From f17ecc8d89ff28e51cd24ef334ae99140c3b5ae4 Mon Sep 17 00:00:00 2001
From: Tim Blackbird <justthecooldude@gmail.com>
Date: Thu, 17 Jul 2025 16:51:34 +0200
Subject: [PATCH] Add `observer_no_target` test back

---
 crates/bevy_ecs/src/observer/mod.rs | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/crates/bevy_ecs/src/observer/mod.rs b/crates/bevy_ecs/src/observer/mod.rs
index 70e405882e..ae8ab9b09a 100644
--- a/crates/bevy_ecs/src/observer/mod.rs
+++ b/crates/bevy_ecs/src/observer/mod.rs
@@ -527,6 +527,11 @@ mod tests {
     #[component(storage = "SparseSet")]
     struct S;
 
+    #[derive(EntityEvent)]
+    struct EventA;
+
+    impl BroadcastEvent for EventA {}
+
     #[derive(EntityEvent)]
     struct EntityEventA;
 
@@ -839,6 +844,28 @@ mod tests {
         assert_eq!(vec!["add_ab"], world.resource::<Order>().0);
     }
 
+    #[test]
+    fn observer_no_target() {
+        let mut world = World::new();
+        world.init_resource::<Order>();
+
+        let system: fn(On<EventA>) = |_| {
+            panic!("Trigger routed to non-targeted entity.");
+        };
+        world.spawn_empty().observe(system);
+        world.add_observer(move |obs: On<EventA>, mut res: ResMut<Order>| {
+            assert_eq!(obs.target(), Entity::PLACEHOLDER);
+            res.observed("event_a");
+        });
+
+        // TODO: ideally this flush is not necessary, but right now observe() returns WorldEntityMut
+        // and therefore does not automatically flush.
+        world.flush();
+        world.trigger(EventA);
+        world.flush();
+        assert_eq!(vec!["event_a"], world.resource::<Order>().0);
+    }
+
     #[test]
     fn observer_entity_routing() {
         let mut world = World::new();