electron/docs/api/breaking-changes.md

Breaking Changes

Breaking changes will be documented here, and deprecation warnings added to JS code where possible, at least one major version before the change is made.

FIXME comments

The FIXME string is used in code comments to denote things that should be fixed for future releases. See https://github.com/electron/electron/search?q=fixme

Planned Breaking API Changes (9.0)

<webview>.getWebContents()

This API, which was deprecated in Electron 8.0, is now removed.

// Removed in Electron 9.0
webview.getWebContents()
// Replace with
const { remote } = require('electron')
remote.webContents.fromId(webview.getWebContentsId())

webFrame.setLayoutZoomLevelLimits()

Chromium has removed support for changing the layout zoom level limits, and it is beyond Electron's capacity to maintain it. The function was deprecated in Electron 8.x, and has been removed in Electron 9.x. The layout zoom level limits are now fixed at a minimum of 0.25 and a maximum of 5.0, as defined here.

Sending non-JS objects over IPC now throws an exception

In Electron 8.0, IPC was changed to use the Structured Clone Algorithm, bringing significant performance improvements. To help ease the transition, the old IPC serialization algorithm was kept and used for some objects that aren't serializable with Structured Clone. In particular, DOM objects (e.g. Element, Location and DOMMatrix), Node.js objects backed by C++ classes (e.g. process.env, some members of Stream), and Electron objects backed by C++ classes (e.g. WebContents, BrowserWindow and WebFrame) are not serializable with Structured Clone. Whenever the old algorithm was invoked, a deprecation warning was printed.

In Electron 9.0, the old serialization algorithm has been removed, and sending such non-serializable objects will now throw an "object could not be cloned" error.

Planned Breaking API Changes (8.0)

Values sent over IPC are now serialized with Structured Clone Algorithm

The algorithm used to serialize objects sent over IPC (through ipcRenderer.send, ipcRenderer.sendSync, WebContents.send and related methods) has been switched from a custom algorithm to V8's built-in Structured Clone Algorithm, the same algorithm used to serialize messages for postMessage. This brings about a 2x performance improvement for large messages, but also brings some breaking changes in behavior.

• Sending Functions, Promises, WeakMaps, WeakSets, or objects containing any such values, over IPC will now throw an exception, instead of silently converting the functions to undefined.

// Previously:
ipcRenderer.send('channel', { value: 3, someFunction: () => {} })
// => results in { value: 3 } arriving in the main process

// From Electron 8:
ipcRenderer.send('channel', { value: 3, someFunction: () => {} })
// => throws Error("() => {} could not be cloned.")

• NaN, Infinity and -Infinity will now be correctly serialized, instead of being converted to null.
• Objects containing cyclic references will now be correctly serialized, instead of being converted to null.
• Set, Map, Error and RegExp values will be correctly serialized, instead of being converted to {}.
• BigInt values will be correctly serialized, instead of being converted to null.
• Sparse arrays will be serialized as such, instead of being converted to dense arrays with nulls.
• Date objects will be transferred as Date objects, instead of being converted to their ISO string representation.
• Typed Arrays (such as Uint8Array, Uint16Array, Uint32Array and so on) will be transferred as such, instead of being converted to Node.js Buffer.
• Node.js Buffer objects will be transferred as Uint8Arrays. You can convert a Uint8Array back to a Node.js Buffer by wrapping the underlying ArrayBuffer:

Buffer.from(value.buffer, value.byteOffset, value.byteLength)

Sending any objects that aren't native JS types, such as DOM objects (e.g. Element, Location, DOMMatrix), Node.js objects (e.g. process.env, Stream), or Electron objects (e.g. WebContents, BrowserWindow, WebFrame) is deprecated. In Electron 8, these objects will be serialized as before with a DeprecationWarning message, but starting in Electron 9, sending these kinds of objects will throw a 'could not be cloned' error.

<webview>.getWebContents()

This API is implemented using the remote module, which has both performance and security implications. Therefore its usage should be explicit.

// Deprecated
webview.getWebContents()
// Replace with
const { remote } = require('electron')
remote.webContents.fromId(webview.getWebContentsId())

However, it is recommended to avoid using the remote module altogether.

// main
const { ipcMain, webContents } = require('electron')

const getGuestForWebContents = function (webContentsId, contents) {
  const guest = webContents.fromId(webContentsId)
  if (!guest) {
    throw new Error(`Invalid webContentsId: ${webContentsId}`)
  }
  if (guest.hostWebContents !== contents) {
    throw new Error(`Access denied to webContents`)
  }
  return guest
}

ipcMain.handle('openDevTools', (event, webContentsId) => {
  const guest = getGuestForWebContents(webContentsId, event.sender)
  guest.openDevTools()
})

// renderer
const { ipcRenderer } = require('electron')

ipcRenderer.invoke('openDevTools', webview.getWebContentsId())

webFrame.setLayoutZoomLevelLimits()

Chromium has removed support for changing the layout zoom level limits, and it is beyond Electron's capacity to maintain it. The function will emit a warning in Electron 8.x, and cease to exist in Electron 9.x. The layout zoom level limits are now fixed at a minimum of 0.25 and a maximum of 5.0, as defined here.

Planned Breaking API Changes (7.0)

Node Headers URL

This is the URL specified as disturl in a .npmrc file or as the --dist-url command line flag when building native Node modules. Both will be supported for the foreseeable future but it is recommended that you switch.

Deprecated: https://atom.io/download/electron

Replace with: https://electronjs.org/headers

session.clearAuthCache(options)

The session.clearAuthCache API no longer accepts options for what to clear, and instead unconditionally clears the whole cache.

// Deprecated
session.clearAuthCache({ type: 'password' })
// Replace with
session.clearAuthCache()

powerMonitor.querySystemIdleState

// Removed in Electron 7.0
powerMonitor.querySystemIdleState(threshold, callback)
// Replace with synchronous API
const idleState = getSystemIdleState(threshold)

powerMonitor.querySystemIdleTime

// Removed in Electron 7.0
powerMonitor.querySystemIdleTime(callback)
// Replace with synchronous API
const idleTime = getSystemIdleTime()

webFrame Isolated World APIs

// Removed in Electron 7.0
webFrame.setIsolatedWorldContentSecurityPolicy(worldId, csp)
webFrame.setIsolatedWorldHumanReadableName(worldId, name)
webFrame.setIsolatedWorldSecurityOrigin(worldId, securityOrigin)
// Replace with
webFrame.setIsolatedWorldInfo(
  worldId,
  {
    securityOrigin: 'some_origin',
    name: 'human_readable_name',
    csp: 'content_security_policy'
  })

Removal of deprecated marked property on getBlinkMemoryInfo

This property was removed in Chromium 77, and as such is no longer available.

webkitdirectory attribute for <input type="file"/>

The webkitdirectory property on HTML file inputs allows them to select folders. Previous versions of Electron had an incorrect implementation where the event.target.files of the input returned a FileList that returned one File corresponding to the selected folder.

As of Electron 7, that FileList is now list of all files contained within the folder, similarly to Chrome, Firefox, and Edge (link to MDN docs).

As an illustration, take a folder with this structure:

folder
├── file1
├── file2
└── file3

In Electron <=6, this would return a FileList with a File object for:

path/to/folder

In Electron 7, this now returns a FileList with a File object for:

/path/to/folder/file3
/path/to/folder/file2
/path/to/folder/file1

Note that webkitdirectory no longer exposes the path to the selected folder. If you require the path to the selected folder rather than the folder contents, see the dialog.showOpenDialog API (link).

Planned Breaking API Changes (6.0)

win.setMenu(null)

// Deprecated
win.setMenu(null)
// Replace with
win.removeMenu()

contentTracing.getTraceBufferUsage()

// Deprecated
contentTracing.getTraceBufferUsage((percentage, value) => {
  // do something
})
// Replace with
contentTracing.getTraceBufferUsage().then(infoObject => {
  // infoObject has percentage and value fields
})

electron.screen in renderer process

// Deprecated
require('electron').screen
// Replace with
require('electron').remote.screen

require in sandboxed renderers

// Deprecated
require('child_process')
// Replace with
require('electron').remote.require('child_process')

// Deprecated
require('fs')
// Replace with
require('electron').remote.require('fs')

// Deprecated
require('os')
// Replace with
require('electron').remote.require('os')

// Deprecated
require('path')
// Replace with
require('electron').remote.require('path')

powerMonitor.querySystemIdleState

// Deprecated
powerMonitor.querySystemIdleState(threshold, callback)
// Replace with synchronous API
const idleState = getSystemIdleState(threshold)

powerMonitor.querySystemIdleTime

// Deprecated
powerMonitor.querySystemIdleTime(callback)
// Replace with synchronous API
const idleTime = getSystemIdleTime()

app.enableMixedSandbox

// Deprecated
app.enableMixedSandbox()

Mixed-sandbox mode is now enabled by default.

Tray

Under macOS Catalina our former Tray implementation breaks. Apple's native substitute doesn't support changing the highlighting behavior.

// Deprecated
tray.setHighlightMode(mode)
// API will be removed in v7.0 without replacement.

Planned Breaking API Changes (5.0)

new BrowserWindow({ webPreferences })

The following webPreferences option default values are deprecated in favor of the new defaults listed below.

Property	Deprecated Default	New Default
contextIsolation	false	true
nodeIntegration	true	false
webviewTag	nodeIntegration if set else true	false

E.g. Re-enabling the webviewTag

const w = new BrowserWindow({
  webPreferences: {
    webviewTag: true
  }
})

nativeWindowOpen

Child windows opened with the nativeWindowOpen option will always have Node.js integration disabled, unless nodeIntegrationInSubFrames is `true.

Privileged Schemes Registration

Renderer process APIs webFrame.setRegisterURLSchemeAsPrivileged and webFrame.registerURLSchemeAsBypassingCSP as well as browser process API protocol.registerStandardSchemes have been removed. A new API, protocol.registerSchemesAsPrivileged has been added and should be used for registering custom schemes with the required privileges. Custom schemes are required to be registered before app ready.

webFrame Isolated World APIs

// Deprecated
webFrame.setIsolatedWorldContentSecurityPolicy(worldId, csp)
webFrame.setIsolatedWorldHumanReadableName(worldId, name)
webFrame.setIsolatedWorldSecurityOrigin(worldId, securityOrigin)
// Replace with
webFrame.setIsolatedWorldInfo(
  worldId,
  {
    securityOrigin: 'some_origin',
    name: 'human_readable_name',
    csp: 'content_security_policy'
  })

webFrame.setSpellCheckProvider

The spellCheck callback is now asynchronous, and autoCorrectWord parameter has been removed.

// Deprecated
webFrame.setSpellCheckProvider('en-US', true, {
  spellCheck: (text) => {
    return !spellchecker.isMisspelled(text)
  }
})
// Replace with
webFrame.setSpellCheckProvider('en-US', {
  spellCheck: (words, callback) => {
    callback(words.filter(text => spellchecker.isMisspelled(text)))
  }
})

Planned Breaking API Changes (4.0)

The following list includes the breaking API changes made in Electron 4.0.

app.makeSingleInstance

// Deprecated
app.makeSingleInstance((argv, cwd) => {
  /* ... */
})
// Replace with
app.requestSingleInstanceLock()
app.on('second-instance', (event, argv, cwd) => {
  /* ... */
})

app.releaseSingleInstance

// Deprecated
app.releaseSingleInstance()
// Replace with
app.releaseSingleInstanceLock()

app.getGPUInfo

app.getGPUInfo('complete')
// Now behaves the same with `basic` on macOS
app.getGPUInfo('basic')

win_delay_load_hook

When building native modules for windows, the win_delay_load_hook variable in the module's binding.gyp must be true (which is the default). If this hook is not present, then the native module will fail to load on Windows, with an error message like Cannot find module. See the native module guide for more.

Breaking API Changes (3.0)

The following list includes the breaking API changes in Electron 3.0.

app

// Deprecated
app.getAppMemoryInfo()
// Replace with
app.getAppMetrics()

// Deprecated
const metrics = app.getAppMetrics()
const { memory } = metrics[0] // Deprecated property

BrowserWindow

// Deprecated
let optionsA = { webPreferences: { blinkFeatures: '' } }
let windowA = new BrowserWindow(optionsA)
// Replace with
let optionsB = { webPreferences: { enableBlinkFeatures: '' } }
let windowB = new BrowserWindow(optionsB)

// Deprecated
window.on('app-command', (e, cmd) => {
  if (cmd === 'media-play_pause') {
    // do something
  }
})
// Replace with
window.on('app-command', (e, cmd) => {
  if (cmd === 'media-play-pause') {
    // do something
  }
})

clipboard

// Deprecated
clipboard.readRtf()
// Replace with
clipboard.readRTF()

// Deprecated
clipboard.writeRtf()
// Replace with
clipboard.writeRTF()

// Deprecated
clipboard.readHtml()
// Replace with
clipboard.readHTML()

// Deprecated
clipboard.writeHtml()
// Replace with
clipboard.writeHTML()

crashReporter

// Deprecated
crashReporter.start({
  companyName: 'Crashly',
  submitURL: 'https://crash.server.com',
  autoSubmit: true
})
// Replace with
crashReporter.start({
  companyName: 'Crashly',
  submitURL: 'https://crash.server.com',
  uploadToServer: true
})

nativeImage

// Deprecated
nativeImage.createFromBuffer(buffer, 1.0)
// Replace with
nativeImage.createFromBuffer(buffer, {
  scaleFactor: 1.0
})

process

// Deprecated
const info = process.getProcessMemoryInfo()

screen

// Deprecated
screen.getMenuBarHeight()
// Replace with
screen.getPrimaryDisplay().workArea

session

// Deprecated
ses.setCertificateVerifyProc((hostname, certificate, callback) => {
  callback(true)
})
// Replace with
ses.setCertificateVerifyProc((request, callback) => {
  callback(0)
})

Tray

// Deprecated
tray.setHighlightMode(true)
// Replace with
tray.setHighlightMode('on')

// Deprecated
tray.setHighlightMode(false)
// Replace with
tray.setHighlightMode('off')

webContents

// Deprecated
webContents.openDevTools({ detach: true })
// Replace with
webContents.openDevTools({ mode: 'detach' })

// Removed
webContents.setSize(options)
// There is no replacement for this API

webFrame

// Deprecated
webFrame.registerURLSchemeAsSecure('app')
// Replace with
protocol.registerStandardSchemes(['app'], { secure: true })

// Deprecated
webFrame.registerURLSchemeAsPrivileged('app', { secure: true })
// Replace with
protocol.registerStandardSchemes(['app'], { secure: true })

<webview>

// Removed
webview.setAttribute('disableguestresize', '')
// There is no replacement for this API

// Removed
webview.setAttribute('guestinstance', instanceId)
// There is no replacement for this API

// Keyboard listeners no longer work on webview tag
webview.onkeydown = () => { /* handler */ }
webview.onkeyup = () => { /* handler */ }

Node Headers URL

This is the URL specified as disturl in a .npmrc file or as the --dist-url command line flag when building native Node modules.

Deprecated: https://atom.io/download/atom-shell

Replace with: https://atom.io/download/electron

Breaking API Changes (2.0)

The following list includes the breaking API changes made in Electron 2.0.

BrowserWindow

// Deprecated
let optionsA = { titleBarStyle: 'hidden-inset' }
let windowA = new BrowserWindow(optionsA)
// Replace with
let optionsB = { titleBarStyle: 'hiddenInset' }
let windowB = new BrowserWindow(optionsB)

menu

// Removed
menu.popup(browserWindow, 100, 200, 2)
// Replaced with
menu.popup(browserWindow, { x: 100, y: 200, positioningItem: 2 })

nativeImage

// Removed
nativeImage.toPng()
// Replaced with
nativeImage.toPNG()

// Removed
nativeImage.toJpeg()
// Replaced with
nativeImage.toJPEG()

process

• process.versions.electron and process.version.chrome will be made read-only properties for consistency with the other process.versions properties set by Node.

webContents

// Removed
webContents.setZoomLevelLimits(1, 2)
// Replaced with
webContents.setVisualZoomLevelLimits(1, 2)

webFrame

// Removed
webFrame.setZoomLevelLimits(1, 2)
// Replaced with
webFrame.setVisualZoomLevelLimits(1, 2)

<webview>

// Removed
webview.setZoomLevelLimits(1, 2)
// Replaced with
webview.setVisualZoomLevelLimits(1, 2)

Duplicate ARM Assets

Each Electron release includes two identical ARM builds with slightly different filenames, like electron-v1.7.3-linux-arm.zip and electron-v1.7.3-linux-armv7l.zip. The asset with the v7l prefix was added to clarify to users which ARM version it supports, and to disambiguate it from future armv6l and arm64 assets that may be produced.

The file without the prefix is still being published to avoid breaking any setups that may be consuming it. Starting at 2.0, the unprefixed file will no longer be published.

For details, see 6986 and 7189.