Creates metronome test, refactors RandomMoveAttr for easier testing

src/data/move.ts

@@ -5476,8 +5476,12 @@ export class RandomMoveAttr extends CallMoveAttr {
    * Invalid moves are indicated by what is passed in to invalidMoves: @constant {invalidMetronomeMoves}
    */
   apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): Promise<boolean> {
-    const moveIds = Utils.getEnumValues(Moves).filter(m => !this.invalidMoves.includes(m) && !allMoves[m].name.endsWith(" (N)"));
-    const moveId = moveIds[user.randSeedInt(moveIds.length)];
+    const moveIds = Utils.getEnumValues(Moves).map(m => !this.invalidMoves.includes(m) && !allMoves[m].name.endsWith(" (N)") ? m : Moves.NONE);
+    let moveId: Moves = Moves.NONE;
+    do {
+      moveId = moveIds[user.randSeedInt(moveIds.length)];
+    }
+    while (moveId === Moves.NONE);
     return super.apply(user, target, allMoves[moveId], args);
   }
 }

src/test/moves/metronome.test.ts

@@ -0,0 +1,65 @@
+import { SemiInvulnerableTag } from "#app/data/battler-tags";
+import { Abilities } from "#app/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, it, expect, vi } from "vitest";
+
+describe("Moves - Metronome", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override
+      .moveset([Moves.METRONOME])
+      .battleType("single")
+      .startingLevel(100)
+      .enemyLevel(100)
+      .enemySpecies(Species.SHUCKLE)
+      .enemyMoveset(Moves.SPLASH)
+      .enemyAbility(Abilities.BALL_FETCH);
+  });
+
+  it("should have one semi-invulnerable turn and deal damage on the second turn when a semi-invulnerable move is called", async () => {
+    await game.classicMode.startBattle([Species.REGIELEKI]);
+    const player = game.scene.getPlayerPokemon()!;
+    const enemy = game.scene.getEnemyPokemon()!;
+    vi.spyOn(player, "randSeedInt").mockReturnValue(Moves.DIVE);
+
+    game.move.select(Moves.METRONOME);
+    await game.toNextTurn();
+
+    expect(player.getTag(SemiInvulnerableTag)).toBeTruthy();
+    await game.move.forceHit(); // Force hit on Dive, required due to randSeedInt mock making hitCheck return false every time.
+
+    await game.toNextTurn();
+    expect(player.getTag(SemiInvulnerableTag)).toBeFalsy();
+    expect(enemy.isFullHp()).toBeFalsy();
+  });
+
+  // FAILS UNTIL KEV'S MOVE PHASE REFACTOR IS PUT IN
+  // it("should apply secondary effects of a move", async () => {
+  //   await game.classicMode.startBattle([Species.REGIELEKI]);
+  //   const player = game.scene.getPlayerPokemon()!;
+  //   vi.spyOn(player, "randSeedInt").mockReturnValue(Moves.WOOD_HAMMER);
+
+  //   game.move.select(Moves.METRONOME);
+  //   await game.phaseInterceptor.to("MoveEffectPhase"); // Metronome has its own MoveEffectPhase, followed by Wood Hammer's MoveEffectPhase
+  //   await game.move.forceHit(); // Calls forceHit on Wood Hammer's MoveEffectPhase, required due to randSeedInt mock making hitCheck return false every time.
+  //   await game.toNextTurn();
+
+  //   expect(player.isFullHp()).toBeFalsy();
+  // });
+});