A recursive Promise.all() that works on objects

main.js

const zipObject = function (keys, values) {
  const result = {};

  keys.forEach((key, i) => {
    result[key] = values[i];
  });

  return result;
};

const recursiveObjectPromiseAll = function (obj) {
  const keys = Object.keys(obj);
  return Promise.all(keys.map(key => {
    const value = obj[key];
    // Promise.resolve(value) !== value should work, but !value.then always works
    if (typeof value === 'object' && !value.then) {
      return recursiveObjectPromiseAll(value);
    }
    return value;
  }))
    .then(result => zipObject(keys, result));
};

shorter ;)

const zipObject = (keys = [], values = []) => keys.reduce((accumulator, key, index) => Object.assign(accumulator,{[key]: values[index]}),{});

I would probably author zipObject like this:

const zipObject = (keys = [], values = []) => {
  return keys.reduce((accumulator, key, index) => {
    accumulator[key] = values[index]
    return accumulator
  }, {})
}

:)