[BUG] Fix the bug where transformed pokemon failed to load sprite on reload if it was not the base form

src/system/pokemon-data.ts

@@ -3,7 +3,7 @@ import { globalScene } from "#app/global-scene";
 import type { Gender } from "../data/gender";
 import type { Nature } from "#enums/nature";
 import type { PokeballType } from "#enums/pokeball";
-import { getPokemonSpecies } from "../data/pokemon-species";
+import { getPokemonSpecies, getPokemonSpeciesForm } from "../data/pokemon-species";
 import { Status } from "../data/status-effect";
 import Pokemon, { EnemyPokemon, PokemonMove, PokemonSummonData } from "../field/pokemon";
 import { TrainerSlot } from "../data/trainer-config";
@@ -14,6 +14,7 @@ import { Moves } from "#enums/moves";
 import type { Species } from "#enums/species";
 import { CustomPokemonData } from "#app/data/custom-pokemon-data";
 import type { PokemonType } from "#enums/pokemon-type";
+import { getSpeciesFormChangeMessage } from "#app/data/pokemon-forms";
 
 export default class PokemonData {
   public id: number;
@@ -63,6 +64,7 @@ export default class PokemonData {
   public bossSegments?: number;
 
   public summonData: PokemonSummonData;
+  public summonDataSpeciesFormIndex: number;
 
   /** Data that can customize a Pokemon in non-standard ways from its Species */
   public customPokemonData: CustomPokemonData;
@@ -145,8 +147,9 @@ export default class PokemonData {
       this.moveset = sourcePokemon.moveset;
       if (!forHistory) {
         this.status = sourcePokemon.status;
-        if (this.player) {
+        if (this.player && sourcePokemon.summonData) {
           this.summonData = sourcePokemon.summonData;
+          this.summonDataSpeciesFormIndex = this.getSummonDataSpeciesFormIndex();
         }
       }
     } else {
@@ -171,6 +174,7 @@ export default class PokemonData {
         this.summonData.moveset = source.summonData.moveset?.map(m => PokemonMove.loadMove(m));
         this.summonData.types = source.summonData.types;
         this.summonData.speciesForm = source.summonData.speciesForm;
+        this.summonDataSpeciesFormIndex = source.summonDataSpeciesFormIndex;
 
         if (source.summonData.tags) {
           this.summonData.tags = source.summonData.tags?.map(t => loadBattlerTag(t));
@@ -214,13 +218,28 @@ export default class PokemonData {
           this,
         );
     if (this.summonData) {
-      // when loading from saved session, recover summonData.speciesFrom species object
+      // when loading from saved session, recover summonData.speciesFrom and form index species object
       // used to stay transformed on reload session
       if (this.summonData.speciesForm) {
-        this.summonData.speciesForm = getPokemonSpecies(this.summonData.speciesForm.speciesId);
+        this.summonData.speciesForm = getPokemonSpeciesForm(
+          this.summonData.speciesForm.speciesId,
+          this.summonDataSpeciesFormIndex,
+        );
       }
       ret.primeSummonData(this.summonData);
     }
     return ret;
   }
+
+  /**
+   * Method to save summon data species form index
+   * Necessary in case the pokemon is transformed
+   * to reload the correct form
+   */
+  getSummonDataSpeciesFormIndex(): number {
+    if (this.summonData.speciesForm) {
+      return this.summonData.speciesForm.formIndex;
+    }
+    return 0;
+  }
 }

test/abilities/imposter.test.ts

@@ -160,4 +160,30 @@ describe("Abilities - Imposter", () => {
     expect(playerMoveset.length).toEqual(1);
     expect(playerMoveset[0]?.moveId).toEqual(Moves.SPLASH);
   });
+
+  it("should stay transformed with the correct form after reload", async () => {
+    game.override.moveset([Moves.ABSORB]);
+    game.override.enemySpecies(Species.UNOWN);
+    await game.classicMode.startBattle([Species.DITTO]);
+
+    const enemy = game.scene.getEnemyPokemon()!;
+
+    // change form
+    enemy.species.forms[5];
+    enemy.species.formIndex = 5;
+
+    game.move.select(Moves.SPLASH);
+    await game.doKillOpponents();
+    await game.toNextWave();
+
+    expect(game.scene.getCurrentPhase()?.constructor.name).toBe("CommandPhase");
+    expect(game.scene.currentBattle.waveIndex).toBe(2);
+
+    await game.reload.reloadSession();
+
+    const playerReloaded = game.scene.getPlayerPokemon()!;
+
+    expect(playerReloaded.getSpeciesForm().speciesId).toBe(enemy.getSpeciesForm().speciesId);
+    expect(playerReloaded.getSpeciesForm().formIndex).toBe(enemy.getSpeciesForm().formIndex);
+  });
 });

test/moves/transform.test.ts

@@ -164,4 +164,35 @@ describe("Moves - Transform", () => {
     expect(playerMoveset.length).toEqual(1);
     expect(playerMoveset[0]?.moveId).toEqual(Moves.MEMENTO);
   });
+
+  it("should stay transformed with the correct form after reload", async () => {
+    game.override.enemyMoveset([]).moveset([]);
+    game.override.enemySpecies(Species.DARMANITAN);
+
+    await game.classicMode.startBattle([Species.DITTO]);
+
+    const player = game.scene.getPlayerPokemon()!;
+    const enemy = game.scene.getEnemyPokemon()!;
+
+    // change form
+    enemy.species.forms[1];
+    enemy.species.formIndex = 1;
+
+    game.move.changeMoveset(player, Moves.TRANSFORM);
+    game.move.changeMoveset(enemy, Moves.MEMENTO);
+
+    game.move.select(Moves.TRANSFORM);
+    await game.setTurnOrder([BattlerIndex.PLAYER, BattlerIndex.ENEMY]);
+    await game.toNextWave();
+
+    expect(game.scene.getCurrentPhase()?.constructor.name).toBe("CommandPhase");
+    expect(game.scene.currentBattle.waveIndex).toBe(2);
+
+    await game.reload.reloadSession();
+
+    const playerReloaded = game.scene.getPlayerPokemon()!;
+
+    expect(playerReloaded.getSpeciesForm().speciesId).toBe(enemy.getSpeciesForm().speciesId);
+    expect(playerReloaded.getSpeciesForm().formIndex).toBe(enemy.getSpeciesForm().formIndex);
+  });
 });