How to use the webtorrent/package.json.version function in webtorrent

// property on Windows, and `CFBundleShortVersionString` on Mac.
  appVersion: pkg.version,

  // Package the application's source code into an archive, using Electron's archive
  // format. Mitigates issues around long path names on Windows and slightly speeds up
  // require().
  asar: {
    // A glob expression, that unpacks the files with matching names to the
    // "app.asar.unpacked" directory.
    unpack: 'WebTorrent*'
  },

  // The build version of the application. Maps to the FileVersion metadata property on
  // Windows, and CFBundleVersion on Mac. Note: Windows requires the build version to
  // start with a number. We're using the version of the underlying WebTorrent library.
  buildVersion: require('webtorrent/package.json').version,

  // The application source directory.
  dir: config.ROOT_PATH,

  // Pattern which specifies which files to ignore when copying files to create the
  // package(s).
  ignore: /^\/src|^\/dist|\/(appveyor.yml|\.appveyor.yml|\.github|appdmg|AUTHORS|CONTRIBUTORS|bench|benchmark|benchmark\.js|bin|bower\.json|component\.json|coverage|doc|docs|docs\.mli|dragdrop\.min\.js|example|examples|example\.html|example\.js|externs|ipaddr\.min\.js|Makefile|min|minimist|perf|rusha|simplepeer\.min\.js|simplewebsocket\.min\.js|static\/screenshot\.png|test|tests|test\.js|tests\.js|webtorrent\.min\.js|\.[^/]*|.*\.md|.*\.markdown)$/,

  // The application name.
  name: config.APP_NAME,

  // The base directory where the finished package(s) are created.
  out: DIST_PATH,

  // Replace an already existing output directory.
  overwrite: true,

// property on Windows, and `CFBundleShortVersionString` on OS X.
  'app-version': pkg.version,

  // Package the application's source code into an archive, using Electron's archive
  // format. Mitigates issues around long path names on Windows and slightly speeds up
  // require().
  asar: true,

  // A glob expression, that unpacks the files with matching names to the
  // "app.asar.unpacked" directory.
  'asar-unpack': 'WebTorrent*',

  // The build version of the application. Maps to the FileVersion metadata property on
  // Windows, and CFBundleVersion on OS X. Note: Windows requires the build version to
  // start with a number. We're using the version of the underlying WebTorrent library.
  'build-version': require('webtorrent/package.json').version,

  // The application source directory.
  dir: config.ROOT_PATH,

  // Pattern which specifies which files to ignore when copying files to create the
  // package(s).
  ignore: /^\/dist|\/(appveyor.yml|\.appveyor.yml|\.github|appdmg|AUTHORS|CONTRIBUTORS|bench|benchmark|benchmark\.js|bin|bower\.json|component\.json|coverage|doc|docs|docs\.mli|dragdrop\.min\.js|example|examples|example\.html|example\.js|externs|ipaddr\.min\.js|Makefile|min|minimist|perf|rusha|simplepeer\.min\.js|simplewebsocket\.min\.js|static\/screenshot\.png|test|tests|test\.js|tests\.js|webtorrent\.min\.js|\.[^\/]*|.*\.md|.*\.markdown)$/,

  // The application name.
  name: config.APP_NAME,

  // The base directory where the finished package(s) are created.
  out: DIST_PATH,

  // Replace an already existing output directory.
  overwrite: true,