How to use the @parcel/workers.isWorker function in @parcel/workers

if (align === 'right') {
    return pad + text;
  }

  return text + pad;
}

// Count visible characters in a string
function stringWidth(string) {
  return countBreaks(stripAnsi('' + string));
}

// If we are in a worker, make a proxy class which will
// send the logger calls to the main process via IPC.
// These are handled in WorkerFarm and directed to handleMessage above.
if (WorkerFarm.isWorker()) {
  class LoggerProxy {}
  for (let method of Object.getOwnPropertyNames(Logger.prototype)) {
    LoggerProxy.prototype[method] = (...args) => {
      WorkerFarm.callMaster(
        {
          location: __filename,
          method,
          args
        },
        false
      );
    };
  }

  module.exports = new LoggerProxy();
} else {

export function installPackage(
  fs: FileSystem,
  modules: Array,
  filePath: FilePath,
  options?: InstallOptions,
): Promise {
  if (WorkerFarm.isWorker()) {
    let workerApi = WorkerFarm.getWorkerApi();
    return workerApi.callMaster({
      location: __filename,
      args: [fs, modules, filePath, options],
      method: '_addToInstallQueue',
    });
  }

  return _addToInstallQueue(fs, modules, filePath, options);
}