feat: error handling overhaul (#65)

Author: heilhead

Cargo.toml

@@ -30,6 +30,8 @@ url = "2.3"
 warp = { version = "0.3", default-features = false }
 serde_json = "1.0"
 rand = "0.8.5"
+futures-util = "0.3"
+once_cell = "1.19"
 
 [[example]]
 name = "websocket_client"

examples/websocket_client.rs

@@ -1,6 +1,6 @@
 use {
     relay_client::{
-        error::Error,
+        error::ClientError,
         websocket::{Client, CloseFrame, ConnectionHandler, PublishedMessage},
         ConnectionOptions,
     },
@@ -49,11 +49,11 @@ impl ConnectionHandler for Handler {
         );
     }
 
-    fn inbound_error(&mut self, error: Error) {
+    fn inbound_error(&mut self, error: ClientError) {
         println!("[{}] inbound error: {error}", self.name);
     }
 
-    fn outbound_error(&mut self, error: Error) {
+    fn outbound_error(&mut self, error: ClientError) {
         println!("[{}] outbound error: {error}", self.name);
     }
 }

relay_client/src/error.rs

@@ -1,3 +1,5 @@
+use relay_rpc::rpc::{self, error::ServiceError};
+
 pub type BoxError = Box<dyn std::error::Error + Send + Sync>;
 
 /// Errors generated while parsing
@@ -23,7 +25,7 @@ pub enum RequestBuildError {
 
 /// Possible Relay client errors.
 #[derive(Debug, thiserror::Error)]
-pub enum Error {
+pub enum ClientError {
     #[error("Failed to build connection request: {0}")]
     RequestBuilder(#[from] RequestBuildError),
 
@@ -42,15 +44,69 @@ pub enum Error {
     #[error("Invalid response ID")]
     InvalidResponseId,
 
+    #[error("Invalid error response")]
+    InvalidErrorResponse,
+
     #[error("Serialization failed: {0}")]
     Serialization(serde_json::Error),
 
     #[error("Deserialization failed: {0}")]
     Deserialization(serde_json::Error),
 
-    #[error("RPC error ({code}): {message}")]
-    Rpc { code: i32, message: String },
+    #[error("RPC error: code={code} data={data:?} message={message}")]
+    Rpc {
+        code: i32,
+        message: String,
+        data: Option<String>,
+    },
 
     #[error("Invalid request type")]
     InvalidRequestType,
 }
+
+impl From<rpc::ErrorData> for ClientError {
+    fn from(err: rpc::ErrorData) -> Self {
+        Self::Rpc {
+            code: err.code,
+            message: err.message,
+            data: err.data,
+        }
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error<T> {
+    /// Client errors encountered while performing the request.
+    #[error(transparent)]
+    Client(ClientError),
+
+    /// Error response received from the relay.
+    #[error(transparent)]
+    Response(#[from] rpc::Error<T>),
+}
+
+impl<T: ServiceError> From<ClientError> for Error<T> {
+    fn from(err: ClientError) -> Self {
+        match err {
+            ClientError::Rpc {
+                code,
+                message,
+                data,
+            } => {
+                let err = rpc::ErrorData {
+                    code,
+                    message,
+                    data,
+                };
+
+                match rpc::Error::try_from(err) {
+                    Ok(err) => Error::Response(err),
+
+                    Err(_) => Error::Client(ClientError::InvalidErrorResponse),
+                }
+            }
+
+            _ => Error::Client(err),
+        }
+    }
+}

relay_client/src/http.rs

@@ -1,6 +1,6 @@
 use {
     crate::{
-        error::{BoxError, Error},
+        error::{BoxError, ClientError, Error},
         ConnectionOptions,
         MessageIdGenerator,
     },
@@ -9,15 +9,15 @@ use {
         auth::ed25519_dalek::SigningKey,
         domain::{DecodedClientId, SubscriptionId, Topic},
         jwt::{self, JwtError, VerifyableClaims},
-        rpc::{self, Receipt, RequestPayload},
+        rpc::{self, Receipt, ServiceRequest},
     },
     std::{sync::Arc, time::Duration},
     url::Url,
 };
 
 pub type TransportError = reqwest::Error;
-pub type Response<T> = Result<<T as RequestPayload>::Response, Error>;
-pub type EmptyResponse = Result<(), Error>;
+pub type Response<T> = Result<<T as ServiceRequest>::Response, Error<<T as ServiceRequest>::Error>>;
+pub type EmptyResponse<T> = Result<(), Error<<T as ServiceRequest>::Error>>;
 
 #[derive(Debug, thiserror::Error)]
 pub enum RequestParamsError {
@@ -41,9 +41,6 @@ pub enum HttpClientError {
 
     #[error("JWT error: {0}")]
     Jwt(#[from] JwtError),
-
-    #[error("RPC error: code={} message={}", .0.code, .0.message)]
-    RpcError(rpc::ErrorData),
 }
 
 #[derive(Debug, Clone)]
@@ -82,7 +79,7 @@ pub struct Client {
 }
 
 impl Client {
-    pub fn new(opts: &ConnectionOptions) -> Result<Self, Error> {
+    pub fn new(opts: &ConnectionOptions) -> Result<Self, ClientError> {
         let mut headers = HeaderMap::new();
         opts.update_request_headers(&mut headers)?;
 
@@ -111,11 +108,14 @@ impl Client {
         tag: u32,
         ttl: Duration,
         prompt: bool,
-    ) -> EmptyResponse {
+    ) -> EmptyResponse<rpc::Publish> {
         let ttl_secs = ttl
             .as_secs()
             .try_into()
-            .map_err(|_| HttpClientError::InvalidRequest(RequestParamsError::InvalidTtl.into()))?;
+            .map_err(|_| {
+                HttpClientError::InvalidRequest(RequestParamsError::InvalidTtl.into()).into()
+            })
+            .map_err(Error::Client)?;
 
         self.request(rpc::Publish {
             topic,
@@ -175,7 +175,8 @@ impl Client {
             .ttl
             .as_secs()
             .try_into()
-            .map_err(|err| HttpClientError::InvalidRequest(Box::new(err)))?;
+            .map_err(|err| HttpClientError::InvalidRequest(Box::new(err)).into())
+            .map_err(Error::Client)?;
         let exp = iat + ttl_sec;
 
         let claims = rpc::WatchRegisterClaims {
@@ -194,7 +195,11 @@ impl Client {
         };
 
         let payload = rpc::WatchRegister {
-            register_auth: claims.encode(keypair).map_err(HttpClientError::Jwt)?,
+            register_auth: claims
+                .encode(keypair)
+                .map_err(HttpClientError::Jwt)
+                .map_err(ClientError::from)
+                .map_err(Error::Client)?,
         };
 
         self.request(payload).await
@@ -230,7 +235,11 @@ impl Client {
         };
 
         let payload = rpc::WatchUnregister {
-            unregister_auth: claims.encode(keypair).map_err(HttpClientError::Jwt)?,
+            unregister_auth: claims
+                .encode(keypair)
+                .map_err(HttpClientError::Jwt)
+                .map_err(ClientError::from)
+                .map_err(Error::Client)?,
         };
 
         self.request(payload).await
@@ -299,45 +308,50 @@ impl Client {
 
     pub(crate) async fn request<T>(&self, payload: T) -> Response<T>
     where
-        T: RequestPayload,
+        T: ServiceRequest,
     {
         let payload = rpc::Payload::Request(rpc::Request {
             id: self.id_generator.next(),
             jsonrpc: rpc::JSON_RPC_VERSION.clone(),
             params: payload.into_params(),
         });
 
-        let result = self
-            .client
-            .post(self.url.clone())
-            .json(&payload)
-            .send()
-            .await
-            .map_err(HttpClientError::Transport)?;
+        let response = async {
+            let result = self
+                .client
+                .post(self.url.clone())
+                .json(&payload)
+                .send()
+                .await
+                .map_err(HttpClientError::Transport)?;
 
-        let status = result.status();
+            let status = result.status();
 
-        if !status.is_success() {
-            let body = result.text().await;
-            return Err(HttpClientError::InvalidHttpCode(status, body).into());
-        }
+            if !status.is_success() {
+                let body = result.text().await;
+                return Err(HttpClientError::InvalidHttpCode(status, body));
+            }
 
-        let response = result
-            .json::<rpc::Payload>()
-            .await
-            .map_err(|_| HttpClientError::InvalidResponse)?;
+            result
+                .json::<rpc::Payload>()
+                .await
+                .map_err(|_| HttpClientError::InvalidResponse)
+        }
+        .await
+        .map_err(ClientError::from)
+        .map_err(Error::Client)?;
 
         match response {
             rpc::Payload::Response(rpc::Response::Success(response)) => {
                 serde_json::from_value(response.result)
-                    .map_err(|_| HttpClientError::InvalidResponse.into())
+                    .map_err(|_| Error::Client(HttpClientError::InvalidResponse.into()))
             }
 
             rpc::Payload::Response(rpc::Response::Error(response)) => {
-                Err(HttpClientError::RpcError(response.error).into())
+                Err(ClientError::from(response.error).into())
             }
 
-            _ => Err(HttpClientError::InvalidResponse.into()),
+            _ => Err(Error::Client(HttpClientError::InvalidResponse.into())),
         }
     }
 }

relay_client/src/lib.rs

@@ -1,5 +1,5 @@
 use {
-    crate::error::{Error, RequestBuildError},
+    crate::error::{ClientError, RequestBuildError},
     ::http::HeaderMap,
     relay_rpc::{
         auth::{SerializedAuthToken, RELAY_WEBSOCKET_ADDRESS},

relay_client/src/websocket.rs

@@ -1,6 +1,6 @@
 use {
     self::connection::{connection_event_loop, ConnectionControl},
-    crate::{error::Error, ConnectionOptions},
+    crate::{error::ClientError, ConnectionOptions},
     relay_rpc::{
         domain::{MessageId, SubscriptionId, Topic},
         rpc::{
@@ -114,11 +114,11 @@ pub trait ConnectionHandler: Send + 'static {
 
     /// Called when an inbound error occurs, such as data deserialization
     /// failure, or an unknown response message ID.
-    fn inbound_error(&mut self, _error: Error) {}
+    fn inbound_error(&mut self, _error: ClientError) {}
 
     /// Called when an outbound error occurs, i.e. failed to write to the
     /// websocket stream.
-    fn outbound_error(&mut self, _error: Error) {}
+    fn outbound_error(&mut self, _error: ClientError) {}
 }
 
 /// The Relay WebSocket RPC client.
@@ -291,7 +291,7 @@ impl Client {
     }
 
     /// Opens a connection to the Relay.
-    pub async fn connect(&self, opts: &ConnectionOptions) -> Result<(), Error> {
+    pub async fn connect(&self, opts: &ConnectionOptions) -> Result<(), ClientError> {
         let (tx, rx) = oneshot::channel();
         let request = opts.as_ws_request()?;
 
@@ -300,24 +300,24 @@ impl Client {
             .send(ConnectionControl::Connect { request, tx })
             .is_ok()
         {
-            rx.await.map_err(|_| Error::ChannelClosed)?
+            rx.await.map_err(|_| ClientError::ChannelClosed)?
         } else {
-            Err(Error::ChannelClosed)
+            Err(ClientError::ChannelClosed)
         }
     }
 
     /// Closes the Relay connection.
-    pub async fn disconnect(&self) -> Result<(), Error> {
+    pub async fn disconnect(&self) -> Result<(), ClientError> {
         let (tx, rx) = oneshot::channel();
 
         if self
             .control_tx
             .send(ConnectionControl::Disconnect { tx })
             .is_ok()
         {
-            rx.await.map_err(|_| Error::ChannelClosed)?
+            rx.await.map_err(|_| ClientError::ChannelClosed)?
         } else {
-            Err(Error::ChannelClosed)
+            Err(ClientError::ChannelClosed)
         }
     }
 
@@ -330,7 +330,7 @@ impl Client {
                 unreachable!();
             };
 
-            request.tx.send(Err(Error::ChannelClosed)).ok();
+            request.tx.send(Err(ClientError::ChannelClosed)).ok();
         }
     }
 }