fix: StrengthSap fails at -6 attack on defender

src/choice_effects.rs

@@ -276,13 +276,15 @@ pub fn modify_choice(
                     accuracy: 0,
                 },
             });
-            let defender_attack =
-                defending_side.calculate_boosted_stat(PokemonBoostableStat::Attack);
-            let attacker_maxhp = attacking_side.get_active_immutable().maxhp;
-            attacker_choice.heal = Some(Heal {
-                target: MoveTarget::User,
-                amount: defender_attack as f32 / attacker_maxhp as f32,
-            });
+            if defending_side.attack_boost != -6 {
+                let defender_attack =
+                    defending_side.calculate_boosted_stat(PokemonBoostableStat::Attack);
+                let attacker_maxhp = attacking_side.get_active_immutable().maxhp;
+                attacker_choice.heal = Some(Heal {
+                    target: MoveTarget::User,
+                    amount: defender_attack as f32 / attacker_maxhp as f32,
+                });
+            }
         }
         Choices::TERABLAST => {
             let active = attacking_side.get_active_immutable();

tests/test_battle_mechanics.rs

@@ -9132,6 +9132,26 @@ fn test_strengthsap() {
     assert_eq!(expected_instructions, vec_of_instructions);
 }
 
+#[test]
+fn test_strengthsap_fails_at_negative_6_boost_on_opponent() {
+    let mut state = State::default();
+    state.side_one.get_active().maxhp = 500;
+    state.side_one.get_active().hp = 100;
+    state.side_two.attack_boost = -6;
+
+    let vec_of_instructions = set_moves_on_pkmn_and_call_generate_instructions(
+        &mut state,
+        Choices::STRENGTHSAP,
+        Choices::SPLASH,
+    );
+
+    let expected_instructions = vec![StateInstructions {
+        percentage: 100.0,
+        instruction_list: vec![],
+    }];
+    assert_eq!(expected_instructions, vec_of_instructions);
+}
+
 #[test]
 fn test_yawn_gets_applied_and_swapped_with_next_turn_volatile() {
     let mut state = State::default();