StandardRPCLink Decoding fails in HMR?

[adnanbrq]

The following error appears only on the client after an oRPC-related file has been hot-reloaded.
In my case, I’m using a TanStack Start-based application combined with oRPC’s TanStack Query integration.

Initially, visiting the site works fine. But when an oRPC-related file is changed as described the route's loader seems to kick in, and that’s when the error occurs. There’s no trace of it on the server, and I’m unable to debug the request.

Examle loader:

loader: async ({ context: { queryClient }, params }) => {
  await queryClient.ensureQueryData(orpcQueryUtils.users.get.queryOptions({ input: { id: params.id } }));
  return {};
},

Error

Error: Internal Server Error
    at StandardRPCLinkCodec.decode (PATH/node_modules/.pnpm/@orpc+client@0.52.0/node_modules/@orpc/client/dist/shared/client.DhAxdT4W.mjs:258:13)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async #call (PATH/node_modules/.pnpm/@orpc+client@0.52.0/node_modules/@orpc/client/dist/shared/client.DhAxdT4W.mjs:32:20)
    at async PATH/node_modules/.pnpm/@orpc+client@0.52.0/node_modules/@orpc/client/dist/shared/client.DhAxdT4W.mjs:21:22
    at async next (PATH/node_modules/.pnpm/@orpc+shared@0.52.0/node_modules/@orpc/shared/dist/index.mjs:66:14)
    at async intercept (PATH/node_modules/.pnpm/@orpc+shared@0.52.0/node_modules/@orpc/shared/dist/index.mjs:73:10)
    at async procedureClient (PATH/node_modules/.pnpm/@orpc+client@0.52.0/node_modules/@orpc/client/dist/index.mjs:38:12)
    ```

[unnoq]

Thanks @adnanbrq for reporting this. Could you please provide more details, such as an MVP? HRM issues are usually not related to oRPC. Also, try changing your Tanstack start version.

[adnanbrq]

Hey @unnoq ,

I've created a repo that demonstrates the issue. While reproducing it, I noticed that the problem only occurs when a layout fetches data and its children do as well though this setup should be valid.

Repo:
https://github.com/adnanbrq/tanstack-start-orpc

[unnoq]

This appears to be a Tanstack issue specific to your current SSR setup (or Tanstack problem with SSR and HMR).

• First Request: An invalid oRPC response (not processed by oRPC) returned a 500 status, which is correctly treated as an internal server error.
• Second Request: The request was handled properly by oRPC, as indicated by the "receive requests?" log.

It seems that an HMR issue on SSR might be temporarily making the server unavailable.

[adnanbrq]

Yes this might be related to how TanStack handles SSR with HMR.

Thanks for taking a look into it! 👍🏼
It can be a bit annoying during development, but since it doesn’t happen in production builds, I guess I can live with it 🙂