Workaround cloudflare bugs

[Rich-Harris]

Encountered some subtle but fatal issues trying to run SvelteKit in a cloudflare worker. For some reason this code...

kit/packages/kit/src/runtime/server/page/load_node.js

Line 213 in f8fe544

return Reflect.get(response, key, receiver);

...results in the following error:

TypeError: Method ok called on incompatible receiver [object Object]

I don't understand how, but changing it to Reflect.get(response, key, response) seems to do the trick.

Separately, the Headers object (in the global scope, or instantiated as the headers property of a Request instance) doesn't appear to follow the standard. In a browser, Headers.prototype contains a forEach method; in a worker, that method is missing, but there's an additional getAll method which isn't present in browsers (perhaps because the only header that needs to be represented with multiple values, rather than being comma-separated, is the set-cookie header which can never appear in a browser).

Regardless of the origin of the bug, this PR appears to fix it.

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[lukeed]

This is not Workers-specific. It's an illegal invocation in a browser runtime, too. For example:

let res = new Response('hello', { status: 201 });
let proxy1 = new Proxy(res, {
    get(r, k, rec) {
        console.log({ r, k, rec });
        return Reflect.get(r, k, rec);
    }
});

proxy1.status;
// logs: {r: Response, k: "status", rec: Proxy}
// throws: Uncaught TypeError: Illegal invocation

let proxy2 = new Proxy(res, {
    get(r, k) {
        console.log({ r, k });
        return Reflect.get(r, k, r);
        // or return Reflect.get(r, k);    
    }
});

proxy2.status;
// logs: {r: Response, k: "status" }
//=> 201

[Rich-Harris]

Oh, interesting, thanks. I guess node-fetch is the thing with aberrant behaviour. The Headers issue stands though AFAICT

[lukeed]

Yup, I forwarded the report. Thanks again for raising it 👍