p-race

p-race

A better Promise.race()

Improvements:

• Fixes the silly behavior of Promise.race() returning a forever pending promise when supplied an empty iterable, which could create some really hard to debug problems. Promise.race() returns the first promise to fulfill or reject. Check out p-any if you like to get the first promise to fulfill.
• Supports aborting promises using AbortSignal.

Install

npm install p-race

Usage

import pRace from 'p-race';

Promise.race([]);
// Returns a forever pending promise…

pRace([]);
//=> [RangeError: Expected the input to contain at least one item]

API

pRace(iterable | executor)

iterable

Type: Iterable<Promise | unknown>

executor

Type: signal => Iterable<Promise | unknown>

signal

Type: AbortSignal

You can pass the signal to each iterable's element to abort remaining promises when resolve the first promise.

Requires Node.js 16 or later.

import pRace from 'p-race';

pRace(signal => [
	fetch('/api', {signal}),
	setTimeout(10, {signal}),
]);
// Remaining promises other than first one will be aborted.

Related

• p-any - Wait for any promise to be fulfilled
• More…