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    @shanyue/promise-utils
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    2.0.4 • Public • Published

    promise-utils

    A few tools about promise, like delay, map, filter and retry.

    npm version build status install size npm downloads

    Install

    $ npm install @shanyue/promise-utils

    Require node > 10.x

    Usage

    import { map, filter, retry, sleep } from '@shanyue/promise-utils'
     
     
    // Output: [2, 3, 4, 5]
    await map([Promise.resolve(1), 2, 3, 4], (x: number) => x + 1)
     
    // Output: [1, 3]
    await filter([Promise.resolve(1), 2, 3, 4], (x: number) => Boolean(x % 2))
     
    await sleep(300)
     
    await retry(() => Promise.resolve(3), { times: 3 })

    API

    map(input, mapper, [options])

    Map promises concurrently

    • input: Promise or any value
    • mapper: Expected to return a Promise or value.
    • options.concurrency: Number of concurrently pending promises.
    import { map } from '@shanyue/promise-utils'
     
    // Output: [2, 3, 4, 5]
    await map([Promise.resolve(1), 2, 3, 4], (x: number) => x + 1)
     
    // Output: [2, 3, 4, 5]
    await map([Promise.resolve(1), 2, 3, 4], (x: number) => Promise.resolve(x + 1))
     
    // After 4 * 300ms,Output: [2, 3, 4, 5]
    await map([1, 2, 3, 4], async x => {
      await sleep(300)
      return x + 1
    }, { concurrency: 1 })

    filter(input, filterer, [options])

    Filter promises concurrently

    • input: Promise or any value.
    • filterer: Expected to return boolean-like value.
    • options.concurrency: Number of concurrently pending promises.
    import { filter } from '@shanyue/promise-utils'
     
    // Output: [1, 3]
    await filter([Promise.resolve(1), 2, 3, 4], (x: any) => Boolean(x % 2))
     
    // Output: [1, 3]
    await filter([Promise.resolve(1), 2, 3, 4], (x: any) => Promise.resolve(Boolean(x % 2)))

    retry(input, [options])

    Retry promise

    • input: Promise or any value.
    • options.times: Number of concurrently pending promises.
    • options.attemptNumber: Number of concurrently pending promises.
    import { retry, AbortError } from '@shanyue/promise-utils'
     
    // Output: 'ok'
    await retry(async attemptNumber => {
      return attemptNumber === 3 ? 'ok' : Promise.reject(new Error('error'))
    }, {
      times: 3
    })
     
    // Output: 'ok'
    await retry(async attemptNumber => {
      return attemptNumber === 3 ? 'ok' : Promise.reject(new Error('error'))
    }, {
      times: 3,
      onFailedAttempt: async (e) => {
        console.log(e)
        // retry delay 1s
        await sleep(1000)
      }
    })
     
     
    // AbortError fail-fast
    try {
      await retry(async () => {
        const err = new AbortError('hello')
        return Promise.reject(err)
      }, {
        times: 3
      })
    } catch (e) {
    }

    sleep(ms)

    import { retry } from '@shanyue/promise-utils'
     
    // delay 1s
    await sleep(1000)

    Install

    npm i @shanyue/promise-utils

    DownloadsWeekly Downloads

    24

    Version

    2.0.4

    License

    ISC

    Unpacked Size

    42.3 kB

    Total Files

    56

    Last publish

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