Inverse of ES6 Promise.all

Inverse of Promise.all()

// Inspired by Jordan Harband(https://github.com/ljharb)

let user1 = { role: 'A'};
let user2 = { role: 'B'};
let user3 = { role: 'C'};

const checkA = x => {
  return new Promise ( function (resolve, reject) {
      if (x.role === 'A') {
        return resolve("CheckA resolved");
      } else {
        return reject("CheckA rejected");
      }
  });
};

const checkB = x => {
  return new Promise ( function (resolve, reject) {
      if (x.role === 'B') {
        return resolve("CheckB resolved");
      } else {
        return reject("CheckB rejected");
      }
  });
};


function antiAll(promises) { 
  const thrower = x => { throw x; }; 
  const identity = x => x; 
  return Promise.all(promises.map(x => x.then(thrower, identity)))
    .then(thrower, identity); 
}
antiAll([checkA(user1), checkB(user1)])
.then((res) => {
  console.log(res);
})
.catch( (err) => {
  console.log(err);
});