From Discord: Fixing Array Length Mismatch Error in RPC Handler

[effect-bot]

Summary

The conversation revolves around an error encountered in an RPC handler from the Effect Typescript library. The error message states: "handler must return an array of responses with the same length as the requests".

• Issue Understanding: The error appears when there is a mismatch between the number of requests sent and the number of responses received. This happens in batched requests where the client expects a response for each request.

• Potential Causes: One user identified an issue when doing custom encoding server-side using msw. Another pointed out that the error might occur if the RPC schema is incorrect, specifically if an undefined error is thrown.

• Resolution Attempts: Users suggest checking the schema and ensuring it aligns with the RPC definitions. Also, custom implementations or encoding might need review.

Key Takeaways:

1. Ensure request and response arrays match in length during batched RPC calls.
2. Check the RPC schema for mismatches or missing error definitions.
3. Consider reviewing any custom server-side handling or encoding if discrepancies occur.
4. Improved error messages could be beneficial, and a community member proposed contributing a PR for better error handling.

Discord thread

https://discord.com/channels/795981131316985866/1296767660490625034

[evelant]

If your rpc handler fails with an error that is not defined in your rpc schema you get a very unhelpful error on the client: RuntimeException: @effect/rpc: handler must return an array of responses with the same length as the requests.. I'll see if I can make a PR to improve error handling in this case.

[tim-smart]

FYI: #4362

[evelant]

Ah is that likely to resolve this? If so I won't bother with a PR.

edit: a quick skim and it looks like a total rewrite of rpc so I'd guess yes, this will no longer be an issue