message: Clean up resources when process exits.
diff: @@ -102,6 +102,7 @@ export function fork(modulePath: string, args: string[], options: IForkOpts, cal
  }
  serverClosed = true;
  + process.removeListener('exit', closeServer);
  stdOutServer.close();
  };
  @@ -123,4 +124,7 @@ export function fork(modulePath: string, args: string[], options: IForkOpts, cal
  closeServer();
  reject(err);
  });
  +
  + // On exit still close server
  + process.once('exit', closeServer);
  }
  