Fix exec-server in-order request handling and stdio transport

Co-authored-by: Codex <noreply@openai.com>

codex-rs/exec-server/tests/initialize.rs

@@ -0,0 +1,39 @@
+#![cfg(unix)]
+
+mod common;
+
+use codex_app_server_protocol::JSONRPCMessage;
+use codex_app_server_protocol::JSONRPCResponse;
+use codex_exec_server::InitializeParams;
+use codex_exec_server::InitializeResponse;
+use common::exec_server::exec_server;
+use pretty_assertions::assert_eq;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn exec_server_accepts_initialize() -> anyhow::Result<()> {
+    let mut server = exec_server().await?;
+    let initialize_id = server
+        .send_request(
+            "initialize",
+            serde_json::to_value(InitializeParams {
+                client_name: "exec-server-test".to_string(),
+            })?,
+        )
+        .await?;
+
+    let response = server.next_event().await?;
+    let JSONRPCMessage::Response(JSONRPCResponse { id, result }) = response else {
+        panic!("expected initialize response");
+    };
+    assert_eq!(id, initialize_id);
+    let initialize_response: InitializeResponse = serde_json::from_value(result)?;
+    assert_eq!(
+        initialize_response,
+        InitializeResponse {
+            protocol_version: "exec-server.v0".to_string()
+        }
+    );
+
+    server.shutdown().await?;
+    Ok(())
+}

codex-rs/exec-server/tests/process.rs

@@ -0,0 +1,74 @@
+#![cfg(unix)]
+
+mod common;
+
+use codex_app_server_protocol::JSONRPCMessage;
+use codex_app_server_protocol::JSONRPCResponse;
+use codex_exec_server::InitializeParams;
+use codex_exec_server::ExecResponse;
+use common::exec_server::exec_server;
+use pretty_assertions::assert_eq;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn exec_server_stubs_process_start_over_websocket() -> anyhow::Result<()> {
+    let mut server = exec_server().await?;
+    let initialize_id = server
+        .send_request(
+            "initialize",
+            serde_json::to_value(InitializeParams {
+                client_name: "exec-server-test".to_string(),
+            })?,
+        )
+        .await?;
+    let _ = server
+        .wait_for_event(|event| {
+            matches!(
+                event,
+                JSONRPCMessage::Response(JSONRPCResponse { id, .. }) if id == &initialize_id
+            )
+        })
+        .await?;
+
+    server
+        .send_notification(
+            "initialized",
+            serde_json::json!({}),
+        )
+        .await?;
+
+    let process_start_id = server
+        .send_request(
+            "process/start",
+            serde_json::json!({
+                "processId": "proc-1",
+                "argv": ["true"],
+                "cwd": std::env::current_dir()?,
+                "env": {},
+                "tty": false,
+                "arg0": null
+            }),
+        )
+        .await?;
+    let response = server
+        .wait_for_event(|event| {
+            matches!(
+                event,
+                JSONRPCMessage::Response(JSONRPCResponse { id, .. }) if id == &process_start_id
+            )
+        })
+        .await?;
+    let JSONRPCMessage::Response(JSONRPCResponse { id, result }) = response else {
+        panic!("expected process/start response");
+    };
+    assert_eq!(id, process_start_id);
+    let process_start_response: ExecResponse = serde_json::from_value(result)?;
+    assert_eq!(
+        process_start_response,
+        ExecResponse {
+            process_id: "proc-1".to_string()
+        }
+    );
+
+    server.shutdown().await?;
+    Ok(())
+}

codex-rs/exec-server/tests/stdio_smoke.rs

@@ -41,6 +41,7 @@ use tokio::time::timeout;
 async fn exec_server_accepts_initialize_over_stdio() -> anyhow::Result<()> {
     let binary = cargo_bin("codex-exec-server")?;
     let mut child = Command::new(binary);
+    child.args(["--listen", "stdio://"]);
     child.stdin(Stdio::piped());
     child.stdout(Stdio::piped());
     child.stderr(Stdio::inherit());

codex-rs/exec-server/tests/websocket.rs

@@ -0,0 +1,65 @@
+#![cfg(unix)]
+
+mod common;
+
+use codex_app_server_protocol::JSONRPCError;
+use codex_app_server_protocol::JSONRPCMessage;
+use codex_app_server_protocol::JSONRPCResponse;
+use codex_exec_server::InitializeParams;
+use codex_exec_server::InitializeResponse;
+use common::exec_server::exec_server;
+use pretty_assertions::assert_eq;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn exec_server_reports_malformed_websocket_json_and_keeps_running() -> anyhow::Result<()> {
+    let mut server = exec_server().await?;
+    server.send_raw_text("not-json").await?;
+
+    let response = server
+        .wait_for_event(|event| matches!(event, JSONRPCMessage::Error(_)))
+        .await?;
+    let JSONRPCMessage::Error(JSONRPCError { id, error }) = response else {
+        panic!("expected malformed-message error response");
+    };
+    assert_eq!(id, codex_app_server_protocol::RequestId::Integer(-1));
+    assert_eq!(error.code, -32600);
+    assert!(
+        error
+            .message
+            .starts_with("failed to parse websocket JSON-RPC message from exec-server websocket"),
+        "unexpected malformed-message error: {}",
+        error.message
+    );
+
+    let initialize_id = server
+        .send_request(
+            "initialize",
+            serde_json::to_value(InitializeParams {
+                client_name: "exec-server-test".to_string(),
+            })?,
+        )
+        .await?;
+
+    let response = server
+        .wait_for_event(|event| {
+            matches!(
+                event,
+                JSONRPCMessage::Response(JSONRPCResponse { id, .. }) if id == &initialize_id
+            )
+        })
+        .await?;
+    let JSONRPCMessage::Response(JSONRPCResponse { id, result }) = response else {
+        panic!("expected initialize response after malformed input");
+    };
+    assert_eq!(id, initialize_id);
+    let initialize_response: InitializeResponse = serde_json::from_value(result)?;
+    assert_eq!(
+        initialize_response,
+        InitializeResponse {
+            protocol_version: "exec-server.v0".to_string()
+        }
+    );
+
+    server.shutdown().await?;
+    Ok(())
+}