[bug]: file router object array input types

[marier-nico]

Provide environment information

System:
    OS: macOS 15.1.1
    CPU: (8) arm64 Apple M1 Pro
    Memory: 89.81 MB / 16.00 GB
    Shell: 3.7.1 - /opt/homebrew/bin/fish
  Binaries:
    Node: 20.12.0 - ~/.volta/tools/image/node/20.12.0/bin/node
    Yarn: 4.0.0-rc.42 - ~/.volta/tools/image/yarn/4.0.0-rc.42/bin/yarn
    npm: 10.5.0 - ~/.volta/tools/image/node/20.12.0/bin/npm
    pnpm: 9.5.0 - ~/.volta/bin/pnpm
    bun: 1.1.15 - ~/.volta/bin/bun
  Browsers:
    Chrome: 132.0.6834.160
    Safari: 18.1.1
  npmPackages:
    @uploadthing/react: ^7.1.5 => 7.1.5
    typescript: ^5.5.3 => 5.7.3
    uploadthing: ^7.4.4 => 7.4.4

Describe the bug

The following typescript error occurs when trying to use an array of objects in the input of a file router

    Types of property '_input' are incompatible.
      Type '{ media: { id: string; }[]; }' is not assignable to type 'Json'.
        Type '{ media: { id: string; }[]; }' is not assignable to type 'JsonObject'.
          Property 'media' is incompatible with index signature.
            Type '{ id: string; }[]' is not assignable to type 'JsonValue | JsonObject | JsonArray'.
              Type '{ id: string; }[]' is not assignable to type 'JsonArray'.
                Type '{ id: string; }' is not assignable to type 'JsonValue'.

The documentation only highlights that the input must be JSON serializable, which it is, so this feels like the internal json type isn't quite right. If it's intentional, it'd be helpful to mention it in the docs.

Link to reproduction

https://stackblitz.com/edit/github-uvnavyz9?file=src%2Fserver%2Fuploadthing.ts&view=editor

To reproduce

Check src/server/uploadthing.ts (line 40) in the reproduction link. When the sandbox loads, you can see the type error.

And just to have it here also, this input schema gives the error : const imageSchema = z.object({ media: z.array(z.object({ id: z.string() })) });

Additional information

It feels like the fix might just be to change these types in @uploadthing/shared, but in any case I wanted to file this to make sure I didn't miss anything 👀

type JsonValue = string | number | boolean | null | undefined;
type JsonArray = JsonValue[]; // --> use Json[] instead?
type JsonObject = {
    [key: string]: JsonValue | JsonObject | JsonArray; // --> maybe here too
};
type Json = JsonValue | JsonObject | JsonArray;

👨‍👧‍👦 Contributing

• 🙋‍♂️ Yes, I'd be down to file a PR fixing this bug!

Code of Conduct

• I agree to follow this project's Code of Conduct