Properly deal with additional messages sent from kraken

swap/src/kraken.rs

@@ -7,8 +7,7 @@ use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use std::convert::TryFrom;
 use tokio::sync::watch;
-use tokio_tungstenite::tungstenite::protocol::CloseFrame;
-use tokio_tungstenite::tungstenite::Message;
+use tokio_tungstenite::tungstenite;
 use tracing::{error, trace};
 
 pub async fn connect() -> Result<watch::Receiver<Result<Rate, Error>>> {
@@ -22,9 +21,9 @@ pub async fn connect() -> Result<watch::Receiver<Result<Rate, Error>>> {
     tokio::spawn(async move {
         while let Some(msg) = rate_stream.next().await {
             let msg = match msg {
-                Ok(Message::Text(msg)) => msg,
-                Ok(Message::Close(close_frame)) => {
-                    if let Some(CloseFrame { code, reason }) = close_frame {
+                Ok(tungstenite::Message::Text(msg)) => msg,
+                Ok(tungstenite::Message::Close(close_frame)) => {
+                    if let Some(tungstenite::protocol::CloseFrame { code, reason }) = close_frame {
                         error!(
                             "Kraken rate stream was closed with code {} and reason: {}",
                             code, reason
@@ -32,7 +31,7 @@ pub async fn connect() -> Result<watch::Receiver<Result<Rate, Error>>> {
                     } else {
                         error!("Kraken rate stream was closed without code and reason");
                     }
-                    let _ = rate_update.send(Err(Error::CloseMessage));
+                    let _ = rate_update.send(Err(Error::ConnectionClosed));
                     continue;
                 }
                 Ok(msg) => {
@@ -43,26 +42,37 @@ pub async fn connect() -> Result<watch::Receiver<Result<Rate, Error>>> {
                     continue;
                 }
                 Err(e) => {
-                    error!("Error when reading from Kraken rate stream: {}", e);
+                    error!(%e, "Error when reading from Kraken rate stream");
                     let _ = rate_update.send(Err(e.into()));
                     continue;
                 }
             };
 
-            // If we encounter a heartbeat we skip it and iterate again
-            if msg.eq(r#"{"event":"heartbeat"}"#) {
-                continue;
-            }
-
-            let ticker = match serde_json::from_str::<TickerUpdate>(&msg) {
-                Ok(ticker) => ticker,
-                Err(e) => {
-                    let _ = rate_update.send(Err(e.into()));
+            let update = match serde_json::from_str::<Event>(&msg) {
+                Ok(Event::SystemStatus) => {
+                    tracing::debug!("Connected to Kraken websocket API");
                     continue;
                 }
+                Ok(Event::SubscriptionStatus) => {
+                    tracing::debug!("Subscribed to updates for ticker");
+                    continue;
+                }
+                Ok(Event::Heartbeat) => {
+                    tracing::trace!("Received heartbeat message");
+                    continue;
+                }
+                // if the message is not an event, it is a ticker update or an unknown event
+                Err(_) => match serde_json::from_str::<TickerUpdate>(&msg) {
+                    Ok(ticker) => ticker,
+                    Err(e) => {
+                        tracing::warn!(%e, "Failed to deserialize message '{}' as ticker update", msg);
+                        let _ = rate_update.send(Err(Error::UnknownMessage { msg }));
+                        continue;
+                    }
+                },
             };
 
-            let rate = match Rate::try_from(ticker) {
+            let rate = match Rate::try_from(update) {
                 Ok(rate) => rate,
                 Err(e) => {
                     let _ = rate_update.send(Err(e));
@@ -94,12 +104,12 @@ const SUBSCRIBE_XMR_BTC_TICKER_PAYLOAD: &str = r#"
 pub enum Error {
     #[error("Rate has not yet been retrieved from Kraken websocket API")]
     NotYetRetrieved,
-    #[error("Received close message from Kraken")]
-    CloseMessage,
-    #[error("Websocket: ")]
+    #[error("The Kraken server closed the websocket connection")]
+    ConnectionClosed,
+    #[error("Websocket: {0}")]
     WebSocket(String),
-    #[error("Serde: ")]
-    Serde(String),
+    #[error("Received unknown message from Kraken: {msg}")]
+    UnknownMessage { msg: String },
     #[error("Data field is missing")]
     DataFieldMissing,
     #[error("Ask Rate Element is of unexpected type")]
@@ -110,16 +120,21 @@ pub enum Error {
     BitcoinParseAmount(#[from] ParseAmountError),
 }
 
-impl From<tokio_tungstenite::tungstenite::Error> for Error {
-    fn from(err: tokio_tungstenite::tungstenite::Error) -> Self {
+impl From<tungstenite::Error> for Error {
+    fn from(err: tungstenite::Error) -> Self {
         Error::WebSocket(format!("{:#}", err))
     }
 }
 
-impl From<serde_json::Error> for Error {
-    fn from(err: serde_json::Error) -> Self {
-        Error::Serde(format!("{:#}", err))
-    }
+#[derive(Debug, Serialize, Deserialize, PartialEq)]
+#[serde(tag = "event")]
+enum Event {
+    #[serde(rename = "systemStatus")]
+    SystemStatus,
+    #[serde(rename = "heartbeat")]
+    Heartbeat,
+    #[serde(rename = "subscriptionStatus")]
+    SubscriptionStatus,
 }
 
 #[derive(Debug, Serialize, Deserialize)]
@@ -176,10 +191,28 @@ impl TryFrom<TickerUpdate> for Rate {
 mod tests {
     use super::*;
 
-    #[tokio::test]
-    async fn deserialize_ticker_update() {
-        let sample_response = r#"[980,{"a":["0.00521900",4,"4.84775132"],"b":["0.00520600",70,"70.35668921"],"c":["0.00520700","0.00000186"],"v":["18530.40510860","18531.94887860"],"p":["0.00489493","0.00489490"],"t":[5017,5018],"l":["0.00448300","0.00448300"],"h":["0.00525000","0.00525000"],"o":["0.00450000","0.00451000"]},"ticker","XMR/XBT"]"#;
+    #[test]
+    fn can_deserialize_system_status_event() {
+        let event = r#"{"connectionID":14859574189081089471,"event":"systemStatus","status":"online","version":"1.8.1"}"#;
 
-        let _ = serde_json::from_str::<TickerUpdate>(sample_response).unwrap();
+        let event = serde_json::from_str::<Event>(event).unwrap();
+
+        assert_eq!(event, Event::SystemStatus)
+    }
+
+    #[test]
+    fn can_deserialize_subscription_status_event() {
+        let event = r#"{"channelID":980,"channelName":"ticker","event":"subscriptionStatus","pair":"XMR/XBT","status":"subscribed","subscription":{"name":"ticker"}}"#;
+
+        let event = serde_json::from_str::<Event>(event).unwrap();
+
+        assert_eq!(event, Event::SubscriptionStatus)
+    }
+
+    #[test]
+    fn deserialize_ticker_update() {
+        let message = r#"[980,{"a":["0.00440700",7,"7.35318535"],"b":["0.00440200",7,"7.57416678"],"c":["0.00440700","0.22579000"],"v":["273.75489000","4049.91233351"],"p":["0.00446205","0.00441699"],"t":[123,1310],"l":["0.00439400","0.00429900"],"h":["0.00450000","0.00450000"],"o":["0.00449100","0.00433700"]},"ticker","XMR/XBT"]"#;
+
+        let _ = serde_json::from_str::<TickerUpdate>(message).unwrap();
     }
 }