrentSummary.files) {
-      var message = ''
+      let message = ''
       if (torrentSummary.error === 'path-missing') {
         // Special case error: this torrent's download dir or file is missing
         message = 'Missing path: ' + TorrentSummary.getFileOrFolder(torrentSummary)
@@ -268,7 +268,7 @@ module.exports = class TorrentList extends React.Component {
       )
     } else {
       // We do know the files. List them and show download stats for each one
-      var fileRows = torrentSummary.files
+      const fileRows = torrentSummary.files
         .filter((file) => !file.path.includes('/.____padding_file/'))
         .map((file, index) => ({ file, index }))
         .map((object) => this.renderFileRow(torrentSummary, object.file, object.index))
@@ -295,28 +295,28 @@ module.exports = class TorrentList extends React.Component {
   renderFileRow (torrentSummary, file, index) {
     // First, find out how much of the file we've downloaded
     // Are we even torrenting it?
-    var isSelected = torrentSummary.selections && torrentSummary.selections[index]
+    const isSelected = torrentSummary.selections && torrentSummary.selections[index]
-    var isDone = false // Are we finished torrenting it?
+    let isDone = false // Are we finished torrenting it?
-    var progress = ''
+    let progress = ''
     if (torrentSummary.progress && torrentSummary.progress.files &&
         torrentSummary.progress.files[index]) {
-      var fileProg = torrentSummary.progress.files[index]
+      const fileProg = torrentSummary.progress.files[index]
       isDone = fileProg.numPiecesPresent === fileProg.numPieces
       progress = Math.round(100 * fileProg.numPiecesPresent / fileProg.numPieces) + '%'
     }
 
     // Second, for media files where we saved our position, show how far we got
-    var positionElem
+    let positionElem
     if (file.currentTime) {
       // Radial progress bar. 0% = start from 0:00, 270% = 3/4 of the way thru
       positionElem = this.renderRadialProgressBar(file.currentTime / file.duration)
     }
 
     // Finally, render the file as a table row
-    var isPlayable = TorrentPlayer.isPlayable(file)
+    const isPlayable = TorrentPlayer.isPlayable(file)
-    var infoHash = torrentSummary.infoHash
+    const infoHash = torrentSummary.infoHash
-    var icon
+    let icon
-    var handleClick
+    let handleClick
     if (isPlayable) {
       icon = 'play_arrow' /* playable? add option to play */
       handleClick = dispatcher('playFile', infoHash, index)
@@ -327,7 +327,7 @@ module.exports = class TorrentList extends React.Component {
         : (e) => e.stopPropagation() // noop if file is not ready
     }
     // TODO: add a css 'disabled' class to indicate that a file cannot be opened/streamed
-    var rowClass = ''
+    let rowClass = ''
     if (!isSelected) rowClass = 'disabled' // File deselected, not being torrented
     if (!isDone && !isPlayable) rowClass = 'disabled' // Can't open yet, can't stream
     return (
@@ -354,9 +354,9 @@ module.exports = class TorrentList extends React.Component {
   }
 
   renderRadialProgressBar (fraction, cssClass) {
-    var rotation = 360 * fraction
+    const rotation = 360 * fraction
-    var transformFill = {transform: 'rotate(' + (rotation / 2) + 'deg)'}
+    const transformFill = {transform: 'rotate(' + (rotation / 2) + 'deg)'}
-    var transformFix = {transform: 'rotate(' + rotation + 'deg)'}
+    const transformFix = {transform: 'rotate(' + rotation + 'deg)'}
 
     return (
       <div key='radial-progress' className={'radial-progress ' + cssClass}>
@@ -376,7 +376,7 @@ module.exports = class TorrentList extends React.Component {
 }
 
 function getErrorMessage (torrentSummary) {
-  var err = torrentSummary.error
+  const err = torrentSummary.error
   if (err === 'path-missing') {
     return (
       <span>

src/renderer/webtorrent.js

@@ -2,26 +2,26 @@
 // process from the main window.
 console.time('init')
 
-var crypto = require('crypto')
+const crypto = require('crypto')
-var deepEqual = require('deep-equal')
+const deepEqual = require('deep-equal')
-var defaultAnnounceList = require('create-torrent').announceList
+const defaultAnnounceList = require('create-torrent').announceList
-var electron = require('electron')
+const electron = require('electron')
-var fs = require('fs-extra')
+const fs = require('fs-extra')
-var musicmetadata = require('musicmetadata')
+const musicmetadata = require('musicmetadata')
-var networkAddress = require('network-address')
+const networkAddress = require('network-address')
-var path = require('path')
+const path = require('path')
-var WebTorrent = require('webtorrent')
+const WebTorrent = require('webtorrent')
-var zeroFill = require('zero-fill')
+const zeroFill = require('zero-fill')
 
-var crashReporter = require('../crash-reporter')
+const crashReporter = require('../crash-reporter')
-var config = require('../config')
+const config = require('../config')
-var torrentPoster = require('./lib/torrent-poster')
+const torrentPoster = require('./lib/torrent-poster')
 
 // Report when the process crashes
 crashReporter.init()
 
 // Send & receive messages from the main window
-var ipc = electron.ipcRenderer
+const ipc = electron.ipcRenderer
 
 // Force use of webtorrent trackers on all torrents
 global.WEBTORRENT_ANNOUNCE = defaultAnnounceList
@@ -31,7 +31,7 @@ global.WEBTORRENT_ANNOUNCE = defaultAnnounceList
 /**
  * WebTorrent version.
  */
-var VERSION = require('../../package.json').version
+const VERSION = require('../../package.json').version
 
 /**
  * Version number in Azureus-style. Generated from major and minor semver version.
@@ -39,7 +39,7 @@ var VERSION = require('../../package.json').version
  *   '0.16.1' -> '0016'
  *   '1.2.5' -> '0102'
  */
-var VERSION_STR = VERSION.match(/([0-9]+)/g)
+const VERSION_STR = VERSION.match(/([0-9]+)/g)
   .slice(0, 2)
   .map((v) => zeroFill(2, v))
   .join('')
@@ -51,19 +51,19 @@ var VERSION_STR = VERSION.match(/([0-9]+)/g)
  * For example:
  *   '-WW0102-'...
  */
-var VERSION_PREFIX = '-WD' + VERSION_STR + '-'
+const VERSION_PREFIX = '-WD' + VERSION_STR + '-'
 
 // Connect to the WebTorrent and BitTorrent networks. WebTorrent Desktop is a hybrid
 // client, as explained here: https://webtorrent.io/faq
-var client = window.client = new WebTorrent({
+const client = window.client = new WebTorrent({
   peerId: Buffer.from(VERSION_PREFIX + crypto.randomBytes(6).toString('hex'))
 })
 
 // WebTorrent-to-HTTP streaming sever
-var server = null
+let server = null
 
 // Used for diffing, so we only send progress updates when necessary
-var prevProgress = null
+let prevProgress = null
 
 init()
 
@@ -105,7 +105,7 @@ function init () {
 function startTorrenting (torrentKey, torrentID, path, fileModtimes, selections) {
   console.log('starting torrent %s: %s', torrentKey, torrentID)
 
-  var torrent = client.add(torrentID, {
+  const torrent = client.add(torrentID, {
     path: path,
     fileModtimes: fileModtimes
   })
@@ -121,15 +121,15 @@ function startTorrenting (torrentKey, torrentID, path, fileModtimes, selections)
 }
 
 function stopTorrenting (infoHash) {
-  var torrent = client.get(infoHash)
+  const torrent = client.get(infoHash)
   if (torrent) torrent.destroy()
 }
 
 // Create a new torrent, start seeding
 function createTorrent (torrentKey, options) {
   console.log('creating torrent', torrentKey, options)
-  var paths = options.files.map((f) => f.path)
+  const paths = options.files.map((f) => f.path)
-  var torrent = client.seed(paths, options)
+  const torrent = client.seed(paths, options)
   torrent.key = torrentKey
   addTorrentEvents(torrent)
   ipc.send('wt-new-torrent')
@@ -147,14 +147,14 @@ function addTorrentEvents (torrent) {
   torrent.on('done', torrentDone)
 
   function torrentMetadata () {
-    var info = getTorrentInfo(torrent)
+    const info = getTorrentInfo(torrent)
     ipc.send('wt-metadata', torrent.key, info)
 
     updateTorrentProgress()
   }
 
   function torrentReady () {
-    var info = getTorrentInfo(torrent)
+    const info = getTorrentInfo(torrent)
     ipc.send('wt-ready', torrent.key, info)
     ipc.send('wt-ready-' + torrent.infoHash, torrent.key, info) // TODO: hack
 
@@ -162,7 +162,7 @@ function addTorrentEvents (torrent) {
   }
 
   function torrentDone () {
-    var info = getTorrentInfo(torrent)
+    const info = getTorrentInfo(torrent)
     ipc.send('wt-done', torrent.key, info)
 
     updateTorrentProgress()
@@ -198,9 +198,9 @@ function getTorrentFileInfo (file) {
 // Every time we resolve a magnet URI, save the torrent file so that we never
 // have to download it again. Never ask the DHT the same question twice.
 function saveTorrentFile (torrentKey) {
-  var torrent = getTorrent(torrentKey)
+  const torrent = getTorrent(torrentKey)
   checkIfTorrentFileExists(torrent.infoHash, function (torrentPath, exists) {
-    var fileName = torrent.infoHash + '.torrent'
+    const fileName = torrent.infoHash + '.torrent'
     if (exists) {
       // We've already saved the file
       return ipc.send('wt-file-saved', torrentKey, fileName)
@@ -220,7 +220,7 @@ function saveTorrentFile (torrentKey) {
 // Checks whether we've already resolved a given infohash to a torrent file
 // Calls back with (torrentPath, exists). Logs, does not call back on error
 function checkIfTorrentFileExists (infoHash, cb) {
-  var torrentPath = path.join(config.TORRENT_PATH, infoHash + '.torrent')
+  const torrentPath = path.join(config.TORRENT_PATH, infoHash + '.torrent')
   fs.exists(torrentPath, function (exists) {
     cb(torrentPath, exists)
   })
@@ -229,14 +229,14 @@ function checkIfTorrentFileExists (infoHash, cb) {
 // Save a JPG that represents a torrent.
 // Auto chooses either a frame from a video file, an image, etc
 function generateTorrentPoster (torrentKey) {
-  var torrent = getTorrent(torrentKey)
+  const torrent = getTorrent(torrentKey)
   torrentPoster(torrent, function (err, buf, extension) {
     if (err) return console.log('error generating poster: %o', err)
     // save it for next time
     fs.mkdirp(config.POSTER_PATH, function (err) {
       if (err) return console.log('error creating poster dir: %o', err)
-      var posterFileName = torrent.infoHash + extension
+      const posterFileName = torrent.infoHash + extension
-      var posterFilePath = path.join(config.POSTER_PATH, posterFileName)
+      const posterFilePath = path.join(config.POSTER_PATH, posterFileName)
       fs.writeFile(posterFilePath, buf, function (err) {
         if (err) return console.log('error saving poster: %o', err)
         // show the poster
@@ -247,7 +247,7 @@ function generateTorrentPoster (torrentKey) {
 }
 
 function updateTorrentProgress () {
-  var progress = getTorrentProgress()
+  const progress = getTorrentProgress()
   // TODO: diff torrent-by-torrent, not once for the whole update
   if (prevProgress && deepEqual(progress, prevProgress, {strict: true})) {
     return /* don't send heavy object if it hasn't changed */
@@ -258,19 +258,19 @@ function updateTorrentProgress () {
 
 function getTorrentProgress () {
   // First, track overall progress
-  var progress = client.progress
+  const progress = client.progress
-  var hasActiveTorrents = client.torrents.some(function (torrent) {
+  const hasActiveTorrents = client.torrents.some(function (torrent) {
     return torrent.progress !== 1
   })
 
   // Track progress for every file in each torrent
   // TODO: ideally this would be tracked by WebTorrent, which could do it
   // more efficiently than looping over torrent.bitfield
-  var torrentProg = client.torrents.map(function (torrent) {
+  const torrentProg = client.torrents.map(function (torrent) {
-    var fileProg = torrent.files && torrent.files.map(function (file, index) {
+    const fileProg = torrent.files && torrent.files.map(function (file, index) {
-      var numPieces = file._endPiece - file._startPiece + 1
+      const numPieces = file._endPiece - file._startPiece + 1
-      var numPiecesPresent = 0
+      let numPiecesPresent = 0
-      for (var piece = file._startPiece; piece <= file._endPiece; piece++) {
+      for (let piece = file._startPiece; piece <= file._endPiece; piece++) {
         if (torrent.bitfield.get(piece)) numPiecesPresent++
       }
       return {
@@ -302,7 +302,7 @@ function getTorrentProgress () {
 }
 
 function startServer (infoHash) {
-  var torrent = client.get(infoHash)
+  const torrent = client.get(infoHash)
   if (torrent.ready) startServerFromReadyTorrent(torrent)
   else torrent.once('ready', () => startServerFromReadyTorrent(torrent))
 }
@@ -313,9 +313,9 @@ function startServerFromReadyTorrent (torrent, cb) {
   // start the streaming torrent-to-http server
   server = torrent.createServer()
   server.listen(0, function () {
-    var port = server.address().port
+    const port = server.address().port
-    var urlSuffix = ':' + port
+    const urlSuffix = ':' + port
-    var info = {
+    const info = {
       torrentKey: torrent.key,
       localURL: 'http://localhost' + urlSuffix,
       networkURL: 'http://' + networkAddress() + urlSuffix
@@ -333,8 +333,8 @@ function stopServer () {
 }
 
 function getAudioMetadata (infoHash, index) {
-  var torrent = client.get(infoHash)
+  const torrent = client.get(infoHash)
-  var file = torrent.files[index]
+  const file = torrent.files[index]
   musicmetadata(file.createReadStream(), function (err, info) {
     if (err) return
     console.log('got audio metadata for %s: %o', file.name, info)
@@ -344,7 +344,7 @@ function getAudioMetadata (infoHash, index) {
 
 function selectFiles (torrentOrInfoHash, selections) {
   // Get the torrent object
-  var torrent
+  let torrent
   if (typeof torrentOrInfoHash === 'string') {
     torrent = client.get(torrentOrInfoHash)
   } else {
@@ -369,8 +369,8 @@ function selectFiles (torrentOrInfoHash, selections) {
   torrent.deselect(0, torrent.pieces.length - 1, false)
 
   // Add selections (individual files)
-  for (var i = 0; i < selections.length; i++) {
+  for (let i = 0; i < selections.length; i++) {
-    var file = torrent.files[i]
+    const file = torrent.files[i]
     if (selections[i]) {
       file.select()
     } else {
@@ -383,7 +383,7 @@ function selectFiles (torrentOrInfoHash, selections) {
 // Gets a WebTorrent handle by torrentKey
 // Throws an Error if we're not currently torrenting anything w/ that key
 function getTorrent (torrentKey) {
-  var ret = client.torrents.find((x) => x.key === torrentKey)
+  const ret = client.torrents.find((x) => x.key === torrentKey)
   if (!ret) throw new Error('missing torrent key ' + torrentKey)
   return ret
 }