refactor: convert more files to typescript (#16820)

lib/common/atom-binding-setup.ts

@@ -1,7 +1,5 @@
-'use strict'
-
-module.exports = function atomBindingSetup (binding, processType) {
-  return function atomBinding (name) {
+export function atomBindingSetup (binding: typeof process['binding'], processType: typeof process['type']): typeof process['atomBinding'] {
+  return function atomBinding (name: string) {
     try {
       return binding(`atom_${processType}_${name}`)
     } catch (error) {

lib/common/init.ts

@@ -1,9 +1,11 @@
-'use strict'
+import * as timers from 'timers'
+import * as util from 'util'
 
-const timers = require('timers')
-const util = require('util')
+import { atomBindingSetup } from '@electron/internal/common/atom-binding-setup'
 
-process.atomBinding = require('@electron/internal/common/atom-binding-setup')(process.binding, process.type)
+process.atomBinding = atomBindingSetup(process.binding, process.type)
+
+type AnyFn = (...args: any[]) => any
 
 // setImmediate and process.nextTick makes use of uv_check and uv_prepare to
 // run the callbacks, however since we only run uv loop on requests, the
@@ -11,19 +13,25 @@ process.atomBinding = require('@electron/internal/common/atom-binding-setup')(pr
 // which would delay the callbacks for arbitrary long time. So we should
 // initiatively activate the uv loop once setImmediate and process.nextTick is
 // called.
-const wrapWithActivateUvLoop = function (func) {
+const wrapWithActivateUvLoop = function <T extends AnyFn> (func: T): T {
   return wrap(func, function (func) {
-    return function () {
+    return function (this: any, ...args: any[]) {
       process.activateUvLoop()
-      return func.apply(this, arguments)
+      return func.apply(this, args)
     }
-  })
+  }) as T
 }
 
-function wrap (func, wrapper) {
+/**
+ * Casts to any below for func are due to Typescript not supporting symbols
+ * in index signatures
+ *
+ * Refs: https://github.com/Microsoft/TypeScript/issues/1863
+ */
+function wrap <T extends AnyFn> (func: T, wrapper: (fn: AnyFn) => T) {
   const wrapped = wrapper(func)
-  if (func[util.promisify.custom]) {
-    wrapped[util.promisify.custom] = wrapper(func[util.promisify.custom])
+  if ((func as any)[util.promisify.custom]) {
+    (wrapped as any)[util.promisify.custom] = wrapper((func as any)[util.promisify.custom])
   }
   return wrapped
 }
@@ -47,7 +55,11 @@ if (process.platform === 'win32') {
   const { Readable } = require('stream')
   const stdin = new Readable()
   stdin.push(null)
-  process.__defineGetter__('stdin', function () {
-    return stdin
+  Object.defineProperty(process, 'stdin', {
+    configurable: false,
+    enumerable: true,
+    get () {
+      return stdin
+    }
   })
 }

lib/common/reset-search-paths.ts

@@ -1,6 +1,5 @@
-'use strict'
+import * as path from 'path'
 
-const path = require('path')
 const Module = require('module')
 
 // Clear Node's global search paths.
@@ -8,13 +7,13 @@ Module.globalPaths.length = 0
 
 // Clear current and parent(init.js)'s search paths.
 module.paths = []
-module.parent.paths = []
+module.parent!.paths = []
 
 // Prevent Node from adding paths outside this app to search paths.
 const resourcesPathWithTrailingSlash = process.resourcesPath + path.sep
 const originalNodeModulePaths = Module._nodeModulePaths
-Module._nodeModulePaths = function (from) {
-  const paths = originalNodeModulePaths(from)
+Module._nodeModulePaths = function (from: string) {
+  const paths: string[] = originalNodeModulePaths(from)
   const fromPath = path.resolve(from) + path.sep
   // If "from" is outside the app then we do nothing.
   if (fromPath.startsWith(resourcesPathWithTrailingSlash)) {
@@ -31,9 +30,9 @@ const INTERNAL_MODULE_PREFIX = '@electron/internal/'
 
 // Patch Module._resolveFilename to always require the Electron API when
 // require('electron') is done.
-const electronPath = path.join(__dirname, '..', process.type, 'api', 'exports', 'electron.js')
+const electronPath = path.join(__dirname, '..', process.type!, 'api', 'exports', 'electron.js')
 const originalResolveFilename = Module._resolveFilename
-Module._resolveFilename = function (request, parent, isMain) {
+Module._resolveFilename = function (request: string, parent: NodeModule, isMain: boolean) {
   if (request === 'electron') {
     return electronPath
   } else if (request.startsWith(INTERNAL_MODULE_PREFIX) && request.length > INTERNAL_MODULE_PREFIX.length) {