node-fetch-retry-timeout

Yet Another node-fetch-retry-timeout (YANFRT)

Minimalistic drop-in replacement for node-fetch. Created because other alternatives were not good for me (and believe me: I really tried hard to avoid creating yet another node-fetch extra feature package).

Notable differences from default node-fetch behaviour:

1. Default redirect strategy is 'manual' so we get 30x redirects as responses
2. Response timeout is 20s
3. Will consider each 50x response as a bad one and will retry (pass retryOnHttpResponse: false to disable)

Why, god, why?

Major differences from https://www.npmjs.com/package/@adobe/node-fetch-retry:

1. In YANFRT, Retries are configured by amount of attempts and not by total allowed duration of request (more convenient when request latency is fluctuating between 1 and 20 seconds like in most of my use cases)
2. One simple retry strategy: just amount of attempts and delay between requests
3. No Apache OpenWhisk and no other fat

Differences compared to https://www.npmjs.com/package/fetch-retry :

1. YANFRT is based on node-fetch
2. More flexible retry on http response codes (not an array of codes but a callback so you can do (response.status >= 400 && response.status <= 600) || response.status == 302

Differences compared to https://www.npmjs.com/package/node-fetch-retry :

1. YANFRT has timeouts handling based on AbortController
2. Can retry based on http response statuses

Unique feature

Since version 1.2 YANFRT supports changing opts of request on each retry (via beforeRetry optional callback). This allows switching broken proxies. See /test/ folder ("can change agent on retry" test)

Installation

npm i node-fetch-retry-timeout

Example

  const fetch = require('node-fetch-retry-timeout')
  let response = await fetch('https://google.com', {
    method: 'GET', 
    retry: 2, // number attempts to retry
    pause: 500, // pause between requests (ms)
    timeout: 5000,  // timeout PER 1 REQUEST (ms)
    retryOnHttpResponse: r => r.status >= 500, // this is the default implementation of retryOnHttpResponse, pass false to disable
    beforeRetry: (retryNum, error) => { // switch opts on retry (retryNum == 1 before first retry is initiated, check the existence of error.response for advanced logic)
      return { headers: { 'Switch header': 'header-value' }, agent: SomeRandomAgent }
    }
  })

Running tests

npm run test