Cache interceptor does not process capitalized `Cache-Control` header in request

[zdm]

Bug Description

Cache interceptor does not process Cache-Control: no-store request header if header name is capitalized.

In code we can see that you look for lowercased header name only.

You should convert header names to lowercase before search for cache-control;

Reproducible By

Please. see above.

Expected Behavior

Please. see above.

Logs & Screenshots

Environment

undici v7

Additional context

[mcollina]

Can you add a reproduction? It's working correctly here.

[zdm]

import { Agent, fetch, interceptors } from "undici";

const dispatcher = new Agent().compose( interceptors.cache() );

for ( let n = 0; n < 2; n++ ) {
    const res = await fetch( "https://httpbingo.org/cache/60", {
        dispatcher,
        "headers": {
            "X-Data": new Date().toISOString(),
            "Cache-Control": "no-store",
        },
    } );

    console.log( ( await res.json() ).headers[ "X-Data" ] );
}

1. You can see, that data not changed - this means, that cached response used.
2. If you change Cache-Control header to the lower case - cache will be bypassed.

[mcollina]

Ah right, thanks!

[ronag]

@mcollina this is related to that "normalizeHeaders" function I was working on that would always normalize the user passed headers. I think we should probably have a "pre-interceptor" that always does this to make things easier down chain.

[metcoder95]

Cannot be done on the DispatcherBase#dispatch directly?