feat(transport): add domain error type to GrpcTransportActor

server/crates/arbiter-server/tests/user_agent.rs

@@ -1,5 +1,30 @@
 mod common;
 
+use arbiter_proto::proto::UserAgentResponse;
+use arbiter_server::actors::user_agent::UserAgentError;
+use kameo::{Actor, actor::Recipient, actor::Spawn, prelude::Message};
+
+/// A no-op actor that discards any messages it receives.
+#[derive(Actor)]
+struct NullSink;
+
+impl Message<Result<UserAgentResponse, UserAgentError>> for NullSink {
+    type Reply = ();
+
+    async fn handle(
+        &mut self,
+        _msg: Result<UserAgentResponse, UserAgentError>,
+        _ctx: &mut kameo::prelude::Context<Self, Self::Reply>,
+    ) -> Self::Reply {
+    }
+}
+
+/// Creates a `Recipient` that silently discards all messages.
+fn null_recipient() -> Recipient<Result<UserAgentResponse, UserAgentError>> {
+    let actor_ref = NullSink::spawn(NullSink);
+    actor_ref.recipient()
+}
+
 #[path = "user_agent/auth.rs"]
 mod auth;
 #[path = "user_agent/unseal.rs"]