https://github.com/sindresorhus/p-race

A better `Promise.race()`
https://github.com/sindresorhus/p-race

Last synced: 3 months ago
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A better `Promise.race()`

• Host: GitHub
• URL: https://github.com/sindresorhus/p-race
• Owner: sindresorhus
• License: mit
• Created: 2016-10-21T06:33:32.000Z (about 8 years ago)
• Default Branch: main
• Last Pushed: 2022-12-13T15:14:20.000Z (about 2 years ago)
• Last Synced: 2024-04-13T17:47:45.670Z (9 months ago)
• Language: JavaScript
• Size: 13.7 KB
• Stars: 45
• Watchers: 6
• Forks: 5
• Open Issues: 0
• Metadata Files:
  • Readme: readme.md
  • License: license

Awesome Lists containing this project

• promise-fun - p-race

README

        
# p-race

> A better [`Promise.race()`](https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Promise/race)

Improvements:

- Fixes the [silly behavior](https://github.com/domenic/promises-unwrapping/issues/75) 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`](https://github.com/sindresorhus/p-any) if you like to get the first promise to fulfill.

- Supports aborting promises using [`AbortSignal`](https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal).

## Install

```sh

npm install p-race

```

## Usage

```js

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`

#### executor

Type: `signal => Iterable`

##### signal

Type: [`AbortSignal`](https://developer.mozilla.org/en-US/docs/Web/API/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.*

```js

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](https://github.com/sindresorhus/p-any) - Wait for any promise to be fulfilled

- [More…](https://github.com/sindresorhus/promise-fun)