Caching issue with fetch response: Incorrect behavior observed

[alejogschwind]

Describe the bug

We ran into this issue while we were trying to do two similar GET requests to our API but with different headers. It seems that the caching system it's using only the URL and the body to create the key. Could you consider adding headers, too? Thanks

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-igyc9t?file=src%2Froutes%2F%2Bpage.js,src%2Froutes%2F%2Bpage.svelte&terminal=dev

You need to download the project to don't run into a CORS issue with the API.

Logs

No response

System Info

System:
    OS: macOS 12.5
    CPU: (10) arm64 Apple M1 Pro
    Memory: 5.28 GB / 16.00 GB
    Shell: 3.5.1 - /opt/homebrew/bin/fish
  Binaries:
    Node: 16.18.0 - ~/.nvm/versions/node/v16.18.0/bin/node
    Yarn: 1.22.19 - /opt/homebrew/bin/yarn
    npm: 8.19.2 - ~/.nvm/versions/node/v16.18.0/bin/npm
  Browsers:
    Chrome: 109.0.5414.119
    Safari: 15.6
  npmPackages:
    @sveltejs/adapter-auto: ^1.0.0 => 1.0.2 
    @sveltejs/kit: ^1.0.0 => 1.3.1 
    svelte: ^3.54.0 => 3.55.1 
    vite: ^4.0.0 => 4.0.4

Severity

annoyance

Additional Information

No response

[benmccann]

Out of curiosity, what are the headers that are different or what's a use case for this?

[alejogschwind]

If the headers are not taken into account when building the caching key, the same URL and body may result in different responses depending on the headers, leading to incorrect data being served from the cache.

Or am I missing something?

[alejogschwind]

One example could be same URL, same body and different cookies.

[benmccann]

I'm not disagreeing. I was just curious to know when you actually ran into this

[alejogschwind]

We attempted to retrieve a resource with a session, but received a 401 error. To fix this, we attempted a re-authentication call followed by the original resource call using the correct credentials. Then we realize that the server was returning 401 for both calls.

This is how we found the issue.