Add FORM_CHANGE_BATTLE_TERASTALLIZATION + allow species to force tera types

src/battle_script_commands.c

@@ -2050,7 +2050,7 @@ static void Cmd_adjustdamage(void)
         gLastUsedItem = gBattleMons[gBattlerTarget].item;
         gSpecialStatuses[gBattlerTarget].focusBanded = FALSE;
         gSpecialStatuses[gBattlerTarget].focusSashed = FALSE;
-        
+
     }
     else if (gSpecialStatuses[gBattlerTarget].sturdied)
     {
@@ -3172,8 +3172,8 @@ void SetMoveEffect(bool32 primary, bool32 certain)
                 {
                     gBattleMons[gEffectBattler].status2 |= sStatusFlagsForMoveEffects[gBattleScripting.moveEffect];
                     gBattlescriptCurrInstr++;
-                } 
-                else 
+                }
+                else
                 {
                     gBattlescriptCurrInstr++;
                 }
@@ -6243,7 +6243,7 @@ static void Cmd_moveend(void)
                         break;
                     }
                 }
-                
+
                 if (!(gBattleStruct->lastMoveFailed & gBitTable[gBattlerAttacker]
                     || (!gSpecialStatuses[gBattlerAttacker].dancerUsedMove
                         && gBattleStruct->bouncedMoveIsUsed)))
@@ -6341,9 +6341,9 @@ static void Cmd_moveend(void)
               && (gMoveResultFlags & MOVE_RESULT_NO_EFFECT)         // And it is unusable
               && (gBattleMons[gBattlerAttacker].status2 & STATUS2_LOCK_CONFUSE) != STATUS2_LOCK_CONFUSE_TURN(1))  // And won't end this turn
                 CancelMultiTurnMoves(gBattlerAttacker); // Cancel it
-            
-            
-        
+
+
+
             if (gBattleStruct->savedAttackerCount > 0)
             {
                 // #if TESTING
@@ -16845,8 +16845,8 @@ void BS_AllySwitchFailChance(void)
 void BS_SetPhotonGeyserCategory(void)
 {
     NATIVE_ARGS();
-    if (!(gMovesInfo[gCurrentMove].effect == EFFECT_TERA_BLAST && !IsTerastallized(gBattlerAttacker))
-     && !(gMovesInfo[gCurrentMove].effect == EFFECT_TERA_STARSTORM && gBattleMons[gBattlerAttacker].species != SPECIES_TERAPAGOS_STELLAR))
+    if (!((gMovesInfo[gCurrentMove].effect == EFFECT_TERA_BLAST && !IsTerastallized(gBattlerAttacker))
+            || (gMovesInfo[gCurrentMove].effect == EFFECT_TERA_STARSTORM && !(IsTerastallized(gBattlerAttacker) && gBattleMons[gBattlerAttacker].species == SPECIES_TERAPAGOS_STELLAR))))
         gBattleStruct->swapDamageCategory = (GetCategoryBasedOnStats(gBattlerAttacker) == DAMAGE_CATEGORY_PHYSICAL);
     gBattlescriptCurrInstr = cmd->nextInstr;
 }

src/pokemon.c

@@ -2774,14 +2774,18 @@ u32 GetBoxMonData3(struct BoxPokemon *boxMon, s32 field, u8 *data)
             break;
         case MON_DATA_TERA_TYPE:
             if (gSpeciesInfo[substruct0->species].forceTeraType)
+            {
                 retVal = gSpeciesInfo[substruct0->species].forceTeraType;
-            else if (substruct0->teraType == 0) // Tera Type hasn't been modified so we can just use the personality
+            }
+            else if (substruct0->teraType == TYPE_NONE) // Tera Type hasn't been modified so we can just use the personality
             {
                 const u8 *types = gSpeciesInfo[substruct0->species].types;
                 retVal = (boxMon->personality & 0x1) == 0 ? types[0] : types[1];
             }
             else
+            {
                 retVal = substruct0->teraType;
+            }
             break;
         case MON_DATA_EVOLUTION_TRACKER:
             evoTracker.asField.a = substruct1->evolutionTracker1;

test/battle/gimmick/terastal.c

@@ -686,7 +686,7 @@ SINGLE_BATTLE_TEST("(TERA) Protean cannot change the type of a Terastallized Pok
         PLAYER(SPECIES_GRENINJA) { Ability(ABILITY_PROTEAN); TeraType(TYPE_GRASS); }
         OPPONENT(SPECIES_WOBBUFFET);
     } WHEN {
-        TURN { MOVE(player, MOVE_BUBBLE, tera: TRUE); 
+        TURN { MOVE(player, MOVE_BUBBLE, tera: TRUE);
                MOVE(opponent, MOVE_EMBER); }
     } SCENE {
         MESSAGE("Greninja used Bubble!");
@@ -793,3 +793,22 @@ SINGLE_BATTLE_TEST("(TERA) All type indicators function correctly")
         TURN { MOVE(player, MOVE_CELEBRATE, tera: TRUE); }
     }
 }
+
+SINGLE_BATTLE_TEST("(TERA) Pokemon with Tera forms change upon Terastallizing")
+{
+    u32 species1;
+    u32 species2;
+    PARAMETRIZE { species1 = SPECIES_OGERPON_TEAL_MASK; species2 = SPECIES_OGERPON_TEAL_MASK_TERA; }
+    PARAMETRIZE { species1 = SPECIES_OGERPON_WELLSPRING_MASK; species2 = SPECIES_OGERPON_WELLSPRING_MASK_TERA; }
+    PARAMETRIZE { species1 = SPECIES_OGERPON_HEARTHFLAME_MASK; species2 = SPECIES_OGERPON_HEARTHFLAME_MASK_TERA; }
+    PARAMETRIZE { species1 = SPECIES_OGERPON_CORNERSTONE_MASK; species2 = SPECIES_OGERPON_CORNERSTONE_MASK_TERA; }
+    PARAMETRIZE { species1 = SPECIES_TERAPAGOS_TERASTAL; species2 = SPECIES_TERAPAGOS_STELLAR; }
+    GIVEN {
+        PLAYER(species1);
+        OPPONENT(SPECIES_WOBBUFFET);
+    } WHEN {
+        TURN { MOVE(player, MOVE_CELEBRATE, tera: TRUE); }
+    } THEN {
+        EXPECT_EQ(player->species, species2);
+    }
+}

test/battle/move_effect/tera_starstorm.c

@@ -0,0 +1,61 @@
+#include "global.h"
+#include "test/battle.h"
+
+ASSUMPTIONS
+{
+    ASSUME(gMovesInfo[MOVE_TERA_STARSTORM].effect == EFFECT_TERA_STARSTORM);
+}
+
+SINGLE_BATTLE_TEST("Tera Starstorm changes from Normal-type to Stellar-type if used by Terapagos-Stellar")
+{
+    GIVEN {
+        ASSUME(gMovesInfo[MOVE_TERA_STARSTORM].type == TYPE_NORMAL);
+        PLAYER(SPECIES_TERAPAGOS_STELLAR);
+        OPPONENT(SPECIES_MISDREAVUS);
+    } WHEN {
+        TURN { MOVE(player, MOVE_TERA_STARSTORM); }
+    } SCENE {
+        MESSAGE("Terapagos used Tera Starstorm!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TERA_STARSTORM, player);
+        HP_BAR(opponent);
+        NOT { MESSAGE("It doesn't affect Foe Misdreavus…"); }
+    }
+}
+
+DOUBLE_BATTLE_TEST("Tera Starstorm targets both opponents in a double battle if used by Terapagos-Stellar")
+{
+    GIVEN {
+        ASSUME(gMovesInfo[MOVE_TERA_STARSTORM].target == MOVE_TARGET_SELECTED);
+        PLAYER(SPECIES_TERAPAGOS_STELLAR);
+        PLAYER(SPECIES_WYNAUT);
+        OPPONENT(SPECIES_WOBBUFFET);
+        OPPONENT(SPECIES_WYNAUT);
+    } WHEN {
+        TURN { MOVE(playerLeft, MOVE_TERA_STARSTORM, target:opponentLeft); }
+    } SCENE {
+        MESSAGE("Terapagos used Tera Starstorm!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TERA_STARSTORM, playerLeft);
+        HP_BAR(opponentLeft);
+        HP_BAR(opponentRight);
+    }
+}
+
+SINGLE_BATTLE_TEST("Tera Starstorm becomes a physical move if the user is Terapagos-Stellar, is Terastallized, and has a higher Attack stat", s16 damage)
+{
+    bool32 tera;
+    PARAMETRIZE { tera = FALSE; }
+    PARAMETRIZE { tera = TRUE; }
+    GIVEN {
+        ASSUME(gMovesInfo[MOVE_TERA_STARSTORM].category == DAMAGE_CATEGORY_SPECIAL);
+        PLAYER(SPECIES_TERAPAGOS_STELLAR) { Attack(100); SpAttack(50); }
+        OPPONENT(SPECIES_WOBBUFFET) { Defense(200); SpDefense(200); }
+    } WHEN {
+        TURN { MOVE(player, MOVE_TERA_STARSTORM, tera: tera); }
+    } SCENE {
+        MESSAGE("Terapagos used Tera Starstorm!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_TERA_STARSTORM, player);
+        HP_BAR(opponent, captureDamage: &results[i].damage);
+    } FINALLY {
+        EXPECT_MUL_EQ(results[0].damage, UQ_4_12(2.5), results[1].damage);
+    }
+}