feat: collision helper, ghost/pacman collision events, collision tests

minor format updates from copilot's commit

tests/collision.rs

@@ -0,0 +1,150 @@
+use bevy_ecs::{event::Events, prelude::*, system::RunSystemOnce, world::World};
+
+use pacman::{
+    error::GameError,
+    events::GameEvent,
+    map::builder::Map,
+    systems::{
+        collision::{check_collision, collision_system},
+        components::{Collider, EntityType, Ghost, GhostCollider, ItemCollider, PacmanCollider},
+        movement::Position,
+    },
+};
+
+fn create_test_world() -> World {
+    let mut world = World::new();
+
+    // Add required resources
+    world.insert_resource(Events::<GameEvent>::default());
+    world.insert_resource(Events::<GameError>::default());
+
+    // Add a minimal test map
+    world.insert_resource(create_test_map());
+
+    world
+}
+
+fn create_test_map() -> Map {
+    use pacman::constants::RAW_BOARD;
+    Map::new(RAW_BOARD).expect("Failed to create test map")
+}
+
+fn spawn_test_pacman(world: &mut World) -> Entity {
+    world
+        .spawn((Position::Stopped { node: 0 }, Collider { size: 10.0 }, PacmanCollider))
+        .id()
+}
+
+fn spawn_test_item(world: &mut World) -> Entity {
+    world
+        .spawn((
+            Position::Stopped { node: 0 },
+            Collider { size: 8.0 },
+            ItemCollider,
+            EntityType::Pellet,
+        ))
+        .id()
+}
+
+fn spawn_test_ghost(world: &mut World) -> Entity {
+    world
+        .spawn((
+            Position::Stopped { node: 0 },
+            Collider { size: 12.0 },
+            GhostCollider,
+            Ghost::Blinky,
+            EntityType::Ghost,
+        ))
+        .id()
+}
+
+fn spawn_test_ghost_at_node(world: &mut World, node: usize) -> Entity {
+    world
+        .spawn((
+            Position::Stopped { node },
+            Collider { size: 12.0 },
+            GhostCollider,
+            Ghost::Blinky,
+            EntityType::Ghost,
+        ))
+        .id()
+}
+
+#[test]
+fn test_collider_collision_detection() {
+    let collider1 = Collider { size: 10.0 };
+    let collider2 = Collider { size: 8.0 };
+
+    // Test collision detection
+    assert!(collider1.collides_with(collider2.size, 5.0)); // Should collide (distance < 9.0)
+    assert!(!collider1.collides_with(collider2.size, 15.0)); // Should not collide (distance > 9.0)
+}
+
+#[test]
+fn test_check_collision_helper() {
+    let map = create_test_map();
+    let pos1 = Position::Stopped { node: 0 };
+    let pos2 = Position::Stopped { node: 0 }; // Same position
+    let collider1 = Collider { size: 10.0 };
+    let collider2 = Collider { size: 8.0 };
+
+    // Test collision at same position
+    let result = check_collision(&pos1, &collider1, &pos2, &collider2, &map);
+    assert!(result.is_ok());
+    assert!(result.unwrap()); // Should collide at same position
+
+    // Test collision at different positions
+    let pos3 = Position::Stopped { node: 1 }; // Different position
+    let result = check_collision(&pos1, &collider1, &pos3, &collider2, &map);
+    assert!(result.is_ok());
+    // May or may not collide depending on actual node positions
+}
+
+#[test]
+fn test_collision_system_pacman_item() {
+    let mut world = create_test_world();
+    let _pacman = spawn_test_pacman(&mut world);
+    let _item = spawn_test_item(&mut world);
+
+    // Run collision system - should not panic
+    world
+        .run_system_once(collision_system)
+        .expect("System should run successfully");
+}
+
+#[test]
+fn test_collision_system_pacman_ghost() {
+    let mut world = create_test_world();
+    let _pacman = spawn_test_pacman(&mut world);
+    let _ghost = spawn_test_ghost(&mut world);
+
+    // Run collision system - should not panic
+    world
+        .run_system_once(collision_system)
+        .expect("System should run successfully");
+}
+
+#[test]
+fn test_collision_system_no_collision() {
+    let mut world = create_test_world();
+    let _pacman = spawn_test_pacman(&mut world);
+    let _ghost = spawn_test_ghost_at_node(&mut world, 1); // Different node
+
+    // Run collision system - should not panic
+    world
+        .run_system_once(collision_system)
+        .expect("System should run successfully");
+}
+
+#[test]
+fn test_collision_system_multiple_entities() {
+    let mut world = create_test_world();
+    let _pacman = spawn_test_pacman(&mut world);
+    let _item = spawn_test_item(&mut world);
+    let _ghost = spawn_test_ghost(&mut world);
+
+    // Run collision system - should not panic
+    world
+        .run_system_once(collision_system)
+        .expect("System should run successfully");
+}