28 files changed, 157 insertions, 44 deletions
diff --git a/azalea-client/build.rs b/azalea-client/build.rs
new file mode 100644
index 00000000..49ef62db
--- /dev/null
+++ b/azalea-client/build.rs
@@ -0,0 +1,43 @@
+use std::{
+    fs::{self, File},
+    io::Write,
+};
+
+fn main() {
+    // Tell Cargo that if the given file changes, to rerun this build script.
+    println!("cargo::rerun-if-changed=tests");
+
+    let Ok(paths) = fs::read_dir("tests/simulation") else {
+        return;
+    };
+
+    let mut modules = Vec::new();
+
+    for path in paths {
+        let Ok(path) = path else {
+            continue;
+        };
+        let path = path.path();
+        if path.extension().is_none_or(|ext| ext != "rs") {
+            continue;
+        }
+        let mod_name = path.with_extension("");
+        let mod_name = mod_name.file_name().unwrap().to_string_lossy().to_string();
+        if mod_name == "mod" {
+            continue;
+        }
+        modules.push(mod_name);
+    }
+
+    let Ok(mut mod_rs) = File::create("tests/simulation/mod.rs") else {
+        return;
+    };
+    let _ = writeln!(
+        mod_rs,
+        "// This file is @generated by `azalea-client/build.rs`.\n"
+    );
+    modules.sort();
+    for mod_name in modules {
+        let _ = writeln!(mod_rs, "mod {mod_name};");
+    }
+}
diff --git a/azalea-client/src/test_utils/simulation.rs b/azalea-client/src/test_utils/simulation.rs
index 5a1c9c52..a6bc22ab 100644
--- a/azalea-client/src/test_utils/simulation.rs
+++ b/azalea-client/src/test_utils/simulation.rs
@@ -57,8 +57,9 @@ pub struct Simulation {
 }
 
 impl Simulation {
-    pub fn new(initial_connection_protocol: ConnectionProtocol) -> Self {
+    pub fn new(conn_protocol: ConnectionProtocol) -> Self {
         let mut app = create_simulation_app();
+
         let mut entity = app.world_mut().spawn_empty();
         let (player, rt) =
             create_local_player_bundle(entity.id(), ConnectionProtocol::Configuration);
@@ -78,7 +79,7 @@ impl Simulation {
         let mut simulation = Self { app, entity, rt };
 
         #[allow(clippy::single_match)]
-        match initial_connection_protocol {
+        match conn_protocol {
             ConnectionProtocol::Configuration => {}
             ConnectionProtocol::Game => {
                 simulation.receive_packet(ClientboundRegistryData {
@@ -97,7 +98,7 @@ impl Simulation {
                 simulation.receive_packet(ClientboundFinishConfiguration);
                 simulation.tick();
             }
-            _ => unimplemented!("unsupported ConnectionProtocol {initial_connection_protocol:?}"),
+            _ => unimplemented!("unsupported ConnectionProtocol {conn_protocol:?}"),
         }
 
         simulation
@@ -300,10 +301,13 @@ fn create_local_player_bundle(
 fn create_simulation_app() -> App {
     let mut app = App::new();
 
+    let mut plugins = bevy_app::PluginGroup::build(crate::DefaultPlugins);
     #[cfg(feature = "log")]
-    app.add_plugins(
-        bevy_app::PluginGroup::build(crate::DefaultPlugins).disable::<bevy_log::LogPlugin>(),
-    );
+    {
+        plugins = plugins.disable::<bevy_log::LogPlugin>();
+    }
+
+    app.add_plugins(plugins);
 
     app.edit_schedule(bevy_app::Main, |schedule| {
         // makes test results more reproducible
diff --git a/azalea-client/src/test_utils/tracing.rs b/azalea-client/src/test_utils/tracing.rs
index 207a4625..3be92260 100644
--- a/azalea-client/src/test_utils/tracing.rs
+++ b/azalea-client/src/test_utils/tracing.rs
@@ -1,27 +1,67 @@
+use std::sync::LazyLock;
+
 use bevy_log::tracing_subscriber::{
-    self, EnvFilter, Layer,
+    self, EnvFilter, Layer, Registry,
+    filter::Filtered,
+    fmt,
     layer::{Context, SubscriberExt},
+    reload::{self, Handle},
     util::SubscriberInitExt,
 };
+use parking_lot::{Mutex, MutexGuard};
 use tracing::{Event, Level, Subscriber};
 
-pub fn init_tracing() {
-    init_tracing_with_level(Level::WARN);
+static LOCK: LazyLock<Mutex<()>> = LazyLock::new(|| Mutex::new(()));
+
+pub fn init<'a>() -> MutexGuard<'a, ()> {
+    init_with_level(Level::WARN)
+}
+
+// can't treat these as one layer due to https://github.com/tokio-rs/tracing/issues/1629
+struct LayerReloadHandles {
+    filter: Handle<Filtered<fmt::Layer<Registry>, EnvFilter, Registry>, Registry>,
+    test: Handle<TestTracingLayer, Registry>,
 }
 
-pub fn init_tracing_with_level(max_level: Level) {
+static RELOAD_HANDLES: LazyLock<LayerReloadHandles> = LazyLock::new(|| {
+    let (filter_layer, filter_reload_handle) = reload::Layer::new(
+        fmt::layer().with_filter(
+            EnvFilter::builder()
+                .with_default_directive(Level::WARN.into())
+                .from_env_lossy(),
+        ),
+    );
+    let (test_layer, test_reload_handle) = reload::Layer::new(TestTracingLayer {
+        panic_on_level: Level::WARN,
+    });
+
     tracing_subscriber::registry()
-        .with(
-            tracing_subscriber::fmt::layer().with_filter(
-                EnvFilter::builder()
-                    .with_default_directive(max_level.into())
-                    .from_env_lossy(),
-            ),
-        )
-        .with(TestTracingLayer {
-            panic_on_level: max_level,
-        })
+        .with(filter_layer.and_then(test_layer))
         .init();
+
+    LayerReloadHandles {
+        filter: filter_reload_handle,
+        test: test_reload_handle,
+    }
+});
+
+pub fn init_with_level<'a>(max_level: Level) -> MutexGuard<'a, ()> {
+    let lock = LOCK.lock();
+
+    RELOAD_HANDLES
+        .filter
+        .modify(|layer| {
+            *layer.filter_mut() = EnvFilter::builder()
+                .with_default_directive(max_level.into())
+                .from_env_lossy()
+        })
+        .unwrap();
+    RELOAD_HANDLES
+        .test
+        .modify(|layer| layer.panic_on_level = max_level)
+        .unwrap();
+
+    lock
 }
 
 struct TestTracingLayer {
@@ -31,7 +71,7 @@ impl<S: Subscriber> Layer<S> for TestTracingLayer {
     fn on_event(&self, event: &Event<'_>, _ctx: Context<'_, S>) {
         let level = *event.metadata().level();
         if level <= self.panic_on_level {
-            panic!("logged on level {level}");
+            panic!("Logged on level {level}.");
         }
     }
 }
diff --git a/azalea-client/tests/main.rs b/azalea-client/tests/main.rs
new file mode 100644
index 00000000..4030c61d
--- /dev/null
+++ b/azalea-client/tests/main.rs
@@ -0,0 +1 @@
+mod simulation;
diff --git a/azalea-client/tests/change_dimension_to_nether_and_back.rs b/azalea-client/tests/simulation/change_dimension_to_nether_and_back.rs
index 134c7cbf..2d4fb749 100644
--- a/azalea-client/tests/change_dimension_to_nether_and_back.rs
+++ b/azalea-client/tests/simulation/change_dimension_to_nether_and_back.rs
@@ -11,7 +11,7 @@ use simdnbt::owned::{NbtCompound, NbtTag};
 
 #[test]
 fn test_change_dimension_to_nether_and_back() {
-    init_tracing();
+    let _lock = init();
 
     generic_test_change_dimension_to_nether_and_back(true);
     generic_test_change_dimension_to_nether_and_back(false);
diff --git a/azalea-client/tests/client_disconnect.rs b/azalea-client/tests/simulation/client_disconnect.rs
index fc17da0c..0956fbfa 100644
--- a/azalea-client/tests/client_disconnect.rs
+++ b/azalea-client/tests/simulation/client_disconnect.rs
@@ -4,7 +4,7 @@ use azalea_world::InstanceName;
 
 #[test]
 fn test_client_disconnect() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
 
diff --git a/azalea-client/tests/close_open_container.rs b/azalea-client/tests/simulation/close_open_container.rs
index 32a9874d..033451f1 100644
--- a/azalea-client/tests/close_open_container.rs
+++ b/azalea-client/tests/simulation/close_open_container.rs
@@ -10,7 +10,7 @@ use azalea_registry::builtin::MenuKind;
 
 #[test]
 fn test_close_open_container() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
 
diff --git a/azalea-client/tests/correct_movement.rs b/azalea-client/tests/simulation/correct_movement.rs
index de494111..2a1a8f26 100644
--- a/azalea-client/tests/correct_movement.rs
+++ b/azalea-client/tests/simulation/correct_movement.rs
@@ -15,7 +15,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_correct_movement() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     let sent_packets = SentPackets::new(&mut simulation);
diff --git a/azalea-client/tests/correct_sneak_movement.rs b/azalea-client/tests/simulation/correct_sneak_movement.rs
index 1186ce8b..73abb26f 100644
--- a/azalea-client/tests/correct_sneak_movement.rs
+++ b/azalea-client/tests/simulation/correct_sneak_movement.rs
@@ -15,7 +15,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_correct_sneak_movement() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     let sent_packets = SentPackets::new(&mut simulation);
diff --git a/azalea-client/tests/correct_sprint_sneak_movement.rs b/azalea-client/tests/simulation/correct_sprint_sneak_movement.rs
index 8ab955b8..a96c7024 100644
--- a/azalea-client/tests/correct_sprint_sneak_movement.rs
+++ b/azalea-client/tests/simulation/correct_sprint_sneak_movement.rs
@@ -15,7 +15,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_correct_sprint_sneak_movement() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     let sent_packets = SentPackets::new(&mut simulation);
diff --git a/azalea-client/tests/despawn_entities_when_changing_dimension.rs b/azalea-client/tests/simulation/despawn_entities_when_changing_dimension.rs
index 466da948..8619bb2d 100644
--- a/azalea-client/tests/despawn_entities_when_changing_dimension.rs
+++ b/azalea-client/tests/simulation/despawn_entities_when_changing_dimension.rs
@@ -13,7 +13,7 @@ use simdnbt::owned::{NbtCompound, NbtTag};
 
 #[test]
 fn test_despawn_entities_when_changing_dimension() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Configuration);
     simulation.receive_packet(ClientboundRegistryData {
diff --git a/azalea-client/tests/enchantments.rs b/azalea-client/tests/simulation/enchantments.rs
index 4486fba1..f9834230 100644
--- a/azalea-client/tests/enchantments.rs
+++ b/azalea-client/tests/simulation/enchantments.rs
@@ -11,7 +11,7 @@ use simdnbt::owned::{NbtCompound, NbtTag};
 
 #[test]
 fn test_enchantments() {
-    init_tracing();
+    let _lock = init();
 
     let mut s = Simulation::new(ConnectionProtocol::Configuration);
     s.receive_packet(ClientboundRegistryData {
diff --git a/azalea-client/tests/fast_login.rs b/azalea-client/tests/simulation/fast_login.rs
index 5a653425..270f4464 100644
--- a/azalea-client/tests/fast_login.rs
+++ b/azalea-client/tests/simulation/fast_login.rs
@@ -10,7 +10,7 @@ use simdnbt::owned::{NbtCompound, NbtTag};
 
 #[test]
 fn test_fast_login() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Configuration);
     assert!(simulation.has_component::<InConfigState>());
diff --git a/azalea-client/tests/login_to_dimension_with_same_name.rs b/azalea-client/tests/simulation/login_to_dimension_with_same_name.rs
index 4adced62..917c50bb 100644
--- a/azalea-client/tests/login_to_dimension_with_same_name.rs
+++ b/azalea-client/tests/simulation/login_to_dimension_with_same_name.rs
@@ -14,7 +14,7 @@ use simdnbt::owned::{NbtCompound, NbtTag};
 
 #[test]
 fn test_login_to_dimension_with_same_name() {
-    init_tracing();
+    let _lock = init();
 
     generic_test_login_to_dimension_with_same_name(true);
     generic_test_login_to_dimension_with_same_name(false);
diff --git a/azalea-client/tests/mine_block_rollback.rs b/azalea-client/tests/simulation/mine_block_rollback.rs
index 7d2ed1a5..98440f76 100644
--- a/azalea-client/tests/mine_block_rollback.rs
+++ b/azalea-client/tests/simulation/mine_block_rollback.rs
@@ -8,7 +8,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_mine_block_rollback() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     simulation.receive_packet(default_login_packet());
diff --git a/azalea-client/tests/mine_block_timing_hand.rs b/azalea-client/tests/simulation/mine_block_timing_hand.rs
index d3dd9c30..53571089 100644
--- a/azalea-client/tests/mine_block_timing_hand.rs
+++ b/azalea-client/tests/simulation/mine_block_timing_hand.rs
@@ -19,7 +19,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_mine_block_timing_hand() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     let sent_packets = SentPackets::new(&mut simulation);
diff --git a/azalea-client/tests/mine_block_without_rollback.rs b/azalea-client/tests/simulation/mine_block_without_rollback.rs
index b6020ea2..71f360c4 100644
--- a/azalea-client/tests/mine_block_without_rollback.rs
+++ b/azalea-client/tests/simulation/mine_block_without_rollback.rs
@@ -8,7 +8,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_mine_block_without_rollback() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     simulation.receive_packet(default_login_packet());
diff --git a/azalea-client/tests/simulation/mod.rs b/azalea-client/tests/simulation/mod.rs
new file mode 100644
index 00000000..d090862b
--- /dev/null
+++ b/azalea-client/tests/simulation/mod.rs
@@ -0,0 +1,25 @@
+// This file is @generated by `azalea-client/build.rs`.
+
+mod change_dimension_to_nether_and_back;
+mod client_disconnect;
+mod close_open_container;
+mod correct_movement;
+mod correct_sneak_movement;
+mod correct_sprint_sneak_movement;
+mod despawn_entities_when_changing_dimension;
+mod enchantments;
+mod fast_login;
+mod login_to_dimension_with_same_name;
+mod mine_block_rollback;
+mod mine_block_timing_hand;
+mod mine_block_without_rollback;
+mod move_and_despawn_entity;
+mod move_despawned_entity;
+mod packet_order;
+mod packet_order_set_carried_item;
+mod receive_spawn_entity_and_start_config_packet;
+mod receive_start_config_packet;
+mod reply_to_ping_with_pong;
+mod set_health_before_login;
+mod teleport_movement;
+mod ticks_alive;
diff --git a/azalea-client/tests/move_and_despawn_entity.rs b/azalea-client/tests/simulation/move_and_despawn_entity.rs
index 8a143243..6c334a47 100644
--- a/azalea-client/tests/move_and_despawn_entity.rs
+++ b/azalea-client/tests/simulation/move_and_despawn_entity.rs
@@ -12,7 +12,7 @@ use azalea_world::MinecraftEntityId;
 
 #[test]
 fn test_move_and_despawn_entity() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     simulation.receive_packet(default_login_packet());
diff --git a/azalea-client/tests/move_despawned_entity.rs b/azalea-client/tests/simulation/move_despawned_entity.rs
index dad2a710..7a171dae 100644
--- a/azalea-client/tests/move_despawned_entity.rs
+++ b/azalea-client/tests/simulation/move_despawned_entity.rs
@@ -9,7 +9,7 @@ use tracing::Level;
 
 #[test]
 fn test_move_despawned_entity() {
-    init_tracing_with_level(Level::ERROR); // a warning is expected here
+    let _lock = init_with_level(Level::ERROR); // a warning is expected here
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     simulation.receive_packet(default_login_packet());
diff --git a/azalea-client/tests/packet_order.rs b/azalea-client/tests/simulation/packet_order.rs
index 619ed0b6..ef99b938 100644
--- a/azalea-client/tests/packet_order.rs
+++ b/azalea-client/tests/simulation/packet_order.rs
@@ -15,7 +15,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_packet_order() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     let sent_packets = SentPackets::new(&mut simulation);
diff --git a/azalea-client/tests/packet_order_set_carried_item.rs b/azalea-client/tests/simulation/packet_order_set_carried_item.rs
index e8ac386f..cae7c56a 100644
--- a/azalea-client/tests/packet_order_set_carried_item.rs
+++ b/azalea-client/tests/simulation/packet_order_set_carried_item.rs
@@ -21,7 +21,7 @@ use azalea_registry::builtin::BlockKind;
 
 #[test]
 fn test_packet_order_set_carried_item() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     let sent_packets = SentPackets::new(&mut simulation);
diff --git a/azalea-client/tests/receive_spawn_entity_and_start_config_packet.rs b/azalea-client/tests/simulation/receive_spawn_entity_and_start_config_packet.rs
index dfb1fef9..13dd38fc 100644
--- a/azalea-client/tests/receive_spawn_entity_and_start_config_packet.rs
+++ b/azalea-client/tests/simulation/receive_spawn_entity_and_start_config_packet.rs
@@ -10,7 +10,7 @@ use uuid::Uuid;
 
 #[test]
 fn test_receive_spawn_entity_and_start_config_packet() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     simulation.receive_packet(default_login_packet());
diff --git a/azalea-client/tests/receive_start_config_packet.rs b/azalea-client/tests/simulation/receive_start_config_packet.rs
index bb948488..f87d65da 100644
--- a/azalea-client/tests/receive_start_config_packet.rs
+++ b/azalea-client/tests/simulation/receive_start_config_packet.rs
@@ -4,7 +4,7 @@ use azalea_world::InstanceName;
 
 #[test]
 fn test_receive_start_config_packet() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
 
diff --git a/azalea-client/tests/reply_to_ping_with_pong.rs b/azalea-client/tests/simulation/reply_to_ping_with_pong.rs
index 6b7cb4ca..f77bf4bf 100644
--- a/azalea-client/tests/reply_to_ping_with_pong.rs
+++ b/azalea-client/tests/simulation/reply_to_ping_with_pong.rs
@@ -18,7 +18,7 @@ use simdnbt::owned::{NbtCompound, NbtTag};
 
 #[test]
 fn reply_to_ping_with_pong() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Configuration);
 
diff --git a/azalea-client/tests/set_health_before_login.rs b/azalea-client/tests/simulation/set_health_before_login.rs
index 4c1ec3f6..7d183b80 100644
--- a/azalea-client/tests/set_health_before_login.rs
+++ b/azalea-client/tests/simulation/set_health_before_login.rs
@@ -10,7 +10,7 @@ use simdnbt::owned::{NbtCompound, NbtTag};
 
 #[test]
 fn test_set_health_before_login() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Configuration);
     assert!(simulation.has_component::<InConfigState>());
diff --git a/azalea-client/tests/teleport_movement.rs b/azalea-client/tests/simulation/teleport_movement.rs
index 03df5b92..06a8f0b6 100644
--- a/azalea-client/tests/teleport_movement.rs
+++ b/azalea-client/tests/simulation/teleport_movement.rs
@@ -20,7 +20,7 @@ use azalea_world::MinecraftEntityId;
 
 #[test]
 fn test_teleport_movement() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     let sent_packets = SentPackets::new(&mut simulation);
diff --git a/azalea-client/tests/ticks_alive.rs b/azalea-client/tests/simulation/ticks_alive.rs
index f2081002..655504db 100644
--- a/azalea-client/tests/ticks_alive.rs
+++ b/azalea-client/tests/simulation/ticks_alive.rs
@@ -3,7 +3,7 @@ use azalea_protocol::packets::ConnectionProtocol;
 
 #[test]
 fn counter_increments_and_resets_on_disconnect() {
-    init_tracing();
+    let _lock = init();
 
     let mut simulation = Simulation::new(ConnectionProtocol::Game);
     simulation.tick();