fetch-enhanced

fetch-enhanced

fetch-enhanced wraps a provided fetch-like function like undici or node-fetch and adds:

• HTTP Proxy discovery from standard environment variables
• HTTP Request Timeout support
• Accessible agent/dispatcher options

Usage

import {fetch as undiciFetch} from "undici";
import fetchEnhanced from "fetch-enhanced";

const fetch = fetchEnhanced(undiciFetch, {undici: true});
await fetch("https://example.com");

API

fetchEnhanced(fetchImplementation, opts)

• fetchImplementation: Function A fetch-like module that takes (url, opts) and a agent (like node-fetch) or dispatcher (like undici) option.
• opts Object Required.
  • agentCacheSize: number Size of the agent cache. Default: 512.
  • undici: boolean Whether the fetch implementation is undici. Required.

Returns: A wrapped fetch function.

fetch(url, [opts])

• opts Object
  • timeout: number Request timeout in milliseconds. Default: 0 (meaning no timeout).
  • noProxy: boolean Explicitely disable any proxy server use. Default: false.
  • agent: http.Agent Custom HTTP agent. When specified, proxy discovery will no longer work.
  • agentOpts: object Agent or Dispatcher options.Default: {maxSockets: 64, keepAlive: false}
    • agentOpts.noProxy: boolean Do not use proxy in any case. Default: false.
  • Any valid fetch module option, like for node-fetch

TimeoutError

Error class that can be used for err instanceof TimeoutError:

import {TimeoutError} from "fetch-enhanced";

try {
  await fetch("https://example.com", {timeout: 0});
} catch (err) {
  console.log(err instanceof TimeoutError);
  // => true
}

fetch.clearCache()

Clear the agent cache and destroys all cached agents. This is generally only neccessary when the proxy environment variables are expected to change during runtime.

process.env.HTTPS_PROXY = "https://proxy1.dev";
await fetch("https://example.com");
fetch.clearCache();
process.env.HTTPS_PROXY = "https://proxy2.dev";
await fetch("https://example.com");

© silverwind, distributed under BSD licence