How to return array of promises inside map in javascript

Question

function handler(){
    const results = [].map((item) => {
      a();
      b();
    })
    Promise.allSettled(results);
  }

  function a() {
    // returns promise
  }
  function b() {
    // returns promise
  }
}

How to modify the above code so that I can pass array of promises to promise.allSettled(results)

I tried this but not sure if this is correct way?

function handler() {
    const results = [].map((item) => {
      const out1 = a();
      const out2 = b();
      return [...out1, ...out2];
    })
    Promise.allSettled(results);
}

you want flatMap

epascarello
– epascarello

2022-11-22 17:01:05 +00:00
Commented Nov 22, 2022 at 17:01 — epascarello
– epascarello, Commented Nov 22, 2022 at 17:01

epascarello · Accepted Answer · 2022-11-22 17:15:07Z

1

Use flatMap

const a = [1,2,3,4,5,6];

const b = a.flatMap(v => [Promise.resolve(a), Promise.reject(a)])

Promise.allSettled(b).then(x => console.log(x));

edited Nov 22, 2022 at 17:15

answered Nov 22, 2022 at 17:09

epascarello

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Comments

codinn.dev · Accepted Answer · 2022-11-22 17:08:57Z

0

This should work

function handler() {
    const results = [].map((item) => {
      const out1 = a();
      const out2 = b();
      return [...out1, ...out2];
    })
    Promise.allSettled(results.flat());
}

answered Nov 22, 2022 at 17:08

codinn.dev

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