[Bug] Palafin should not swap to Hero form when switching due to faint (#3532)

* Palafin should not swap to Hero form when switching due to faint

Also add more tests for Zero to Hero

* Use `.isFainted()` instead of checking HP

src/data/ability.ts

@@ -5296,7 +5296,7 @@ export function initAbilities() {
       .attr(NoTransformAbilityAbAttr)
       .attr(NoFusionAbilityAbAttr)
       .attr(PostBattleInitFormChangeAbAttr, () => 0)
-      .attr(PreSwitchOutFormChangeAbAttr, () => 1)
+      .attr(PreSwitchOutFormChangeAbAttr, (pokemon) => !pokemon.isFainted() ? 1 : pokemon.formIndex)
       .bypassFaint(),
     new Ability(Abilities.COMMANDER, 9)
       .attr(UncopiableAbilityAbAttr)

src/test/abilities/zero_to_hero.test.ts

@@ -6,13 +6,16 @@ import { Moves } from "#enums/moves";
 import { Species } from "#enums/species";
 import GameManager from "#test/utils/gameManager";
 import { getMovePosition } from "#test/utils/gameManagerUtils";
-import { afterEach, beforeAll, beforeEach, describe, expect, test } from "vitest";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+import { SPLASH_ONLY } from "../utils/testUtils";
 
 const TIMEOUT = 20 * 1000;
 
 describe("Abilities - ZERO TO HERO", () => {
   let phaserGame: Phaser.Game;
   let game: GameManager;
+  const baseForm = 0;
+  const heroForm = 1;
 
   beforeAll(() => {
     phaserGame = new Phaser.Game({
@@ -26,41 +29,83 @@ describe("Abilities - ZERO TO HERO", () => {
 
   beforeEach(() => {
     game = new GameManager(phaserGame);
-    const moveToUse = Moves.SPLASH;
-    game.override.battleType("single");
-    game.override.ability(Abilities.ZERO_TO_HERO);
-    game.override.moveset([moveToUse]);
-    game.override.enemyMoveset([Moves.TACKLE, Moves.TACKLE, Moves.TACKLE, Moves.TACKLE]);
+    game.override
+      .battleType("single")
+      .moveset(SPLASH_ONLY)
+      .enemyMoveset(SPLASH_ONLY)
+      .enemyAbility(Abilities.BALL_FETCH);
   });
 
-  test(
-    "check if fainted pokemon switches to base form on arena reset",
-    async () => {
-      const baseForm = 0,
-        heroForm = 1;
-      game.override.startingWave(4);
-      game.override.starterForms({
-        [Species.PALAFIN]: heroForm,
-      });
+  it("should swap to base form on arena reset", async () => {
+    game.override.startingWave(4);
+    game.override.starterForms({
+      [Species.PALAFIN]: heroForm,
+    });
 
-      await game.startBattle([Species.MAGIKARP, Species.PALAFIN]);
+    await game.startBattle([Species.FEEBAS, Species.PALAFIN, Species.PALAFIN]);
 
-      const palafin = game.scene.getParty().find((p) => p.species.speciesId === Species.PALAFIN)!;
-      expect(palafin).not.toBe(undefined);
-      expect(palafin.formIndex).toBe(heroForm);
+    const palafin1 = game.scene.getParty()[1];
+    const palafin2 = game.scene.getParty()[2];
+    expect(palafin1.formIndex).toBe(heroForm);
+    expect(palafin2.formIndex).toBe(heroForm);
+    palafin2.hp = 0;
+    palafin2.status = new Status(StatusEffect.FAINT);
+    expect(palafin2.isFainted()).toBe(true);
 
-      palafin.hp = 0;
-      palafin.status = new Status(StatusEffect.FAINT);
-      expect(palafin.isFainted()).toBe(true);
+    game.doAttack(getMovePosition(game.scene, 0, Moves.SPLASH));
+    await game.doKillOpponents();
+    await game.phaseInterceptor.to(TurnEndPhase);
+    game.doSelectModifier();
+    await game.phaseInterceptor.to(QuietFormChangePhase);
+    await game.phaseInterceptor.to(QuietFormChangePhase);
 
-      game.doAttack(getMovePosition(game.scene, 0, Moves.SPLASH));
-      await game.doKillOpponents();
-      await game.phaseInterceptor.to(TurnEndPhase);
-      game.doSelectModifier();
-      await game.phaseInterceptor.to(QuietFormChangePhase);
+    expect(palafin1.formIndex).toBe(baseForm);
+    expect(palafin2.formIndex).toBe(baseForm);
+  }, TIMEOUT);
 
-      expect(palafin.formIndex).toBe(baseForm);
-    },
-    TIMEOUT
-  );
+  it("should swap to Hero form when switching out during a battle", async () => {
+    await game.startBattle([Species.PALAFIN, Species.FEEBAS]);
+
+    const palafin = game.scene.getPlayerPokemon()!;
+    expect(palafin.formIndex).toBe(baseForm);
+
+    game.doSwitchPokemon(1);
+    await game.phaseInterceptor.to(QuietFormChangePhase);
+    expect(palafin.formIndex).toBe(heroForm);
+  }, TIMEOUT);
+
+  it("should not swap to Hero form if switching due to faint", async () => {
+    await game.startBattle([Species.PALAFIN, Species.FEEBAS]);
+
+    const palafin = game.scene.getPlayerPokemon()!;
+    expect(palafin.formIndex).toBe(baseForm);
+
+    game.doAttack(getMovePosition(game.scene, 0, Moves.SPLASH));
+    await game.killPokemon(palafin);
+    game.doSelectPartyPokemon(1);
+    await game.toNextTurn();
+    expect(palafin.formIndex).toBe(baseForm);
+  }, TIMEOUT);
+
+  it("should stay hero form if fainted and then revived", async () => {
+    game.override.starterForms({
+      [Species.PALAFIN]: heroForm,
+    });
+
+    await game.startBattle([Species.PALAFIN, Species.FEEBAS]);
+
+    const palafin = game.scene.getPlayerPokemon()!;
+    expect(palafin.formIndex).toBe(heroForm);
+
+    game.doAttack(getMovePosition(game.scene, 0, Moves.SPLASH));
+    await game.killPokemon(palafin);
+    game.doSelectPartyPokemon(1);
+    await game.toNextTurn();
+
+    game.doRevivePokemon(1);
+    game.doSwitchPokemon(1);
+    await game.toNextTurn();
+
+    expect(palafin.formIndex).toBe(heroForm);
+  }, TIMEOUT);
 });