Hero waves march on the strongest master

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/rival.rs

@@ -507,4 +507,35 @@ mod tests {
         }
         assert!(fought, "heroes fight the rival master");
     }
+
+    #[test]
+    fn hero_waves_march_on_the_strongest_master() {
+        let mut g = (1..200u32).map(|s| Game::new_free(s, 160, 160, 1)).find(|g| g.rivals.len() == 1 && g.gate_on).unwrap();
+        let side = g.rivals[0].side;
+        let (rx, ry) = g.rivals[0].centre();
+        let army = |g: &mut Game, side: u8, x: f32, y: f32, n: usize| {
+            for k in 0..n {
+                let id = g.spawn(EK::Ogre, false, x + k as f32 * 0.2, y, 6);
+                if let Some(e) = g.ents.iter_mut().find(|e| e.id == id) {
+                    e.side = side;
+                }
+            }
+        };
+        // the rival master is far stronger: the wave marches on him and is measured against him
+        g.gold = 0.0;
+        army(&mut g, side, rx, ry + 2.0, 8);
+        assert_eq!(g.wave_goal(), side);
+        let before = g.ents.len();
+        g.spawn_wave();
+        let heroes: Vec<&Ent> = g.ents[before..].iter().filter(|e| e.hero).collect();
+        assert!(!heroes.is_empty());
+        assert!(heroes.iter().all(|e| e.target == Some(side)), "the wave marches on the rival");
+        // now the player is the strongest: the next wave comes for him
+        let (cx, cy) = g.map.core;
+        army(&mut g, 0, cx as f32 + 1.5, cy as f32 + 4.0, 20);
+        assert_eq!(g.wave_goal(), 0);
+        let before = g.ents.len();
+        g.spawn_wave();
+        assert!(g.ents[before..].iter().filter(|e| e.hero).all(|e| e.target.is_none()), "the wave comes for the player");
+    }
 }