const pred = () => Math.random() > 0.5;

const authSuccess = () => new Promise(
  ( resolve, reject ) => pred() ? resolve(200) : reject('Network Error')
); // produce network errors just to be more realistic

const authFail = () => new Promise(
  ( resolve, reject ) => pred() ? resolve(401) : reject('Network Error')
); // omitting the Response interface as it's not needed in the example

const wrapped = net => options => new Promise(( resolve, reject ) => net(options).then(
  code => code !== 401 ? resolve('Data') : reject('Unauthorized'), // this is not necessarily the only then() in chain
  reject
));

console.clear(); // useful in repls

wrapped(authSuccess)().then(console.log, console.log); // using console.log as simplest effect