Describe the bug

I have a route like this: /@[username].
Up until recently, I just used the @ character as the name of the folder.
With the introduction of named layouts, I've had to get rid of the @ character as it was failing to build, and as someone on Discord suggested, I changed it to %40. This worked fine locally, and all my tests passed so I made the change.

However, when actually deployed to cloudflare pages with the cloudflare adapter, it fails to fetch any .js files under that path. It returns an http 200, but empty content. The page usually fails either due to mimetype checks, or some other error depending on the browser.

Failed to fetch dynamically imported module: https://<mysite>/_app/pages/%40_username_/index.svelte-71303df9.js

Reproduction

Using the cloudflare adapter, use a route with %40 somewhere in the path.

Logs

Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "null". Strict MIME type checking is enforced for module scripts per HTML spec.

System Info

System:
    OS: macOS 12.3.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 626.66 MB / 32.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 18.1.0 - /opt/homebrew/bin/node
    npm: 8.8.0 - /opt/homebrew/bin/npm
  Browsers:
    Chrome: 101.0.4951.64
    Safari: 15.4
  npmPackages:
    @sveltejs/adapter-cloudflare: next => 1.0.0-next.19 
    @sveltejs/kit: next => 1.0.0-next.338 
    svelte: ^3.46.0 => 3.48.0

Severity

blocking an upgrade

Additional Information

No response