fix (sync): resolve listener deadlock and ensure client is cloned

We ensure the client is cloned as it is a lightweight clone and enables
concurrency. See hyperium/tonic#33

lib/core/src/sync/mod.rs

@@ -108,18 +108,19 @@ impl SyncService for BreezSyncService {
     }
 
     async fn listen(self: Arc<Self>) -> Result<()> {
-        let Some(ref mut client) = *self.client.lock().await else {
-            return Err(anyhow!(
-                "Cannot run `get_changes_since`: client not connected"
-            ));
+        let Some(mut client) = self.client.lock().await.clone() else {
+            return Err(anyhow!("Cannot listen to changes: client not connected"));
         };
 
         let request = ListenChangesRequest::new(utils::now(), self.signer.clone())
             .map_err(|err| anyhow!("Could not sign ListenChangesRequest: {err:?}"))?;
-        let mut stream = client.listen_changes(request).await?.into_inner();
 
         let cloned = self.clone();
         tokio::spawn(async move {
+            let mut stream = match client.listen_changes(request).await {
+                Ok(res) => res.into_inner(),
+                Err(err) => return warn!("Could not listen to changes: {err:?}"),
+            };
             debug!("Sync service: Started listening to changes");
             while let Some(message) = stream.next().await {
                 match message {
@@ -155,7 +156,7 @@ impl SyncService for BreezSyncService {
     }
 
     async fn get_changes_since(&self, from_id: i64) -> Result<Vec<Record>> {
-        let Some(ref mut client) = *self.client.lock().await else {
+        let Some(mut client) = self.client.lock().await.clone() else {
             return Err(anyhow!(
                 "Cannot run `get_changes_since`: client not connected"
             ));
@@ -169,7 +170,7 @@ impl SyncService for BreezSyncService {
     }
 
     async fn set_record(&self, data: SyncData) -> Result<()> {
-        let Some(ref mut client) = *self.client.lock().await else {
+        let Some(mut client) = self.client.lock().await.clone() else {
             return Err(anyhow!("Cannot run `set_record`: client not connected"));
         };