From 3053be345b17e5842ed4f95a39191a80380c7562 Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 10:19:52 -0700
Subject: [PATCH 01/13] Remove unneeded returns

---
 lib/browser/guest-view-manager.js            |  6 ++--
 lib/renderer/web-view/guest-view-internal.js | 14 ++++----
 lib/renderer/web-view/web-view-attributes.js | 27 +++++++--------
 lib/renderer/web-view/web-view.js            | 36 +++++++++-----------
 4 files changed, 39 insertions(+), 44 deletions(-)

diff --git a/lib/browser/guest-view-manager.js b/lib/browser/guest-view-manager.js
index 2f8ffefebc1c..e967d70925c8 100644
--- a/lib/browser/guest-view-manager.js
+++ b/lib/browser/guest-view-manager.js
@@ -48,7 +48,7 @@ const embedderElementsMap = {}
 
 // Moves the last element of array to the first one.
 const moveLastToFirst = function (list) {
-  return list.unshift(list.pop())
+  list.unshift(list.pop())
 }
 
 // Generate guestInstanceId.
@@ -227,7 +227,7 @@ const destroyGuest = function (embedder, guestInstanceId) {
   delete guestInstances[guestInstanceId]
 
   const key = embedder.getId() + '-' + guestInstance.elementInstanceId
-  return delete embedderElementsMap[key]
+  delete embedderElementsMap[key]
 }
 
 // Once an embedder has had a guest attached we watch it for destruction to
@@ -281,7 +281,7 @@ ipcMain.on('ELECTRON_GUEST_VIEW_MANAGER_DESTROY_GUEST', function (event, guestIn
 
 ipcMain.on('ELECTRON_GUEST_VIEW_MANAGER_SET_SIZE', function (event, guestInstanceId, params) {
   const guestInstance = guestInstances[guestInstanceId]
-  return guestInstance != null ? guestInstance.guest.setSize(params) : void 0
+  guestInstance != null ? guestInstance.guest.setSize(params) : void 0
 })
 
 // Returns WebContents from its guest id.
diff --git a/lib/renderer/web-view/guest-view-internal.js b/lib/renderer/web-view/guest-view-internal.js
index 9947c27eeed0..0bc1787a9f55 100644
--- a/lib/renderer/web-view/guest-view-internal.js
+++ b/lib/renderer/web-view/guest-view-internal.js
@@ -57,7 +57,7 @@ var dispatchEvent = function (webView, eventName, eventKey, ...args) {
   }
   webView.dispatchEvent(domEvent)
   if (eventName === 'load-commit') {
-    return webView.onLoadCommit(domEvent)
+    webView.onLoadCommit(domEvent)
   }
 }
 
@@ -83,7 +83,7 @@ module.exports = {
       webView.dispatchEvent(domEvent)
     })
 
-    return ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId, function (event, ...args) {
+    ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId, function (event, ...args) {
       var domEvent, f, i, j, len, ref1
       domEvent = new Event('size-changed')
       ref1 = ['oldWidth', 'oldHeight', 'newWidth', 'newHeight']
@@ -98,21 +98,21 @@ module.exports = {
     ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + viewInstanceId)
     ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-' + viewInstanceId)
     ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-' + viewInstanceId)
-    return ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId)
+    ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId)
   },
   createGuest: function (params, callback) {
     requestId++
     ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_CREATE_GUEST', params, requestId)
-    return ipcRenderer.once('ELECTRON_RESPONSE_' + requestId, callback)
+    ipcRenderer.once('ELECTRON_RESPONSE_' + requestId, callback)
   },
   attachGuest: function (elementInstanceId, guestInstanceId, params) {
     ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_ATTACH_GUEST', elementInstanceId, guestInstanceId, params)
-    return webFrame.attachGuest(elementInstanceId)
+    webFrame.attachGuest(elementInstanceId)
   },
   destroyGuest: function (guestInstanceId) {
-    return ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_DESTROY_GUEST', guestInstanceId)
+    ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_DESTROY_GUEST', guestInstanceId)
   },
   setSize: function (guestInstanceId, params) {
-    return ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_SET_SIZE', guestInstanceId, params)
+    ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_SET_SIZE', guestInstanceId, params)
   }
 }
diff --git a/lib/renderer/web-view/web-view-attributes.js b/lib/renderer/web-view/web-view-attributes.js
index f87fca312238..8c2ec0944eaa 100644
--- a/lib/renderer/web-view/web-view-attributes.js
+++ b/lib/renderer/web-view/web-view-attributes.js
@@ -32,7 +32,7 @@ class WebViewAttribute {
 
   // Sets the attribute's value.
   setValue (value) {
-    return this.webViewImpl.webviewNode.setAttribute(this.name, value || '')
+    this.webViewImpl.webviewNode.setAttribute(this.name, value || '')
   }
 
   // Changes the attribute's value without triggering its mutation handler.
@@ -67,9 +67,9 @@ class BooleanAttribute extends WebViewAttribute {
 
   setValue (value) {
     if (!value) {
-      return this.webViewImpl.webviewNode.removeAttribute(this.name)
+      this.webViewImpl.webviewNode.removeAttribute(this.name)
     } else {
-      return this.webViewImpl.webviewNode.setAttribute(this.name, '')
+      this.webViewImpl.webviewNode.setAttribute(this.name, '')
     }
   }
 }
@@ -84,7 +84,7 @@ class AutosizeDimensionAttribute extends WebViewAttribute {
     if (!this.webViewImpl.guestInstanceId) {
       return
     }
-    return guestViewInternal.setSize(this.webViewImpl.guestInstanceId, {
+    guestViewInternal.setSize(this.webViewImpl.guestInstanceId, {
       enableAutoSize: this.webViewImpl.attributes[webViewConstants.ATTRIBUTE_AUTOSIZE].getValue(),
       min: {
         width: parseInt(this.webViewImpl.attributes[webViewConstants.ATTRIBUTE_MINWIDTH].getValue() || 0),
@@ -125,7 +125,7 @@ class PartitionAttribute extends WebViewAttribute {
     }
     if (newValue === 'persist:') {
       this.validPartitionId = false
-      return window.console.error(webViewConstants.ERROR_MSG_INVALID_PARTITION_ATTRIBUTE)
+      window.console.error(webViewConstants.ERROR_MSG_INVALID_PARTITION_ATTRIBUTE)
     }
   }
 }
@@ -141,18 +141,15 @@ class GuestInstanceAttribute extends WebViewAttribute {
     if (this.webViewImpl.webviewNode.hasAttribute(this.name)) {
       return parseInt(this.webViewImpl.webviewNode.getAttribute(this.name))
     }
-    return undefined
   }
 
   // Sets the attribute's value.
   setValue (value) {
     if (!value) {
-      return this.webViewImpl.webviewNode.removeAttribute(this.name)
+      this.webViewImpl.webviewNode.removeAttribute(this.name)
+    } else if (!isNaN(value)) {
+      this.webViewImpl.webviewNode.setAttribute(this.name, value)
     }
-    if (isNaN(value)) {
-      return
-    }
-    return this.webViewImpl.webviewNode.setAttribute(this.name, value)
   }
 
   handleMutation (oldValue, newValue) {
@@ -192,7 +189,7 @@ class SrcAttribute extends WebViewAttribute {
     // is possible for this change to get picked up asyncronously by src's
     // mutation observer |observer|, and then get handled even though we do not
     // want to handle this mutation.
-    return this.observer.takeRecords()
+    this.observer.takeRecords()
   }
 
   handleMutation (oldValue, newValue) {
@@ -206,7 +203,7 @@ class SrcAttribute extends WebViewAttribute {
       this.setValueIgnoreMutation(oldValue)
       return
     }
-    return this.parse()
+    this.parse()
   }
 
   // The purpose of this mutation observer is to catch assignment to the src
@@ -232,7 +229,7 @@ class SrcAttribute extends WebViewAttribute {
       attributeOldValue: true,
       attributeFilter: [this.name]
     }
-    return this.observer.observe(this.webViewImpl.webviewNode, params)
+    this.observer.observe(this.webViewImpl.webviewNode, params)
   }
 
   parse () {
@@ -259,7 +256,7 @@ class SrcAttribute extends WebViewAttribute {
       opts.userAgent = useragent
     }
     guestContents = remote.getGuestWebContents(this.webViewImpl.guestInstanceId)
-    return guestContents.loadURL(this.getValue(), opts)
+    guestContents.loadURL(this.getValue(), opts)
   }
 }
 
diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index dee602b03b2f..cb63627dddc2 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -82,7 +82,7 @@ var WebViewImpl = (function () {
 
   // Sets the <webview>.request property.
   WebViewImpl.prototype.setRequestPropertyOnWebViewNode = function (request) {
-    return Object.defineProperty(this.webviewNode, 'request', {
+    Object.defineProperty(this.webviewNode, 'request', {
       value: request,
       enumerable: true
     })
@@ -119,7 +119,7 @@ var WebViewImpl = (function () {
     }
 
     // Let the changed attribute handle its own mutation
-    return this.attributes[attributeName].handleMutation(oldValue, newValue)
+    this.attributes[attributeName].handleMutation(oldValue, newValue)
   }
 
   WebViewImpl.prototype.handleBrowserPluginAttributeMutation = function (attributeName, oldValue, newValue) {
@@ -129,10 +129,9 @@ var WebViewImpl = (function () {
 
       // Track when the element resizes using the element resize callback.
       webFrame.registerElementResizeCallback(this.internalInstanceId, this.onElementResize.bind(this))
-      if (!this.guestInstanceId) {
-        return
+      if (this.guestInstanceId) {
+        guestViewInternal.attachGuest(this.internalInstanceId, this.guestInstanceId, this.buildParams())
       }
-      return guestViewInternal.attachGuest(this.internalInstanceId, this.guestInstanceId, this.buildParams())
     }
   }
 
@@ -157,7 +156,7 @@ var WebViewImpl = (function () {
 
       // Only fire the DOM event if the size of the <webview> has actually
       // changed.
-      return this.dispatchEvent(webViewEvent)
+      this.dispatchEvent(webViewEvent)
     }
   }
 
@@ -177,7 +176,7 @@ var WebViewImpl = (function () {
     resizeEvent.newHeight = newSize.height
     this.dispatchEvent(resizeEvent)
     if (this.guestInstanceId) {
-      return guestViewInternal.setSize(this.guestInstanceId, {
+      guestViewInternal.setSize(this.guestInstanceId, {
         normal: newSize
       })
     }
@@ -190,7 +189,7 @@ var WebViewImpl = (function () {
   }
 
   WebViewImpl.prototype.dispatchEvent = function (webViewEvent) {
-    return this.webviewNode.dispatchEvent(webViewEvent)
+    this.webviewNode.dispatchEvent(webViewEvent)
   }
 
   // Adds an 'on<event>' property on the webview, which can be used to set/unset
@@ -284,10 +283,9 @@ var registerBrowserPluginElement = function () {
   proto.attributeChangedCallback = function (name, oldValue, newValue) {
     var internal
     internal = v8Util.getHiddenValue(this, 'internal')
-    if (!internal) {
-      return
+    if (internal) {
+      internal.handleBrowserPluginAttributeMutation(name, oldValue, newValue)
     }
-    return internal.handleBrowserPluginAttributeMutation(name, oldValue, newValue)
   }
   proto.attachedCallback = function () {
     // Load the plugin immediately.
@@ -313,10 +311,9 @@ var registerWebViewElement = function () {
   proto.attributeChangedCallback = function (name, oldValue, newValue) {
     var internal
     internal = v8Util.getHiddenValue(this, 'internal')
-    if (!internal) {
-      return
+    if (internal) {
+      internal.handleWebviewAttributeMutation(name, oldValue, newValue)
     }
-    return internal.handleWebviewAttributeMutation(name, oldValue, newValue)
   }
   proto.detachedCallback = function () {
     var internal
@@ -340,9 +337,10 @@ var registerWebViewElement = function () {
       internal.elementAttached = true
       instance = internal.attributes[webViewConstants.ATTRIBUTE_GUESTINSTANCE].getValue()
       if (instance) {
-        return internal.attachGuestInstance(instance)
+        internal.attachGuestInstance(instance)
+      } else {
+        internal.attributes[webViewConstants.ATTRIBUTE_SRC].parse()
       }
-      return internal.attributes[webViewConstants.ATTRIBUTE_SRC].parse()
     }
   }
 
@@ -424,7 +422,7 @@ var registerWebViewElement = function () {
   createNonBlockHandler = function (m) {
     return function (...args) {
       const internal = v8Util.getHiddenValue(this, 'internal')
-      return ipcRenderer.send.apply(ipcRenderer, ['ELECTRON_BROWSER_ASYNC_CALL_TO_GUEST_VIEW', null, internal.guestInstanceId, m].concat(args))
+      ipcRenderer.send.apply(ipcRenderer, ['ELECTRON_BROWSER_ASYNC_CALL_TO_GUEST_VIEW', null, internal.guestInstanceId, m].concat(args))
     }
   }
   for (j = 0, len1 = nonblockMethods.length; j < len1; j++) {
@@ -460,7 +458,7 @@ var registerWebViewElement = function () {
   delete proto.createdCallback
   delete proto.attachedCallback
   delete proto.detachedCallback
-  return delete proto.attributeChangedCallback
+  delete proto.attributeChangedCallback
 }
 
 var useCapture = true
@@ -471,7 +469,7 @@ var listener = function (event) {
   }
   registerBrowserPluginElement()
   registerWebViewElement()
-  return window.removeEventListener(event.type, listener, useCapture)
+  window.removeEventListener(event.type, listener, useCapture)
 }
 
 window.addEventListener('readystatechange', listener, true)

From 712b15286c242bada72f42b0ff7f75b5ae2ca47b Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 10:39:40 -0700
Subject: [PATCH 02/13] Use let/const instead of var

---
 lib/browser/guest-view-manager.js            | 29 +++---
 lib/renderer/web-view/guest-view-internal.js | 36 ++++----
 lib/renderer/web-view/web-view-attributes.js | 23 ++---
 lib/renderer/web-view/web-view.js            | 97 +++++++++-----------
 4 files changed, 85 insertions(+), 100 deletions(-)

diff --git a/lib/browser/guest-view-manager.js b/lib/browser/guest-view-manager.js
index e967d70925c8..4183e178daa7 100644
--- a/lib/browser/guest-view-manager.js
+++ b/lib/browser/guest-view-manager.js
@@ -77,7 +77,6 @@ const createGuest = function (embedder, params) {
 
   // Init guest web view after attached.
   guest.on('did-attach', function () {
-    let opts
     params = this.attachParams
     delete this.attachParams
     this.viewInstanceId = params.instanceId
@@ -97,7 +96,7 @@ const createGuest = function (embedder, params) {
       }
     })
     if (params.src) {
-      opts = {}
+      const opts = {}
       if (params.httpreferrer) {
         opts.httpReferrer = params.httpreferrer
       }
@@ -146,11 +145,9 @@ const createGuest = function (embedder, params) {
 
 // Attach the guest to an element of embedder.
 const attachGuest = function (embedder, elementInstanceId, guestInstanceId, params) {
-  let guest, guestInstance, key, oldKey, oldGuestInstanceId, ref1, webPreferences
-
   // Destroy the old guest when attaching.
-  key = (embedder.getId()) + '-' + elementInstanceId
-  oldGuestInstanceId = embedderElementsMap[key]
+  const key = (embedder.getId()) + '-' + elementInstanceId
+  const oldGuestInstanceId = embedderElementsMap[key]
   if (oldGuestInstanceId != null) {
     // Reattachment to the same guest is just a no-op.
     if (oldGuestInstanceId === guestInstanceId) {
@@ -160,24 +157,24 @@ const attachGuest = function (embedder, elementInstanceId, guestInstanceId, para
     destroyGuest(embedder, oldGuestInstanceId)
   }
 
-  guestInstance = guestInstances[guestInstanceId]
+  const guestInstance = guestInstances[guestInstanceId]
   // If this isn't a valid guest instance then do nothing.
   if (!guestInstance) {
     return
   }
-  guest = guestInstance.guest
+  const {guest} = guestInstance
 
   // If this guest is already attached to an element then remove it
   if (guestInstance.elementInstanceId) {
-    oldKey = (guestInstance.embedder.getId()) + '-' + guestInstance.elementInstanceId
+    const oldKey = (guestInstance.embedder.getId()) + '-' + guestInstance.elementInstanceId
     delete embedderElementsMap[oldKey]
     webViewManager.removeGuest(guestInstance.embedder, guestInstanceId)
     guestInstance.embedder.send('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + guest.viewInstanceId)
   }
 
-  webPreferences = {
+  const webPreferences = {
     guestInstanceId: guestInstanceId,
-    nodeIntegration: (ref1 = params.nodeintegration) != null ? ref1 : false,
+    nodeIntegration: params.nodeintegration != null ? params.nodeintegration : false,
     plugins: params.plugins,
     zoomFactor: params.zoomFactor,
     webSecurity: !params.disablewebsecurity,
@@ -217,7 +214,7 @@ const destroyGuest = function (embedder, guestInstanceId) {
     return
   }
 
-  let guestInstance = guestInstances[guestInstanceId]
+  const guestInstance = guestInstances[guestInstanceId]
   if (embedder !== guestInstance.embedder) {
     return
   }
@@ -280,12 +277,12 @@ ipcMain.on('ELECTRON_GUEST_VIEW_MANAGER_DESTROY_GUEST', function (event, guestIn
 })
 
 ipcMain.on('ELECTRON_GUEST_VIEW_MANAGER_SET_SIZE', function (event, guestInstanceId, params) {
-  const guestInstance = guestInstances[guestInstanceId]
-  guestInstance != null ? guestInstance.guest.setSize(params) : void 0
+  const guest = getGuest(guestInstanceId)
+  if (guest != null) guest.setSize(params)
 })
 
 // Returns WebContents from its guest id.
-exports.getGuest = function (guestInstanceId) {
+const getGuest = function (guestInstanceId) {
   const guestInstance = guestInstances[guestInstanceId]
   return guestInstance != null ? guestInstance.guest : void 0
 }
@@ -295,4 +292,6 @@ const getEmbedder = function (guestInstanceId) {
   const guestInstance = guestInstances[guestInstanceId]
   return guestInstance != null ? guestInstance.embedder : void 0
 }
+
+exports.getGuest = getGuest
 exports.getEmbedder = getEmbedder
diff --git a/lib/renderer/web-view/guest-view-internal.js b/lib/renderer/web-view/guest-view-internal.js
index 0bc1787a9f55..1f3ba1b193a9 100644
--- a/lib/renderer/web-view/guest-view-internal.js
+++ b/lib/renderer/web-view/guest-view-internal.js
@@ -1,11 +1,10 @@
 'use strict'
 
-const ipcRenderer = require('electron').ipcRenderer
-const webFrame = require('electron').webFrame
+const {ipcRenderer, webFrame} = require('electron')
 
-var requestId = 0
+let requestId = 0
 
-var WEB_VIEW_EVENTS = {
+const WEB_VIEW_EVENTS = {
   'load-commit': ['url', 'isMainFrame'],
   'did-attach': [],
   'did-finish-load': [],
@@ -40,19 +39,19 @@ var WEB_VIEW_EVENTS = {
   'update-target-url': ['url']
 }
 
-var DEPRECATED_EVENTS = {
+const DEPRECATED_EVENTS = {
   'page-title-updated': 'page-title-set'
 }
 
-var dispatchEvent = function (webView, eventName, eventKey, ...args) {
-  var domEvent, f, i, j, len, ref1
+const dispatchEvent = function (webView, eventName, eventKey, ...args) {
+  let f, i, j, len
   if (DEPRECATED_EVENTS[eventName] != null) {
     dispatchEvent.apply(null, [webView, DEPRECATED_EVENTS[eventName], eventKey].concat(args))
   }
-  domEvent = new Event(eventName)
-  ref1 = WEB_VIEW_EVENTS[eventKey]
-  for (i = j = 0, len = ref1.length; j < len; i = ++j) {
-    f = ref1[i]
+  const domEvent = new Event(eventName)
+  const props = WEB_VIEW_EVENTS[eventKey]
+  for (i = j = 0, len = props.length; j < len; i = ++j) {
+    f = props[i]
     domEvent[f] = args[i]
   }
   webView.dispatchEvent(domEvent)
@@ -64,11 +63,10 @@ var dispatchEvent = function (webView, eventName, eventKey, ...args) {
 module.exports = {
   registerEvents: function (webView, viewInstanceId) {
     ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + viewInstanceId, function () {
-      var domEvent
       webFrame.detachGuest(webView.internalInstanceId)
       webView.guestInstanceId = undefined
       webView.reset()
-      domEvent = new Event('destroyed')
+      const domEvent = new Event('destroyed')
       webView.dispatchEvent(domEvent)
     })
 
@@ -77,18 +75,18 @@ module.exports = {
     })
 
     ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-' + viewInstanceId, function (event, channel, ...args) {
-      var domEvent = new Event('ipc-message')
+      const domEvent = new Event('ipc-message')
       domEvent.channel = channel
       domEvent.args = args
       webView.dispatchEvent(domEvent)
     })
 
     ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId, function (event, ...args) {
-      var domEvent, f, i, j, len, ref1
-      domEvent = new Event('size-changed')
-      ref1 = ['oldWidth', 'oldHeight', 'newWidth', 'newHeight']
-      for (i = j = 0, len = ref1.length; j < len; i = ++j) {
-        f = ref1[i]
+      let f, i, j, len
+      const domEvent = new Event('size-changed')
+      const props = ['oldWidth', 'oldHeight', 'newWidth', 'newHeight']
+      for (i = j = 0, len = props.length; j < len; i = ++j) {
+        f = props[i]
         domEvent[f] = args[i]
       }
       webView.onSizeChanged(domEvent)
diff --git a/lib/renderer/web-view/web-view-attributes.js b/lib/renderer/web-view/web-view-attributes.js
index 8c2ec0944eaa..fdd76c85721d 100644
--- a/lib/renderer/web-view/web-view-attributes.js
+++ b/lib/renderer/web-view/web-view-attributes.js
@@ -6,9 +6,9 @@ const webViewConstants = require('./web-view-constants')
 const remote = require('electron').remote
 
 // Helper function to resolve url set in attribute.
-var a = document.createElement('a')
+const a = document.createElement('a')
 
-var resolveURL = function (url) {
+const resolveURL = function (url) {
   if (url === '') return ''
   a.href = url
   return a.href
@@ -211,9 +211,8 @@ class SrcAttribute extends WebViewAttribute {
   // where the webview guest has crashed and navigating to the same address
   // spawns off a new process.
   setupMutationObserver () {
-    var params
     this.observer = new MutationObserver((mutations) => {
-      var i, len, mutation, newValue, oldValue
+      let i, len, mutation, newValue, oldValue
       for (i = 0, len = mutations.length; i < len; i++) {
         mutation = mutations[i]
         oldValue = mutation.oldValue
@@ -224,7 +223,7 @@ class SrcAttribute extends WebViewAttribute {
         this.handleMutation(oldValue, newValue)
       }
     })
-    params = {
+    const params = {
       attributes: true,
       attributeOldValue: true,
       attributeFilter: [this.name]
@@ -233,7 +232,6 @@ class SrcAttribute extends WebViewAttribute {
   }
 
   parse () {
-    var guestContents, httpreferrer, opts, useragent
     if (!this.webViewImpl.elementAttached || !this.webViewImpl.attributes[webViewConstants.ATTRIBUTE_PARTITION].validPartitionId || !this.getValue()) {
       return
     }
@@ -246,16 +244,16 @@ class SrcAttribute extends WebViewAttribute {
     }
 
     // Navigate to |this.src|.
-    opts = {}
-    httpreferrer = this.webViewImpl.attributes[webViewConstants.ATTRIBUTE_HTTPREFERRER].getValue()
+    const opts = {}
+    const httpreferrer = this.webViewImpl.attributes[webViewConstants.ATTRIBUTE_HTTPREFERRER].getValue()
     if (httpreferrer) {
       opts.httpReferrer = httpreferrer
     }
-    useragent = this.webViewImpl.attributes[webViewConstants.ATTRIBUTE_USERAGENT].getValue()
+    const useragent = this.webViewImpl.attributes[webViewConstants.ATTRIBUTE_USERAGENT].getValue()
     if (useragent) {
       opts.userAgent = useragent
     }
-    guestContents = remote.getGuestWebContents(this.webViewImpl.guestInstanceId)
+    const guestContents = remote.getGuestWebContents(this.webViewImpl.guestInstanceId)
     guestContents.loadURL(this.getValue(), opts)
   }
 }
@@ -281,12 +279,11 @@ class PreloadAttribute extends WebViewAttribute {
   }
 
   getValue () {
-    var preload, protocol
     if (!this.webViewImpl.webviewNode.hasAttribute(this.name)) {
       return this.value
     }
-    preload = resolveURL(this.webViewImpl.webviewNode.getAttribute(this.name))
-    protocol = preload.substr(0, 5)
+    let preload = resolveURL(this.webViewImpl.webviewNode.getAttribute(this.name))
+    const protocol = preload.substr(0, 5)
     if (protocol !== 'file:') {
       console.error(webViewConstants.ERROR_MSG_INVALID_PRELOAD_ATTRIBUTE)
       preload = ''
diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index cb63627dddc2..b6818e344aad 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -8,19 +8,18 @@ const v8Util = process.atomBinding('v8_util')
 const guestViewInternal = require('./guest-view-internal')
 const webViewConstants = require('./web-view-constants')
 
-var hasProp = {}.hasOwnProperty
+const hasProp = {}.hasOwnProperty
 
 // ID generator.
-var nextId = 0
+let nextId = 0
 
-var getNextId = function () {
+const getNextId = function () {
   return ++nextId
 }
 
 // Represents the internal state of the WebView node.
-var WebViewImpl = (function () {
+const WebViewImpl = (function () {
   function WebViewImpl (webviewNode) {
-    var shadowRoot
     this.webviewNode = webviewNode
     v8Util.setHiddenValue(this.webviewNode, 'internal', this)
     this.attached = false
@@ -30,7 +29,7 @@ var WebViewImpl = (function () {
     // on* Event handlers.
     this.on = {}
     this.browserPluginNode = this.createBrowserPluginNode()
-    shadowRoot = this.webviewNode.createShadowRoot()
+    const shadowRoot = this.webviewNode.createShadowRoot()
     shadowRoot.innerHTML = '<!DOCTYPE html><style type="text/css">:host { display: flex; }</style>'
     this.setupWebViewAttributes()
     this.setupFocusPropagation()
@@ -52,7 +51,7 @@ var WebViewImpl = (function () {
   WebViewImpl.prototype.createBrowserPluginNode = function () {
     // We create BrowserPlugin as a custom element in order to observe changes
     // to attributes synchronously.
-    var browserPluginNode = new WebViewImpl.BrowserPlugin()
+    const browserPluginNode = new WebViewImpl.BrowserPlugin()
     v8Util.setHiddenValue(browserPluginNode, 'internal', this)
     return browserPluginNode
   }
@@ -136,18 +135,16 @@ var WebViewImpl = (function () {
   }
 
   WebViewImpl.prototype.onSizeChanged = function (webViewEvent) {
-    var maxHeight, maxWidth, minHeight, minWidth, newHeight, newWidth, node, width
-    newWidth = webViewEvent.newWidth
-    newHeight = webViewEvent.newHeight
-    node = this.webviewNode
-    width = node.offsetWidth
+    const {newHeight, newWidth} = webViewEvent
+    const node = this.webviewNode
+    const width = node.offsetWidth
 
     // Check the current bounds to make sure we do not resize <webview>
     // outside of current constraints.
-    maxWidth = this.attributes[webViewConstants.ATTRIBUTE_MAXWIDTH].getValue() | width
-    maxHeight = this.attributes[webViewConstants.ATTRIBUTE_MAXHEIGHT].getValue() | width
-    minWidth = this.attributes[webViewConstants.ATTRIBUTE_MINWIDTH].getValue() | width
-    minHeight = this.attributes[webViewConstants.ATTRIBUTE_MINHEIGHT].getValue() | width
+    const maxWidth = this.attributes[webViewConstants.ATTRIBUTE_MAXWIDTH].getValue() | width
+    const maxHeight = this.attributes[webViewConstants.ATTRIBUTE_MAXHEIGHT].getValue() | width
+    let minWidth = this.attributes[webViewConstants.ATTRIBUTE_MINWIDTH].getValue() | width
+    let minHeight = this.attributes[webViewConstants.ATTRIBUTE_MINHEIGHT].getValue() | width
     minWidth = Math.min(minWidth, maxWidth)
     minHeight = Math.min(minHeight, maxHeight)
     if (!this.attributes[webViewConstants.ATTRIBUTE_AUTOSIZE].getValue() || (newWidth >= minWidth && newWidth <= maxWidth && newHeight >= minHeight && newHeight <= maxHeight)) {
@@ -162,8 +159,7 @@ var WebViewImpl = (function () {
 
   WebViewImpl.prototype.onElementResize = function (newSize) {
     // Dispatch the 'resize' event.
-    var resizeEvent
-    resizeEvent = new Event('resize', {
+    const resizeEvent = new Event('resize', {
       bubbles: true
     })
 
@@ -195,8 +191,7 @@ var WebViewImpl = (function () {
   // Adds an 'on<event>' property on the webview, which can be used to set/unset
   // an event handler.
   WebViewImpl.prototype.setupEventProperty = function (eventName) {
-    var propertyName
-    propertyName = 'on' + eventName.toLowerCase()
+    const propertyName = 'on' + eventName.toLowerCase()
     return Object.defineProperty(this.webviewNode, propertyName, {
       get: () => {
         return this.on[propertyName]
@@ -216,14 +211,13 @@ var WebViewImpl = (function () {
 
   // Updates state upon loadcommit.
   WebViewImpl.prototype.onLoadCommit = function (webViewEvent) {
-    var newValue, oldValue
-    oldValue = this.webviewNode.getAttribute(webViewConstants.ATTRIBUTE_SRC)
-    newValue = webViewEvent.url
+    const oldValue = this.webviewNode.getAttribute(webViewConstants.ATTRIBUTE_SRC)
+    const newValue = webViewEvent.url
     if (webViewEvent.isMainFrame && (oldValue !== newValue)) {
       // Touching the src attribute triggers a navigation. To avoid
       // triggering a page reload on every guest-initiated navigation,
       // we do not handle this mutation.
-      return this.attributes[webViewConstants.ATTRIBUTE_SRC].setValueIgnoreMutation(newValue)
+      this.attributes[webViewConstants.ATTRIBUTE_SRC].setValueIgnoreMutation(newValue)
     }
   }
 
@@ -232,17 +226,15 @@ var WebViewImpl = (function () {
   }
 
   WebViewImpl.prototype.buildParams = function () {
-    var attribute, attributeName, css, elementRect, params, ref1
-    params = {
+    const params = {
       instanceId: this.viewInstanceId,
       userAgentOverride: this.userAgentOverride,
       zoomFactor: webFrame.getZoomFactor()
     }
-    ref1 = this.attributes
-    for (attributeName in ref1) {
-      if (!hasProp.call(ref1, attributeName)) continue
-      attribute = ref1[attributeName]
-      params[attributeName] = attribute.getValue()
+    for (const attributeName in this.attributes) {
+      if (hasProp.call(this.attributes, attributeName)) {
+        params[attributeName] = this.attributes[attributeName].getValue()
+      }
     }
 
     // When the WebView is not participating in layout (display:none)
@@ -250,8 +242,8 @@ var WebViewImpl = (function () {
     // However, in the case where the WebView has a fixed size we can
     // use that value to initially size the guest so as to avoid a relayout of
     // the on display:block.
-    css = window.getComputedStyle(this.webviewNode, null)
-    elementRect = this.webviewNode.getBoundingClientRect()
+    const css = window.getComputedStyle(this.webviewNode, null)
+    const elementRect = this.webviewNode.getBoundingClientRect()
     params.elementWidth = parseInt(elementRect.width) || parseInt(css.getPropertyValue('width'))
     params.elementHeight = parseInt(elementRect.height) || parseInt(css.getPropertyValue('height'))
     return params
@@ -271,8 +263,8 @@ var WebViewImpl = (function () {
 })()
 
 // Registers browser plugin <object> custom element.
-var registerBrowserPluginElement = function () {
-  var proto = Object.create(HTMLObjectElement.prototype)
+const registerBrowserPluginElement = function () {
+  const proto = Object.create(HTMLObjectElement.prototype)
   proto.createdCallback = function () {
     this.setAttribute('type', 'application/browser-plugin')
     this.setAttribute('id', 'browser-plugin-' + getNextId())
@@ -298,13 +290,12 @@ var registerBrowserPluginElement = function () {
   delete proto.createdCallback
   delete proto.attachedCallback
   delete proto.detachedCallback
-  return delete proto.attributeChangedCallback
+  delete proto.attributeChangedCallback
 }
 
 // Registers <webview> custom element.
 var registerWebViewElement = function () {
-  var createBlockHandler, createNonBlockHandler, i, j, len, len1, m, methods, nonblockMethods, proto
-  proto = Object.create(HTMLObjectElement.prototype)
+  const proto = Object.create(HTMLObjectElement.prototype)
   proto.createdCallback = function () {
     return new WebViewImpl(this)
   }
@@ -345,7 +336,7 @@ var registerWebViewElement = function () {
   }
 
   // Public-facing API methods.
-  methods = [
+  const methods = [
     'getURL',
     'loadURL',
     'getTitle',
@@ -394,7 +385,7 @@ var registerWebViewElement = function () {
     'showDefinitionForSelection',
     'capturePage'
   ]
-  nonblockMethods = [
+  const nonblockMethods = [
     'insertCSS',
     'insertText',
     'send',
@@ -405,7 +396,7 @@ var registerWebViewElement = function () {
   ]
 
   // Forward proto.foo* method calls to WebViewImpl.foo*.
-  createBlockHandler = function (m) {
+  const createBlockHandler = function (m) {
     return function (...args) {
       const internal = v8Util.getHiddenValue(this, 'internal')
       if (internal.webContents) {
@@ -415,28 +406,28 @@ var registerWebViewElement = function () {
       }
     }
   }
-  for (i = 0, len = methods.length; i < len; i++) {
-    m = methods[i]
-    proto[m] = createBlockHandler(m)
+  for (let i = 0, len = methods.length; i < len; i++) {
+    const method = methods[i]
+    proto[method] = createBlockHandler(method)
   }
-  createNonBlockHandler = function (m) {
+  const createNonBlockHandler = function (m) {
     return function (...args) {
       const internal = v8Util.getHiddenValue(this, 'internal')
       ipcRenderer.send.apply(ipcRenderer, ['ELECTRON_BROWSER_ASYNC_CALL_TO_GUEST_VIEW', null, internal.guestInstanceId, m].concat(args))
     }
   }
-  for (j = 0, len1 = nonblockMethods.length; j < len1; j++) {
-    m = nonblockMethods[j]
-    proto[m] = createNonBlockHandler(m)
+  for (let j = 0, len1 = nonblockMethods.length; j < len1; j++) {
+    const method = nonblockMethods[j]
+    proto[method] = createNonBlockHandler(method)
   }
 
   proto.executeJavaScript = function (code, hasUserGesture, callback) {
-    var internal = v8Util.getHiddenValue(this, 'internal')
+    const internal = v8Util.getHiddenValue(this, 'internal')
     if (typeof hasUserGesture === 'function') {
       callback = hasUserGesture
       hasUserGesture = false
     }
-    let requestId = getNextId()
+    const requestId = getNextId()
     ipcRenderer.send('ELECTRON_BROWSER_ASYNC_CALL_TO_GUEST_VIEW', requestId, internal.guestInstanceId, 'executeJavaScript', code, hasUserGesture)
     ipcRenderer.once(`ELECTRON_RENDERER_ASYNC_CALL_TO_GUEST_VIEW_RESPONSE_${requestId}`, function (event, result) {
       if (callback) callback(result)
@@ -445,7 +436,7 @@ var registerWebViewElement = function () {
 
   // WebContents associated with this webview.
   proto.getWebContents = function () {
-    var internal = v8Util.getHiddenValue(this, 'internal')
+    const internal = v8Util.getHiddenValue(this, 'internal')
     return internal.webContents
   }
 
@@ -461,9 +452,9 @@ var registerWebViewElement = function () {
   delete proto.attributeChangedCallback
 }
 
-var useCapture = true
+const useCapture = true
 
-var listener = function (event) {
+const listener = function (event) {
   if (document.readyState === 'loading') {
     return
   }

From 48bcad87c2de460f5704a8b13b95f5db9b58fbaa Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 10:39:40 -0700
Subject: [PATCH 03/13] Use template strings

---
 lib/browser/guest-view-manager.js            | 35 +++++++++-----------
 lib/renderer/web-view/guest-view-internal.js | 18 +++++-----
 lib/renderer/web-view/web-view.js            |  8 ++---
 3 files changed, 28 insertions(+), 33 deletions(-)

diff --git a/lib/browser/guest-view-manager.js b/lib/browser/guest-view-manager.js
index 4183e178daa7..a1ed7b940886 100644
--- a/lib/browser/guest-view-manager.js
+++ b/lib/browser/guest-view-manager.js
@@ -108,14 +108,17 @@ const createGuest = function (embedder, params) {
     guest.allowPopups = params.allowpopups
   })
 
+  const sendToEmbedder = (channel, ...args) => {
+    const embedder = getEmbedder(guestInstanceId)
+    if (embedder) {
+      embedder.send(`${channel}-${guest.viewInstanceId}`, ...args)
+    }
+  }
+
   // Dispatch events to embedder.
   const fn = function (event) {
     guest.on(event, function (_, ...args) {
-      const embedder = getEmbedder(guestInstanceId)
-      if (!embedder) {
-        return
-      }
-      embedder.send.apply(embedder, ['ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-' + guest.viewInstanceId, event].concat(args))
+      sendToEmbedder('ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT', event, ...args)
     })
   }
   for (const event of supportedWebViewEvents) {
@@ -124,20 +127,12 @@ const createGuest = function (embedder, params) {
 
   // Dispatch guest's IPC messages to embedder.
   guest.on('ipc-message-host', function (_, [channel, ...args]) {
-    const embedder = getEmbedder(guestInstanceId)
-    if (!embedder) {
-      return
-    }
-    embedder.send.apply(embedder, ['ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-' + guest.viewInstanceId, channel].concat(args))
+    sendToEmbedder('ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE', channel, ...args)
   })
 
   // Autosize.
   guest.on('size-changed', function (_, ...args) {
-    const embedder = getEmbedder(guestInstanceId)
-    if (!embedder) {
-      return
-    }
-    embedder.send.apply(embedder, ['ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + guest.viewInstanceId].concat(args))
+    sendToEmbedder('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED', ...args)
   })
 
   return guestInstanceId
@@ -146,7 +141,7 @@ const createGuest = function (embedder, params) {
 // Attach the guest to an element of embedder.
 const attachGuest = function (embedder, elementInstanceId, guestInstanceId, params) {
   // Destroy the old guest when attaching.
-  const key = (embedder.getId()) + '-' + elementInstanceId
+  const key = `${embedder.getId()}-${elementInstanceId}`
   const oldGuestInstanceId = embedderElementsMap[key]
   if (oldGuestInstanceId != null) {
     // Reattachment to the same guest is just a no-op.
@@ -166,10 +161,10 @@ const attachGuest = function (embedder, elementInstanceId, guestInstanceId, para
 
   // If this guest is already attached to an element then remove it
   if (guestInstance.elementInstanceId) {
-    const oldKey = (guestInstance.embedder.getId()) + '-' + guestInstance.elementInstanceId
+    const oldKey = `${guestInstance.embedder.getId()}-${guestInstance.elementInstanceId}`
     delete embedderElementsMap[oldKey]
     webViewManager.removeGuest(guestInstance.embedder, guestInstanceId)
-    guestInstance.embedder.send('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + guest.viewInstanceId)
+    guestInstance.embedder.send(`ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-${guest.viewInstanceId}`)
   }
 
   const webPreferences = {
@@ -223,7 +218,7 @@ const destroyGuest = function (embedder, guestInstanceId) {
   guestInstance.guest.destroy()
   delete guestInstances[guestInstanceId]
 
-  const key = embedder.getId() + '-' + guestInstance.elementInstanceId
+  const key = `${embedder.getId()}-${guestInstance.elementInstanceId}`
   delete embedderElementsMap[key]
 }
 
@@ -265,7 +260,7 @@ const watchEmbedder = function (embedder) {
 }
 
 ipcMain.on('ELECTRON_GUEST_VIEW_MANAGER_CREATE_GUEST', function (event, params, requestId) {
-  event.sender.send('ELECTRON_RESPONSE_' + requestId, createGuest(event.sender, params))
+  event.sender.send(`ELECTRON_RESPONSE_${requestId}`, createGuest(event.sender, params))
 })
 
 ipcMain.on('ELECTRON_GUEST_VIEW_MANAGER_ATTACH_GUEST', function (event, elementInstanceId, guestInstanceId, params) {
diff --git a/lib/renderer/web-view/guest-view-internal.js b/lib/renderer/web-view/guest-view-internal.js
index 1f3ba1b193a9..2d2b269e1989 100644
--- a/lib/renderer/web-view/guest-view-internal.js
+++ b/lib/renderer/web-view/guest-view-internal.js
@@ -62,7 +62,7 @@ const dispatchEvent = function (webView, eventName, eventKey, ...args) {
 
 module.exports = {
   registerEvents: function (webView, viewInstanceId) {
-    ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + viewInstanceId, function () {
+    ipcRenderer.on(`ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-${viewInstanceId}`, function () {
       webFrame.detachGuest(webView.internalInstanceId)
       webView.guestInstanceId = undefined
       webView.reset()
@@ -70,18 +70,18 @@ module.exports = {
       webView.dispatchEvent(domEvent)
     })
 
-    ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-' + viewInstanceId, function (event, eventName, ...args) {
+    ipcRenderer.on(`ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-${viewInstanceId}`, function (event, eventName, ...args) {
       dispatchEvent.apply(null, [webView, eventName, eventName].concat(args))
     })
 
-    ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-' + viewInstanceId, function (event, channel, ...args) {
+    ipcRenderer.on(`ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-${viewInstanceId}`, function (event, channel, ...args) {
       const domEvent = new Event('ipc-message')
       domEvent.channel = channel
       domEvent.args = args
       webView.dispatchEvent(domEvent)
     })
 
-    ipcRenderer.on('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId, function (event, ...args) {
+    ipcRenderer.on(`ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-${viewInstanceId}`, function (event, ...args) {
       let f, i, j, len
       const domEvent = new Event('size-changed')
       const props = ['oldWidth', 'oldHeight', 'newWidth', 'newHeight']
@@ -93,15 +93,15 @@ module.exports = {
     })
   },
   deregisterEvents: function (viewInstanceId) {
-    ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-' + viewInstanceId)
-    ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-' + viewInstanceId)
-    ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-' + viewInstanceId)
-    ipcRenderer.removeAllListeners('ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-' + viewInstanceId)
+    ipcRenderer.removeAllListeners(`ELECTRON_GUEST_VIEW_INTERNAL_DESTROY_GUEST-${viewInstanceId}`)
+    ipcRenderer.removeAllListeners(`ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-${viewInstanceId}`)
+    ipcRenderer.removeAllListeners(`ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-${viewInstanceId}`)
+    ipcRenderer.removeAllListeners(`ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-${viewInstanceId}`)
   },
   createGuest: function (params, callback) {
     requestId++
     ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_CREATE_GUEST', params, requestId)
-    ipcRenderer.once('ELECTRON_RESPONSE_' + requestId, callback)
+    ipcRenderer.once(`ELECTRON_RESPONSE_${requestId}`, callback)
   },
   attachGuest: function (elementInstanceId, guestInstanceId, params) {
     ipcRenderer.send('ELECTRON_GUEST_VIEW_MANAGER_ATTACH_GUEST', elementInstanceId, guestInstanceId, params)
diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index b6818e344aad..03b44e12e49d 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -148,8 +148,8 @@ const WebViewImpl = (function () {
     minWidth = Math.min(minWidth, maxWidth)
     minHeight = Math.min(minHeight, maxHeight)
     if (!this.attributes[webViewConstants.ATTRIBUTE_AUTOSIZE].getValue() || (newWidth >= minWidth && newWidth <= maxWidth && newHeight >= minHeight && newHeight <= maxHeight)) {
-      node.style.width = newWidth + 'px'
-      node.style.height = newHeight + 'px'
+      node.style.width = `${newWidth}px`
+      node.style.height = `${newHeight}px`
 
       // Only fire the DOM event if the size of the <webview> has actually
       // changed.
@@ -191,7 +191,7 @@ const WebViewImpl = (function () {
   // Adds an 'on<event>' property on the webview, which can be used to set/unset
   // an event handler.
   WebViewImpl.prototype.setupEventProperty = function (eventName) {
-    const propertyName = 'on' + eventName.toLowerCase()
+    const propertyName = `on${eventName.toLowerCase()}`
     return Object.defineProperty(this.webviewNode, propertyName, {
       get: () => {
         return this.on[propertyName]
@@ -267,7 +267,7 @@ const registerBrowserPluginElement = function () {
   const proto = Object.create(HTMLObjectElement.prototype)
   proto.createdCallback = function () {
     this.setAttribute('type', 'application/browser-plugin')
-    this.setAttribute('id', 'browser-plugin-' + getNextId())
+    this.setAttribute('id', `browser-plugin-${getNextId()}`)
 
     // The <object> node fills in the <webview> container.
     this.style.flex = '1 1 auto'

From 76f96bd99c7ccffe5d9e7ec330fb915ffcbc21c4 Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 10:51:13 -0700
Subject: [PATCH 04/13] Destructure requires

---
 lib/browser/guest-view-manager.js            | 3 +--
 lib/renderer/web-view/web-view-attributes.js | 2 +-
 lib/renderer/web-view/web-view.js            | 4 +---
 3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/lib/browser/guest-view-manager.js b/lib/browser/guest-view-manager.js
index a1ed7b940886..639353609517 100644
--- a/lib/browser/guest-view-manager.js
+++ b/lib/browser/guest-view-manager.js
@@ -1,7 +1,6 @@
 'use strict'
 
-const ipcMain = require('electron').ipcMain
-const webContents = require('electron').webContents
+const {ipcMain, webContents} = require('electron')
 const parseFeaturesString = require('../common/parse-features-string')
 
 // Doesn't exist in early initialization.
diff --git a/lib/renderer/web-view/web-view-attributes.js b/lib/renderer/web-view/web-view-attributes.js
index fdd76c85721d..e495667e30f8 100644
--- a/lib/renderer/web-view/web-view-attributes.js
+++ b/lib/renderer/web-view/web-view-attributes.js
@@ -3,7 +3,7 @@
 const WebViewImpl = require('./web-view')
 const guestViewInternal = require('./guest-view-internal')
 const webViewConstants = require('./web-view-constants')
-const remote = require('electron').remote
+const {remote} = require('electron')
 
 // Helper function to resolve url set in attribute.
 const a = document.createElement('a')
diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index 03b44e12e49d..70b5a88f01c1 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -1,8 +1,6 @@
 'use strict'
 
-const webFrame = require('electron').webFrame
-const remote = require('electron').remote
-const ipcRenderer = require('electron').ipcRenderer
+const {ipcRenderer, remote, webFrame} = require('electron')
 
 const v8Util = process.atomBinding('v8_util')
 const guestViewInternal = require('./guest-view-internal')

From 6eab14359c3cfbfe140e262a03c134e843e25da1 Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 10:55:12 -0700
Subject: [PATCH 05/13] Use ES6 style class for WebViewImpl

---
 lib/renderer/web-view/web-view.js | 38 +++++++++++++++----------------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index 70b5a88f01c1..755173422130 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -16,8 +16,8 @@ const getNextId = function () {
 }
 
 // Represents the internal state of the WebView node.
-const WebViewImpl = (function () {
-  function WebViewImpl (webviewNode) {
+class WebViewImpl {
+  constructor (webviewNode) {
     this.webviewNode = webviewNode
     v8Util.setHiddenValue(this.webviewNode, 'internal', this)
     this.attached = false
@@ -46,7 +46,7 @@ const WebViewImpl = (function () {
     ipcRenderer.on('ELECTRON_RENDERER_WINDOW_VISIBILITY_CHANGE', this.onVisibilityChanged)
   }
 
-  WebViewImpl.prototype.createBrowserPluginNode = function () {
+  createBrowserPluginNode () {
     // We create BrowserPlugin as a custom element in order to observe changes
     // to attributes synchronously.
     const browserPluginNode = new WebViewImpl.BrowserPlugin()
@@ -55,7 +55,7 @@ const WebViewImpl = (function () {
   }
 
   // Resets some state upon reattaching <webview> element to the DOM.
-  WebViewImpl.prototype.reset = function () {
+  reset () {
     // Unlisten the zoom-level-changed event.
     webFrame.removeListener('zoom-level-changed', this.onZoomLevelChanged)
     ipcRenderer.removeListener('ELECTRON_RENDERER_WINDOW_VISIBILITY_CHANGE', this.onVisibilityChanged)
@@ -78,14 +78,14 @@ const WebViewImpl = (function () {
   }
 
   // Sets the <webview>.request property.
-  WebViewImpl.prototype.setRequestPropertyOnWebViewNode = function (request) {
+  setRequestPropertyOnWebViewNode (request) {
     Object.defineProperty(this.webviewNode, 'request', {
       value: request,
       enumerable: true
     })
   }
 
-  WebViewImpl.prototype.setupFocusPropagation = function () {
+  setupFocusPropagation () {
     if (!this.webviewNode.hasAttribute('tabIndex')) {
       // <webview> needs a tabIndex in order to be focusable.
       // TODO(fsamuel): It would be nice to avoid exposing a tabIndex attribute
@@ -110,7 +110,7 @@ const WebViewImpl = (function () {
   // a BrowserPlugin property will update the corresponding BrowserPlugin
   // attribute, if necessary. See BrowserPlugin::UpdateDOMAttribute for more
   // details.
-  WebViewImpl.prototype.handleWebviewAttributeMutation = function (attributeName, oldValue, newValue) {
+  handleWebviewAttributeMutation (attributeName, oldValue, newValue) {
     if (!this.attributes[attributeName] || this.attributes[attributeName].ignoreMutation) {
       return
     }
@@ -119,7 +119,7 @@ const WebViewImpl = (function () {
     this.attributes[attributeName].handleMutation(oldValue, newValue)
   }
 
-  WebViewImpl.prototype.handleBrowserPluginAttributeMutation = function (attributeName, oldValue, newValue) {
+  handleBrowserPluginAttributeMutation (attributeName, oldValue, newValue) {
     if (attributeName === webViewConstants.ATTRIBUTE_INTERNALINSTANCEID && !oldValue && !!newValue) {
       this.browserPluginNode.removeAttribute(webViewConstants.ATTRIBUTE_INTERNALINSTANCEID)
       this.internalInstanceId = parseInt(newValue)
@@ -132,7 +132,7 @@ const WebViewImpl = (function () {
     }
   }
 
-  WebViewImpl.prototype.onSizeChanged = function (webViewEvent) {
+  onSizeChanged (webViewEvent) {
     const {newHeight, newWidth} = webViewEvent
     const node = this.webviewNode
     const width = node.offsetWidth
@@ -155,7 +155,7 @@ const WebViewImpl = (function () {
     }
   }
 
-  WebViewImpl.prototype.onElementResize = function (newSize) {
+  onElementResize (newSize) {
     // Dispatch the 'resize' event.
     const resizeEvent = new Event('resize', {
       bubbles: true
@@ -176,19 +176,19 @@ const WebViewImpl = (function () {
     }
   }
 
-  WebViewImpl.prototype.createGuest = function () {
+  createGuest () {
     return guestViewInternal.createGuest(this.buildParams(), (event, guestInstanceId) => {
       this.attachGuestInstance(guestInstanceId)
     })
   }
 
-  WebViewImpl.prototype.dispatchEvent = function (webViewEvent) {
+  dispatchEvent (webViewEvent) {
     this.webviewNode.dispatchEvent(webViewEvent)
   }
 
   // Adds an 'on<event>' property on the webview, which can be used to set/unset
   // an event handler.
-  WebViewImpl.prototype.setupEventProperty = function (eventName) {
+  setupEventProperty (eventName) {
     const propertyName = `on${eventName.toLowerCase()}`
     return Object.defineProperty(this.webviewNode, propertyName, {
       get: () => {
@@ -208,7 +208,7 @@ const WebViewImpl = (function () {
   }
 
   // Updates state upon loadcommit.
-  WebViewImpl.prototype.onLoadCommit = function (webViewEvent) {
+  onLoadCommit (webViewEvent) {
     const oldValue = this.webviewNode.getAttribute(webViewConstants.ATTRIBUTE_SRC)
     const newValue = webViewEvent.url
     if (webViewEvent.isMainFrame && (oldValue !== newValue)) {
@@ -219,11 +219,11 @@ const WebViewImpl = (function () {
     }
   }
 
-  WebViewImpl.prototype.onAttach = function (storagePartitionId) {
+  onAttach (storagePartitionId) {
     return this.attributes[webViewConstants.ATTRIBUTE_PARTITION].setValue(storagePartitionId)
   }
 
-  WebViewImpl.prototype.buildParams = function () {
+  buildParams () {
     const params = {
       instanceId: this.viewInstanceId,
       userAgentOverride: this.userAgentOverride,
@@ -247,7 +247,7 @@ const WebViewImpl = (function () {
     return params
   }
 
-  WebViewImpl.prototype.attachGuestInstance = function (guestInstanceId) {
+  attachGuestInstance (guestInstanceId) {
     this.guestInstanceId = guestInstanceId
     this.attributes[webViewConstants.ATTRIBUTE_GUESTINSTANCE].setValueIgnoreMutation(guestInstanceId)
     this.webContents = remote.getGuestWebContents(this.guestInstanceId)
@@ -256,9 +256,7 @@ const WebViewImpl = (function () {
     }
     return guestViewInternal.attachGuest(this.internalInstanceId, this.guestInstanceId, this.buildParams())
   }
-
-  return WebViewImpl
-})()
+}
 
 // Registers browser plugin <object> custom element.
 const registerBrowserPluginElement = function () {

From 0e1c2b0fcbba56b4320ffbf162392647be9c273c Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 11:09:53 -0700
Subject: [PATCH 06/13] Use for/of and remove loop variables

---
 lib/renderer/web-view/guest-view-internal.js | 18 +++++++-----------
 lib/renderer/web-view/web-view-attributes.js |  8 +++-----
 lib/renderer/web-view/web-view.js            |  7 +++----
 3 files changed, 13 insertions(+), 20 deletions(-)

diff --git a/lib/renderer/web-view/guest-view-internal.js b/lib/renderer/web-view/guest-view-internal.js
index 2d2b269e1989..9f3bbf0dacfd 100644
--- a/lib/renderer/web-view/guest-view-internal.js
+++ b/lib/renderer/web-view/guest-view-internal.js
@@ -44,16 +44,13 @@ const DEPRECATED_EVENTS = {
 }
 
 const dispatchEvent = function (webView, eventName, eventKey, ...args) {
-  let f, i, j, len
   if (DEPRECATED_EVENTS[eventName] != null) {
-    dispatchEvent.apply(null, [webView, DEPRECATED_EVENTS[eventName], eventKey].concat(args))
+    dispatchEvent(webView, DEPRECATED_EVENTS[eventName], eventKey, ...args)
   }
   const domEvent = new Event(eventName)
-  const props = WEB_VIEW_EVENTS[eventKey]
-  for (i = j = 0, len = props.length; j < len; i = ++j) {
-    f = props[i]
-    domEvent[f] = args[i]
-  }
+  WEB_VIEW_EVENTS[eventKey].forEach((prop, index) => {
+    domEvent[prop] = args[index]
+  })
   webView.dispatchEvent(domEvent)
   if (eventName === 'load-commit') {
     webView.onLoadCommit(domEvent)
@@ -82,12 +79,11 @@ module.exports = {
     })
 
     ipcRenderer.on(`ELECTRON_GUEST_VIEW_INTERNAL_SIZE_CHANGED-${viewInstanceId}`, function (event, ...args) {
-      let f, i, j, len
       const domEvent = new Event('size-changed')
       const props = ['oldWidth', 'oldHeight', 'newWidth', 'newHeight']
-      for (i = j = 0, len = props.length; j < len; i = ++j) {
-        f = props[i]
-        domEvent[f] = args[i]
+      for (let i = 0; i < props.length; i++) {
+        const prop = props[i]
+        domEvent[prop] = args[i]
       }
       webView.onSizeChanged(domEvent)
     })
diff --git a/lib/renderer/web-view/web-view-attributes.js b/lib/renderer/web-view/web-view-attributes.js
index e495667e30f8..51814b734927 100644
--- a/lib/renderer/web-view/web-view-attributes.js
+++ b/lib/renderer/web-view/web-view-attributes.js
@@ -212,11 +212,9 @@ class SrcAttribute extends WebViewAttribute {
   // spawns off a new process.
   setupMutationObserver () {
     this.observer = new MutationObserver((mutations) => {
-      let i, len, mutation, newValue, oldValue
-      for (i = 0, len = mutations.length; i < len; i++) {
-        mutation = mutations[i]
-        oldValue = mutation.oldValue
-        newValue = this.getValue()
+      for (const mutation of mutations) {
+        const {oldValue} = mutation
+        const newValue = this.getValue()
         if (oldValue !== newValue) {
           return
         }
diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index 755173422130..f260c208fb18 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -402,18 +402,17 @@ var registerWebViewElement = function () {
       }
     }
   }
-  for (let i = 0, len = methods.length; i < len; i++) {
-    const method = methods[i]
+  for (const method of methods) {
     proto[method] = createBlockHandler(method)
   }
+
   const createNonBlockHandler = function (m) {
     return function (...args) {
       const internal = v8Util.getHiddenValue(this, 'internal')
       ipcRenderer.send.apply(ipcRenderer, ['ELECTRON_BROWSER_ASYNC_CALL_TO_GUEST_VIEW', null, internal.guestInstanceId, m].concat(args))
     }
   }
-  for (let j = 0, len1 = nonblockMethods.length; j < len1; j++) {
-    const method = nonblockMethods[j]
+  for (const method of nonblockMethods) {
     proto[method] = createNonBlockHandler(method)
   }
 

From 89a26684e5c45a3685f556b1299a6df62b5cc66f Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 11:31:08 -0700
Subject: [PATCH 07/13] Return webContents directly

---
 lib/renderer/web-view/web-view.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index f260c208fb18..29a1945decc1 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -431,8 +431,7 @@ var registerWebViewElement = function () {
 
   // WebContents associated with this webview.
   proto.getWebContents = function () {
-    const internal = v8Util.getHiddenValue(this, 'internal')
-    return internal.webContents
+    return v8Util.getHiddenValue(this, 'internal').webContents
   }
 
   window.WebView = webFrame.registerEmbedderCustomElement('webview', {

From e4d6aa30a15636438a87b4cf4555ddaed2ca04ac Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 11:37:11 -0700
Subject: [PATCH 08/13] Do truthy check in if block

---
 lib/renderer/web-view/web-view-attributes.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/renderer/web-view/web-view-attributes.js b/lib/renderer/web-view/web-view-attributes.js
index 51814b734927..f42fcc5e781b 100644
--- a/lib/renderer/web-view/web-view-attributes.js
+++ b/lib/renderer/web-view/web-view-attributes.js
@@ -66,10 +66,10 @@ class BooleanAttribute extends WebViewAttribute {
   }
 
   setValue (value) {
-    if (!value) {
-      this.webViewImpl.webviewNode.removeAttribute(this.name)
-    } else {
+    if (value) {
       this.webViewImpl.webviewNode.setAttribute(this.name, '')
+    } else {
+      this.webViewImpl.webviewNode.removeAttribute(this.name)
     }
   }
 }

From 0485069c7b56236a6dc01df491ca0f0951a68d0b Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 11:37:18 -0700
Subject: [PATCH 09/13] Use spread operator

---
 lib/renderer/web-view/guest-view-internal.js | 2 +-
 lib/renderer/web-view/web-view.js            | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/renderer/web-view/guest-view-internal.js b/lib/renderer/web-view/guest-view-internal.js
index 9f3bbf0dacfd..f07ded2c3155 100644
--- a/lib/renderer/web-view/guest-view-internal.js
+++ b/lib/renderer/web-view/guest-view-internal.js
@@ -68,7 +68,7 @@ module.exports = {
     })
 
     ipcRenderer.on(`ELECTRON_GUEST_VIEW_INTERNAL_DISPATCH_EVENT-${viewInstanceId}`, function (event, eventName, ...args) {
-      dispatchEvent.apply(null, [webView, eventName, eventName].concat(args))
+      dispatchEvent(webView, eventName, eventName, ...args)
     })
 
     ipcRenderer.on(`ELECTRON_GUEST_VIEW_INTERNAL_IPC_MESSAGE-${viewInstanceId}`, function (event, channel, ...args) {
diff --git a/lib/renderer/web-view/web-view.js b/lib/renderer/web-view/web-view.js
index 29a1945decc1..fc8b9a4abdde 100644
--- a/lib/renderer/web-view/web-view.js
+++ b/lib/renderer/web-view/web-view.js
@@ -396,7 +396,7 @@ var registerWebViewElement = function () {
     return function (...args) {
       const internal = v8Util.getHiddenValue(this, 'internal')
       if (internal.webContents) {
-        return internal.webContents[m].apply(internal.webContents, args)
+        return internal.webContents[m](...args)
       } else {
         throw new Error(`Cannot call ${m} because the webContents is unavailable. The WebView must be attached to the DOM and the dom-ready event emitted before this method can be called.`)
       }
@@ -409,7 +409,7 @@ var registerWebViewElement = function () {
   const createNonBlockHandler = function (m) {
     return function (...args) {
       const internal = v8Util.getHiddenValue(this, 'internal')
-      ipcRenderer.send.apply(ipcRenderer, ['ELECTRON_BROWSER_ASYNC_CALL_TO_GUEST_VIEW', null, internal.guestInstanceId, m].concat(args))
+      ipcRenderer.send('ELECTRON_BROWSER_ASYNC_CALL_TO_GUEST_VIEW', null, internal.guestInstanceId, m, ...args)
     }
   }
   for (const method of nonblockMethods) {

From 16f57b219b0bed00ec7edca53577b29efb8f2ef2 Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 15:12:54 -0700
Subject: [PATCH 10/13] Add resize event spec

---
 spec/webview-spec.js | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/spec/webview-spec.js b/spec/webview-spec.js
index d1acbeb80cd8..2c0b8098cef9 100644
--- a/spec/webview-spec.js
+++ b/spec/webview-spec.js
@@ -1256,4 +1256,40 @@ describe('<webview> tag', function () {
       document.body.appendChild(webview)
     })
   })
+
+  describe('DOM events', function () {
+    let div
+
+    beforeEach(function () {
+      div = document.createElement('div')
+      div.style.width = '100px'
+      div.style.height = '10px'
+      div.style.overflow = 'hidden'
+      webview.style.height = '100%'
+      webview.style.width = '100%'
+    })
+
+    afterEach(function () {
+      if (div != null) div.remove()
+    })
+
+    it('emits resize events', function (done) {
+      webview.addEventListener('dom-ready', function () {
+        div.style.width = '1234px'
+        div.style.height = '789px'
+      })
+
+      webview.addEventListener('resize', function onResize (event) {
+        webview.removeEventListener('resize', onResize)
+        assert.equal(event.newWidth, 1234)
+        assert.equal(event.newHeight, 789)
+        assert.equal(event.target, webview)
+        done()
+      })
+
+      webview.src = 'file://' + fixtures + '/pages/a.html'
+      div.appendChild(webview)
+      document.body.appendChild(div)
+    })
+  })
 })

From 19a5d2ba2bc9886557098932ba9970bae0d74e02 Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Thu, 3 Nov 2016 16:43:16 -0700
Subject: [PATCH 11/13] Use window close helper instead of destroying for
 coverage

---
 spec/webview-spec.js | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/spec/webview-spec.js b/spec/webview-spec.js
index 2c0b8098cef9..4fb9694b1b31 100644
--- a/spec/webview-spec.js
+++ b/spec/webview-spec.js
@@ -3,6 +3,7 @@ const path = require('path')
 const http = require('http')
 const url = require('url')
 const {app, session, getGuestWebContents, ipcMain, BrowserWindow} = require('electron').remote
+const {closeWindow} = require('./window-helpers')
 
 describe('<webview> tag', function () {
   this.timeout(20000)
@@ -21,10 +22,7 @@ describe('<webview> tag', function () {
       document.body.appendChild(webview)
     }
     webview.remove()
-    if (w) {
-      w.destroy()
-      w = null
-    }
+    return closeWindow(w).then(function () { w = null })
   })
 
   it('works without script tag in page', function (done) {

From 3c18de9c5aba8139982ca03ff6c6b5c7b890fc1f Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Mon, 7 Nov 2016 08:24:58 -0800
Subject: [PATCH 12/13] Only return when guestInstance is non-null

---
 lib/browser/guest-view-manager.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/browser/guest-view-manager.js b/lib/browser/guest-view-manager.js
index 639353609517..e36e66855689 100644
--- a/lib/browser/guest-view-manager.js
+++ b/lib/browser/guest-view-manager.js
@@ -278,13 +278,13 @@ ipcMain.on('ELECTRON_GUEST_VIEW_MANAGER_SET_SIZE', function (event, guestInstanc
 // Returns WebContents from its guest id.
 const getGuest = function (guestInstanceId) {
   const guestInstance = guestInstances[guestInstanceId]
-  return guestInstance != null ? guestInstance.guest : void 0
+  if (guestInstance != null) return guestInstance.guest
 }
 
 // Returns the embedder of the guest.
 const getEmbedder = function (guestInstanceId) {
   const guestInstance = guestInstances[guestInstanceId]
-  return guestInstance != null ? guestInstance.embedder : void 0
+  if (guestInstance != null) return guestInstance.embedder
 }
 
 exports.getGuest = getGuest

From 73774f21b7e519857ce23dda2656ba3ec6aacfcd Mon Sep 17 00:00:00 2001
From: Kevin Sawicki <kevinsawicki@gmail.com>
Date: Mon, 7 Nov 2016 08:28:02 -0800
Subject: [PATCH 13/13] :art:

---
 lib/browser/guest-view-manager.js | 2 +-
 spec/webview-spec.js              | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/browser/guest-view-manager.js b/lib/browser/guest-view-manager.js
index e36e66855689..556441f6332d 100644
--- a/lib/browser/guest-view-manager.js
+++ b/lib/browser/guest-view-manager.js
@@ -109,7 +109,7 @@ const createGuest = function (embedder, params) {
 
   const sendToEmbedder = (channel, ...args) => {
     const embedder = getEmbedder(guestInstanceId)
-    if (embedder) {
+    if (embedder != null) {
       embedder.send(`${channel}-${guest.viewInstanceId}`, ...args)
     }
   }
diff --git a/spec/webview-spec.js b/spec/webview-spec.js
index 4fb9694b1b31..e00bc222549a 100644
--- a/spec/webview-spec.js
+++ b/spec/webview-spec.js
@@ -1285,7 +1285,7 @@ describe('<webview> tag', function () {
         done()
       })
 
-      webview.src = 'file://' + fixtures + '/pages/a.html'
+      webview.src = `file://${fixtures}/pages/a.html`
       div.appendChild(webview)
       document.body.appendChild(div)
     })