# p-first

> make your Promise support getting first fulfilled Promise

Latest version **1.1.0** (published 2019-04-30) · ISC license · 0 weekly downloads

## Install

```sh
npm install p-first
pnpm add p-first
yarn add p-first
bun add p-first
```

## Health

**Score 25/100 (F)** — status: abandoned.

Positive: has types; esm support; no vulnerabilities.

Warnings: low downloads.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.1.0 |
| Published | 2019-04-30 |
| First published | 2019-04-30 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Dependencies | 0 |
| Unpacked size | 7.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 1 |
| Maintainers | huruji |

## Links

- npm: https://www.npmjs.com/package/p-first
- Repository: https://github.com/huruji/p-first
- Homepage: https://github.com/huruji/p-first#readme
- Issues: https://github.com/huruji/p-first/issues
- npm.io page: https://npm.io/package/p-first

## Recent versions

- 1.1.0 (latest) — 2019-04-30

## README

中文 | [English](./README_EN.md)

# p-first

让你的 Promise 支持获取第一个变为 fulfilled 状态的函数

> 不同于 `Promise.race` 不管是 fulfilled 或者是 rejected 状态都会返回

## How to use

```bash
npm i p-first -S
```

```js
import first from 'p-first'

first(yourPromises)
```

或者你可以拓展你的 `Promise` 构造函数

```js
Promise.first = first
```

## real world use

你有两个 Ajax api 获取相同的数据，但是你不知道哪个 Ajax api 会先返回，也无法预测哪个 Ajax api 会出问题, 你可以使用 `p-first` 来获取**第一个成功返回**的数据

```js
const p1 = new Promise(resolve => {
    setTimeout(() => {
        resolve (12)
    }, 5000)
})

const p2 = new Promise(resolve => {
    setTimeout (() => {
        resolve ('huruji')
    }, 1000)
})

const p3 = new Promise((resolve, reject) => {
    reject(404)
})

Promise.first([p1, p3, p2]).then(data => {
    console.log(data)
})

// output: huruji
```

## catch error

当没有一个 Promise 变为了 fulfilled 状态，你可以在 `.catch` 中捕获 error

```js
const p1 = new Promise((resolve, reject) => {
    setTimeout(() => {
        reject (12)
    }, 5000)
})

const p2 = new Promise((resolve, reject) => {
    setTimeout (() => {
        reject('huruji')
    }, 1000)
})

const p3 = new Promise((resolve, reject) => {
    reject(404)
})

Promise.first([p1, p3, p2]).then(data => {
    console.log(data)
}).catch((errs) => {
    console.log('have errors')
    console.log(errs)
})

// have errors
// [12, 404, 'huruji']
```

---
_Source: https://npm.io/package/p-first · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._