do we want to do this for TurnStart too? in case a JSON RPC error gets thrown for turn/start

hmm, should we figure out a less brittle way to do this? maybe define shared constants for the strings?

hmm yeah... ideally there's a way to match on CodexErrorInfo instead of JSONRPCErrorError because then you'll have stronger type guarantees

or maybe you can just cast data.get("codexErrorInfo") back to CodexErrorInfo and then pull out turnKind

what do you think of adding something well-typed here actually, so we don't have to do string parsing on JSONRPCErrorError?

maybe:

ErrorResponse {
    connection_id: u64,
    request_id: RequestId,
    error: JSONRPCErrorError,
    type: Option<JsonRpcErrorType>,
}

where type is something like:

pub enum JsonRpcErrorType {
    Turn(TurnRequestError),
    Input(InputError),
}

pub enum TurnRequestError {
    NoActiveTurn,
    ExpectedTurnMismatch,
    ActiveTurnNotSteerable { turn_kind: NonSteerableTurnKind },
}

pub enum InputError {
    Empty,
    TooLarge { max_chars: usize, actual_chars: usize },
}

something like that? just brainstorming

nit: i've seen this function defined in a bunch of places at this point, should we centralize it somewhere? can do in a followup

hmm let's revert this? i don't think it's worth tracking this one

this is a lot of boilerplate, any way we can eliminate this?