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    headers-utils
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    3.0.2 • Public • Published

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    headers-utils

    A Headers class polyfill and transformation library.

    Motivation

    Various request issuing libraries utilize a different format of headers. This library chooses the Headers instance as the middle-ground between server and client, and provides functions to convert that instance to primitives and vice-versa.

    Install

    $ npm install headers-utils

    Polyfill

    This package exports the Headers class that polyfills the native window.Headers implementation. This allows you to construct and manage headers using the same API in non-browser environments.

    import { Headers } from 'headers-utils'
    
    const headers = new Headers({
      Accept: '*/*',
      'Content-Type': 'application/json',
    })
    
    headers.get('accept') // "*/*"

    Methods

    The Headers polyfill instance supports the same methods as the standard Headers instance:

    As well as the iterator methods:

    Custom methods

    In addition, the polyfill instance has the following methods:

    • .all()

    Returns the object of the normalized header name/value pairs.

    const headers = new Headers({
      Accept: '*/*',
      'Content-Type': 'application/json',
    })
    
    headers.all()
    // { "accept": "*/*", "content-type": "application/json" }
    • .raw()

    Similar to the .all() method, .raw() returns an object consisting of the header name/value pairs, but preserving raw header names.

    const headers = new Headers({
      Accept: '*/*',
      'Content-Type': 'application/json',
    })
    
    headers.raw()
    // { "Accept": "*/*", "Content-Type": "application/json" }

    Transformations

    Headers ⭢ N

    • headersToString: (h: Headers): string
    import { headersToString } from 'headers-utils'
    
    headersToString(
      new Headers({
        connection: 'keep-alive',
        'content-type': ['text/plain', 'image/png'],
      })
    )
    // connetion: keep-alive
    // content-type: text/plain, image/png
    • headersToList: (h: Headers): Array<[string, string | string[]]>
    import { headersToList } from 'headers-utils'
    
    headersToList(
      new Headers({
        connection: 'keep-alive',
        'content-type': ['text/plain', 'image/png'],
      })
    )
    // [['connection', 'keep-alive'], ['content-type', ['text/plain', 'image/png']]]
    • headersToObject: (h: Headers): Record<string, string | string[]>
    import { headersToObject } from 'headers-utils'
    
    headersToObject(
      new Headers({
        connection: 'keep-alive',
        'content-type': ['text/plain', 'image/png'],
      })
    )
    // { connection: 'keep-alive', 'content-type': ['text/plain', 'image/png'] }

    N ⭢ Headers

    • stringToHeaders: (s: string): Headers
    import { stringToHeaders } from 'headers-utils'
    
    
    const stringToHeaders(`
    connection: keep-alive
    content-type: text/plain, image/png
    `)
    // Headers { connection: 'keep-alive', 'content-type': ['text/plain', 'image/png'] }
    • listToHeaders: (l: Array<[string, string | string[]]>): Headers
    import { listToHeaders } from 'headers-utils'
    
    listToHeaders([
      ['connection', 'keep-alive'],
      ['content-type', ['text/plain', 'image/png']],
    ])
    // Headers { connection: 'keep-alive', 'content-type': ['text/plain', 'image/png'] }
    • objectToHeaders: (o: Record<string, string | string[] | undefined>): Headers
    import { objectToHeaders } from 'headers-utils'
    
    objectToHeaders({
      connection: 'keep-alive',
      'content-type': ['text/plain', 'image/png'],
    })
    // Headers { connection: 'keep-alive', 'content-type': ['text/plain', 'image/png'] }

    Utilities

    • reduceHeadersObject: <R>(o: Record<string, string | string[]>, reducer: (acc: R, name: string, value: string | string[]) => R) => R
    import { reduceHeadersObject } from 'headers-utils'
    
    reduceHeadersObject <
      HeadersObject >
      ({
        Accept: '*/*',
        'Content-Type': ['application/json', 'text/plain'],
      },
      (headers, name, value) => {
        headers[name.toLowerCase()] = value
        return headers
      },
      {})
    // { 'accept': '*/*', 'content-type': ['application/json', 'text/plain'] }
    • appendHeader: (o: Record<string, string | string[]>, n: string, v: string | string[]): Record<string, string | string[]>
    import { appendHeader } from 'headers-utils'
    
    appendHeader(
      { 'content-type': 'application/json' },
      'content-type',
      'text/plain'
    )
    // { 'content-type': ['application/json', 'text/plain']}
    • flattenHeadersList: (l: Array<[string, string | string[]]>): Array<string, string>
    import { flattenHeadersList } from 'headers-utils'
    
    flattenHeadersList([['content-type', ['text/plain', 'image/png']]])
    // ['content-type', 'text/plain; image/png']
    • flattenHeadersObject: (o: Record<string, string | string[]>): Record<string, string>
    import { flattenHeadersObject } from 'headers-utils'
    
    flattenHeadersObject({
      'content-type': ['text/plain', 'image/png'],
    })
    // { 'content-type': 'text/plain; image/png' }

    Keywords

    none

    Install

    npm i headers-utils

    DownloadsWeekly Downloads

    722,582

    Version

    3.0.2

    License

    MIT

    Unpacked Size

    32.4 kB

    Total Files

    36

    Last publish

    Collaborators

    • kettanaito