Add NoSuchKeyError as possible errorcode

build.rs

@@ -14,7 +14,7 @@ fn main() {
 #[cfg(feature = "genproto")]
 fn generate_protos() {
 	download_file(
-				"https://raw.githubusercontent.com/lightningdevkit/vss-server/e1a88afd61f56d7e8e90a32036ca12389e36fe44/app/src/main/proto/vss.proto",
+				"https://raw.githubusercontent.com/lightningdevkit/vss-server/62e888e1bd3305d23b15da857edffaf527163048/app/src/main/proto/vss.proto",
 				"src/proto/vss.proto",
 		).unwrap();
 

src/error.rs

@@ -10,9 +10,20 @@ use std::fmt::{Display, Formatter};
 /// information regarding each error code and corresponding use-cases.
 #[derive(Debug)]
 pub enum VssError {
+	/// Please refer to [`ErrorCode::NoSuchKeyException`].
+	NoSuchKeyError(String),
+
+	/// Please refer to [`ErrorCode::InvalidRequestException`].
 	InvalidRequestError(String),
+
+	/// Please refer to [`ErrorCode::ConflictException`].
 	ConflictError(String),
+
+	/// Please refer to [`ErrorCode::InternalServerException`].
 	InternalServerError(String),
+
+	/// There is an unknown error, it could be a client-side bug, unrecognized error-code, network error
+	/// or something else.
 	InternalError(String),
 }
 
@@ -33,6 +44,9 @@ impl VssError {
 impl Display for VssError {
 	fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
 		match self {
+			VssError::NoSuchKeyError(message) => {
+				write!(f, "Requested key does not exist: {}", message)
+			}
 			VssError::InvalidRequestError(message) => {
 				write!(f, "Request sent to VSS Storage was invalid: {}", message)
 			}
@@ -54,6 +68,7 @@ impl Error for VssError {}
 impl From<ErrorResponse> for VssError {
 	fn from(error_response: ErrorResponse) -> Self {
 		match error_response.error_code() {
+			ErrorCode::NoSuchKeyException => VssError::NoSuchKeyError(error_response.message),
 			ErrorCode::InvalidRequestException => VssError::InvalidRequestError(error_response.message),
 			ErrorCode::ConflictException => VssError::ConflictError(error_response.message),
 			ErrorCode::InternalServerException => VssError::InternalServerError(error_response.message),

src/types.rs

@@ -10,7 +10,10 @@ pub struct GetObjectRequest {
 	/// Authorization and billing can also be performed at the `store_id` level.
 	#[prost(string, tag = "1")]
 	pub store_id: ::prost::alloc::string::String,
-	/// `Key` for which the value is to be fetched.
+	/// The key of the value to be fetched.
+	///
+	/// If the specified `key` does not exist, returns `ErrorCode.NO_SUCH_KEY_EXCEPTION` in the
+	/// the `ErrorResponse`.
 	///
 	/// Consistency Guarantee:
 	/// Get(read) operations against a `key` are consistent reads and will reflect all previous writes,
@@ -287,17 +290,19 @@ pub struct KeyValue {
 pub enum ErrorCode {
 	/// Default protobuf Enum value. Will not be used as `ErrorCode` by server.
 	Unknown = 0,
-	/// CONFLICT_EXCEPTION is used when the request contains mismatched version (either key or global)
+	/// Used when the request contains mismatched version (either key or global)
 	/// in `PutObjectRequest`. For more info refer `PutObjectRequest`.
 	ConflictException = 1,
-	/// INVALID_REQUEST_EXCEPTION is used in the following cases:
+	/// Used in the following cases:
 	///    - The request was missing a required argument.
 	///    - The specified argument was invalid, incomplete or in the wrong format.
 	///    - The request body of api cannot be deserialized into corresponding protobuf object.
 	InvalidRequestException = 2,
-	/// An internal server error occurred, client is probably at no fault and can safely retry this
-	/// error with exponential backoff.
+	/// Used when an internal server error occurred, client is probably at no fault and can safely retry
+	/// this error with exponential backoff.
 	InternalServerException = 3,
+	/// Used when the specified `key` in a `GetObjectRequest` does not exist.
+	NoSuchKeyException = 4,
 }
 impl ErrorCode {
 	/// String value of the enum field names used in the ProtoBuf definition.
@@ -310,6 +315,7 @@ impl ErrorCode {
 			ErrorCode::ConflictException => "CONFLICT_EXCEPTION",
 			ErrorCode::InvalidRequestException => "INVALID_REQUEST_EXCEPTION",
 			ErrorCode::InternalServerException => "INTERNAL_SERVER_EXCEPTION",
+			ErrorCode::NoSuchKeyException => "NO_SUCH_KEY_EXCEPTION",
 		}
 	}
 	/// Creates an enum from field names used in the ProtoBuf definition.
@@ -319,6 +325,7 @@ impl ErrorCode {
 			"CONFLICT_EXCEPTION" => Some(Self::ConflictException),
 			"INVALID_REQUEST_EXCEPTION" => Some(Self::InvalidRequestException),
 			"INTERNAL_SERVER_EXCEPTION" => Some(Self::InternalServerException),
+			"NO_SUCH_KEY_EXCEPTION" => Some(Self::NoSuchKeyException),
 			_ => None,
 		}
 	}

tests/tests.rs

@@ -149,6 +149,30 @@ mod tests {
 		mock_server.expect(1).assert();
 	}
 
+	#[tokio::test]
+	async fn test_no_such_key_err_handling() {
+		let base_url = mockito::server_url();
+		let vss_client = VssClient::new(&base_url);
+
+		// NoSuchKeyError
+		let error_response = ErrorResponse {
+			error_code: ErrorCode::NoSuchKeyException.into(),
+			message: "NoSuchKeyException".to_string(),
+		};
+		let mock_server = mockito::mock("POST", GET_OBJECT_ENDPOINT)
+			.with_status(409)
+			.with_body(&error_response.encode_to_vec())
+			.create();
+
+		let get_result = vss_client
+			.get_object(&GetObjectRequest { store_id: "store".to_string(), key: "non_existent_key".to_string() })
+			.await;
+		assert!(matches!(get_result.unwrap_err(), VssError::NoSuchKeyError { .. }));
+
+		// Verify 1 request hit the server
+		mock_server.expect(1).assert();
+	}
+
 	#[tokio::test]
 	async fn test_invalid_request_err_handling() {
 		let base_url = mockito::server_url();