[Ability] Implement Wonder Skin (#2231)

* implement wonder skin

* add unit tests

* fixes

* move applyPreDefendAbAttrs

src/data/ability.ts

@@ -574,6 +574,24 @@ export class MoveImmunityAbAttr extends PreDefendAbAttr {
   }
 }
 
+/**
+ * Reduces the accuracy of status moves used against the Pokémon with this ability to 50%.
+ * Used by Wonder Skin.
+ *
+ * @extends PreDefendAbAttr
+ */
+export class WonderSkinAbAttr extends PreDefendAbAttr {
+  applyPreDefend(pokemon: Pokemon, passive: boolean, attacker: Pokemon, move: Move, cancelled: Utils.BooleanHolder, args: any[]): boolean {
+    const moveAccuracy = args[0] as Utils.NumberHolder;
+    if (move.category === MoveCategory.STATUS && moveAccuracy.value >= 50) {
+      moveAccuracy.value = 50;
+      return true;
+    }
+
+    return false;
+  }
+}
+
 export class MoveImmunityStatChangeAbAttr extends MoveImmunityAbAttr {
   private stat: BattleStat;
   private levels: integer;
@@ -4250,8 +4268,8 @@ export function initAbilities() {
       .attr(BlockWeatherDamageAttr, WeatherType.SANDSTORM)
       .condition(getWeatherCondition(WeatherType.SANDSTORM)),
     new Ability(Abilities.WONDER_SKIN, 5)
-      .ignorable()
+      .attr(WonderSkinAbAttr)
-      .unimplemented(),
+      .ignorable(),
     new Ability(Abilities.ANALYTIC, 5)
       .attr(MovePowerBoostAbAttr, (user, target, move) => !!target.getLastXMoves(1).find(m => m.turn === target.scene.currentBattle.turn) || user.scene.currentBattle.turnCommands[target.getBattlerIndex()].command !== Command.FIGHT, 1.3),
     new Ability(Abilities.ILLUSION, 5)

src/phases.ts

@@ -26,7 +26,7 @@ import { Gender } from "./data/gender";
 import { Weather, WeatherType, getRandomWeatherType, getTerrainBlockMessage, getWeatherDamageMessage, getWeatherLapseMessage } from "./data/weather";
 import { TempBattleStat } from "./data/temp-battle-stat";
 import { ArenaTagSide, ArenaTrapTag, MistTag, TrickRoomTag } from "./data/arena-tag";
-import { CheckTrappedAbAttr, IgnoreOpponentStatChangesAbAttr, IgnoreOpponentEvasionAbAttr, PostAttackAbAttr, PostBattleAbAttr, PostDefendAbAttr, PostSummonAbAttr, PostTurnAbAttr, PostWeatherLapseAbAttr, PreSwitchOutAbAttr, PreWeatherDamageAbAttr, ProtectStatAbAttr, RedirectMoveAbAttr, BlockRedirectAbAttr, RunSuccessAbAttr, StatChangeMultiplierAbAttr, SuppressWeatherEffectAbAttr, SyncEncounterNatureAbAttr, applyAbAttrs, applyCheckTrappedAbAttrs, applyPostAttackAbAttrs, applyPostBattleAbAttrs, applyPostDefendAbAttrs, applyPostSummonAbAttrs, applyPostTurnAbAttrs, applyPostWeatherLapseAbAttrs, applyPreStatChangeAbAttrs, applyPreSwitchOutAbAttrs, applyPreWeatherEffectAbAttrs, BattleStatMultiplierAbAttr, applyBattleStatMultiplierAbAttrs, IncrementMovePriorityAbAttr, applyPostVictoryAbAttrs, PostVictoryAbAttr, BlockNonDirectDamageAbAttr as BlockNonDirectDamageAbAttr, applyPostKnockOutAbAttrs, PostKnockOutAbAttr, PostBiomeChangeAbAttr, applyPostFaintAbAttrs, PostFaintAbAttr, IncreasePpAbAttr, PostStatChangeAbAttr, applyPostStatChangeAbAttrs, AlwaysHitAbAttr, PreventBerryUseAbAttr, StatChangeCopyAbAttr, PokemonTypeChangeAbAttr, applyPreAttackAbAttrs, applyPostMoveUsedAbAttrs, PostMoveUsedAbAttr, MaxMultiHitAbAttr, HealFromBerryUseAbAttr } from "./data/ability";
+import { CheckTrappedAbAttr, IgnoreOpponentStatChangesAbAttr, IgnoreOpponentEvasionAbAttr, PostAttackAbAttr, PostBattleAbAttr, PostDefendAbAttr, PostSummonAbAttr, PostTurnAbAttr, PostWeatherLapseAbAttr, PreSwitchOutAbAttr, PreWeatherDamageAbAttr, ProtectStatAbAttr, RedirectMoveAbAttr, BlockRedirectAbAttr, RunSuccessAbAttr, StatChangeMultiplierAbAttr, SuppressWeatherEffectAbAttr, SyncEncounterNatureAbAttr, applyAbAttrs, applyCheckTrappedAbAttrs, applyPostAttackAbAttrs, applyPostBattleAbAttrs, applyPostDefendAbAttrs, applyPostSummonAbAttrs, applyPostTurnAbAttrs, applyPostWeatherLapseAbAttrs, applyPreStatChangeAbAttrs, applyPreSwitchOutAbAttrs, applyPreWeatherEffectAbAttrs, BattleStatMultiplierAbAttr, applyBattleStatMultiplierAbAttrs, IncrementMovePriorityAbAttr, applyPostVictoryAbAttrs, PostVictoryAbAttr, BlockNonDirectDamageAbAttr as BlockNonDirectDamageAbAttr, applyPostKnockOutAbAttrs, PostKnockOutAbAttr, PostBiomeChangeAbAttr, applyPostFaintAbAttrs, PostFaintAbAttr, IncreasePpAbAttr, PostStatChangeAbAttr, applyPostStatChangeAbAttrs, AlwaysHitAbAttr, PreventBerryUseAbAttr, StatChangeCopyAbAttr, PokemonTypeChangeAbAttr, applyPreAttackAbAttrs, applyPostMoveUsedAbAttrs, PostMoveUsedAbAttr, MaxMultiHitAbAttr, HealFromBerryUseAbAttr, WonderSkinAbAttr, applyPreDefendAbAttrs } from "./data/ability";
 import { Unlockables, getUnlockableName } from "./system/unlockables";
 import { getBiomeKey } from "./field/arena";
 import { BattleType, BattlerIndex, TurnCommand } from "./battle";
@@ -3012,6 +3012,7 @@ export class MoveEffectPhase extends PokemonPhase {
     const moveAccuracy = new Utils.NumberHolder(this.move.getMove().accuracy);
 
     applyMoveAttrs(VariableAccuracyAttr, user, target, this.move.getMove(), moveAccuracy);
+    applyPreDefendAbAttrs(WonderSkinAbAttr, target, user, this.move.getMove(), { value: false }, moveAccuracy);
 
     if (moveAccuracy.value === -1) {
       return true;

src/test/abilities/wonder_skin.test.ts

@@ -0,0 +1,138 @@
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+import Phaser from "phaser";
+import GameManager from "#app/test/utils/gameManager";
+import * as overrides from "#app/overrides";
+import { Species } from "#enums/species";
+import { TurnEndPhase, } from "#app/phases";
+import { Moves } from "#enums/moves";
+import { getMovePosition } from "#app/test/utils/gameManagerUtils";
+import { Abilities } from "#enums/abilities";
+import Move, { allMoves } from "#app/data/move.js";
+import { MoveAbilityBypassAbAttr, WonderSkinAbAttr } from "#app/data/ability.js";
+import { NumberHolder } from "#app/utils.js";
+import Pokemon from "#app/field/pokemon.js";
+
+describe("Abilities - Wonder Skin", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    vi.spyOn(overrides, "SINGLE_BATTLE_OVERRIDE", "get").mockReturnValue(true);
+    vi.spyOn(overrides, "OPP_ABILITY_OVERRIDE", "get").mockReturnValue(Abilities.WONDER_SKIN);
+    vi.spyOn(overrides, "MOVESET_OVERRIDE", "get").mockReturnValue([Moves.TACKLE, Moves.CHARM]);
+    vi.spyOn(overrides, "OPP_MOVESET_OVERRIDE", "get").mockReturnValue([Moves.SPLASH, Moves.SPLASH, Moves.SPLASH, Moves.SPLASH]);
+  });
+
+  it("lowers accuracy of status moves to 50%", async () => {
+    await game.startBattle([Species.MAGIKARP]);
+
+    game.doAttack(getMovePosition(game.scene, 0, Moves.CHARM));
+
+    const appliedAccuracy = getAppliedMoveAccuracy(game.scene.getEnemyPokemon(), game.scene.getPlayerPokemon(), allMoves[Moves.CHARM]);
+
+    await game.phaseInterceptor.to(TurnEndPhase);
+
+    expect(appliedAccuracy).not.toBe(undefined);
+    expect(appliedAccuracy).not.toBe(100);
+    expect(appliedAccuracy).toBe(50);
+  });
+
+  it("does not lower accuracy of non-status moves", async () => {
+    await game.startBattle([Species.MAGIKARP]);
+
+    game.doAttack(getMovePosition(game.scene, 0, Moves.TACKLE));
+
+    const appliedAccuracy = getAppliedMoveAccuracy(game.scene.getEnemyPokemon(), game.scene.getPlayerPokemon(), allMoves[Moves.TACKLE]);
+
+    await game.phaseInterceptor.to(TurnEndPhase);
+
+    expect(appliedAccuracy).not.toBe(undefined);
+    expect(appliedAccuracy).toBe(100);
+    expect(appliedAccuracy).not.toBe(50);
+  });
+
+  it("does not affect pokemon with Mold Breaker", async () => {
+    vi.spyOn(overrides, "ABILITY_OVERRIDE", "get").mockReturnValue(Abilities.MOLD_BREAKER);
+
+    await game.startBattle([Species.MAGIKARP]);
+
+    game.doAttack(getMovePosition(game.scene, 0, Moves.CHARM));
+
+    const appliedAccuracy = getAppliedMoveAccuracy(game.scene.getEnemyPokemon(), game.scene.getPlayerPokemon(), allMoves[Moves.CHARM]);
+
+    await game.phaseInterceptor.to(TurnEndPhase);
+
+    expect(appliedAccuracy).not.toBe(undefined);
+    expect(appliedAccuracy).toBe(100);
+    expect(appliedAccuracy).not.toBe(50);
+  });
+
+  it("does not affect pokemon with Teravolt", async () => {
+    vi.spyOn(overrides, "ABILITY_OVERRIDE", "get").mockReturnValue(Abilities.TERAVOLT);
+
+    await game.startBattle([Species.MAGIKARP]);
+
+    game.doAttack(getMovePosition(game.scene, 0, Moves.CHARM));
+
+    const appliedAccuracy = getAppliedMoveAccuracy(game.scene.getEnemyPokemon(), game.scene.getPlayerPokemon(), allMoves[Moves.CHARM]);
+
+    await game.phaseInterceptor.to(TurnEndPhase);
+
+    expect(appliedAccuracy).not.toBe(undefined);
+    expect(appliedAccuracy).toBe(100);
+    expect(appliedAccuracy).not.toBe(50);
+  });
+
+  it("does not affect pokemon with Turboblaze", async () => {
+    vi.spyOn(overrides, "ABILITY_OVERRIDE", "get").mockReturnValue(Abilities.TURBOBLAZE);
+
+    await game.startBattle([Species.MAGIKARP]);
+
+    game.doAttack(getMovePosition(game.scene, 0, Moves.CHARM));
+
+    const appliedAccuracy = getAppliedMoveAccuracy(game.scene.getEnemyPokemon(), game.scene.getPlayerPokemon(), allMoves[Moves.CHARM]);
+
+    await game.phaseInterceptor.to(TurnEndPhase);
+
+    expect(appliedAccuracy).not.toBe(undefined);
+    expect(appliedAccuracy).toBe(100);
+    expect(appliedAccuracy).not.toBe(50);
+  });
+});
+
+/**
+ * Calculates the adjusted applied accuracy of a move.
+ *
+ * @param defender - The defending Pokémon.
+ * @param attacker - The attacking Pokémon.
+ * @param move - The move being used by the attacker.
+ * @returns The adjusted accuracy of the move.
+ */
+const getAppliedMoveAccuracy = (defender: Pokemon, attacker: Pokemon, move: Move) => {
+  const accuracyHolder = new NumberHolder(move.accuracy);
+
+  /**
+     * Simulate ignoring ability
+     * @see MoveAbilityBypassAbAttr
+     */
+  if (attacker.hasAbilityWithAttr(MoveAbilityBypassAbAttr)) {
+    return accuracyHolder.value;
+  }
+
+  const wonderSkinInstance = new WonderSkinAbAttr();
+
+  wonderSkinInstance.applyPreDefend(defender, false, attacker, move, { value: false }, [ accuracyHolder ]);
+
+  return accuracyHolder.value;
+};