Add unit test for entity-despawns with interest-management

lightyear/src/server/relevance/immediate.rs

@@ -296,9 +296,14 @@ impl Plugin for NetworkRelevancePlugin {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::prelude::server::Replicate;
+    use crate::prelude::{client, ClientConnectionManager, NetworkRelevanceMode};
+    use crate::shared::replication::components::ReplicationGroupId;
+    use crate::tests::stepper::{BevyStepper, TEST_CLIENT_ID};
     use bevy::ecs::system::RunSystemOnce;
 
     /// Multiple entities gain relevance for a given client
+    /// Check that interest management works correctly
     #[test]
     fn test_multiple_relevance_gain() {
         let mut app = App::new();
@@ -420,4 +425,76 @@ mod tests {
             &ClientRelevance::Maintained
         );
     }
+
+    /// https://github.com/cBournhonesque/lightyear/issues/637
+    /// Make sure that entity despawns aren't replicated to clients that don't have visibility of the entity
+    /// E1 gains relevance with C1, E1 is replicated
+    /// E1 loses relevance with C1, E1 is despawned
+    /// E1 gets despawned on server -> we shouldn't send an extra despawn message to C1
+    #[test]
+    fn test_redundant_despawn() {
+        // tracing_subscriber::FmtSubscriber::builder()
+        //     .with_max_level(tracing::Level::DEBUG)
+        //     .init();
+        let mut stepper = BevyStepper::default();
+
+        let client = ClientId::Netcode(TEST_CLIENT_ID);
+        let server_entity = stepper
+            .server_app
+            .world_mut()
+            .spawn(Replicate {
+                relevance_mode: NetworkRelevanceMode::InterestManagement,
+                ..Default::default()
+            })
+            .id();
+        stepper
+            .server_app
+            .world_mut()
+            .resource_mut::<RelevanceManager>()
+            .gain_relevance(client, server_entity);
+
+        stepper.frame_step();
+        stepper.frame_step();
+
+        // check that entity is replicated, since it's relevant
+        let client_entity = stepper
+            .client_app
+            .world()
+            .resource::<client::ConnectionManager>()
+            .replication_receiver
+            .remote_entity_map
+            .get_local(server_entity)
+            .expect("server entity was not replicated to client");
+
+        // lose relevance, check that entity is despawned
+        stepper
+            .server_app
+            .world_mut()
+            .resource_mut::<RelevanceManager>()
+            .lose_relevance(client, server_entity);
+        stepper.frame_step();
+        stepper.frame_step();
+        assert!(stepper
+            .client_app
+            .world()
+            .get_entity(client_entity)
+            .is_err());
+
+        // despawn entity on the server
+        // we shouldn't send an extra Despawn message to the client
+        // We check this by making sure that the next_action_message on the receiver channel is 2
+        // (because we received one spawn and one despawn)
+        stepper.server_app.world_mut().despawn(server_entity);
+        stepper.frame_step();
+        stepper.frame_step();
+        let channel = stepper
+            .client_app
+            .world()
+            .resource::<ClientConnectionManager>()
+            .replication_receiver
+            .group_channels
+            .get(&ReplicationGroupId(server_entity.to_bits()))
+            .unwrap();
+        assert_eq!(channel.actions_pending_recv_message_id.0, 2);
+    }
 }

lightyear/src/server/relevance/room.rs

@@ -1131,9 +1131,9 @@ mod tests {
     // C1 and E2 leaves room 2 and joins room 1: visibility gained (and entity spawned)
     #[test]
     fn test_multiple_clients_leave_enter_room() {
-        tracing_subscriber::FmtSubscriber::builder()
-            .with_max_level(tracing::Level::DEBUG)
-            .init();
+        // tracing_subscriber::FmtSubscriber::builder()
+        //     .with_max_level(tracing::Level::DEBUG)
+        //     .init();
         let mut stepper = MultiBevyStepper::default();
         let c1 = ClientId::Netcode(TEST_CLIENT_ID_1);
         let c2 = ClientId::Netcode(TEST_CLIENT_ID_2);