projectharmonia · Shatur · May 21, 2025 · May 21, 2025
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Rename `replication_registry::despawn_recursive` into `replication_registry::despawn`.
 - `ReplicationRule` now stores `Vec<ComponentRule>` instead of `Vec<(ComponentId, FnsId)>`
 - `RuleFns` now available from prelude.
+- Initialize channels in `App::finish` instead of `Startup`. It's called automatically on `App::run`, but in tests you need to call `App::finish` manually.
 - Rules created with the same priority now evaluated in their creation order.
 - Component removals and insertions for an entity are now buffered and applied as bundles to avoid triggering observers without all components being inserted or removed. This also significantly improves performance by avoiding extra archetype moves and lookups.
 - The `Replicated` component is no longer automatically inserted into non-replicated entities spawned from replicated components.

diff --git a/bevy_replicon_example_backend/tests/backend.rs b/bevy_replicon_example_backend/tests/backend.rs
@@ -17,7 +17,8 @@ fn connect_disconnect() {
                 ..Default::default()
             }),
             RepliconExampleBackendPlugins,
-        ));
+        ))
+        .finish();
     }
 
     setup(&mut server_app, &mut client_app).unwrap();
@@ -62,7 +63,8 @@ fn replication() {
                 ..Default::default()
             }),
             RepliconExampleBackendPlugins,
-        ));
+        ))
+        .finish();
     }
 
     setup(&mut server_app, &mut client_app).unwrap();

diff --git a/src/client.rs b/src/client.rs
@@ -64,7 +64,6 @@ impl Plugin for ClientPlugin {
                 PostUpdate,
                 (ClientSet::Send, ClientSet::SendPackets).chain(),
             )
-            .add_systems(Startup, setup_channels)
             .add_systems(
                 PreUpdate,
                 receive_replication
@@ -78,11 +77,13 @@ impl Plugin for ClientPlugin {
         if **app.world().resource::<TrackMutateMessages>() {
             app.init_resource::<ServerMutateTicks>();
         }
-    }
-}
 
-fn setup_channels(mut client: ResMut<RepliconClient>, channels: Res<RepliconChannels>) {
-    client.setup_server_channels(channels.server_channels().len());
+        app.world_mut()
+            .resource_scope(|world, mut client: Mut<RepliconClient>| {
+                let channels = world.resource::<RepliconChannels>();
+                client.setup_server_channels(channels.server_channels().len());
+            });
+    }
 }
 
 /// Receives and applies replication messages from the server.

diff --git a/src/server.rs b/src/server.rs
@@ -110,7 +110,6 @@ impl Plugin for ServerPlugin {
             .add_observer(handle_connects)
             .add_observer(handle_disconnects)
             .add_observer(buffer_despawns)
-            .add_systems(Startup, setup_channels)
             .add_systems(
                 PreUpdate,
                 (
@@ -175,10 +174,14 @@ impl Plugin for ServerPlugin {
             app.register_required_components::<ConnectedClient, ReplicatedClient>();
         }
     }
-}
 
-fn setup_channels(mut server: ResMut<RepliconServer>, channels: Res<RepliconChannels>) {
-    server.setup_client_channels(channels.client_channels().len());
+    fn finish(&self, app: &mut App) {
+        app.world_mut()
+            .resource_scope(|world, mut server: Mut<RepliconServer>| {
+                let channels = world.resource::<RepliconChannels>();
+                server.setup_client_channels(channels.client_channels().len());
+            });
+    }
 }
 
 /// Increments current server tick which causes the server to replicate this frame.

diff --git a/src/shared/backend/replicon_channels.rs b/src/shared/backend/replicon_channels.rs
@@ -3,6 +3,9 @@ use log::debug;
 
 /// A resource with all channels used by Replicon.
 ///
+/// Initialized in [`ClientPlugin::finish`](crate::client::ClientPlugin) and
+/// [`ServerPlugin::finish`](crate::server::ServerPlugin).
+///
 /// Channel IDs are represented by [`usize`], but backends may limit the number of channels.
 ///
 /// The first two channels are used for replication. For more details, see [`ReplicationChannel`].

diff --git a/src/test_app.rs b/src/test_app.rs
@@ -25,7 +25,8 @@ for app in [&mut server_app, &mut client_app] {
             tick_policy: TickPolicy::EveryFrame, // To tick each app update.
             ..Default::default()
         }),
-    ));
+    ))
+    .finish(); // Don't forget to call `finish`.
 }
 
 // Simulate connection between two apps:

diff --git a/tests/connection.rs b/tests/connection.rs
@@ -14,8 +14,7 @@ fn client_to_server() {
     let mut server_app = App::new();
     let mut client_app = App::new();
     for app in [&mut server_app, &mut client_app] {
-        app.add_plugins((MinimalPlugins, RepliconPlugins));
-        app.update();
+        app.add_plugins((MinimalPlugins, RepliconPlugins)).finish();
     }
 
     const MESSAGES: &[&[u8]] = &[&[0], &[1]];
@@ -44,8 +43,7 @@ fn server_to_client() {
     let mut server_app = App::new();
     let mut client_app = App::new();
     for app in [&mut server_app, &mut client_app] {
-        app.add_plugins((MinimalPlugins, RepliconPlugins));
-        app.update();
+        app.add_plugins((MinimalPlugins, RepliconPlugins)).finish();
     }
 
     const MESSAGES: &[&[u8]] = &[&[0], &[1]];
@@ -71,13 +69,7 @@ fn connect_disconnect() {
     let mut server_app = App::new();
     let mut client_app = App::new();
     for app in [&mut server_app, &mut client_app] {
-        app.add_plugins((
-            MinimalPlugins,
-            RepliconPlugins.set(ServerPlugin {
-                tick_policy: TickPolicy::EveryFrame,
-                ..Default::default()
-            }),
-        ));
+        app.add_plugins((MinimalPlugins, RepliconPlugins)).finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -102,15 +94,7 @@ fn connect_disconnect() {
 #[test]
 fn client_cleanup_on_disconnect() {
     let mut app = App::new();
-    app.add_plugins((
-        MinimalPlugins,
-        RepliconPlugins.set(ServerPlugin {
-            tick_policy: TickPolicy::EveryFrame,
-            ..Default::default()
-        }),
-    ));
-
-    app.update();
+    app.add_plugins((MinimalPlugins, RepliconPlugins)).finish();
 
     let mut client = app.world_mut().resource_mut::<RepliconClient>();
     client.set_status(RepliconClientStatus::Connected);
@@ -129,15 +113,7 @@ fn client_cleanup_on_disconnect() {
 #[test]
 fn server_cleanup_on_stop() {
     let mut app = App::new();
-    app.add_plugins((
-        MinimalPlugins,
-        RepliconPlugins.set(ServerPlugin {
-            tick_policy: TickPolicy::EveryFrame,
-            ..Default::default()
-        }),
-    ));
-
-    app.update();
+    app.add_plugins((MinimalPlugins, RepliconPlugins)).finish();
 
     let mut server = app.world_mut().resource_mut::<RepliconServer>();
     server.set_running(true);
@@ -158,13 +134,7 @@ fn server_cleanup_on_stop() {
 #[test]
 fn client_disconnected() {
     let mut app = App::new();
-    app.add_plugins((
-        MinimalPlugins,
-        RepliconPlugins.set(ServerPlugin {
-            tick_policy: TickPolicy::EveryFrame,
-            ..Default::default()
-        }),
-    ));
+    app.add_plugins((MinimalPlugins, RepliconPlugins)).finish();
 
     app.update();
 
@@ -188,7 +158,8 @@ fn server_inactive() {
             tick_policy: TickPolicy::EveryFrame,
             ..Default::default()
         }),
-    ));
+    ))
+    .finish();
 
     app.update();
 
@@ -217,7 +188,8 @@ fn deferred_replication() {
                 replicate_after_connect: false,
                 ..Default::default()
             }),
-        ));
+        ))
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);

diff --git a/tests/despawn.rs b/tests/despawn.rs
@@ -15,7 +15,8 @@ fn single() {
                 tick_policy: TickPolicy::EveryFrame,
                 ..Default::default()
             }),
-        ));
+        ))
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -52,7 +53,8 @@ fn with_hierarchy() {
                 tick_policy: TickPolicy::EveryFrame,
                 ..Default::default()
             }),
-        ));
+        ))
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -98,7 +100,8 @@ fn after_spawn() {
                 ..Default::default()
             }),
         ))
-        .replicate::<TestComponent>();
+        .replicate::<TestComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -129,7 +132,8 @@ fn hidden() {
                 visibility_policy: VisibilityPolicy::Whitelist, // Hide all spawned entities by default.
                 ..Default::default()
             }),
-        ));
+        ))
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);

diff --git a/tests/insertion.rs b/tests/insertion.rs
@@ -27,7 +27,8 @@ fn table_storage() {
                 ..Default::default()
             }),
         ))
-        .replicate::<TableComponent>();
+        .replicate::<TableComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -64,7 +65,8 @@ fn sparse_set_storage() {
                 ..Default::default()
             }),
         ))
-        .replicate::<SparseSetComponent>();
+        .replicate::<SparseSetComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -101,7 +103,8 @@ fn immutable() {
                 ..Default::default()
             }),
         ))
-        .replicate::<ImmutableComponent>();
+        .replicate::<ImmutableComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -151,7 +154,8 @@ fn mapped_existing_entity() {
                 ..Default::default()
             }),
         ))
-        .replicate::<MappedComponent>();
+        .replicate::<MappedComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -200,7 +204,8 @@ fn mapped_new_entity() {
                 ..Default::default()
             }),
         ))
-        .replicate::<MappedComponent>();
+        .replicate::<MappedComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -246,7 +251,8 @@ fn multiple_components() {
             }),
         ))
         .replicate::<ComponentA>()
-        .replicate::<ComponentB>();
+        .replicate::<ComponentB>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -291,7 +297,8 @@ fn command_fns() {
             }),
         ))
         .replicate::<OriginalComponent>()
-        .set_command_fns(replace, command_fns::default_remove::<ReplacedComponent>);
+        .set_command_fns(replace, command_fns::default_remove::<ReplacedComponent>)
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -335,7 +342,8 @@ fn marker() {
         .set_marker_fns::<ReplaceMarker, _>(
             replace,
             command_fns::default_remove::<ReplacedComponent>,
-        );
+        )
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -382,7 +390,8 @@ fn group() {
                 ..Default::default()
             }),
         ))
-        .replicate_bundle::<(ComponentA, ComponentB)>();
+        .replicate_bundle::<(ComponentA, ComponentB)>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -418,7 +427,8 @@ fn not_replicated() {
                 tick_policy: TickPolicy::EveryFrame,
                 ..Default::default()
             }),
-        ));
+        ))
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -455,7 +465,8 @@ fn after_removal() {
                 ..Default::default()
             }),
         ))
-        .replicate::<TestComponent>();
+        .replicate::<TestComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -507,7 +518,8 @@ fn before_started_replication() {
                 ..Default::default()
             }),
         ))
-        .replicate::<TestComponent>();
+        .replicate::<TestComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -553,7 +565,8 @@ fn after_started_replication() {
                 ..Default::default()
             }),
         ))
-        .replicate::<TestComponent>();
+        .replicate::<TestComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);
@@ -592,7 +605,8 @@ fn confirm_history() {
                 ..Default::default()
             }),
         ))
-        .replicate::<TestComponent>();
+        .replicate::<TestComponent>()
+        .finish();
     }
 
     server_app.connect_client(&mut client_app);