Corrects mirror move implementation, rewrite unit test to adjust

src/battle.ts

@@ -88,8 +88,6 @@ export default class Battle {
   public enemyFaints: number = 0;
   public playerFaintsHistory: FaintLogEntry[] = [];
   public enemyFaintsHistory: FaintLogEntry[] = [];
-  /** The list of moves used since the beginning of the battle */
-  public moveHistory: TurnMove[] = [];
 
 
   public mysteryEncounterType?: MysteryEncounterType;

src/data/move.ts

@@ -5973,6 +5973,7 @@ export class FirstMoveTypeAttr extends MoveEffectAttr {
 
 export class CallMoveAttr extends OverrideMoveEffectAttr {
   protected invalidMoves: Moves[];
+  protected hasTarget: boolean;
   async apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): Promise<boolean> {
     const replaceMoveTarget = move.moveTarget === MoveTarget.NEAR_OTHER ? MoveTarget.NEAR_ENEMY : undefined;
     const moveTargets = getMoveTargets(user, move.id, replaceMoveTarget);
@@ -5981,7 +5982,7 @@ export class CallMoveAttr extends OverrideMoveEffectAttr {
     }
     const targets = moveTargets.multiple || moveTargets.targets.length === 1
       ? moveTargets.targets
-      : [ moveTargets.targets[user.randSeedInt(moveTargets.targets.length)] ];
+      : [ this.hasTarget ? target.getBattlerIndex() : moveTargets.targets[user.randSeedInt(moveTargets.targets.length)] ]; // account for Mirror Move having a target already
     user.getMoveQueue().push({ move: move.id, targets: targets, virtual: true, ignorePP: true });
     user.scene.unshiftPhase(new MovePhase(user.scene, user, targets, new PokemonMove(move.id, 0, 0, true), true, true));
 
@@ -6502,25 +6503,19 @@ export class CopyMoveAttr extends CallMoveAttr {
   }
 
   apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): Promise<boolean> {
-    if (this.mirrorMove) {
-      const lastMove = user.scene.currentBattle.moveHistory.filter(m => m.targets.includes(user.getBattlerIndex()))[0].move;
-      return super.apply(user, target, allMoves[lastMove], args);
-    } else {
-      return super.apply(user, target, allMoves[user.scene.currentBattle.lastMove], args);
-    }
+    this.hasTarget = this.mirrorMove;
+    const lastMove = this.mirrorMove ? target.getLastXMoves()[0].move : user.scene.currentBattle.lastMove;
+    return super.apply(user, target, allMoves[lastMove], args);
   }
 
   getCondition(): MoveConditionFunc {
     return (user, target, move) => {
       if (this.mirrorMove) {
-        if (user.scene.currentBattle.moveHistory.filter(m => m.targets.includes(user.getBattlerIndex())).length === 0) {
-          return false;
-        }
-      } else if (user.scene.currentBattle.lastMove === undefined) {
-        return false;
+        return target.getMoveHistory().length !== 0;
+      } else {
+        const lastMove = user.scene.currentBattle.lastMove;
+        return lastMove !== undefined && !this.invalidMoves.includes(lastMove);
       }
-      const lastMove = this.mirrorMove ? user.turnData.attacksReceived[0]?.move : user.scene.currentBattle.lastMove;
-      return !this.invalidMoves.includes(lastMove);
     };
   }
 }
@@ -7906,7 +7901,7 @@ export function initMoves() {
       .unimplemented(),
     new SelfStatusMove(Moves.METRONOME, Type.NORMAL, -1, 10, -1, 0, 1)
       .attr(RandomMoveAttr, invalidMetronomeMoves),
-    new SelfStatusMove(Moves.MIRROR_MOVE, Type.FLYING, -1, 20, -1, 0, 1)
+    new StatusMove(Moves.MIRROR_MOVE, Type.FLYING, -1, 20, -1, 0, 1)
       .attr(CopyMoveAttr, true),
     new AttackMove(Moves.SELF_DESTRUCT, Type.NORMAL, MoveCategory.PHYSICAL, 200, 100, 5, -1, 0, 1)
       .attr(SacrificialAttr)

src/phases/move-phase.ts

@@ -274,10 +274,6 @@ export class MovePhase extends BattlePhase {
       // The last move used is unaffected by moves that fail
       if (success) {
         this.scene.currentBattle.lastMove = this.move.moveId;
-        this.scene.currentBattle.moveHistory.unshift({
-          move: this.move.moveId,
-          targets: this.targets
-        });
       }
     }
 

src/test/moves/mirror_move.test.ts

@@ -34,15 +34,20 @@ describe("Moves - Mirror Move", () => {
       .enemyMoveset(Moves.SPLASH);
   });
 
-  it("should use the last move targeted at the user", async () => {
-    game.override.enemyMoveset(Moves.TACKLE);
-    await game.classicMode.startBattle([ Species.FEEBAS ]);
+  it("should use the last move that the target", async () => {
+    game.override
+      .battleType("double")
+      .enemyMoveset([ Moves.TACKLE, Moves.GROWL ]);
+    await game.classicMode.startBattle([ Species.FEEBAS, Species.MAGIKARP ]);
 
-    game.move.select(Moves.MIRROR_MOVE);
-    await game.setTurnOrder([ BattlerIndex.ENEMY, BattlerIndex.PLAYER ]);
+    game.move.select(Moves.MIRROR_MOVE, 0, BattlerIndex.ENEMY); // target's last move is Tackle, enemy should receive damage from Mirror Move copying Tackle
+    game.move.select(Moves.SPLASH, 1);
+    await game.forceEnemyMove(Moves.TACKLE, BattlerIndex.PLAYER_2);
+    await game.forceEnemyMove(Moves.GROWL, BattlerIndex.PLAYER_2);
+    await game.setTurnOrder([ BattlerIndex.ENEMY, BattlerIndex.ENEMY_2, BattlerIndex.PLAYER_2, BattlerIndex.PLAYER ]);
     await game.toNextTurn();
 
-    expect(game.scene.getEnemyPokemon()!.isFullHp()).toBeFalsy();
+    expect(game.scene.getEnemyField()[0].isFullHp()).toBeFalsy();
   });
 
   it("should apply secondary effects of a move", async () => {
@@ -56,24 +61,7 @@ describe("Moves - Mirror Move", () => {
     expect(game.scene.getEnemyPokemon()!.getStatStage(Stat.SPDEF)).toBe(-2);
   });
 
-  it("should fail if the user has never been targeted", { repeats: 10 }, async () => {
-    game.override
-      .battleType("double")
-      .startingLevel(100)
-      .enemyMoveset([ Moves.TACKLE, Moves.SPLASH ]);
-    await game.classicMode.startBattle([ Species.FEEBAS, Species.MAGIKARP ]);
-
-    game.move.select(Moves.MIRROR_MOVE);
-    game.move.select(Moves.SPLASH, 1);
-    await game.forceEnemyMove(Moves.TACKLE, BattlerIndex.PLAYER_2);
-    await game.forceEnemyMove(Moves.SPLASH);
-    await game.setTurnOrder([ BattlerIndex.ENEMY, BattlerIndex.ENEMY_2, BattlerIndex.PLAYER_2, BattlerIndex.PLAYER ]);
-    await game.toNextTurn();
-
-    expect(game.scene.getPlayerField()![0].getLastXMoves()[0].result).toBe(MoveResult.FAIL);
-  });
-
-  it("should copy status moves that target the user", async () => {
+  it("should be able to copy status moves", async () => {
     game.override.enemyMoveset(Moves.GROWL);
     await game.classicMode.startBattle([ Species.FEEBAS ]);
 
@@ -83,4 +71,14 @@ describe("Moves - Mirror Move", () => {
 
     expect(game.scene.getEnemyPokemon()!.getStatStage(Stat.ATK)).toBe(-1);
   });
+
+  it("should fail if the target has not used any moves", async () => {
+    await game.classicMode.startBattle([ Species.FEEBAS ]);
+
+    game.move.select(Moves.MIRROR_MOVE);
+    await game.setTurnOrder([ BattlerIndex.PLAYER, BattlerIndex.ENEMY ]);
+    await game.toNextTurn();
+
+    expect(game.scene.getPlayerPokemon()!.getLastXMoves()[0].result).toBe(MoveResult.FAIL);
+  });
 });