asyn-rs 0.24.0

Rust port of EPICS asyn - async device I/O framework
Documentation 
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use serde::{Deserialize, Serialize};

use super::status::ReplyStatus;

/// Protocol-level error.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct ProtocolError {
    pub status: ReplyStatus,
    pub message: String,
}

impl std::fmt::Display for ProtocolError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{:?}: {}", self.status, self.message)
    }
}

impl std::error::Error for ProtocolError {}

impl From<crate::error::AsynError> for ProtocolError {
    fn from(e: crate::error::AsynError) -> Self {
        // Take the status and the message from their single owners
        // (`AsynError::status()` / `AsynError::message()`), not from a variant
        // match: the partial carriers wrap a genuine timeout/disconnect
        // alongside the bytes already transferred, and both must reach the
        // wire as themselves rather than as a flattened `Error`.
        Self {
            status: e.status().into(),
            message: e.message(),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn serde_roundtrip() {
        let err = ProtocolError {
            status: ReplyStatus::Timeout,
            message: "connection timed out".into(),
        };
        let json = serde_json::to_string(&err).unwrap();
        let back: ProtocolError = serde_json::from_str(&json).unwrap();
        assert_eq!(err, back);
    }

    #[test]
    fn display() {
        let err = ProtocolError {
            status: ReplyStatus::Error,
            message: "bad thing".into(),
        };
        assert_eq!(err.to_string(), "Error: bad thing");
    }
}