Resreq

What is resreq?

It is a modern http client, based on fetch, because it is implemented internally using the onion model, so you can use middleware to intercept requests and responses elegantly.

Learn more

Install

Resreq targets modern browsers and Deno

pnpm install resreq

import Resreq from 'https://esm.sh/resreq'

If you are using a lower version of node, you may need to add some polyfill.

import fetch, { Headers, Request, Response } from 'node-fetch'
import AbortController from 'abort-controller'

globalThis.fetch = fetch
globalThis.Headers = Headers
globalThis.Request = Request
globalThis.Response = Response
globalThis.AbortController = AbortController

Documentation

Get Started

import Resreq from 'resreq'

const resreq = new Resreq({
  baseURL: 'https://example.com',
  responseType: 'json'
})

const res = await resreq.request({
  url: '/api/user',
  method: 'GET',
  params: { foo: 'bar' }
})
console.log(res) // Object

const res = await resreq.get('/api/download', {
  responseType: 'blob'
})
console.log(res) // Blob

Cancel request

const resreq = new Resreq()

const abortController = new AbortController()

resreq.get('https://example.com/api', {
    signal: abortController.signal
  })
  .catch((error) => {
    console.log(error) // Abort error
  })

abortController.abort() // request cancel

Use Middlewares

const resreq = new Resreq({
  baseURL: 'https://example.com'
})

// Intercepting responses and requests using middleware
resreq.use((next) => async (req) => {
  try {
    console.log(req) // Request can be changed here
    const res = await next(req)
    console.log(res) // Response can be changed here
    return res
  } catch (error) {
    console.log(error) // Catch errors here
    throw error
  }
})

const res = await resreq.get('/api', {
  params: { foo: 'bar' }
})

console.log(res)

API

new Resreq(options?:Options)

Create a resreq instance and configure the global options.

const resreq = new Resreq({
  baseURL: 'https://example.com',
  timeout: 10000,
  responseType: 'json',
  throwHttpError: true,
  onDownloadProgress(progress, chunk) {
    console.log(progress, chunk)
  }
})

resreq.request(options?:Options)

Use ”request” to send the request and configure the options.

const resreq = new Resreq({
  baseURL: 'https://example.com'
})

const res = await resreq.request({
  url: '/api',
  method: 'GET',
  params: { foo: 'bar' },
  throwHttpError: true,
  onDownloadProgress(progress, chunk) {
    console.log(progress, chunk)
  }
})

console.log(res)

resreq[method](options?:Options)

Use ”method” to send the request and configure the options

const resreq = new Resreq({
  baseURL: 'https://example.com'
})

const res = await resreq.get('/api', {
  params: { foo: 'bar' },
  throwHttpError: true,
  onDownloadProgress(progress, chunk) {
    console.log(progress, chunk)
  }
})

console.log(res)

resreq.use(middleware:Middleware)

Add headers using middleware.

import Resreq, { Middleware } from 'resreq'

const resreq = new Resreq({
  baseURL: 'https://example.com'
})

// Implement a middleware that set token
const setAccessToken: Middleware = (next) => (req) => {
  req.headers.set('Access-Token', 'foo-bar')
  return next(req)
}

// Register middleware
resreq.use(setAccessToken)

await resreq.get('/api')

Rewriting headers using middleware.

import Resreq, { Req } from 'resreq'

const resreq = new Resreq({
  baseURL: 'https://example.com'
})

resreq.use((next) => async (req) => {
  
  // Create a new request with Req
  const _req = new Req(req, {
    headers: {
      'X-Custom-Header': 'bar'
    }
  })
  
  console.log(_req.headers.get('Content-Type')) // null
  console.log(_req.headers.get('X-Custom-Header')) // bar

  return await next(_req)
})

await resreq.get('/api', {
  headers: {
    'Content-Type': 'application/json',
    'X-Custom-Header': 'foo'
  }
})

Req(request: Req, init: ReqInit | Request)

Res(response: Res, init: ResInit | Response)

In the middleware, use new Req() and new Res() to rewrite the request and response.

import Resreq, { Req, Res } from 'resreq'

const resreq = new Resreq({
  baseURL: 'https://example.com',
})

resreq.use((next) => async (req) => {
  
  const _req = new Req(req, {
    url: 'https://example.com/mock'
  })

  const res = await next(_req)
  return new Res(res, {
    body: { foo: 'bar' }
    status: 200,
  })
})

const res: Response = await resreq.get('/api')

console.log(res.status) // 200
console.log(await res.json()) // { foo: 'bar' }

Warning Req & Res extends from Request and Response; to create a new request and response in the middleware, use new Req() and new Res().

To access the contents of the body in the current middleware, please use Res.clone() to ensure that the res received by the next middleware are unlocked.

Interfaces

Options

Options extends from the RequestInit type with some additional properties

interface Options extends Omit<RequestInit, 'body'> {
  baseURL?: string
  url?: string
  method?: 'GET' | 'POST' | 'PUT' | 'DELETE' | 'HEAD' | 'PATCH'
  params?: Record<string, any>
  body?: BodyInit | Record<string, any>
  meta?: Record<string, any>
  timeout?: number
  responseType?: 'json' | 'arrayBuffer' | 'blob' | 'formData' | 'text' | null | false
  throwHttpError?: boolean
  onDownloadProgress?: ProgressCallback
}

baseURL: The url prefix of the request will be concatenated with the url in resreq[method]() to form a complete request address, the default value is ’ ‘.
url: Request url, the default value is ’ ‘.
method：Request method, the default value is ‘GET’.
params: The params of a resreq.get request are automatically added to the url via the new URLSearchParams method.
body: Based on BodyInit, and adding Record<string, any>, which means you can pass object directly, instead of JSON.stringify(object), which will automatically add Content-Type: application/json request headers.
meta: The extra information that needs to be carried in the request is not really sent to the server, but it can be obtained in Res.meta and Req.meta.
timeout: Specify the number of milliseconds of time before the request, if the time is exceeded the request will be aborted, the default value is 1000ms.
responseType: Set how the response will be parsed, if not set or set to false, the Response instance will be returned, the default value is undefined.
throwHttpError: If true, a status code outside of 200-299 will throw an error, the default value is false.
onDownloadProgress: The download progress hook, which depends on the ReadableStream API, polyfill is required in lower versions of node.

To avoid adding complexity, new Resreq(options) and resreq[method](options), in which ‘options’ are of the same type.

The options defined in new Resreq(options) will take effect globally, resreq[method](options), will override the “global options”, except for the following options which will not be overridden.

meta: The meta within the method will be shallow merged with the global meta.
headers: The headers defined in the method are merged into the global headers.
onDownloadProgress: Defining onDownloadProgress in a method and the global onDownloadProgress are both retained.

ReqInit

Options extends from the RequestInit type with some additional properties.

interface ReqInit extends Omit<RequestInit, 'body'> {
  url?: string
  method?: 'GET' | 'POST' | 'PUT' | 'DELETE' | 'HEAD' | 'PATCH'
  meta?: Record<string, any>
  timeout?: number
  responseType?: ResponseType
  throwHttpError?: boolean
  body?: BodyInit | Record<string, any>
  onDownloadProgress?: ProgressCallback
}

Note That its ‘headers’ behave differently than ‘Options.headers’, which overrides the global headers.

ResInit

ResInit extends from the ResponseInit type with some additional properties.

interface ResInit extends ResponseInit {
  meta?: Record<string, any>
  body?: BodyInit | Record<string, any> | null
  timeout?: number
  responseType?: ResponseType
  throwHttpError?: boolean
  onDownloadProgress?: ProgressCallback
}

Middleware

The middleware must call next(req) to return a promise.

type Middleware = (next: Next) => (req: Req) => Promise<Res>

Standing on the shoulders of giants

Some of the inspiration for this project came from their.

Axios: Promise based HTTP client for the browser and node.js.
Ky: Tiny & elegant JavaScript HTTP client based on the browser Fetch API.
Redux: Predictable state container for JavaScript apps.
Koa: Next generation web framework for node.js.

License

This project is licensed under the MIT License - see the LICENSE file for details.