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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.

npm install p-filter

importpFilterfrom'p-filter';importgetWeatherfrom'get-weather';// Not a real moduleconstplaces=[getCapital('Norway').then(info=>info.name),'Bangkok, Thailand','Berlin, Germany','Tokyo, Japan',];constfilterer=asyncplace=>{constweather=awaitgetWeather(place);returnweather.temperature>30;};constresult=awaitpFilter(places,filterer);console.log(result);//=> ['Bangkok, Thailand']

Returns aPromise that is fulfilled when all promises ininput and ones returned fromfilterer are fulfilled, or rejects if any of the promises reject. The fulfilled value is anArray of the fulfilled values returned fromfilterer ininput order.

Type:Iterable<Promise<unknown> | unknown>

Iterated over concurrently in thefilterer function.

Type:Function

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

Type:object

See thep-map options.

Type:number
Default:Infinity
Minimum:1

The number of concurrently pending promises returned byfilterer.

Returns an async iterable that iterates over the promises initerable and ones returned fromfilterer concurrently, callingfilterer for each element.

import{pFilterIterable}from'p-filter';importgetWeatherfrom'get-weather';// Not a real moduleasyncfunction*getPlaces(){constname=awaitgetCapital('Norway');yieldname;yield'Bangkok, Thailand';yield'Berlin, Germany';yield'Tokyo, Japan';}constplaces=getPlaces();constfilterer=asyncplace=>{constweather=awaitgetWeather(place);returnweather.temperature>30;};forawait(constelementofpFilterIterable(places,filterer)){console.log(element);}//=> ['Bangkok, Thailand']

Type:Iterable<Promise<unknown> | unknown>

Iterated over concurrently in thefilterer function.

Type:Function

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

Type:object

See thep-map options.

Type:number
Default:Infinity
Minimum:1

The number of concurrently pending promises returned byfilterer.

• 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…