Get unlimited public & private packages + team-based management with npm Teams.Learn more »

p-map

3.0.0 • Public • Published

p-map Build Status

Map over promises concurrently

Useful when you need to run promise-returning & async functions multiple times with different inputs concurrently.

Install

$ npm install p-map

Usage

const pMap = require('p-map');
const got = require('got');
 
const sites = [
    getWebsiteFromUsername('https://sindresorhus'), //=> Promise
    'https://ava.li',
    'https://github.com'
];
 
(async () => {
    const mapper = async site => {
        const {requestUrl} = await got.head(site);
        return requestUrl;
    };
 
  const result = await pMap(sites, mapper, {concurrency: 2});
 
    console.log(result);
    //=> ['https://sindresorhus.com/', 'https://ava.li/', 'https://github.com/']
})();

API

pMap(input, mapper, options?)

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.

input

Type: Iterable<Promise | unknown>

Iterated over concurrently in the mapper function.

mapper(element, index)

Type: Function

Expected to return a Promise or value.

options

Type: object

concurrency

Type: number
Default: Infinity
Minimum: 1

Number of concurrently pending promises returned by mapper.

stopOnError

Type: boolean
Default: true

When set to false, instead of stopping when a promise rejects, it will wait for all the promises to settle and then reject with an aggregated error containing all the errors from the rejected promises.

Related

  • p-all - Run promise-returning & async functions concurrently with optional limited concurrency
  • p-filter - Filter promises concurrently
  • p-times - Run promise-returning & async functions a specific number of times concurrently
  • p-props - Like Promise.all() but for Map and Object
  • p-map-series - Map over promises serially
  • p-queue - Promise queue with concurrency control
  • More…

Get professional support for this package with a Tidelift subscription
Tidelift helps make open source sustainable for maintainers while giving companies
assurances about security, maintenance, and licensing for their dependencies.

Install

npm i p-map

DownloadsWeekly Downloads

11,506,373

Version

3.0.0

License

MIT

Unpacked Size

8.39 kB

Total Files

5

Last publish

Collaborators

  • avatar