refactor: consolidate nvim crates, extract server library, and update workspace dependencies

nvim-core/src/lib.rs

@@ -34,9 +34,11 @@ pub async fn send_response(response: JsonRpcResponse) {
     // The MCP StdioTransport MUST use Newline-Delimited JSON (NDJSON).
     // Do NOT use LSP-style HTTP headers (e.g. Content-Length).
     // See MCP protocol spec (SEP-2575) and mcp-go-sdk bufio.Scanner implementation.
+    let mut payload = Vec::with_capacity(msg.len() + 1);
+    payload.extend_from_slice(msg.as_bytes());
+    payload.push(b'\n');
     let mut stdout = tokio::io::stdout();
-    let _ = stdout.write_all(msg.as_bytes()).await;
-    let _ = stdout.write_all(b"\n").await;
+    let _ = stdout.write_all(&payload).await;
     let _ = stdout.flush().await;
 }
 
@@ -169,6 +171,8 @@ pub struct NvimRequest {
 
 use std::sync::atomic::{AtomicU64, Ordering};
 static NEXT_MSGID: AtomicU64 = AtomicU64::new(1);
+static RPC_SEMAPHORE: LazyLock<Arc<tokio::sync::Semaphore>> =
+    LazyLock::new(|| Arc::new(tokio::sync::Semaphore::new(100)));
 static NVIM_CONN: LazyLock<Arc<std::sync::Mutex<Option<mpsc::Sender<NvimRequest>>>>> =
     LazyLock::new(|| Arc::new(std::sync::Mutex::new(None)));
 
@@ -776,7 +780,13 @@ pub async fn run_mcp_loop(app_name: &str, app_version: &str) {
         let app_name = app_name.to_string();
         let app_version = app_version.to_string();
 
+        let permit = RPC_SEMAPHORE.clone().acquire_owned().await;
+        if permit.is_err() {
+            continue;
+        }
+
         tokio::spawn(async move {
+            let _permit = permit;
             let id = msg.id.unwrap_or(json!(null));
 
             match msg.method.as_str() {
@@ -1759,4 +1769,77 @@ mod tests {
         let req = mcp_stdio::read_mcp_message(&mut reader).await;
         assert!(req.is_none());
     }
+
+    #[test]
+    fn test_nvim_state_and_notification() {
+        let params = vec![
+            rmpv::Value::String("CursorMoved".into()),
+            rmpv::Value::Array(vec![
+                rmpv::Value::Nil,
+                rmpv::Value::Integer(15.into()),
+                rmpv::Value::Integer(4.into()),
+                rmpv::Value::Nil,
+            ]),
+        ];
+        handle_nvim_notification(&params);
+        let state = NVIM_STATE.lock().unwrap();
+        assert_eq!(state.cursor, "Line: 15, Column: 4");
+    }
+
+
+    #[tokio::test]
+    async fn test_jsonrpc_structs_and_responses() {
+        let req = JsonRpcRequest {
+            jsonrpc: "2.0".to_string(),
+            id: Some(json!(1)),
+            method: "nvim_get_cursor".to_string(),
+            params: None,
+        };
+        let serialized = serde_json::to_string(&req).unwrap();
+        assert!(serialized.contains("nvim_get_cursor"));
+
+        let resp = JsonRpcResponse {
+            jsonrpc: "2.0".to_string(),
+            id: json!(1),
+            result: Some(json!([1, 0])),
+            error: None,
+        };
+        let resp_str = serde_json::to_string(&resp).unwrap();
+        assert!(resp_str.contains("result"));
+    }
+
+    #[tokio::test]
+    async fn test_nvim_socket_and_interactive_helpers() {
+        let is_int = is_interactive("agy-headless-nvim-1234").await;
+        assert!(!is_int);
+
+        let path = get_socket_path().await;
+        assert!(path.is_ok());
+    }
+
+    #[test]
+    fn test_rmpv_to_json_conversions() {
+        assert_eq!(rmpv_to_json(&rmpv::Value::Nil), serde_json::Value::Null);
+        assert_eq!(rmpv_to_json(&rmpv::Value::Boolean(true)), serde_json::json!(true));
+        assert_eq!(rmpv_to_json(&rmpv::Value::Integer(42.into())), serde_json::json!(42));
+        assert_eq!(rmpv_to_json(&rmpv::Value::F64(3.14)), serde_json::json!(3.14));
+        assert_eq!(rmpv_to_json(&rmpv::Value::String("hello".into())), serde_json::json!("hello"));
+        assert_eq!(rmpv_to_json(&rmpv::Value::Binary(vec![65, 66])), serde_json::json!("Binary([65, 66])"));
+
+        assert_eq!(
+            rmpv_to_json(&rmpv::Value::Array(vec![rmpv::Value::Boolean(false)])),
+            serde_json::json!([false])
+        );
+        let map_val = rmpv::Value::Map(vec![(
+            rmpv::Value::String("key".into()),
+            rmpv::Value::String("val".into()),
+        )]);
+        assert_eq!(rmpv_to_json(&map_val), serde_json::json!({"key": "val"}));
+        let ext_val = rmpv::Value::Ext(1, vec![10, 20]);
+        assert_eq!(rmpv_to_json(&ext_val), serde_json::json!("Ext(1, [10, 20])"));
+    }
 }
+
+
+
+