p-filter

Filter promises concurrently

Useful when you need to run promise-returning & async functions multiple times with different inputs concurrently and get a filtered down result.

Install

$ npm install p-filter

Usage

const pFilter = require('p-filter');
const getWeather = require('get-weather'); // not a real module

const places = [
	getCapital('Norway').then(info => info.name),
	'Bangkok, Thailand',
	'Berlin, Germany',
	'Tokyo, Japan'
];

const filterer = async place => {
	const weather = await getWeather(place);
	return weather.temperature > 30;
};

(async () => {
	const result = await pFilter(places, filterer);

	console.log(result);
	//=> ['Bangkok, Thailand']
})();

API

pFilter(input, filterer, [options])

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

input

Type: Iterable<Promise|any>

Iterated over concurrently in the filterer function.

filterer(element, index)

Type: Function

The filterer function that decides whether an element should be included into result. Expected to return boolean | Promise<boolean>.

options

Type: Object

concurrency

Type: number
Default: Infinity
Minimum: 1

Number of concurrently pending promises returned by filterer.

p-locate - Get the first fulfilled promise that satisfies the provided testing function
p-map - Map over promises concurrently
p-times - Run promise-returning & async functions a specific number of times concurrently
More…

License

Current Tags

3.0.0 ... latest (4 years ago)

2 Versions

3.0.0 ... 4 years ago
2.1.0 ... 6 years ago