Use conditional type aliases to reduce cfg noise on structs

Author: thlsrms

sdks/rust/src/db_connection.rs

@@ -54,6 +54,11 @@ use tokio::{
 
 pub(crate) type SharedCell<T> = Arc<StdMutex<T>>;
 
+#[cfg(not(feature = "web"))]
+type SharedAsyncCell<T> = Arc<TokioMutex<T>>;
+#[cfg(feature = "web")]
+type SharedAsyncCell<T> = SharedCell<T>;
+
 /// Implementation of `DbConnection`, `EventContext`,
 /// and anything else that provides access to the database connection.
 ///
@@ -74,10 +79,7 @@ pub struct DbContextImpl<M: SpacetimeModule> {
 
     /// Receiver channel for WebSocket messages,
     /// which are pre-parsed in the background by [`parse_loop`].
-    #[cfg(not(feature = "web"))]
-    recv: Arc<TokioMutex<mpsc::UnboundedReceiver<ParsedMessage<M>>>>,
-    #[cfg(feature = "web")]
-    recv: SharedCell<mpsc::UnboundedReceiver<ParsedMessage<M>>>,
+    recv: SharedAsyncCell<mpsc::UnboundedReceiver<ParsedMessage<M>>>,
 
     /// Channel into which operations which apparently mutate SDK state,
     /// e.g. registering callbacks, push [`PendingMutation`] messages,
@@ -87,10 +89,7 @@ pub struct DbContextImpl<M: SpacetimeModule> {
 
     /// Receive end of `pending_mutations_send`,
     /// from which [Self::apply_pending_mutations] and friends read mutations.
-    #[cfg(not(feature = "web"))]
-    pending_mutations_recv: Arc<TokioMutex<mpsc::UnboundedReceiver<PendingMutation<M>>>>,
-    #[cfg(feature = "web")]
-    pending_mutations_recv: SharedCell<mpsc::UnboundedReceiver<PendingMutation<M>>>,
+    pending_mutations_recv: SharedAsyncCell<mpsc::UnboundedReceiver<PendingMutation<M>>>,
 
     /// This connection's `Identity`.
     ///

sdks/rust/src/websocket.rs

@@ -33,6 +33,11 @@ use tokio_tungstenite_wasm::{Message as WebSocketMessage, WebSocketStream};
 use crate::compression::decompress_server_message;
 use crate::metrics::CLIENT_METRICS;
 
+#[cfg(not(feature = "web"))]
+type TokioTungsteniteError = tokio_tungstenite::tungstenite::Error;
+#[cfg(feature = "web")]
+type TokioTungsteniteError = tokio_tungstenite_wasm::Error;
+
 #[derive(Error, Debug, Clone)]
 pub enum UriError {
     #[error("Unknown URI scheme {scheme}, expected http, https, ws or wss")]
@@ -59,22 +64,12 @@ pub enum WsError {
     #[error(transparent)]
     UriError(#[from] UriError),
 
-    #[cfg(not(feature = "web"))]
-    #[error("Error in WebSocket connection with {uri}: {source}")]
-    Tungstenite {
-        uri: Uri,
-        #[source]
-        // `Arc` is required for `Self: Clone`, as `tungstenite::Error: !Clone`.
-        source: Arc<tokio_tungstenite::tungstenite::Error>,
-    },
-
-    #[cfg(feature = "web")]
     #[error("Error in WebSocket connection with {uri}: {source}")]
     Tungstenite {
         uri: Uri,
         #[source]
         // `Arc` is required for `Self: Clone`, as `tungstenite::Error: !Clone`.
-        source: Arc<tokio_tungstenite_wasm::Error>,
+        source: Arc<TokioTungsteniteError>,
     },
 
     #[error("Received empty raw message, but valid messages always start with a one-byte compression flag")]