1 files changed, 50 insertions, 0 deletions
diff --git a/src/tools/rust-analyzer/lib/lsp-server/src/error.rs b/src/tools/rust-analyzer/lib/lsp-server/src/error.rs
new file mode 100644
index 000000000..4c934d9ec
--- /dev/null
+++ b/src/tools/rust-analyzer/lib/lsp-server/src/error.rs
@@ -0,0 +1,50 @@
+use std::fmt;
+
+use crate::{Notification, Request};
+
+#[derive(Debug, Clone)]
+pub struct ProtocolError(pub(crate) String);
+
+impl std::error::Error for ProtocolError {}
+
+impl fmt::Display for ProtocolError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(&self.0, f)
+    }
+}
+
+#[derive(Debug)]
+pub enum ExtractError<T> {
+    /// The extracted message was of a different method than expected.
+    MethodMismatch(T),
+    /// Failed to deserialize the message.
+    JsonError { method: String, error: serde_json::Error },
+}
+
+impl std::error::Error for ExtractError<Request> {}
+impl fmt::Display for ExtractError<Request> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            ExtractError::MethodMismatch(req) => {
+                write!(f, "Method mismatch for request '{}'", req.method)
+            }
+            ExtractError::JsonError { method, error } => {
+                write!(f, "Invalid request\nMethod: {method}\n error: {error}",)
+            }
+        }
+    }
+}
+
+impl std::error::Error for ExtractError<Notification> {}
+impl fmt::Display for ExtractError<Notification> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            ExtractError::MethodMismatch(req) => {
+                write!(f, "Method mismatch for notification '{}'", req.method)
+            }
+            ExtractError::JsonError { method, error } => {
+                write!(f, "Invalid notification\nMethod: {method}\n error: {error}")
+            }
+        }
+    }
+}