adapter-cloudflare doesn't understand kit.paths.base

[tv42]

Describe the bug

I wish to use multiple SvelteKit apps on one domain, hence I must use base to separate them, to avoid each one of them thinking they are special and get to own the URL /_app.

If I set svelte.config.js config.kit.paths.base = '/foo', and use the @sveltejs/adapter-cloudflare adapter, npx wrangler@beta pages dev .svelte-kit/cloudflare/ results in it not finding the assets.

It seems SvelteKit assumes that the assets are served with base as a prefix (that is, file _app at the root of the static files is found by the browser at ${base}/_app), while the adapter never considers the value of base.

Reproduction

(sorry, not yet done)

Logs

No response

System Info

System:
    OS: Linux 5.14 NixOS 21.11 (Porcupine) 21.11 (Porcupine)
    CPU: (8) x64 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
    Memory: 34.80 GB / 62.61 GB
    Container: Yes
    Shell: 5.1.8 - /nix/store/xdxv22yb7qnjfyf997r9fx804761z14c-bash-interactive-5.1-p8/bin/bash
  Binaries:
    Node: 16.13.0 - /nix/store/26lslfmvwyhspppbinznh111fyaxx62z-nodejs-16.13.0/bin/node
    npm: 8.1.0 - /nix/store/26lslfmvwyhspppbinznh111fyaxx62z-nodejs-16.13.0/bin/npm
  Browsers:
    Firefox: 94.0.1
  npmPackages:
    @sveltejs/adapter-cloudflare: ^1.0.0-next.2 => 1.0.0-next.2
    @sveltejs/kit: next => 1.0.0-next.191
    svelte: ^3.34.0 => 3.44.0

Severity

serious, but I can work around it

Additional Information

No response