fetch cache behaviour unclear

[mmkal]

Affected URL(s)

https://nodejs.org/dist/latest-v18.x/docs/api/globals.html#fetch

Description of the problem

The docs say that global.fetch is a Browser-compatible implementation of the fetch() function, but it's unclear what that means with respect to caching.

Calling fetch('https://example.com') twice doesn't result in any caching, despite a cache-control response header existing. Similarly calling fetch('https://example.com', {cache: 'force-cache'}) makes two separate requests as well.

Is there a plan to implement caching, or a recommended way for end-users to provide caching? Is the cache property on RequestInit supposed to do something?

[KhafraDev]

Is there a plan to implement caching, or a recommended way for end-users to provide caching?

Yes, I recently implemented CacheStorage into undici (docs) that's tightly coupled with fetch. It's currently an in-memory cache though; in the future I plan to move to a file-backed solution.

Is the cache property on RequestInit supposed to do something?

No, it's added because it's a property on RequestInit, there are a few others that server no purpose in node/don't have any functionality.

[chrisveness]

fetch() in node.js v22.6.0 doesn't appear to respect the Cache-Control header in a response (multiple calls to fetch() will result in multiple hits to the requested resource, despite the presence of a Cache-Control header in the response from the resource).

Is this expected to surface in Node.js in the near future?