BUG: Unhandled rejection for async function when Promise.reject is returned

[Kurtas]

Hello,

I'm getting Unhandled rejection for the following code with v1.4.0

import Promise from 'bluebird';

const dataloaderFn = cmdList => {
  return Promise.mapSeries(cmdList, ({promise, params}) => {
    if (typeof promise === 'function') return promise(params);
    throw new TypeError(`Promise isn't fucntion`);
  });
};
const d = new DataLoader(dataloaderFn, {
  cacheKeyFn: item => item.key,
});
const job = async () => Promise.reject('fail');
const test = {
  key: 'a',
  promise: job,
  params: {},
};
d.load(test).catch(console.log);

The error is catched but node.js also report it as unhandled rejection, here is ouput

Unhandled rejection fail

fail

If you call job().catch(console.log); then it isn't reported as unhandled rejection.

If you also remove async annotation then it works also with DataLoader

[Kurtas]

The problem was in Bluebird petkaantonov/bluebird#1501