Meloetta won't change forms during a monotype challenge

Also removes reversion to Aria form when arena resets

src/data/pokemon-forms.ts

@@ -12,6 +12,7 @@ import { TimeOfDay } from "#enums/time-of-day";
 import { getPokemonNameWithAffix } from "#app/messages";
 import i18next from "i18next";
 import { WeatherType } from "./weather";
+import { Challenges } from "#app/enums/challenges";
 
 export enum FormChangeItem {
   NONE,
@@ -345,6 +346,16 @@ export class SpeciesFormChangePostMoveTrigger extends SpeciesFormChangeMoveTrigg
   }
 }
 
+export class MeloettaFormChangePostMoveTrigger extends SpeciesFormChangePostMoveTrigger {
+  override canChange(pokemon: Pokemon): boolean {
+    if (pokemon.scene.gameMode.hasChallenge(Challenges.SINGLE_TYPE)) {
+      return false;
+    } else {
+      return super.canChange(pokemon);
+    }
+  }
+}
+
 export class SpeciesDefaultFormMatchTrigger extends SpeciesFormChangeTrigger {
   private formKey: string;
 
@@ -759,9 +770,8 @@ export const pokemonFormChanges: PokemonFormChanges = {
     new SpeciesFormChange(Species.KELDEO, "resolute", "ordinary", new SpeciesFormChangeMoveLearnedTrigger(Moves.SECRET_SWORD, false))
   ],
   [Species.MELOETTA]: [
-    new SpeciesFormChange(Species.MELOETTA, "aria", "pirouette", new SpeciesFormChangePostMoveTrigger(Moves.RELIC_SONG), true),
-    new SpeciesFormChange(Species.MELOETTA, "pirouette", "aria", new SpeciesFormChangePostMoveTrigger(Moves.RELIC_SONG), true),
-    new SpeciesFormChange(Species.MELOETTA, "pirouette", "aria", new SpeciesFormChangeActiveTrigger(false), true)
+    new SpeciesFormChange(Species.MELOETTA, "aria", "pirouette", new MeloettaFormChangePostMoveTrigger(Moves.RELIC_SONG), true),
+    new SpeciesFormChange(Species.MELOETTA, "pirouette", "aria", new MeloettaFormChangePostMoveTrigger(Moves.RELIC_SONG), true)
   ],
   [Species.GENESECT]: [
     new SpeciesFormChange(Species.GENESECT, "", "shock", new SpeciesFormChangeItemTrigger(FormChangeItem.SHOCK_DRIVE)),

src/test/moves/relic_song.test.ts

@@ -0,0 +1,81 @@
+import { Type } from "#app/data/type";
+import { Challenges } from "#app/enums/challenges";
+import { Abilities } from "#enums/abilities";
+import { Moves } from "#enums/moves";
+import { Species } from "#enums/species";
+import GameManager from "#test/utils/gameManager";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+
+describe("Moves - Relic Song", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+  const TIMEOUT = 20 * 1000;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override
+      .moveset([Moves.RELIC_SONG, Moves.SPLASH])
+      .battleType("single")
+      .enemyAbility(Abilities.BALL_FETCH)
+      .enemyMoveset(Moves.SPLASH)
+      .enemySpecies(Species.MAGIKARP)
+      .enemyLevel(100);
+  });
+
+  it("swaps Meloetta's form between Aria and Pirouette", async () => {
+    await game.classicMode.startBattle([Species.MELOETTA]);
+
+    const meloetta = game.scene.getPlayerPokemon()!;
+
+    game.move.select(Moves.RELIC_SONG);
+    await game.toNextTurn();
+
+    expect(meloetta.formIndex).toBe(1);
+
+    game.move.select(Moves.RELIC_SONG);
+    await game.phaseInterceptor.to("BerryPhase");
+
+    expect(meloetta.formIndex).toBe(0);
+  }, TIMEOUT);
+
+  it("doesn't swap Meloetta's form during a mono-type challenge", async () => {
+    game.challengeMode.addChallenge(Challenges.SINGLE_TYPE, Type.PSYCHIC + 1, 0);
+    await game.challengeMode.startBattle([Species.MELOETTA]);
+
+    const meloetta = game.scene.getPlayerPokemon()!;
+
+    expect(meloetta.formIndex).toBe(0);
+
+    game.move.select(Moves.RELIC_SONG);
+    await game.phaseInterceptor.to("BerryPhase");
+    await game.toNextTurn();
+
+    expect(meloetta.formIndex).toBe(0);
+  }, TIMEOUT);
+
+  it("doesn't swap Meloetta's form during biome change (arena reset)", async () => {
+    game.override
+      .starterForms({[Species.MELOETTA]: 1})
+      .startingWave(10);
+    await game.classicMode.startBattle([Species.MELOETTA]);
+
+    const meloetta = game.scene.getPlayerPokemon()!;
+
+    game.move.select(Moves.SPLASH);
+    await game.doKillOpponents();
+    await game.toNextWave();
+
+    expect(meloetta.formIndex).toBe(1);
+  }, TIMEOUT);
+});