Fix `require` in script tags of pages for electron renderer process

hackModuleInHtmlForVirtualMachines.js

/**
 * convert `Shared Folders\projects\electron-quick-start`
 * to `Z:\projects\electron-quick-start`
 * See https://github.com/electron/electron/issues/6760
 *
 * Copy the source code to your page
 * or add a script tag with src refering to this module
 * **BEFORE** any module `require` takes place.
 *
 * Now you can `require` modules in HTML script tags as you do in node.
 *
 */

;(function hackModuleInHtmlForVirtualMachines () {
  if (typeof module === 'undefined' || typeof __dirname === 'undefined' || typeof __filename === 'undefined') return

  const path = require('path')

  // All modules except the main module should return
  if (!module.filename || path.isAbsolute(module.filename)) return

  // Only the main module should go here

  // The root of a normal path: '' or 'Z:'
  const root = process.cwd().split(path.sep).shift()
  // Virtual machines may have 'Shared Folders' as the root
  const VMRoot = __dirname.split(path.sep).shift()

  // correct the `__dirname` and `__filename` variable provided to the page
  __dirname = root + __dirname.slice(VMRoot.length)
  __filename = root + __filename.slice(VMRoot.length)

  // Node will use the `filename` and `paths` to locate child modules
  module.filename = __filename
  if (module.paths) {
    const VMPrefixLen = path.resolve(VMRoot).length
    module.paths.forEach((p, i) => {
      module.paths[i] = root + p.slice(VMPrefixLen)
    })
  }
})()