Promise.some :: A cross between Array.some, Promise.all, and Promise.race

promiseSome.js

function promiseSome(promises) ::
  // a cross between Promise.all and Promise.race
  promises = Array.from(promises).filter(e => e)
  return new Promise @ resolve => ::
    const result = []
    result.done = new Promise @ done => ::
      let count = promises.length
      if 0 === count ::
        resolve(result)
        done(result)
        return

      for const p of promises ::
        p.then @ do_append, do_error

      function do_append(ans) ::
        --count
        result.push(ans)
        resolve(result)

        if 0 < count :: return
        done(result)

      function do_error() ::
        --count

        if 0 < count :: return
        done(result)
        resolve(result)

async function answer(v) ::
  await sleep @ 10 + 100 * Math.random()
  return v

async function fail(e) ::
  await sleep @ 10 + 100 * Math.random()
  throw new Error @ e

function sleep(ms) ::
  return new Promise @ resolve =>
    setTimeout @ resolve, ms

main()
async function main() ::
  const outer = promiseSome @ @[]
      answer @ 1942
    , fail @ 'no'
    , fail @ 'noOOOOooOO'
    , answer @ 2142
    , answer @ 2042
    , fail @ 'likely not'
    , answer @ 42

  console.log @ outer

  const inner = await outer

  console.log @ inner, outer

  const done = await inner.done

  console.log @ done, inner, outer