ic-testkit 0.2.2

use std::any::Any;

#[derive(Debug, Eq, PartialEq)]
pub(super) enum PocketIcPanicKind {
    DeadInstanceTransport { message: String },
    Other { message: String },
}

// Extract a stable string message from one panic payload.
pub(super) fn panic_payload_to_string(payload: &(dyn Any + Send)) -> String {
    if let Some(message) = payload.downcast_ref::<String>() {
        return message.clone();
    }
    if let Some(message) = payload.downcast_ref::<&'static str>() {
        return (*message).to_string();
    }

    "non-string panic payload".to_string()
}

// Classify one panic payload so callers can recover dead-instance restores
// without repeating transport-string matching at each call site.
pub(super) fn classify_pocket_ic_panic(payload: Box<dyn Any + Send>) -> PocketIcPanicKind {
    let message = panic_payload_to_string(payload.as_ref());

    if is_dead_instance_transport_error(&message) {
        return PocketIcPanicKind::DeadInstanceTransport { message };
    }

    PocketIcPanicKind::Other { message }
}

// Check whether one panic payload belongs to the dead-instance transport class
// without consuming it, so callers can still resume the original panic.
pub(super) fn panic_is_dead_instance_transport(payload: &(dyn Any + Send)) -> bool {
    matches!(
        classify_pocket_ic_panic(Box::new(panic_payload_to_string(payload))),
        PocketIcPanicKind::DeadInstanceTransport { .. }
    )
}

// Detect the PocketIC transport failure class that means the owned instance
// has already died and cached snapshot restore should rebuild from scratch.
pub(super) fn is_dead_instance_transport_error(message: &str) -> bool {
    message.contains("ConnectionRefused")
        || message.contains("tcp connect error")
        || message.contains("IncompleteMessage")
        || message.contains("connection closed before message completed")
        || message.contains("channel closed")
}

#[cfg(test)]
mod tests {
    use super::{PocketIcPanicKind, classify_pocket_ic_panic, is_dead_instance_transport_error};

    #[test]
    fn dead_instance_transport_error_detects_connection_refused() {
        assert!(is_dead_instance_transport_error(
            "reqwest::Error { source: ConnectError(\"tcp connect error\", 127.0.0.1:1234, Os { code: 111, kind: ConnectionRefused, message: \"Connection refused\" }) }"
        ));
    }

    #[test]
    fn dead_instance_transport_error_detects_incomplete_message() {
        assert!(is_dead_instance_transport_error(
            "reqwest::Error { source: hyper::Error(IncompleteMessage) }"
        ));
    }

    #[test]
    fn classify_pocket_ic_panic_marks_dead_instance_transport() {
        let classified = classify_pocket_ic_panic(Box::new(
            "reqwest::Error { source: hyper::Error(IncompleteMessage) }".to_string(),
        ));

        assert!(matches!(
            classified,
            PocketIcPanicKind::DeadInstanceTransport { .. }
        ));
    }
}