Fixes ability Corrosion (#4037)

* Fixes ability Corrosion

* forgot AI_CanPoisonType

* More tests

* review comments applied

* more review changes

* simplify CanPosionType (original state)

* remove redundant function

---------

Co-authored-by: Bassoonian <iasperbassoonian@gmail.com>

src/battle_ai_util.c

@@ -2750,17 +2750,11 @@ bool32 AI_CanPutToSleep(u32 battlerAtk, u32 battlerDef, u32 defAbility, u32 move
     return TRUE;
 }
 
-static bool32 AI_CanPoisonType(u32 battlerAttacker, u32 battlerTarget, u32 move)
-{
-    return ((AI_DATA->abilities[battlerAttacker] == ABILITY_CORROSION && gBattleMoves[move].split == SPLIT_STATUS)
-            || !(IS_BATTLER_OF_TYPE(battlerTarget, TYPE_POISON) || IS_BATTLER_OF_TYPE(battlerTarget, TYPE_STEEL)));
-}
-
 static bool32 AI_CanBePoisoned(u32 battlerAtk, u32 battlerDef, u32 move)
 {
     u32 ability = AI_DATA->abilities[battlerDef];
 
-    if (!(AI_CanPoisonType(battlerAtk, battlerDef, move))
+    if (!(CanPoisonType(battlerAtk, battlerDef))
      || gSideStatuses[GetBattlerSide(battlerDef)] & SIDE_STATUS_SAFEGUARD
      || gBattleMons[battlerDef].status1 & STATUS1_ANY
      || ability == ABILITY_IMMUNITY

src/battle_script_commands.c

@@ -8123,8 +8123,8 @@ static bool32 HasAttackerFaintedTarget(void)
 
 bool32 CanPoisonType(u8 battlerAttacker, u8 battlerTarget)
 {
-    return ((GetBattlerAbility(battlerAttacker) == ABILITY_CORROSION && gBattleMoves[gCurrentMove].split == SPLIT_STATUS)
+    return GetBattlerAbility(battlerAttacker) == ABILITY_CORROSION
-            || !(IS_BATTLER_OF_TYPE(battlerTarget, TYPE_POISON) || IS_BATTLER_OF_TYPE(battlerTarget, TYPE_STEEL)));
+        || (!IS_BATTLER_OF_TYPE(battlerTarget, TYPE_STEEL) && !IS_BATTLER_OF_TYPE(battlerTarget, TYPE_POISON));
 }
 
 bool32 CanParalyzeType(u8 battlerAttacker, u8 battlerTarget)

test/battle/ability/corrosion.c

@@ -0,0 +1,128 @@
+#include "global.h"
+#include "test/battle.h"
+
+SINGLE_BATTLE_TEST("Corrosion can poison or badly poison a Pokemon regardless of its typing")
+{
+    u16 species;
+
+    PARAMETRIZE { species = SPECIES_ODDISH; }
+    PARAMETRIZE { species = SPECIES_BELDUM; }
+
+    GIVEN {
+        ASSUME(gBattleMoves[MOVE_TWINEEDLE].effect == EFFECT_POISON_HIT);
+        PLAYER(SPECIES_SALANDIT) { Ability(ABILITY_CORROSION); }
+        OPPONENT(species);
+    } WHEN {
+        TURN { MOVE(player, MOVE_TWINEEDLE); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TWINEEDLE, player);
+        HP_BAR(opponent);
+        ANIMATION(ANIM_TYPE_STATUS, B_ANIM_STATUS_PSN, opponent);
+        STATUS_ICON(opponent, poison: TRUE);
+    }
+}
+
+SINGLE_BATTLE_TEST("Corrosion can poison or badly poison a Steel type with a status poison effect")
+{
+    u16 move;
+
+    PARAMETRIZE { move = MOVE_POISON_POWDER; }
+    PARAMETRIZE { move = MOVE_TOXIC; }
+
+    GIVEN {
+        ASSUME(gBattleMoves[MOVE_POISON_POWDER].effect == EFFECT_POISON);
+        ASSUME(gBattleMoves[MOVE_TOXIC].effect == EFFECT_TOXIC);
+        PLAYER(SPECIES_SALANDIT) { Ability(ABILITY_CORROSION); }
+        OPPONENT(SPECIES_BELDUM);
+    } WHEN {
+        TURN { MOVE(player, move); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, move, player);
+        ANIMATION(ANIM_TYPE_STATUS, B_ANIM_STATUS_PSN, opponent);
+        if (move == MOVE_POISON_POWDER)
+            STATUS_ICON(opponent, poison: TRUE);
+        else
+            STATUS_ICON(opponent, badPoison: TRUE);
+    }
+}
+
+SINGLE_BATTLE_TEST("Corrosion does not effect poison type damaging moves if the target is immune to it")
+{
+    GIVEN {
+        ASSUME(gBattleMoves[MOVE_SLUDGE_BOMB].effect == EFFECT_POISON_HIT);
+        PLAYER(SPECIES_SALANDIT) { Ability(ABILITY_CORROSION); }
+        OPPONENT(SPECIES_BELDUM);
+    } WHEN {
+        TURN { MOVE(player, MOVE_SLUDGE_BOMB); }
+    } SCENE {
+        NONE_OF {
+            ANIMATION(ANIM_TYPE_MOVE, MOVE_SLUDGE_BOMB, player);
+            HP_BAR(opponent);
+            ANIMATION(ANIM_TYPE_STATUS, B_ANIM_STATUS_PSN, opponent);
+            STATUS_ICON(opponent, poison: TRUE);
+        }
+    }
+}
+
+SINGLE_BATTLE_TEST("Corrosion can poison Poison- and Steel-type targets if it uses Fling while holding a Toxic Orb or a Poison Barb")
+{
+    u16 heldItem;
+
+    PARAMETRIZE { heldItem = ITEM_POISON_BARB; }
+    PARAMETRIZE { heldItem = ITEM_TOXIC_ORB; }
+
+    GIVEN {
+        ASSUME(gBattleMoves[MOVE_FLING].effect == EFFECT_FLING);
+        ASSUME(gItems[ITEM_POISON_BARB].holdEffect == HOLD_EFFECT_POISON_POWER);
+        ASSUME(gItems[ITEM_TOXIC_ORB].holdEffect == HOLD_EFFECT_TOXIC_ORB);
+        PLAYER(SPECIES_SALANDIT) { Ability(ABILITY_CORROSION); Item(heldItem); }
+        OPPONENT(SPECIES_ODDISH);
+    } WHEN {
+        TURN { MOVE(player, MOVE_FLING); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_FLING, player);
+        HP_BAR(opponent);
+        ANIMATION(ANIM_TYPE_STATUS, B_ANIM_STATUS_PSN, opponent);
+        if (heldItem == ITEM_POISON_BARB)
+            STATUS_ICON(opponent, poison: TRUE);
+        else
+            STATUS_ICON(opponent, badPoison: TRUE);
+    }
+}
+
+SINGLE_BATTLE_TEST("If a Poison- or Steel-type Pokémon with Corrosion holds a Toxic Orb, it will badly poison itself")
+{
+    GIVEN {
+        ASSUME(gItems[ITEM_TOXIC_ORB].holdEffect == HOLD_EFFECT_TOXIC_ORB);
+        PLAYER(SPECIES_SALANDIT) { Ability(ABILITY_CORROSION); Item(ITEM_TOXIC_ORB); }
+        OPPONENT(SPECIES_ODDISH);
+    } WHEN {
+        TURN { }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_STATUS, B_ANIM_STATUS_PSN, player);
+        STATUS_ICON(player, badPoison: TRUE);
+    }
+}
+
+SINGLE_BATTLE_TEST("If a Poison- or Steel-type Pokémon with Corrosion poisons a target with Synchronize, Synchronize will not poison Poison- or Steel-type Pokémon")
+{
+    GIVEN {
+        ASSUME(gBattleMoves[MOVE_TOXIC].effect == EFFECT_TOXIC);
+        PLAYER(SPECIES_SALANDIT) { Ability(ABILITY_CORROSION); }
+        OPPONENT(SPECIES_ABRA) { Ability(ABILITY_SYNCHRONIZE); }
+    } WHEN {
+        TURN { MOVE(player, MOVE_TOXIC); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TOXIC, player);
+        ANIMATION(ANIM_TYPE_STATUS, B_ANIM_STATUS_PSN, opponent);
+        STATUS_ICON(opponent, badPoison: TRUE);
+        NONE_OF {
+            ANIMATION(ANIM_TYPE_STATUS, B_ANIM_STATUS_PSN, player);
+            STATUS_ICON(player, badPoison: TRUE);
+        }
+    }
+}
+
+TO_DO_BATTLE_TEST("Corrosion cannot bypass moves or Abilities that prevent poisoning, such as Safeguard or Immunity");
+TO_DO_BATTLE_TEST("If the Pokémon with this Ability uses Magic Coat to reflect a status move that inflicts poison, the reflected move will be able to poison Poison- or Steel-type Pokémon.");
+TO_DO_BATTLE_TEST("Moves used by a Pokémon with Corrosion that are reflected by Magic Coat or Magic Bounce do not retain the ability to poison Poison- or Steel-type Pokémon.")