angzarr-client 0.2.0

//! Error types for the Angzarr client library.

use tonic::{Code, Status};

/// Error message constants for testing and consistency.
pub mod errmsg {
    /// Connection failure prefix.
    pub const CONNECTION_FAILED: &str = "connection failed: ";
    /// Transport error prefix.
    pub const TRANSPORT_ERROR: &str = "transport error: ";
    /// gRPC error prefix.
    pub const GRPC_ERROR: &str = "grpc error: ";
    /// Invalid argument prefix.
    pub const INVALID_ARGUMENT: &str = "invalid argument: ";
    /// Invalid timestamp prefix.
    pub const INVALID_TIMESTAMP: &str = "invalid timestamp: ";
}

/// Result type for client operations.
pub type Result<T> = std::result::Result<T, ClientError>;

/// Errors that can occur during client operations.
#[derive(Debug, thiserror::Error)]
pub enum ClientError {
    /// Failed to establish connection to the server.
    #[error("{}{msg}", errmsg::CONNECTION_FAILED)]
    Connection { msg: String },

    /// Transport-level error from tonic.
    #[error("{}{source}", errmsg::TRANSPORT_ERROR)]
    Transport {
        #[from]
        source: tonic::transport::Error,
    },

    /// gRPC error from the server.
    #[error("{}{status}", errmsg::GRPC_ERROR)]
    Grpc { status: Box<Status> },

    /// Invalid argument provided by caller.
    #[error("{}{msg}", errmsg::INVALID_ARGUMENT)]
    InvalidArgument { msg: String },

    /// Failed to parse timestamp.
    #[error("{}{msg}", errmsg::INVALID_TIMESTAMP)]
    InvalidTimestamp { msg: String },
}

impl From<Status> for ClientError {
    fn from(status: Status) -> Self {
        ClientError::Grpc {
            status: Box::new(status),
        }
    }
}

impl ClientError {
    /// Returns the error message.
    pub fn message(&self) -> String {
        match self {
            ClientError::Connection { msg } => msg.clone(),
            ClientError::Transport { source } => source.to_string(),
            ClientError::Grpc { status } => status.message().to_string(),
            ClientError::InvalidArgument { msg } => msg.clone(),
            ClientError::InvalidTimestamp { msg } => msg.clone(),
        }
    }

    /// Returns the gRPC status code if this is a gRPC error.
    pub fn code(&self) -> Option<Code> {
        match self {
            ClientError::Grpc { status } => Some(status.code()),
            _ => None,
        }
    }

    /// Returns the underlying gRPC Status if this is a gRPC error.
    pub fn status(&self) -> Option<&Status> {
        match self {
            ClientError::Grpc { status } => Some(status),
            _ => None,
        }
    }

    /// Returns true if this is a "not found" error.
    pub fn is_not_found(&self) -> bool {
        matches!(self.code(), Some(Code::NotFound))
    }

    /// Returns true if this is a "precondition failed" error.
    pub fn is_precondition_failed(&self) -> bool {
        matches!(self.code(), Some(Code::FailedPrecondition))
    }

    /// Returns true if this is an "invalid argument" error.
    pub fn is_invalid_argument(&self) -> bool {
        matches!(self.code(), Some(Code::InvalidArgument))
            || matches!(self, ClientError::InvalidArgument { .. })
    }

    /// Returns true if this is a connection or transport error.
    pub fn is_connection_error(&self) -> bool {
        matches!(
            self,
            ClientError::Connection { .. } | ClientError::Transport { .. }
        )
    }
}

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

    #[test]
    fn test_connection_error_display() {
        let err = ClientError::Connection {
            msg: "refused".to_string(),
        };
        assert_eq!(err.to_string(), "connection failed: refused");
    }

    #[test]
    fn test_connection_error_message() {
        let err = ClientError::Connection {
            msg: "timeout".to_string(),
        };
        assert_eq!(err.message(), "timeout");
    }

    #[test]
    fn test_invalid_argument_error_display() {
        let err = ClientError::InvalidArgument {
            msg: "missing field".to_string(),
        };
        assert_eq!(err.to_string(), "invalid argument: missing field");
    }

    #[test]
    fn test_invalid_argument_error_message() {
        let err = ClientError::InvalidArgument {
            msg: "bad value".to_string(),
        };
        assert_eq!(err.message(), "bad value");
    }

    #[test]
    fn test_invalid_timestamp_error_display() {
        let err = ClientError::InvalidTimestamp {
            msg: "bad format".to_string(),
        };
        assert_eq!(err.to_string(), "invalid timestamp: bad format");
    }

    #[test]
    fn test_invalid_timestamp_error_message() {
        let err = ClientError::InvalidTimestamp {
            msg: "parse failed".to_string(),
        };
        assert_eq!(err.message(), "parse failed");
    }

    #[test]
    fn test_grpc_error_from_status() {
        let status = Status::not_found("resource not found");
        let err: ClientError = status.into();
        assert!(matches!(err, ClientError::Grpc { .. }));
    }

    #[test]
    fn test_grpc_error_message() {
        let status = Status::internal("server error");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert_eq!(err.message(), "server error");
    }

    #[test]
    fn test_grpc_error_code() {
        let status = Status::not_found("missing");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert_eq!(err.code(), Some(Code::NotFound));
    }

    #[test]
    fn test_grpc_error_status() {
        let status = Status::permission_denied("access denied");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        let s = err.status().unwrap();
        assert_eq!(s.code(), Code::PermissionDenied);
        assert_eq!(s.message(), "access denied");
    }

    #[test]
    fn test_non_grpc_error_code_is_none() {
        let err = ClientError::Connection {
            msg: "refused".to_string(),
        };
        assert_eq!(err.code(), None);
    }

    #[test]
    fn test_non_grpc_error_status_is_none() {
        let err = ClientError::InvalidArgument {
            msg: "bad".to_string(),
        };
        assert!(err.status().is_none());
    }

    #[test]
    fn test_is_not_found_true() {
        let status = Status::not_found("missing");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert!(err.is_not_found());
    }

    #[test]
    fn test_is_not_found_false_other_code() {
        let status = Status::internal("error");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert!(!err.is_not_found());
    }

    #[test]
    fn test_is_not_found_false_non_grpc() {
        let err = ClientError::Connection {
            msg: "refused".to_string(),
        };
        assert!(!err.is_not_found());
    }

    #[test]
    fn test_is_precondition_failed_true() {
        let status = Status::failed_precondition("conflict");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert!(err.is_precondition_failed());
    }

    #[test]
    fn test_is_precondition_failed_false() {
        let status = Status::not_found("missing");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert!(!err.is_precondition_failed());
    }

    #[test]
    fn test_is_invalid_argument_grpc_true() {
        let status = Status::invalid_argument("bad input");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert!(err.is_invalid_argument());
    }

    #[test]
    fn test_is_invalid_argument_client_error_true() {
        let err = ClientError::InvalidArgument {
            msg: "missing".to_string(),
        };
        assert!(err.is_invalid_argument());
    }

    #[test]
    fn test_is_invalid_argument_false() {
        let err = ClientError::Connection {
            msg: "refused".to_string(),
        };
        assert!(!err.is_invalid_argument());
    }

    #[test]
    fn test_is_connection_error_connection_true() {
        let err = ClientError::Connection {
            msg: "refused".to_string(),
        };
        assert!(err.is_connection_error());
    }

    #[test]
    fn test_is_connection_error_grpc_false() {
        let status = Status::internal("error");
        let err = ClientError::Grpc {
            status: Box::new(status),
        };
        assert!(!err.is_connection_error());
    }

    #[test]
    fn test_is_connection_error_invalid_argument_false() {
        let err = ClientError::InvalidArgument {
            msg: "bad".to_string(),
        };
        assert!(!err.is_connection_error());
    }
}