Trace response payload in default jsonrpsee middleware (paritytech#…

…12886)

* Trace result in default `jsonrpsee` middleware

* `rpc_metrics::extra`

Co-authored-by: Bastian Köcher <git@kchr.de>

Co-authored-by: Bastian Köcher <git@kchr.de>

client/rpc-servers/src/middleware.rs

@@ -204,8 +204,9 @@ impl RpcMiddleware {
 	}
 
 	/// Called once the JSON-RPC request is finished and response is sent to the output buffer.
-	fn on_response(&self, _result: &str, started_at: std::time::Instant) {
+	fn on_response(&self, result: &str, started_at: std::time::Instant) {
 		log::trace!(target: "rpc_metrics", "[{}] on_response started_at={:?}", self.transport_label, started_at);
+		log::trace!(target: "rpc_metrics::extra", "[{}] result={:?}", self.transport_label, result);
 		self.metrics.requests_finished.with_label_values(&[self.transport_label]).inc();
 	}
 }