diff --git a/lib/.eslintrc b/lib/.eslintrc
new file mode 100644
index 000000000000..7f629e4735d8
--- /dev/null
+++ b/lib/.eslintrc
@@ -0,0 +1,8 @@
+{
+  "parserOptions": {
+    "sourceType": "script"
+  },
+  "rules": {
+    "strict": ["error", "global"]
+  }
+}
diff --git a/lib/browser/api/auto-updater.js b/lib/browser/api/auto-updater.js
index d15fa85a1a4d..db3e8da158c3 100644
--- a/lib/browser/api/auto-updater.js
+++ b/lib/browser/api/auto-updater.js
@@ -1,3 +1,5 @@
+'use strict'
+
 if (process.platform === 'win32') {
   module.exports = require('@electron/internal/browser/api/auto-updater/auto-updater-win')
 } else {
diff --git a/lib/browser/api/auto-updater/auto-updater-native.js b/lib/browser/api/auto-updater/auto-updater-native.js
index c5ed2a94b914..d15a3c2e4a48 100644
--- a/lib/browser/api/auto-updater/auto-updater-native.js
+++ b/lib/browser/api/auto-updater/auto-updater-native.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const EventEmitter = require('events').EventEmitter
 const { autoUpdater, AutoUpdater } = process.atomBinding('auto_updater')
 
diff --git a/lib/browser/api/auto-updater/squirrel-update-win.js b/lib/browser/api/auto-updater/squirrel-update-win.js
index fecf7958cd0a..f1dc9387ca16 100644
--- a/lib/browser/api/auto-updater/squirrel-update-win.js
+++ b/lib/browser/api/auto-updater/squirrel-update-win.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const fs = require('fs')
 const path = require('path')
 const spawn = require('child_process').spawn
diff --git a/lib/browser/api/content-tracing.js b/lib/browser/api/content-tracing.js
index fbf676236b28..81bd70f1ebbf 100644
--- a/lib/browser/api/content-tracing.js
+++ b/lib/browser/api/content-tracing.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = process.atomBinding('content_tracing')
diff --git a/lib/browser/api/exports/electron.js b/lib/browser/api/exports/electron.js
index c2ba8725e494..0cf6c2673205 100644
--- a/lib/browser/api/exports/electron.js
+++ b/lib/browser/api/exports/electron.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const common = require('@electron/internal/common/api/exports/electron')
 // since browser module list is also used in renderer, keep it separate.
 const moduleList = require('@electron/internal/browser/api/module-list')
diff --git a/lib/browser/api/global-shortcut.js b/lib/browser/api/global-shortcut.js
index 9654e095fc06..ec9878ee43e2 100644
--- a/lib/browser/api/global-shortcut.js
+++ b/lib/browser/api/global-shortcut.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = process.atomBinding('global_shortcut').globalShortcut
diff --git a/lib/browser/api/ipc-main.js b/lib/browser/api/ipc-main.js
index 2c2978e97344..d610ac91f981 100644
--- a/lib/browser/api/ipc-main.js
+++ b/lib/browser/api/ipc-main.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const EventEmitter = require('events').EventEmitter
 
 const emitter = new EventEmitter()
diff --git a/lib/browser/api/menu-item-roles.js b/lib/browser/api/menu-item-roles.js
index 5cadcf92b2ed..4055d2fcbef3 100644
--- a/lib/browser/api/menu-item-roles.js
+++ b/lib/browser/api/menu-item-roles.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { app } = require('electron')
 
 const roles = {
diff --git a/lib/browser/api/menu-utils.js b/lib/browser/api/menu-utils.js
index 0a60a88c9e9d..74682d748334 100644
--- a/lib/browser/api/menu-utils.js
+++ b/lib/browser/api/menu-utils.js
@@ -1,3 +1,5 @@
+'use strict'
+
 function splitArray (arr, predicate) {
   const result = arr.reduce((multi, item) => {
     const current = multi[multi.length - 1]
diff --git a/lib/browser/api/module-list.js b/lib/browser/api/module-list.js
index 9f320c5298ed..02d73ec6d5ac 100644
--- a/lib/browser/api/module-list.js
+++ b/lib/browser/api/module-list.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const features = process.atomBinding('features')
 
 // Browser side modules, please sort alphabetically.
diff --git a/lib/browser/api/notification.js b/lib/browser/api/notification.js
index 19eca809f2d7..cc2374c11c77 100644
--- a/lib/browser/api/notification.js
+++ b/lib/browser/api/notification.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { EventEmitter } = require('events')
 const { Notification, isSupported } = process.atomBinding('notification')
 
diff --git a/lib/browser/api/power-monitor.js b/lib/browser/api/power-monitor.js
index 8890b6eb591f..5e3371dcc592 100644
--- a/lib/browser/api/power-monitor.js
+++ b/lib/browser/api/power-monitor.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { EventEmitter } = require('events')
 const { powerMonitor, PowerMonitor } = process.atomBinding('power_monitor')
 
diff --git a/lib/browser/api/power-save-blocker.js b/lib/browser/api/power-save-blocker.js
index 3e3c21fb62ec..964ead8a261d 100644
--- a/lib/browser/api/power-save-blocker.js
+++ b/lib/browser/api/power-save-blocker.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = process.atomBinding('power_save_blocker').powerSaveBlocker
diff --git a/lib/browser/api/protocol.js b/lib/browser/api/protocol.js
index cca01da05bc7..0f1b0e68d16f 100644
--- a/lib/browser/api/protocol.js
+++ b/lib/browser/api/protocol.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { app, session } = require('electron')
 
 // Global protocol APIs.
diff --git a/lib/browser/api/screen.js b/lib/browser/api/screen.js
index 3a911504b6b7..a91df7dda273 100644
--- a/lib/browser/api/screen.js
+++ b/lib/browser/api/screen.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { EventEmitter } = require('events')
 const { screen, Screen } = process.atomBinding('screen')
 
diff --git a/lib/browser/api/session.js b/lib/browser/api/session.js
index 60fed0ce6879..08c10eeff935 100644
--- a/lib/browser/api/session.js
+++ b/lib/browser/api/session.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { EventEmitter } = require('events')
 const { app } = require('electron')
 const { fromPartition, Session, Cookies } = process.atomBinding('session')
diff --git a/lib/browser/api/system-preferences.js b/lib/browser/api/system-preferences.js
index 5d963baae84a..bb663e886fd3 100644
--- a/lib/browser/api/system-preferences.js
+++ b/lib/browser/api/system-preferences.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { EventEmitter } = require('events')
 const { systemPreferences, SystemPreferences } = process.atomBinding('system_preferences')
 
diff --git a/lib/browser/api/touch-bar.js b/lib/browser/api/touch-bar.js
index bb65e20cadb6..ddacc733332e 100644
--- a/lib/browser/api/touch-bar.js
+++ b/lib/browser/api/touch-bar.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { EventEmitter } = require('events')
 
 let nextItemID = 1
diff --git a/lib/browser/api/tray.js b/lib/browser/api/tray.js
index 6f01540e39cd..1c6c108ec67b 100644
--- a/lib/browser/api/tray.js
+++ b/lib/browser/api/tray.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { EventEmitter } = require('events')
 const { Tray } = process.atomBinding('tray')
 
diff --git a/lib/browser/chrome-extension.js b/lib/browser/chrome-extension.js
index 17d4b6dbe1bf..8f10658320ae 100644
--- a/lib/browser/chrome-extension.js
+++ b/lib/browser/chrome-extension.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { app, ipcMain, webContents, BrowserWindow } = require('electron')
 const { getAllWebContents } = process.atomBinding('web_contents')
 const renderProcessPreferences = process.atomBinding('render_process_preferences').forAllWebContents()
diff --git a/lib/common/api/clipboard.js b/lib/common/api/clipboard.js
index b52524d75998..7e3ab510e08b 100644
--- a/lib/common/api/clipboard.js
+++ b/lib/common/api/clipboard.js
@@ -1,3 +1,5 @@
+'use strict'
+
 if (process.platform === 'linux' && process.type === 'renderer') {
   // On Linux we could not access clipboard in renderer process.
   module.exports = require('electron').remote.clipboard
diff --git a/lib/common/api/exports/electron.js b/lib/common/api/exports/electron.js
index 1ec9f799874e..49c670201ee8 100644
--- a/lib/common/api/exports/electron.js
+++ b/lib/common/api/exports/electron.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const moduleList = require('@electron/internal/common/api/module-list')
 
 exports.memoizedGetter = (getter) => {
diff --git a/lib/common/api/module-list.js b/lib/common/api/module-list.js
index b1ae86993fc8..38f3832caf7c 100644
--- a/lib/common/api/module-list.js
+++ b/lib/common/api/module-list.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // Common modules, please sort alphabetically
 module.exports = [
   { name: 'clipboard', file: 'clipboard' },
diff --git a/lib/common/api/native-image.js b/lib/common/api/native-image.js
index 614298f51a0e..f703f9476c3e 100644
--- a/lib/common/api/native-image.js
+++ b/lib/common/api/native-image.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = process.atomBinding('native_image')
diff --git a/lib/common/api/shell.js b/lib/common/api/shell.js
index 78e2a0938ba0..6907d90119e3 100644
--- a/lib/common/api/shell.js
+++ b/lib/common/api/shell.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = process.atomBinding('shell')
diff --git a/lib/common/asar.js b/lib/common/asar.js
index b6d5f859343d..d170ce9f70d9 100644
--- a/lib/common/asar.js
+++ b/lib/common/asar.js
@@ -1,3 +1,5 @@
+'use strict';
+
 (function () {
   const asar = process.binding('atom_common_asar')
   const assert = require('assert')
diff --git a/lib/common/asar_init.js b/lib/common/asar_init.js
index aa3567e8a2dd..d35b976dd823 100644
--- a/lib/common/asar_init.js
+++ b/lib/common/asar_init.js
@@ -1,3 +1,5 @@
+'use strict'
+
 ;(function () { // eslint-disable-line
   return function (process, require, asarSource) {
     const source = process.binding('natives')
diff --git a/lib/common/atom-binding-setup.js b/lib/common/atom-binding-setup.js
index 8292a23d698e..36954f56e0a2 100644
--- a/lib/common/atom-binding-setup.js
+++ b/lib/common/atom-binding-setup.js
@@ -1,3 +1,5 @@
+'use strict'
+
 module.exports = function atomBindingSetup (binding, processType) {
   return function atomBinding (name) {
     try {
diff --git a/lib/common/buffer-utils.js b/lib/common/buffer-utils.js
index baa739986453..8bfdf66ee390 100644
--- a/lib/common/buffer-utils.js
+++ b/lib/common/buffer-utils.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // Note: Don't use destructuring assignment for `Buffer`, or we'll hit a
 // browserify bug that makes the statement invalid, throwing an error in
 // sandboxed renderer.
diff --git a/lib/common/init.js b/lib/common/init.js
index 6a6762376bab..96d43f11330e 100644
--- a/lib/common/init.js
+++ b/lib/common/init.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const timers = require('timers')
 const util = require('util')
 
diff --git a/lib/common/parse-features-string.js b/lib/common/parse-features-string.js
index d6682f639a10..955ab8f480f7 100644
--- a/lib/common/parse-features-string.js
+++ b/lib/common/parse-features-string.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // parses a feature string that has the format used in window.open()
 // - `features` input string
 // - `emit` function(key, value) - called for each parsed KV
diff --git a/lib/common/reset-search-paths.js b/lib/common/reset-search-paths.js
index 11e4e49a097b..5890592e338a 100644
--- a/lib/common/reset-search-paths.js
+++ b/lib/common/reset-search-paths.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const path = require('path')
 const Module = require('module')
 
diff --git a/lib/isolated_renderer/init.js b/lib/isolated_renderer/init.js
index 8a2aba5b7bb8..a13256527ffc 100644
--- a/lib/isolated_renderer/init.js
+++ b/lib/isolated_renderer/init.js
@@ -1,7 +1,7 @@
-/* global binding */
-
 'use strict'
 
+/* global binding */
+
 const { send, sendSync } = binding
 
 const ipcRenderer = {
diff --git a/lib/renderer/api/desktop-capturer.js b/lib/renderer/api/desktop-capturer.js
index 00c657b638ae..0d2e7883ae32 100644
--- a/lib/renderer/api/desktop-capturer.js
+++ b/lib/renderer/api/desktop-capturer.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { ipcRenderer, nativeImage } = require('electron')
 
 const includes = [].includes
diff --git a/lib/renderer/api/exports/electron.js b/lib/renderer/api/exports/electron.js
index c3854259bfc8..63aa8d466202 100644
--- a/lib/renderer/api/exports/electron.js
+++ b/lib/renderer/api/exports/electron.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const common = require('@electron/internal/common/api/exports/electron')
 const moduleList = require('@electron/internal/renderer/api/module-list')
 
diff --git a/lib/renderer/api/module-list.js b/lib/renderer/api/module-list.js
index ed9732ee199c..cc9b12e2d2ad 100644
--- a/lib/renderer/api/module-list.js
+++ b/lib/renderer/api/module-list.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const features = process.atomBinding('features')
 
 // Renderer side modules, please sort alphabetically.
diff --git a/lib/renderer/api/screen.js b/lib/renderer/api/screen.js
index 9eecd49dc5bf..bc1c33e34b56 100644
--- a/lib/renderer/api/screen.js
+++ b/lib/renderer/api/screen.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = require('electron').remote.screen
diff --git a/lib/renderer/chrome-api.js b/lib/renderer/chrome-api.js
index 2d76c0c5ae05..629370b95968 100644
--- a/lib/renderer/chrome-api.js
+++ b/lib/renderer/chrome-api.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { ipcRenderer } = require('electron')
 const Event = require('@electron/internal/renderer/extensions/event')
 const url = require('url')
diff --git a/lib/renderer/content-scripts-injector.js b/lib/renderer/content-scripts-injector.js
index 4ac75fd8cf4a..19727948401e 100644
--- a/lib/renderer/content-scripts-injector.js
+++ b/lib/renderer/content-scripts-injector.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { ipcRenderer } = require('electron')
 const { runInThisContext } = require('vm')
 
diff --git a/lib/renderer/extensions/event.js b/lib/renderer/extensions/event.js
index 4a951407f594..93f5ad2f7e2f 100644
--- a/lib/renderer/extensions/event.js
+++ b/lib/renderer/extensions/event.js
@@ -1,3 +1,5 @@
+'use strict'
+
 class Event {
   constructor () {
     this.listeners = []
diff --git a/lib/renderer/extensions/i18n.js b/lib/renderer/extensions/i18n.js
index b28e61cb8617..027ec322b4aa 100644
--- a/lib/renderer/extensions/i18n.js
+++ b/lib/renderer/extensions/i18n.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // Implementation of chrome.i18n.getMessage
 // https://developer.chrome.com/extensions/i18n#method-getMessage
 //
diff --git a/lib/renderer/extensions/storage.js b/lib/renderer/extensions/storage.js
index f2a560f81c2c..40216c8cfbe5 100644
--- a/lib/renderer/extensions/storage.js
+++ b/lib/renderer/extensions/storage.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const fs = require('fs')
 const path = require('path')
 const { remote } = require('electron')
diff --git a/lib/renderer/extensions/web-navigation.js b/lib/renderer/extensions/web-navigation.js
index d907de1667c8..5ced9d5b79ed 100644
--- a/lib/renderer/extensions/web-navigation.js
+++ b/lib/renderer/extensions/web-navigation.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const Event = require('@electron/internal/renderer/extensions/event')
 const { ipcRenderer } = require('electron')
 
diff --git a/lib/renderer/inspector.js b/lib/renderer/inspector.js
index d6304f59d721..29c7cc12d358 100644
--- a/lib/renderer/inspector.js
+++ b/lib/renderer/inspector.js
@@ -1,3 +1,5 @@
+'use strict'
+
 window.onload = function () {
   // Use menu API to show context menu.
   window.InspectorFrontendHost.showContextMenuAtPoint = createMenu
diff --git a/lib/renderer/security-warnings.js b/lib/renderer/security-warnings.js
index 600eba610179..0ed48a194919 100644
--- a/lib/renderer/security-warnings.js
+++ b/lib/renderer/security-warnings.js
@@ -1,3 +1,5 @@
+'use strict'
+
 let shouldLog = null
 
 /**
diff --git a/lib/renderer/web-frame-init.js b/lib/renderer/web-frame-init.js
index 568f735d5cfc..bffd761612be 100644
--- a/lib/renderer/web-frame-init.js
+++ b/lib/renderer/web-frame-init.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const { ipcRenderer, webFrame } = require('electron')
 const errorUtils = require('@electron/internal/common/error-utils')
 
diff --git a/lib/renderer/web-view/web-view-constants.js b/lib/renderer/web-view/web-view-constants.js
index 327114be508d..86268f15780d 100644
--- a/lib/renderer/web-view/web-view-constants.js
+++ b/lib/renderer/web-view/web-view-constants.js
@@ -1,3 +1,5 @@
+'use strict'
+
 module.exports = {
   // Attributes.
   ATTRIBUTE_NAME: 'name',
diff --git a/lib/renderer/window-setup.js b/lib/renderer/window-setup.js
index c72dfe4318bb..f4ab44adb5bc 100644
--- a/lib/renderer/window-setup.js
+++ b/lib/renderer/window-setup.js
@@ -1,3 +1,5 @@
+'use strict'
+
 // This file should have no requires since it is used by the isolated context
 // preload bundle. Instead arguments should be passed in for everything it
 // needs.
@@ -21,8 +23,6 @@
 // - document.hidden
 // - document.visibilityState
 
-'use strict'
-
 const { defineProperty } = Object
 
 // Helper function to resolve relative url.
diff --git a/lib/sandboxed_renderer/api/exports/child_process.js b/lib/sandboxed_renderer/api/exports/child_process.js
index ff39e96a120e..d1abecfa25e1 100644
--- a/lib/sandboxed_renderer/api/exports/child_process.js
+++ b/lib/sandboxed_renderer/api/exports/child_process.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = require('electron').remote.require('child_process')
diff --git a/lib/sandboxed_renderer/api/exports/electron.js b/lib/sandboxed_renderer/api/exports/electron.js
index 2b69a1fa907b..2992797b7249 100644
--- a/lib/sandboxed_renderer/api/exports/electron.js
+++ b/lib/sandboxed_renderer/api/exports/electron.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const moduleList = require('@electron/internal/sandboxed_renderer/api/module-list')
 
 for (const {
diff --git a/lib/sandboxed_renderer/api/exports/fs.js b/lib/sandboxed_renderer/api/exports/fs.js
index 7342908e59a9..93c46e0293da 100644
--- a/lib/sandboxed_renderer/api/exports/fs.js
+++ b/lib/sandboxed_renderer/api/exports/fs.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = require('electron').remote.require('fs')
diff --git a/lib/sandboxed_renderer/api/exports/os.js b/lib/sandboxed_renderer/api/exports/os.js
index ecd0d38a63a6..bbbbe589235d 100644
--- a/lib/sandboxed_renderer/api/exports/os.js
+++ b/lib/sandboxed_renderer/api/exports/os.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = require('electron').remote.require('os')
diff --git a/lib/sandboxed_renderer/api/exports/path.js b/lib/sandboxed_renderer/api/exports/path.js
index f2b2f2a77fd4..fbc7b1808906 100644
--- a/lib/sandboxed_renderer/api/exports/path.js
+++ b/lib/sandboxed_renderer/api/exports/path.js
@@ -1 +1,3 @@
+'use strict'
+
 module.exports = require('electron').remote.require('path')
diff --git a/lib/sandboxed_renderer/api/ipc-renderer.js b/lib/sandboxed_renderer/api/ipc-renderer.js
index 402fa6cbe80d..629818629234 100644
--- a/lib/sandboxed_renderer/api/ipc-renderer.js
+++ b/lib/sandboxed_renderer/api/ipc-renderer.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const ipcRenderer = require('@electron/internal/renderer/api/ipc-renderer')
 
 const v8Util = process.atomBinding('v8_util')
diff --git a/lib/sandboxed_renderer/api/module-list.js b/lib/sandboxed_renderer/api/module-list.js
index b1d032d40670..e510462a7381 100644
--- a/lib/sandboxed_renderer/api/module-list.js
+++ b/lib/sandboxed_renderer/api/module-list.js
@@ -1,3 +1,5 @@
+'use strict'
+
 const features = process.atomBinding('features')
 
 module.exports = [
diff --git a/lib/sandboxed_renderer/init.js b/lib/sandboxed_renderer/init.js
index d7535c4cf6ba..914562250ce4 100644
--- a/lib/sandboxed_renderer/init.js
+++ b/lib/sandboxed_renderer/init.js
@@ -1,3 +1,5 @@
+'use strict'
+
 /* eslint no-eval: "off" */
 /* global binding, Buffer */
 const events = require('events')