p-map

Map over async/promises concurrently

Control concurrent execution of async/promises functions.

Install

npm install @dinhoabreu/p-map

Usage

const pMap = require('@dinhoabreu/p-map')

const delay = ms => new Promise(resolve => setTimeout(resolve, ms))

const main = async () => {
  const list = Promise.resolve([
    Promise.resolve('google.com'),
    'todomvc.com',
    'github.com'
  ])
  const mapper = async site => {
    await delay(50)
    return `https://${site}`
  }
  const map = pMap(mapper, { concurrency: 2 })
  const result = await map(list)
  console.log(result)
  // => ['https://google.com/', 'https://todomvc.com/', 'https://github.com/']
}

main()

API

pMap(mapper, [options])

Creates a function map(input).

mapper(element, index)

Type: Function

Expected to return a Promise or value.

options

Type: Object

concurrency

Type: number Default: Infinity Minimum: 1

rejectOnError

Type: boolean Default: true

map(input)

With rejectOnError, returns a Promise that is fulfilled when all promises in input and ones returned from mapper are fulfilled, or rejects if any of the promises reject. The fulfilled value is an Array of the fulfilled values returned from mapper in input order.

Without rejectOnError, returns a Promise that is fulfilled when all promises in input and ones returned from mapper are fulfilled. The fulfilled value is an Array of Array the rejected or resolved values returned from mapper in input order. Check our <test/index.js> to see more.

input

Type: Iterable<Promise|any>

Iterated over concurrently in the mapper function.

License

MIT © Edison E. Abreu