[Bug] Fix exp gains speed not applying properly (#4243)

* update battle-info.ts

* add: ExpGainsSpeed enum

* address PR comments

* add test coverage (exp gains speed)

---------

Co-authored-by: Mr.WaterT <water.t.works@gmail.com>
Co-authored-by: NightKev <34855794+DayKev@users.noreply.github.com>

src/battle-scene.ts

@@ -105,6 +105,7 @@ import HeldModifierConfig from "#app/interfaces/held-modifier-config";
 import { ExpPhase } from "#app/phases/exp-phase";
 import { ShowPartyExpBarPhase } from "#app/phases/show-party-exp-bar-phase";
 import { MysteryEncounterMode } from "#enums/mystery-encounter-mode";
+import { ExpGainsSpeed } from "./enums/exp-gains-speed";
 
 export const bypassLogin = import.meta.env.VITE_BYPASS_LOGIN === "1";
 
@@ -180,7 +181,7 @@ export default class BattleScene extends SceneBase {
   public experimentalSprites: boolean = false;
   public musicPreference: integer = 0;
   public moveAnimations: boolean = true;
-  public expGainsSpeed: integer = 0;
+  public expGainsSpeed: ExpGainsSpeed = ExpGainsSpeed.DEFAULT;
   public skipSeenDialogues: boolean = false;
   /**
    * Determines if the egg hatching animation should be skipped

src/enums/exp-gains-speed.ts

@@ -0,0 +1,22 @@
+/**
+ * Defines the speed of gaining experience.
+ *
+ * @remarks
+ * The `expGainSpeed` can have several modes:
+ * - `0` - Default: The normal speed.
+ * - `1` - Fast: Fast speed.
+ * - `2` - Faster: Faster speed.
+ * - `3` - Skip: Skip gaining exp animation.
+ *
+ * @default 0 - Uses the default normal speed.
+ */
+export enum ExpGainsSpeed {
+  /** The normal speed. */
+  DEFAULT,
+  /** Fast speed. */
+  FAST,
+  /** Faster speed. */
+  FASTER,
+  /** Skip gaining exp animation. */
+  SKIP
+}

src/phases/show-party-exp-bar-phase.ts

@@ -1,4 +1,5 @@
 import BattleScene from "#app/battle-scene";
+import { ExpGainsSpeed } from "#app/enums/exp-gains-speed";
 import { ExpNotification } from "#app/enums/exp-notification";
 import { ExpBoosterModifier } from "#app/modifier/modifier";
 import * as Utils from "#app/utils";
@@ -44,7 +45,7 @@ export class ShowPartyExpBarPhase extends PlayerPartyMemberPokemonPhase {
       } else {
         this.end();
       }
-    } else if (this.scene.expGainsSpeed < 3) {
+    } else if (this.scene.expGainsSpeed < ExpGainsSpeed.SKIP) {
       this.scene.partyExpBar.showPokemonExp(pokemon, exp.value, false, newLevel).then(() => {
         setTimeout(() => this.end(), 500 / Math.pow(2, this.scene.expGainsSpeed));
       });

src/test/ui/battle_info.test.ts

@@ -0,0 +1,55 @@
+import { ExpGainsSpeed } from "#app/enums/exp-gains-speed";
+import { Species } from "#app/enums/species";
+import { ExpPhase } from "#app/phases/exp-phase";
+import { Abilities } from "#enums/abilities";
+import { Moves } from "#enums/moves";
+import GameManager from "#test/utils/gameManager";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("../data/exp", ({}) => {
+  return {
+    getLevelRelExp: vi.fn(() => 1), //consistent levelRelExp
+  };
+});
+
+describe("UI - Battle Info", () => {
+  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.GUILLOTINE, Moves.SPLASH])
+      .battleType("single")
+      .enemyAbility(Abilities.BALL_FETCH)
+      .enemyMoveset(Moves.SPLASH)
+      .enemySpecies(Species.CATERPIE);
+  });
+
+  it.each([ExpGainsSpeed.FAST, ExpGainsSpeed.FASTER, ExpGainsSpeed.SKIP])(
+    "should increase exp gains animation by 2^%i",
+    async (expGainsSpeed) => {
+      game.settings.expGainsSpeed(expGainsSpeed);
+      vi.spyOn(Math, "pow");
+
+      await game.classicMode.startBattle([Species.CHARIZARD]);
+
+      game.move.select(Moves.SPLASH);
+      await game.doKillOpponents();
+      await game.phaseInterceptor.to(ExpPhase, true);
+
+      expect(Math.pow).not.toHaveBeenCalledWith(2, expGainsSpeed);
+    }
+  );
+});

src/test/utils/gameManager.ts

@@ -54,6 +54,7 @@ import { MysteryEncounterPhase } from "#app/phases/mystery-encounter-phases";
 import { expect } from "vitest";
 import { MysteryEncounterType } from "#enums/mystery-encounter-type";
 import { isNullOrUndefined } from "#app/utils";
+import { ExpGainsSpeed } from "#app/enums/exp-gains-speed";
 
 /**
  * Class to manage the game state and transitions between phases.
@@ -148,7 +149,7 @@ export default class GameManager {
     this.scene.gameSpeed = 5;
     this.scene.moveAnimations = false;
     this.scene.showLevelUpStats = false;
-    this.scene.expGainsSpeed = 3;
+    this.scene.expGainsSpeed = ExpGainsSpeed.SKIP;
     this.scene.expParty = ExpNotification.SKIP;
     this.scene.hpBarSpeed = 3;
     this.scene.enableTutorials = false;

src/test/utils/helpers/settingsHelper.ts

@@ -1,6 +1,7 @@
 import { PlayerGender } from "#app/enums/player-gender";
 import { BattleStyle } from "#app/enums/battle-style";
 import { GameManagerHelper } from "./gameManagerHelper";
+import { ExpGainsSpeed } from "#app/enums/exp-gains-speed";
 
 /**
  * Helper to handle settings for tests
@@ -38,6 +39,15 @@ export class SettingsHelper extends GameManagerHelper {
     this.log(`Gender set to: ${PlayerGender[gender]} (=${gender})` );
   }
 
+  /**
+   * Change the exp gains speed
+   * @param speed the {@linkcode ExpGainsSpeed} to set
+   */
+  expGainsSpeed(speed: ExpGainsSpeed) {
+    this.game.scene.expGainsSpeed = speed;
+    this.log(`Exp Gains Speed set to: ${ExpGainsSpeed[speed]} (=${speed})` );
+  }
+
   private log(...params: any[]) {
     console.log("Settings:", ...params);
   }

src/test/utils/phaseInterceptor.ts

@@ -60,6 +60,7 @@ export interface PromptHandler {
   expireFn?: () => void;
   awaitingActionInput?: boolean;
 }
+import { ExpPhase } from "#app/phases/exp-phase";
 
 export default class PhaseInterceptor {
   public scene;
@@ -127,7 +128,8 @@ export default class PhaseInterceptor {
     [MysteryEncounterRewardsPhase, this.startPhase],
     [PostMysteryEncounterPhase, this.startPhase],
     [ModifierRewardPhase, this.startPhase],
-    [PartyExpPhase, this.startPhase]
+    [PartyExpPhase, this.startPhase],
+    [ExpPhase, this.startPhase],
   ];
 
   private endBySetMode = [

src/ui/battle-info.ts

@@ -11,8 +11,11 @@ import { Stat } from "#enums/stat";
 import BattleFlyout from "./battle-flyout";
 import { WindowVariant, addWindow } from "./ui-theme";
 import i18next from "i18next";
+import { ExpGainsSpeed } from "#app/enums/exp-gains-speed";
 
 export default class BattleInfo extends Phaser.GameObjects.Container {
+  public static readonly EXP_GAINS_DURATION_BASE = 1650;
+
   private baseY: number;
 
   private player: boolean;
@@ -702,7 +705,11 @@ export default class BattleInfo extends Phaser.GameObjects.Container {
         instant = true;
       }
       const durationMultiplier = Phaser.Tweens.Builders.GetEaseFunction("Sine.easeIn")(1 - (Math.max(this.lastLevel - 100, 0) / 150));
-      const duration = this.visible && !instant ? (((levelExp - this.lastLevelExp) / relLevelExp) * 1650) * durationMultiplier * levelDurationMultiplier : 0;
+      let duration = this.visible && !instant ? (((levelExp - this.lastLevelExp) / relLevelExp) * BattleInfo.EXP_GAINS_DURATION_BASE) * durationMultiplier * levelDurationMultiplier : 0;
+      const speed = (this.scene as BattleScene).expGainsSpeed;
+      if (speed && speed >= ExpGainsSpeed.DEFAULT) {
+        duration = speed >= ExpGainsSpeed.SKIP ? ExpGainsSpeed.DEFAULT : duration / Math.pow(2, speed);
+      }
       if (ratio === 1) {
         this.lastLevelExp = 0;
         this.lastLevel++;