[question] force cache

[sayem314]

What would you like to discuss?

How do I force cache requests with hooks? I have tried this and it doesn't work.

const instance = got.extend({
  cache: new Map(),
  hooks: {
    afterResponse: [
      (response) => {
        response.headers['cache-control'] = 'max-age=600';
        return response;
      },
    ],
  },
});

Checklist

• I have read the documentation.

[sindresorhus]

The issue is that modifying the cache-control header in afterResponse doesn't affect caching because Got has already decided wether to cache the response by that point.

To force caching, you can use the cacheOptions to customize the cache behavior:

import got from 'got';
import Keyv from 'keyv';

const cache = new Keyv();

const instance = got.extend({
	cache,
	cacheOptions: {
		shared: false,
		cacheHeuristic: 1, // Force heuristic caching
		immutableMinTimeToLive: 600000, // 10 minutes
		ignoreCargoCult: false
	}
});

Alternatively, if you want to cache everything regardless of headers, you can override the cache key logic:

const instance = got.extend({
	cache: new Map(),
	hooks: {
		beforeRequest: [
			(options) => {
				// Force cache-friendly headers on the request
				options.headers['cache-control'] = 'public, max-age=600';
			}
		]
	}
});

This way Got will treat all responses as cacheable for 10 minutes.

[devadathanmb]

Is it possible to cache responses to POST requests this way? Or achieve similar behavior in some way?

I understand that POST is considered unsafe in the HTTP semantics sense (i.e., it can cause side effects and isn’t normally cacheable), and also saw some related discussion here

Basically, I’m dealing with an HTTP endpoint that uses broken semantics — it uses POST requests for what are essentially just read-only operations, so I want to cache those responses if possible.