refactor: Port renderer/init to TypeScript (#17027)

* refactor: Port renderer/init to TypeScript

* Update lib/renderer/init.ts

Co-Authored-By: felixrieseberg <felix@felixrieseberg.com>

* refactor: Type this a bit more loosely

* refactor: Type parseOption strictly

filenames.gni

@@ -65,7 +65,7 @@ filenames = {
     "lib/renderer/callbacks-registry.js",
     "lib/renderer/chrome-api.ts",
     "lib/renderer/content-scripts-injector.ts",
-    "lib/renderer/init.js",
+    "lib/renderer/init.ts",
     "lib/renderer/inspector.js",
     "lib/renderer/ipc-renderer-internal-utils.ts",
     "lib/renderer/ipc-renderer-internal.ts",

lib/renderer/init.ts

@@ -1,7 +1,6 @@
-'use strict'
+import { EventEmitter } from 'events'
+import * as path from 'path'
 
-const { EventEmitter } = require('events')
-const path = require('path')
 const Module = require('module')
 
 // We modified the original process.argv to let node.js load the
@@ -34,8 +33,16 @@ webFrameInit()
 // Process command line arguments.
 const { hasSwitch, getSwitchValue } = process.atomBinding('command_line')
 
-const parseOption = function (name, defaultValue, converter = value => value) {
-  return hasSwitch(name) ? converter(getSwitchValue(name)) : defaultValue
+const parseOption = function<T> (
+  name: string, defaultValue: T, converter?: (value: string) => T
+) {
+  return hasSwitch(name)
+    ? (
+      converter
+        ? converter(getSwitchValue(name))
+        : getSwitchValue(name)
+    )
+    : defaultValue
 }
 
 const contextIsolation = hasSwitch('context-isolation')
@@ -46,7 +53,7 @@ const isBackgroundPage = hasSwitch('background-page')
 const usesNativeWindowOpen = hasSwitch('native-window-open')
 
 const preloadScript = parseOption('preload', null)
-const preloadScripts = parseOption('preload-scripts', [], value => value.split(path.delimiter))
+const preloadScripts = parseOption('preload-scripts', [], value => value.split(path.delimiter)) as string[]
 const appPath = parseOption('app-path', null)
 const guestInstanceId = parseOption('guest-instance-id', null, value => parseInt(value))
 const openerId = parseOption('opener-id', null, value => parseInt(value))
@@ -132,9 +139,12 @@ if (nodeIntegration) {
   }
 
   // Redirect window.onerror to uncaughtException.
-  window.onerror = function (message, filename, lineno, colno, error) {
+  window.onerror = function (_message, _filename, _lineno, _colno, error) {
     if (global.process.listeners('uncaughtException').length > 0) {
-      global.process.emit('uncaughtException', error)
+      // We do not want to add `uncaughtException` to our definitions
+      // because we don't want anyone else (anywhere) to throw that kind
+      // of error.
+      global.process.emit('uncaughtException' as any, error as any)
       return true
     } else {
       return false

typings/internal-ambient.d.ts

@@ -36,7 +36,16 @@ declare namespace NodeJS {
   }
 }
 
-declare interface Window {
-  ELECTRON_DISABLE_SECURITY_WARNINGS?: boolean
-  ELECTRON_ENABLE_SECURITY_WARNINGS?: boolean
+declare module NodeJS  {
+  interface Global {
+    require: NodeRequire;
+    module: NodeModule;
+    __filename: string;
+    __dirname: string;
+  }
+}
+
+declare interface Window {
+  ELECTRON_DISABLE_SECURITY_WARNINGS?: boolean;
+  ELECTRON_ENABLE_SECURITY_WARNINGS?: boolean;
 }

typings/internal-electron.d.ts

@@ -103,3 +103,10 @@ declare namespace Chrome {
     type SendMessageCallback = (result: any) => void;
   }
 }
+
+interface Global extends NodeJS.Global {
+  require: NodeRequire;
+  module: NodeModule;
+  __filename: string;
+  __dirname: string;
+}