web3-proxy/web3_proxy/src/frontend/errors.rs

use crate::jsonrpc::JsonRpcForwardedResponse;
use axum::{
    http::StatusCode,
    response::{IntoResponse, Response},
    Json,
};
use derive_more::From;
use serde_json::value::RawValue;
use std::error::Error;

// TODO: take "IntoResult" instead?
pub type FrontendResult = Result<Response, FrontendErrorResponse>;

#[derive(From)]
pub enum FrontendErrorResponse {
    Anyhow(anyhow::Error),
    BoxError(Box<dyn Error>),
}

impl IntoResponse for FrontendErrorResponse {
    fn into_response(self) -> Response {
        todo!("into_response based on the error type")
    }
}

pub async fn handler_404() -> Response {
    let err = anyhow::anyhow!("nothing to see here");

    anyhow_error_into_response(Some(StatusCode::NOT_FOUND), None, err)
}

/// TODO: generic error?
/// handle errors by converting them into something that implements `IntoResponse`
/// TODO: use this. i can't get <https://docs.rs/axum/latest/axum/error_handling/index.html> to work
/// TODO: i think we want a custom result type instead. put the anyhow result inside. then `impl IntoResponse for CustomResult`
pub fn anyhow_error_into_response(
    http_code: Option<StatusCode>,
    id: Option<Box<RawValue>>,
    err: anyhow::Error,
) -> Response {
    // TODO: we might have an id. like if this is for rate limiting, we can use it
    let id = id.unwrap_or_else(|| RawValue::from_string("null".to_string()).unwrap());

    let err = JsonRpcForwardedResponse::from_anyhow_error(err, id);

    // TODO: logs here are too verbose. emit a stat
    // warn!("Responding with error: {:?}", err);

    let code = http_code.unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);

    (code, Json(err)).into_response()
}