function getReactNativeExternals(options) {
  return Promise.all(options.platforms.map(
    (platform) => getReactNativeDependencyNames({
      projectRoots: options.projectRoots || [process.cwd()],
      assetRoots: options.assetRoots || [process.cwd()],
      platform: platform,
    })
  )).then((moduleNamesGroupedByPlatform) => {
    const allReactNativeModules = Array.prototype.concat.apply([], moduleNamesGroupedByPlatform);
    return makeWebpackExternalsConfig(allReactNativeModules);
  });
}
Get a webpack 'externals' config for all React Native internal modules.
@param  {Object} options Options
@param  {String}         options.projectRoot The project root path, where `node_modules/` is found
@return {Object}         A webpack 'externals' config object