Publish harness and TUI open-source

initial sync from the monorepo

crates/codegen/xai-acp-lib/src/channel.rs

@@ -0,0 +1,103 @@
+use std::fmt;
+
+use tokio::sync::{mpsc, oneshot};
+
+use crate::{
+    common::{AcpChannelFailure, AcpResult, acp_channel_failure_error},
+    message::{AcpAgentMessage, AcpArgs, AcpClientMessage, AcpMethod, AcpRequest},
+};
+
+/// Receiver/sender pair, either for client/agent or agent/client message types.
+pub struct AcpChannel<I, O> {
+    pub rx: mpsc::UnboundedReceiver<I>,
+    pub tx: mpsc::UnboundedSender<O>,
+}
+
+impl<I: AcpMethod, O: AcpMethod> AcpChannel<I, O> {
+    pub fn new(rx: mpsc::UnboundedReceiver<I>, tx: mpsc::UnboundedSender<O>) -> Self {
+        Self { rx, tx }
+    }
+}
+
+/// Client channel: receive client messages from agent, send agent messages to agent.
+pub type AcpClientChannel = AcpChannel<AcpClientMessage, AcpAgentMessage>;
+/// Agent channel: receive agent messages from client, send client messages to client.
+pub type AcpAgentChannel = AcpChannel<AcpAgentMessage, AcpClientMessage>;
+
+/// Create a linked pair of client/agent channels.
+pub fn acp_channels() -> (AcpClientChannel, AcpAgentChannel) {
+    let (tx1, rx1) = mpsc::unbounded_channel();
+    let (tx2, rx2) = mpsc::unbounded_channel();
+    (AcpChannel::new(rx1, tx2), AcpChannel::new(rx2, tx1))
+}
+
+pub async fn acp_send<R, T>(request: T, tx: &mpsc::UnboundedSender<R>) -> AcpResult<T::Response>
+where
+    T: AcpRequest,
+    R: From<AcpArgs<T>> + fmt::Debug,
+{
+    let (response_tx, response_rx) = oneshot::channel();
+    let method = request.method_name();
+    let args = AcpArgs {
+        request,
+        response_tx,
+    };
+
+    tx.send(args.into()).map_err(|_| {
+        acp_channel_failure_error(
+            format!("unable to send '{method}' request, channel closed"),
+            AcpChannelFailure::SendFailed,
+        )
+    })?;
+
+    response_rx.await.map_err(|_| {
+        acp_channel_failure_error(
+            format!("unable to receive '{method}' response, channel closed"),
+            AcpChannelFailure::RecvFailed,
+        )
+    })?
+}
+
+#[cfg(test)]
+mod acp_send_failure_tests {
+    use super::acp_send;
+    use crate::common::{AcpChannelFailure, acp_channel_failure};
+    use crate::message::AcpAgentMessage;
+    use agent_client_protocol as acp;
+    use tokio::sync::mpsc;
+
+    fn ext_request() -> acp::ExtRequest {
+        acp::ExtRequest::new(
+            "x.ai/test",
+            serde_json::value::to_raw_value(&serde_json::json!({}))
+                .unwrap()
+                .into(),
+        )
+    }
+
+    #[tokio::test]
+    async fn send_failed_when_receiver_dropped_before_send() {
+        let (tx, rx) = mpsc::unbounded_channel::<AcpAgentMessage>();
+        drop(rx); // no peer listening -> enqueue fails
+        let err = acp_send(ext_request(), &tx).await.unwrap_err();
+        assert_eq!(
+            acp_channel_failure(&err),
+            Some(AcpChannelFailure::SendFailed)
+        );
+    }
+
+    #[tokio::test]
+    async fn recv_failed_when_response_channel_dropped_after_send() {
+        let (tx, mut rx) = mpsc::unbounded_channel::<AcpAgentMessage>();
+        let mut send_fut = Box::pin(acp_send(ext_request(), &tx));
+        // First poll enqueues the request, then parks on the response channel.
+        assert!(futures::poll!(send_fut.as_mut()).is_pending());
+        // The peer "receives" the request then drops it (dropping response_tx).
+        drop(rx.try_recv().expect("request should be enqueued"));
+        let err = send_fut.await.unwrap_err();
+        assert_eq!(
+            acp_channel_failure(&err),
+            Some(AcpChannelFailure::RecvFailed)
+        );
+    }
+}