call async function on each array items

handler.test.js

const test = require('ava')


// testing the logic
const event = {
  Records: [
    {
      Sns: {
        a: 1,
        b: 2,
      }
    },
    {
      Sns: {
        a: 3,
        b: 4,
      }
    },
  ]
};

const actions = event.Records.map((record) => {
  return {
    a: record.Sns.a,
    b: record.Sns.b,
  }
})

const provider = (message) => {
  return `p:${message}`
}

function timeout(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

const af = (provider) => async ({ a, b }) => {
  await timeout(50);
  return { a: provider(a), b: provider(b) }
}

test('await all promise', async t => {
  const res = await Promise.all(actions.map(async act => (await af(provider)(act))))
  t.deepEqual(res, [{ a: 'p:1', b: 'p:2' }, { a: 'p:3', b: 'p:4' }]);
})