Fix bug with notifications during initialization

lib/lsp-server/src/error.rs

@@ -2,7 +2,7 @@ use std::fmt;
 
 use crate::{Notification, Request};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct ProtocolError(pub(crate) String);
 
 impl std::error::Error for ProtocolError {}

lib/lsp-server/src/lib.rs

@@ -126,6 +126,9 @@ impl Connection {
                     self.sender.send(resp.into()).unwrap();
                     continue;
                 }
+                Ok(Message::Notification(n)) if !n.is_exit() => {
+                    continue;
+                }
                 Ok(msg) => Err(ProtocolError(format!("expected initialize request, got {msg:?}"))),
                 Err(e) => {
                     Err(ProtocolError(format!("expected initialize request, got error: {e}")))
@@ -212,3 +215,70 @@ impl Connection {
         Ok(true)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crossbeam_channel::unbounded;
+    use lsp_types::notification::{Exit, Initialized, Notification};
+    use lsp_types::request::{Initialize, Request};
+    use lsp_types::{InitializeParams, InitializedParams};
+    use serde_json::to_value;
+
+    use crate::{Connection, Message, ProtocolError, RequestId};
+
+    struct TestCase {
+        test_messages: Vec<Message>,
+        expected_resp: Result<(RequestId, serde_json::Value), ProtocolError>,
+    }
+
+    fn initialize_start_test(test_case: TestCase) {
+        let (reader_sender, reader_receiver) = unbounded::<Message>();
+        let (writer_sender, writer_receiver) = unbounded::<Message>();
+        let conn = Connection { sender: writer_sender, receiver: reader_receiver };
+
+        for msg in test_case.test_messages {
+            assert!(reader_sender.send(msg).is_ok());
+        }
+
+        let resp = conn.initialize_start();
+        assert_eq!(test_case.expected_resp, resp);
+
+        assert!(writer_receiver.recv_timeout(std::time::Duration::from_secs(1)).is_err());
+    }
+
+    #[test]
+    fn not_exit_notification() {
+        let notification = crate::Notification {
+            method: Initialized::METHOD.to_string(),
+            params: to_value(InitializedParams {}).unwrap(),
+        };
+
+        let params_as_value = to_value(InitializeParams::default()).unwrap();
+        let req_id = RequestId::from(234);
+        let request = crate::Request {
+            id: req_id.clone(),
+            method: Initialize::METHOD.to_string(),
+            params: params_as_value.clone(),
+        };
+
+        initialize_start_test(TestCase {
+            test_messages: vec![notification.into(), request.into()],
+            expected_resp: Ok((req_id, params_as_value)),
+        });
+    }
+
+    #[test]
+    fn exit_notification() {
+        let notification =
+            crate::Notification { method: Exit::METHOD.to_string(), params: to_value(()).unwrap() };
+        let notification_msg = Message::from(notification);
+
+        initialize_start_test(TestCase {
+            test_messages: vec![notification_msg.clone()],
+            expected_resp: Err(ProtocolError(format!(
+                "expected initialize request, got {:?}",
+                notification_msg
+            ))),
+        });
+    }
+}