p-map

  • Version 5.1.0
  • Published
  • 10.3 kB
  • 1 dependency
  • MIT license

Install

npm i p-map
yarn add p-map
pnpm add p-map

Overview

Map over promises concurrently

Index

Variables

Functions

Interfaces

Type Aliases

Variables

variable pMapSkip

const pMapSkip: Symbol;
  • Return this value from a mapper function to skip including the value in the returned array.

    Example 1

    import pMap, {pMapSkip} from 'p-map';
    import got from 'got';
    const sites = [
    getWebsiteFromUsername('sindresorhus'), //=> Promise
    'https://avajs.dev',
    'https://example.invalid',
    'https://github.com'
    ];
    const mapper = async site => {
    try {
    const {requestUrl} = await got.head(site);
    return requestUrl;
    } catch {
    return pMapSkip
    }
    };
    const result = await pMap(sites, mapper, {concurrency: 2});
    console.log(result);
    //=> ['https://sindresorhus.com/', 'https://avajs.dev/', 'https://github.com/']

Functions

function pMap

pMap: <Element, NewElement>(
input: Iterable<Element>,
mapper: Mapper<Element, NewElement>,
options?: Options
) => Promise<Array<Exclude<NewElement, typeof pMapSkip>>>;
  • Parameter input

    Iterated over concurrently in the mapper function.

    Parameter mapper

    Function which is called for every item in input. Expected to return a Promise or value.

    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.

    Example 1

    import pMap from 'p-map';
    import got from 'got';
    const sites = [
    getWebsiteFromUsername('sindresorhus'), //=> Promise
    'https://avajs.dev',
    'https://github.com'
    ];
    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://avajs.dev/', 'https://github.com/']

Interfaces

interface Options

interface Options {}

    property concurrency

    readonly concurrency?: number;
    • Number of concurrently pending promises returned by mapper.

      Must be an integer from 1 and up or Infinity.

      Infinity

    property stopOnError

    readonly stopOnError?: boolean;
    • 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](https://github.com/sindresorhus/aggregate-error) containing all the errors from the rejected promises.

      true

    Type Aliases

    type Mapper

    type Mapper<Element = any, NewElement = unknown> = (
    element: Element,
    index: number
    ) => NewElement | Promise<NewElement>;
    • Function which is called for every item in input. Expected to return a Promise or value.

      Parameter element

      Iterated element.

      Parameter index

      Index of the element in the source array.

    Package Files (1)

    Dependencies (1)

    Dev Dependencies (7)

    Peer Dependencies (0)

    No peer dependencies.

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