Applied review comments, cleaned up code a bit

src/battle-scene.ts

@@ -874,8 +874,8 @@ export default class BattleScene extends SceneBase {
   /**
    * Returns an array of Pokemon on both sides of the battle - player first, then enemy.
    * Does not actually check if the pokemon are on the field or not, and always has length 4 regardless of battle type.
-   * @param activeOnly Whether to consider only active pokemon
+   * @param activeOnly - Whether to consider only active pokemon; default `false`
-   * @returns array of {@linkcode Pokemon}
+   * @returns An array of {@linkcode Pokemon}, as described above.
    */
   public getField(activeOnly = false): Pokemon[] {
     const ret = new Array(4).fill(null);

src/data/abilities/ab-attrs/ab-attr.ts

@@ -6,6 +6,10 @@ export abstract class AbAttr {
   public showAbility: boolean;
   private extraCondition: AbAttrCondition;
 
+  /**
+   * @param showAbility - Whether to show this ability as a flyout during battle; default `true`.
+   * Should be kept in parity with mainline where possible.
+   */
   constructor(showAbility = true) {
     this.showAbility = showAbility;
   }

src/data/abilities/ability.ts

@@ -4045,7 +4045,13 @@ export class PostTurnResetStatusAbAttr extends PostTurnAbAttr {
  */
 export class PostTurnRestoreBerryAbAttr extends PostTurnAbAttr {
   /**
-   * @param procChance - Chance to create an item
+   * Array containing all {@linkcode BerryType | BerryTypes} that are under cap and able to be restored.
+   * Stored inside the class for a minor performance boost
+   */
+  private berriesUnderCap: BerryType[]
+
+  /**
+   * @param procChance - function providing chance to restore an item
    * @see {@linkcode createEatenBerry()}
    */
   constructor(
@@ -4054,19 +4060,19 @@ export class PostTurnRestoreBerryAbAttr extends PostTurnAbAttr {
     super();
   }
 
-  override canApplyPostTurn(pokemon: Pokemon, passive: boolean, simulated: boolean, args: any[]): boolean {
+  override canApplyPostTurn(pokemon: Pokemon, _passive: boolean, _simulated: boolean, _args: any[]): boolean {
-    // check if we have at least 1 recoverable berry (at least 1 berry in berriesEaten is not capped)
+    // Ensure we have at least 1 recoverable berry (at least 1 berry in berriesEaten is not capped)
     const cappedBerries = new Set(
       globalScene.getModifiers(BerryModifier, pokemon.isPlayer()).filter(
-        (bm) => bm.pokemonId === pokemon.id && bm.getCountUnderMax() < 1
+        bm => bm.pokemonId === pokemon.id && bm.getCountUnderMax() < 1
       ).map(bm => bm.berryType)
     );
 
-    const hasBerryUnderCap = pokemon.battleData.berriesEaten.some(
+    this.berriesUnderCap = pokemon.battleData.berriesEaten.filter(
-      (bt) => !cappedBerries.has(bt)
+      bt => !cappedBerries.has(bt)
     );
 
-    if (!hasBerryUnderCap) {
+    if (!this.berriesUnderCap.length) {
       return false;
     }
 
@@ -4076,41 +4082,22 @@ export class PostTurnRestoreBerryAbAttr extends PostTurnAbAttr {
   }
 
   override applyPostTurn(pokemon: Pokemon, passive: boolean, simulated: boolean, args: any[]): void {
-    this.createEatenBerry(pokemon, simulated);
+    if (!simulated) {
+      this.createEatenBerry(pokemon);
+    }
   }
 
   /**
-   * Create a new berry chosen randomly from the berries the pokemon ate this battle
+   * Create a new berry chosen randomly from all berries the pokemon ate this battle
-   * @param pokemon The pokemon with this ability
+   * @param pokemon - The {@linkcode Pokemon} with this ability
-   * @param simulated whether the associated ability call is simulated
    * @returns `true` if a new berry was created
    */
-  createEatenBerry(pokemon: Pokemon, simulated: boolean): boolean {
+  createEatenBerry(pokemon: Pokemon): boolean {
-    // get all berries we just ate that are under cap
+    // Pick a random available berry to yoink
-    const cappedBerries = new Set(
+    const randomIdx = randSeedInt(this.berriesUnderCap.length);
-      globalScene.getModifiers(BerryModifier, pokemon.isPlayer()).filter(
+    const chosenBerryType = this.berriesUnderCap[randomIdx];
-        (bm) => bm.pokemonId === pokemon.id && bm.getCountUnderMax() < 1
-      ).map((bm) => bm.berryType)
-    );
-
-    const berriesEaten = pokemon.battleData.berriesEaten.filter(
-      (bt) => !cappedBerries.has(bt)
-    );
-
-    if (!berriesEaten.length) {
-      return false;
-    }
-
-    if (simulated) {
-      return true;
-    }
-
-    // Pick a random berry to yoink
-    const randomIdx = randSeedInt(berriesEaten.length);
-    const chosenBerryType = berriesEaten[randomIdx];
     pokemon.battleData.berriesEaten.splice(randomIdx, 1); // Remove berry from memory
     const chosenBerry = new BerryModifierType(chosenBerryType);
-    chosenBerry.id = "BERRY" // needed to prevent item deletion; remove after modifier rework
 
     // Add the randomly chosen berry or update the existing one
     const berryModifier = globalScene.findModifier(
@@ -4121,7 +4108,6 @@ export class PostTurnRestoreBerryAbAttr extends PostTurnAbAttr {
     if (berryModifier) {
       berryModifier.stackCount++
     } else {
-      // make new modifier
       const newBerry = new BerryModifier(chosenBerry, pokemon.id, chosenBerryType, 1);
       if (pokemon.isPlayer()) {
         globalScene.addModifier(newBerry);
@@ -4141,19 +4127,19 @@ export class PostTurnRestoreBerryAbAttr extends PostTurnAbAttr {
   * Used by {@linkcode Abilities.CUD_CHEW}.
 */
 export class RepeatBerryNextTurnAbAttr extends PostTurnAbAttr {
-  // no need for constructor; all it does is set `showAbility` which we override before triggering anyways
-
   /**
    * @returns `true` if the pokemon ate anything last turn
    */
   override canApply(pokemon: Pokemon, _passive: boolean, _simulated: boolean, _args: any[]): boolean {
-    this.showAbility = true; // force ability popup if ability triggers
+    // force ability popup for ability triggers on normal turns.
+    // Still not used if ability doesn't proc
+    this.showAbility = true;
     return !!pokemon.summonData.berriesEatenLast.length;
   }
 
   /**
-   * Cause this {@linkcode Pokemon} to regurgitate and eat all berries
+   * Cause this {@linkcode Pokemon} to regurgitate and eat all berries inside its `berriesEatenLast` array.
-   * inside its `berriesEatenLast` array.
+   * Triggers a berry use animation, but does *not* count for other berry or item-related abilities.
    * @param pokemon - The {@linkcode Pokemon} having a bad tummy ache
    * @param _passive - N/A
    * @param _simulated - N/A
@@ -4161,13 +4147,12 @@ export class RepeatBerryNextTurnAbAttr extends PostTurnAbAttr {
    * @param _args - N/A
    */
   override apply(pokemon: Pokemon, _passive: boolean, _simulated: boolean, _cancelled: BooleanHolder | null, _args: any[]): void {
-    // play berry animation
     globalScene.unshiftPhase(
       new CommonAnimPhase(pokemon.getBattlerIndex(), pokemon.getBattlerIndex(), CommonAnim.USE_ITEM),
     );
 
     // Re-apply effects of all berries previously scarfed.
-    // This technically doesn't count as "eating" a berry (for unnerve/stuff cheeks/unburden)
+    // This doesn't count as "eating" a berry (for unnerve/stuff cheeks/unburden) as no item is consumed.
     for (const berryType of pokemon.summonData.berriesEatenLast) {
       getBerryEffectFunc(berryType)(pokemon);
       const bMod = new BerryModifier(new BerryModifierType(berryType), pokemon.id, berryType, 1);
@@ -4179,7 +4164,7 @@ export class RepeatBerryNextTurnAbAttr extends PostTurnAbAttr {
   }
 
   /**
-   * @returns always `true`
+   * @returns always `true` as we always want to move berries into summon data
    */
   override canApplyPostTurn(pokemon: Pokemon, _passive: boolean, _simulated: boolean, _args: any[]): boolean {
     this.showAbility = false; // don't show popup for turn end berry moving (should ideally be hidden)
@@ -4188,11 +4173,12 @@ export class RepeatBerryNextTurnAbAttr extends PostTurnAbAttr {
 
   /**
    * Move this {@linkcode Pokemon}'s `berriesEaten` array from `PokemonTurnData`
-   * into `PokemonSummonData`.
+   * into `PokemonSummonData` on turn end.
-   * @param pokemon The {@linkcode Pokemon} having a nice snack
+   * Both arrays are cleared on switch.
-   * @param _passive N/A
+   * @param pokemon - The {@linkcode Pokemon} having a nice snack
-   * @param _simulated N/A
+   * @param _passive - N/A
-   * @param _args N/A
+   * @param _simulated - N/A
+   * @param _args - N/A
    */
   override applyPostTurn(pokemon: Pokemon, _passive: boolean, _simulated: boolean, _args: any[]): void {
     pokemon.summonData.berriesEatenLast = pokemon.turnData.berriesEaten;
@@ -4565,8 +4551,19 @@ export class DoubleBerryEffectAbAttr extends AbAttr {
   }
 }
 
+/**
+ * Attribute to prevent opposing berry use while on the field.
+ * Used by {@linkcode Abilities.UNNERVE}, {@linkcode Abilities.AS_ONE_GLASTRIER} and {@linkcode Abilities.AS_ONE_SPECTRIER}
+ */
 export class PreventBerryUseAbAttr extends AbAttr {
-  override apply(pokemon: Pokemon, passive: boolean, simulated: boolean, cancelled: BooleanHolder, args: any[]): void {
+  /**
+   * Prevent use of opposing berries.
+   * @param _pokemon - Unused
+   * @param _passive - Unused
+   * @param _simulated - Unused
+   * @param cancelled - {@linkcode BooleanHolder} containing whether to block berry use
+   */
+  override apply(_pokemon: Pokemon, _passive: boolean, _simulated: boolean, cancelled: BooleanHolder): void {
     cancelled.value = true;
   }
 }
@@ -5156,7 +5153,7 @@ export class PostSummonStatStageChangeOnArenaAbAttr extends PostSummonStatStageC
 /**
  * Takes no damage from the first hit of a damaging move.
  * This is used in the Disguise and Ice Face abilities.
- * 
+ *
  * Does not apply to a user's substitute
  * @extends ReceivedMoveDamageMultiplierAbAttr
  */

src/data/battle-anims.ts

@@ -1132,7 +1132,7 @@ export abstract class BattleAnim {
                 if (priority === 0) {
                   // Place the sprite in front of the pokemon on the field.
                   targetSprite = globalScene.getEnemyField().find(p => p) ?? globalScene.getPlayerField().find(p => p);
-                  console.log(typeof targetSprite);
+                  // console.log(typeof targetSprite);
                   moveFunc = globalScene.field.moveBelow;
                 } else if (priority === 2 && this.bgSprite) {
                   moveFunc = globalScene.field.moveAbove;

src/data/moves/move.ts

@@ -2535,10 +2535,10 @@ export class PsychoShiftEffectAttr extends MoveEffectAttr {
     return !target.status && target.canSetStatus(user.status?.effect, true, false, user) ? -10 : 0;
   }
 }
+
 /**
- * The following needs to be implemented for Thief
+ * Attribute to steal items upon this move's use.
- * "If the user faints due to the target's Ability (Rough Skin or Iron Barbs) or held Rocky Helmet, it cannot remove the target's held item."
+ * Used for {@linkcode Moves.THIEF} and {@linkcode Moves.COVET}.
- * "If Knock Off causes a Pokémon with the Sticky Hold Ability to faint, it can now remove that Pokémon's held item."
  */
 export class StealHeldItemChanceAttr extends MoveEffectAttr {
   private chance: number;
@@ -2553,18 +2553,22 @@ export class StealHeldItemChanceAttr extends MoveEffectAttr {
     if (rand > this.chance) {
       return false;
     }
+
     const heldItems = this.getTargetHeldItems(target).filter((i) => i.isTransferable);
-    if (heldItems.length) {
+    if (!heldItems.length) {
-      const poolType = target.isPlayer() ? ModifierPoolType.PLAYER : target.hasTrainer() ? ModifierPoolType.TRAINER : ModifierPoolType.WILD;
+      return false;
-      const highestItemTier = heldItems.map((m) => m.type.getOrInferTier(poolType)).reduce((highestTier, tier) => Math.max(tier!, highestTier), 0); // TODO: is the bang after tier correct?
-      const tierHeldItems = heldItems.filter((m) => m.type.getOrInferTier(poolType) === highestItemTier);
-      const stolenItem = tierHeldItems[user.randSeedInt(tierHeldItems.length)];
-      if (globalScene.tryTransferHeldItemModifier(stolenItem, user, false)) {
-        globalScene.queueMessage(i18next.t("moveTriggers:stoleItem", { pokemonName: getPokemonNameWithAffix(user), targetName: getPokemonNameWithAffix(target), itemName: stolenItem.type.name }));
-        return true;
-      }
     }
-    return false;
+
+    const poolType = target.isPlayer() ? ModifierPoolType.PLAYER : target.hasTrainer() ? ModifierPoolType.TRAINER : ModifierPoolType.WILD;
+    const highestItemTier = heldItems.map((m) => m.type.getOrInferTier(poolType)).reduce((highestTier, tier) => Math.max(tier!, highestTier), 0); // TODO: is the bang after tier correct?
+    const tierHeldItems = heldItems.filter((m) => m.type.getOrInferTier(poolType) === highestItemTier);
+    const stolenItem = tierHeldItems[user.randSeedInt(tierHeldItems.length)];
+    if (!globalScene.tryTransferHeldItemModifier(stolenItem, user, false)) {
+      return false;
+    }
+
+    globalScene.queueMessage(i18next.t("moveTriggers:stoleItem", { pokemonName: getPokemonNameWithAffix(user), targetName: getPokemonNameWithAffix(target), itemName: stolenItem.type.name }));
+    return true;
   }
 
   getTargetHeldItems(target: Pokemon): PokemonHeldItemModifier[] {
@@ -2588,58 +2592,62 @@ export class StealHeldItemChanceAttr extends MoveEffectAttr {
  * Used for Incinerate and Knock Off.
  * Not Implemented Cases: (Same applies for Thief)
  * "If the user faints due to the target's Ability (Rough Skin or Iron Barbs) or held Rocky Helmet, it cannot remove the target's held item."
- * "If Knock Off causes a Pokémon with the Sticky Hold Ability to faint, it can now remove that Pokémon's held item."
+ * "If the Pokémon is knocked out by the attack, Sticky Hold does not protect the held item.""
  */
 export class RemoveHeldItemAttr extends MoveEffectAttr {
 
-  /** Optional restriction for item pool to berries only i.e. Differentiating Incinerate and Knock Off */
+  /** Optional restriction for item pool to berries only; i.e. Incinerate */
   private berriesOnly: boolean;
 
-  constructor(berriesOnly: boolean) {
+  constructor(berriesOnly: boolean = false) {
     super(false);
     this.berriesOnly = berriesOnly;
   }
 
   /**
-   *
+   * Attempt to permanently remove a held
-   * @param user {@linkcode Pokemon} that used the move
+   * @param user - The {@linkcode Pokemon} that used the move
-   * @param target Target {@linkcode Pokemon} that the moves applies to
+   * @param target - The {@linkcode Pokemon} targeted by the move
-   * @param move {@linkcode Move} that is used
+   * @param move - N/A
    * @param args N/A
-   * @returns True if an item was removed
+   * @returns `true` if an item was able to be removed
    */
   apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): boolean {
     if (!this.berriesOnly && target.isPlayer()) { // "Wild Pokemon cannot knock off Player Pokemon's held items" (See Bulbapedia)
       return false;
     }
 
+    // Check for abilities that block item theft
+    // TODO: This should not trigger if the target would faint beforehand
     const cancelled = new BooleanHolder(false);
-    applyAbAttrs(BlockItemTheftAbAttr, target, cancelled); // Check for abilities that block item theft
+    applyAbAttrs(BlockItemTheftAbAttr, target, cancelled);
 
-    if (cancelled.value === true) {
+    if (cancelled.value) {
       return false;
     }
 
-    // Considers entire transferrable item pool by default (Knock Off). Otherwise berries only if specified (Incinerate).
+    // Considers entire transferrable item pool by default (Knock Off).
+    // Otherwise only consider berries (Incinerate).
     let heldItems = this.getTargetHeldItems(target).filter(i => i.isTransferable);
 
     if (this.berriesOnly) {
       heldItems = heldItems.filter(m => m instanceof BerryModifier && m.pokemonId === target.id, target.isPlayer());
     }
 
-    if (heldItems.length) {
+    if (!heldItems.length) {
-      const removedItem = heldItems[user.randSeedInt(heldItems.length)];
+      return false;
+    }
 
-      // Decrease item amount and update icon
+    const removedItem = heldItems[user.randSeedInt(heldItems.length)];
-      target.loseHeldItem(removedItem);
-      globalScene.updateModifiers(target.isPlayer());
 
+    // Decrease item amount and update icon
+    target.loseHeldItem(removedItem);
+    globalScene.updateModifiers(target.isPlayer());
 
-      if (this.berriesOnly) {
+    if (this.berriesOnly) {
-        globalScene.queueMessage(i18next.t("moveTriggers:incineratedItem", { pokemonName: getPokemonNameWithAffix(user), targetName: getPokemonNameWithAffix(target), itemName: removedItem.type.name }));
+      globalScene.queueMessage(i18next.t("moveTriggers:incineratedItem", { pokemonName: getPokemonNameWithAffix(user), targetName: getPokemonNameWithAffix(target), itemName: removedItem.type.name }));
-      } else {
+    } else {
-        globalScene.queueMessage(i18next.t("moveTriggers:knockedOffItem", { pokemonName: getPokemonNameWithAffix(user), targetName: getPokemonNameWithAffix(target), itemName: removedItem.type.name }));
+      globalScene.queueMessage(i18next.t("moveTriggers:knockedOffItem", { pokemonName: getPokemonNameWithAffix(user), targetName: getPokemonNameWithAffix(target), itemName: removedItem.type.name }));
-      }
     }
 
     return true;
@@ -6349,11 +6357,11 @@ export class ForceSwitchOutAttr extends MoveEffectAttr {
 
       if (!allyPokemon?.isActive(true) && switchOutTarget.hp) {
           globalScene.pushPhase(new BattleEndPhase(false));
-                    
+
           if (globalScene.gameMode.hasRandomBiomes || globalScene.isNewBiome()) {
             globalScene.pushPhase(new SelectBiomePhase());
           }
-          
+
           globalScene.pushPhase(new NewBattlePhase());
       }
     }
@@ -8711,7 +8719,10 @@ export function initMoves() {
       .attr(MultiHitPowerIncrementAttr, 3)
       .checkAllHits(),
     new AttackMove(Moves.THIEF, PokemonType.DARK, MoveCategory.PHYSICAL, 60, 100, 25, -1, 0, 2)
-      .attr(StealHeldItemChanceAttr, 0.3),
+      .attr(StealHeldItemChanceAttr, 0.3)
+      .edgeCase(),
+      // Should not be able to steal held item if user faints due to Rough Skin, Iron Barbs, etc.
+      // Should be able to steal items from pokemon with Sticky Hold if the damage causes them to faint
     new StatusMove(Moves.SPIDER_WEB, PokemonType.BUG, -1, 10, -1, 0, 2)
       .condition(failIfGhostTypeCondition)
       .attr(AddBattlerTagAttr, BattlerTagType.TRAPPED, false, true, 1)
@@ -9098,7 +9109,10 @@ export function initMoves() {
       .reflectable(),
     new AttackMove(Moves.KNOCK_OFF, PokemonType.DARK, MoveCategory.PHYSICAL, 65, 100, 20, -1, 0, 3)
       .attr(MovePowerMultiplierAttr, (user, target, move) => target.getHeldItems().filter(i => i.isTransferable).length > 0 ? 1.5 : 1)
-      .attr(RemoveHeldItemAttr, false),
+      .attr(RemoveHeldItemAttr, false)
+      .edgeCase(),
+      // Should not be able to remove held item if user faints due to Rough Skin, Iron Barbs, etc.
+      // Should be able to remove items from pokemon with Sticky Hold if the damage causes them to faint
     new AttackMove(Moves.ENDEAVOR, PokemonType.NORMAL, MoveCategory.PHYSICAL, -1, 100, 5, -1, 0, 3)
       .attr(MatchHpAttr)
       .condition(failOnBossCondition),
@@ -9286,7 +9300,10 @@ export function initMoves() {
       .attr(HighCritAttr)
       .attr(StatusEffectAttr, StatusEffect.POISON),
     new AttackMove(Moves.COVET, PokemonType.NORMAL, MoveCategory.PHYSICAL, 60, 100, 25, -1, 0, 3)
-      .attr(StealHeldItemChanceAttr, 0.3),
+      .attr(StealHeldItemChanceAttr, 0.3)
+      .edgeCase(),
+      // Should not be able to steal held item if user faints due to Rough Skin, Iron Barbs, etc.
+      // Should be able to steal items from pokemon with Sticky Hold if the damage causes them to faint
     new AttackMove(Moves.VOLT_TACKLE, PokemonType.ELECTRIC, MoveCategory.PHYSICAL, 120, 100, 15, 10, 0, 3)
       .attr(RecoilAttr, false, 0.33)
       .attr(StatusEffectAttr, StatusEffect.PARALYSIS)
@@ -9797,7 +9814,9 @@ export function initMoves() {
       .hidesTarget(),
     new AttackMove(Moves.INCINERATE, PokemonType.FIRE, MoveCategory.SPECIAL, 60, 100, 15, -1, 0, 5)
       .target(MoveTarget.ALL_NEAR_ENEMIES)
-      .attr(RemoveHeldItemAttr, true),
+      .attr(RemoveHeldItemAttr, true)
+      .edgeCase(),
+      // Should be able to remove items from pokemon with Sticky Hold if the damage causes them to faint
     new StatusMove(Moves.QUASH, PokemonType.DARK, 100, 15, -1, 0, 5)
       .condition(failIfSingleBattle)
       .condition((user, target, move) => !target.turnData.acted)

src/data/mystery-encounters/encounters/the-winstrate-challenge-encounter.ts

@@ -222,6 +222,7 @@ function endTrainerBattleAndShowDialogue(): Promise<void> {
           globalScene.triggerPokemonFormChange(pokemon, SpeciesFormChangeAbilityTrigger);
         }
 
+        // Each trainer battle is "supposed" to be a new fight, so reset all per-battle activation effects
         pokemon.resetBattleAndWaveData();
         applyPostBattleInitAbAttrs(PostBattleInitAbAttr, pokemon);
       }

src/field/pokemon.ts

@@ -676,9 +676,10 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
   }
 
   /**
-   * Checks if the pokemon is allowed in battle (ie: not fainted, and allowed under any active challenges).
+   * Checks if this {@linkcode Pokemon} is allowed in battle (ie: not fainted, and allowed under any active challenges).
-   * @param onField `true` to also check if the pokemon is currently on the field, defaults to `false`
+   * @param onField `true` to also check if the pokemon is currently on the field; default `false`
-   * @returns `true` if the pokemon is "active". Returns `false` if there is no active {@linkcode BattleScene}
+   * @returns `true` if the pokemon is "active", as described above.
+   * Returns `false` if there is no active {@linkcode BattleScene} or the pokemon is disallowed.
    */
   public isActive(onField = false): boolean {
     if (!globalScene) {
@@ -5696,9 +5697,9 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
   }
 
   /**
-  Reset a {@linkcode Pokemon}'s per-battle {@linkcode PokemonBattleData | battleData},
+   * Reset a {@linkcode Pokemon}'s per-battle {@linkcode PokemonBattleData | battleData},
-  as well as any transient {@linkcode PokemonWaveData | waveData} for the current wave.
+   * as well as any transient {@linkcode PokemonWaveData | waveData} for the current wave.
-  Called before a new battle starts.
+   * Should be called once per arena transition (new biome/trainer battle/Mystery Encounter).
   */
   resetBattleAndWaveData(): void {
     this.battleData = new PokemonBattleData();
@@ -5707,7 +5708,8 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
 
   /**
    * Reset a {@linkcode Pokemon}'s {@linkcode PokemonWaveData | waveData}.
-   * Called once per new wave start as well as by {@linkcode resetBattleAndWaveData}.
+   * Should be called upon starting a new wave in addition to whenever an arena transition occurs.
+   * @see {@linkcode resetBattleAndWaveData()}
    */
   resetWaveData(): void {
     this.waveData = new PokemonWaveData();
@@ -6046,7 +6048,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     let fusionPaletteColors: Map<number, number>;
 
     const originalRandom = Math.random;
-    Math.random = randSeedFloat;
+    Math.random = () => randSeedFloat();
 
     globalScene.executeWithSeedOffset(
       () => {
@@ -7788,11 +7790,11 @@ export class PokemonSummonData {
  * Resets at the start of a new battle (but not on switch).
  */
 export class PokemonBattleData {
-  /** counts the hits the pokemon received during this battle; used for {@linkcode Moves.RAGE_FIST} */
+  /** Counter tracking direct hits this Pokemon has received during this battle; used for {@linkcode Moves.RAGE_FIST} */
   public hitCount = 0;
-  /** Whether this has eaten a berry this battle; used for {@linkcode Moves.BELCH} */
+  /** Whether this Pokemon has eaten a berry this battle; used for {@linkcode Moves.BELCH} */
   public hasEatenBerry: boolean = false;
-  /** A list of all berries eaten in this current battle; used by {@linkcode Abilities.HARVEST} */
+  /** Array containing all berries eaten in this current battle; used by {@linkcode Abilities.HARVEST} */
   public berriesEaten: BerryType[] = [];
 
   constructor(source?: PokemonBattleData | Partial<PokemonBattleData>) {

src/modifier/modifier-type.ts

@@ -789,6 +789,7 @@ export class BerryModifierType extends PokemonHeldItemModifierType implements Ge
     );
 
     this.berryType = berryType;
+    this.id = "BERRY"; // needed to prevent harvest item deletion; remove after modifier rework
   }
 
   get name(): string {

src/phases/battle-end-phase.ts

@@ -58,9 +58,8 @@ export class BattleEndPhase extends BattlePhase {
       globalScene.unshiftPhase(new GameOverPhase(true));
     }
 
-    // reset pokemon wave turn count, apply post battle effects, etc etc.
     for (const pokemon of globalScene.getField()) {
-      if (pokemon?.summonData) {
+      if (pokemon) {
         pokemon.summonData.waveTurnCount = 1;
       }
     }
@@ -82,7 +81,6 @@ export class BattleEndPhase extends BattlePhase {
       }
     }
 
-    // lapse all post battle modifiers that should lapse
     const lapsingModifiers = globalScene.findModifiers(
       m => m instanceof LapsingPersistentModifier || m instanceof LapsingPokemonHeldItemModifier,
     ) as (LapsingPersistentModifier | LapsingPokemonHeldItemModifier)[];

src/phases/berry-phase.ts

@@ -15,7 +15,10 @@ import { CommonAnimPhase } from "./common-anim-phase";
 import { globalScene } from "#app/global-scene";
 import type Pokemon from "#app/field/pokemon";
 
-/** The phase after attacks where the pokemon eat berries */
+/**
+ * The phase after attacks where the pokemon eat berries.
+ * Also triggers Cud Chew's "repeat berry use" effects
+ */
 export class BerryPhase extends FieldPhase {
   start() {
     super.start();
@@ -30,18 +33,17 @@ export class BerryPhase extends FieldPhase {
 
   /**
    * Attempt to eat all of a given {@linkcode Pokemon}'s berries once.
-   * @param pokemon The {@linkcode Pokemon} to check
+   * @param pokemon - The {@linkcode Pokemon} to check
    */
   eatBerries(pokemon: Pokemon): void {
-    // check if we even have anything to eat
     const hasUsableBerry = !!globalScene.findModifier(m => {
       return m instanceof BerryModifier && m.shouldApply(pokemon);
     }, pokemon.isPlayer());
+
     if (!hasUsableBerry) {
       return;
     }
 
-    // Check if any opponents have unnerve to block us from eating berries
     const cancelled = new BooleanHolder(false);
     pokemon.getOpponents().map(opp => applyAbAttrs(PreventBerryUseAbAttr, opp, cancelled));
     if (cancelled.value) {
@@ -57,7 +59,6 @@ export class BerryPhase extends FieldPhase {
       new CommonAnimPhase(pokemon.getBattlerIndex(), pokemon.getBattlerIndex(), CommonAnim.USE_ITEM),
     );
 
-    // try to apply all berry modifiers for this pokemon
     for (const berryModifier of globalScene.applyModifiers(BerryModifier, pokemon.isPlayer(), pokemon)) {
       if (berryModifier.consumed) {
         berryModifier.consumed = false;
@@ -66,8 +67,6 @@ export class BerryPhase extends FieldPhase {
       // No need to track berries being eaten; already done inside applyModifiers
       globalScene.eventTarget.dispatchEvent(new BerryUsedEvent(berryModifier));
     }
-
-    // update held modifiers and such
     globalScene.updateModifiers(pokemon.isPlayer());
 
     // Abilities.CHEEK_POUCH only works once per round of nom noms

src/phases/new-biome-encounter-phase.ts

@@ -7,7 +7,8 @@ export class NewBiomeEncounterPhase extends NextEncounterPhase {
   doEncounter(): void {
     globalScene.playBgm(undefined, true);
 
-    // reset all battle data, perform form changes, etc.
+    // Reset all battle and wave data, perform form changes, etc.
+    // We do this because new biomes are considered "arena transitions" akin to MEs and trainer battles
     for (const pokemon of globalScene.getPlayerParty()) {
       if (pokemon) {
         pokemon.resetBattleAndWaveData();

src/phases/next-encounter-phase.ts

@@ -1,6 +1,10 @@
 import { globalScene } from "#app/global-scene";
 import { EncounterPhase } from "./encounter-phase";
 
+/**
+ * The phase between defeating an encounter and starting another wild wave.
+ * Handles generating, loading and preparing for it.
+ */
 export class NextEncounterPhase extends EncounterPhase {
   start() {
     super.start();
@@ -9,7 +13,9 @@ export class NextEncounterPhase extends EncounterPhase {
   doEncounter(): void {
     globalScene.playBgm(undefined, true);
 
-    // Reset all player transient wave data/intel.
+    // Reset all player transient wave data/intel before starting a new wild encounter.
+    // We exclusively reset wave data here as wild waves are considered one continuous "battle"
+    // for lack of an arena transition.
     for (const pokemon of globalScene.getPlayerParty()) {
       if (pokemon) {
         pokemon.resetWaveData();

src/phases/switch-summon-phase.ts

@@ -240,6 +240,7 @@ export class SwitchSummonPhase extends SummonPhase {
       }
     }
 
+    // No need (or particular use) resetting turn data here on initial send in
     if (this.switchType !== SwitchType.INITIAL_SWITCH) {
       pokemon.resetTurnData();
       pokemon.turnData.switchedInThisTurn = true;

src/system/game-data.ts

@@ -1198,8 +1198,6 @@ export class GameData {
             }
           }
 
-          // load modifier data
-
           if (globalScene.modifiers.length) {
             console.warn("Existing modifiers not cleared on session load, deleting...");
             globalScene.modifiers = [];

src/utils/data.ts

@@ -13,27 +13,23 @@ export function deepCopy(values: object): object {
  * This copies all values from `source` that match properties inside `dest`,
  * checking recursively for non-null nested objects.
 
- * If a property in `src` does not exist in `dest` or its `typeof` evaluates differently, it is skipped.
+ * If a property in `source` does not exist in `dest` or its `typeof` evaluates differently, it is skipped.
  * If it is a non-array object, its properties are recursed into and checked in turn.
  * All other values are copied verbatim.
- * @param dest The object to merge values into
+ * @param dest - The object to merge values into
- * @param source The object to source merged values from
+ * @param source - The object to source merged values from
  * @remarks Do not use for regular objects; this is specifically made for JSON copying.
- * @see deepMergeObjects
  */
 export function deepMergeSpriteData(dest: object, source: object) {
-  // Grab all the keys present in both with similar types
+  for (const key of Object.keys(source)) {
-  const matchingKeys = Object.keys(source).filter(key => {
+    if (
-    const destVal = dest[key];
+      !(key in dest) ||
-    const sourceVal = source[key];
+      typeof source[key] !== typeof dest[key] ||
+      Array.isArray(source[key]) !== Array.isArray(dest[key])
+    ) {
+      continue;
+    }
 
-    return (
-      // 1st part somewhat redundant, but makes it clear that we're explicitly interested in properties that exist in both
-      key in source && Array.isArray(sourceVal) === Array.isArray(destVal) && typeof sourceVal === typeof destVal
-    );
-  });
-
-  for (const key of matchingKeys) {
     // Pure objects get recursed into; everything else gets overwritten
     if (typeof source[key] !== "object" || source[key] === null || Array.isArray(source[key])) {
       dest[key] = source[key];

test/abilities/cud_chew.test.ts

@@ -126,7 +126,7 @@ describe("Abilities - Cud Chew", () => {
       game.move.select(Moves.STUFF_CHEEKS);
       await game.toNextTurn();
 
-      // Ate 2 petayas from moves + 1 of each at turn end; all 4 get moved on turn end
+      // Ate 2 petayas from moves + 1 of each at turn end; all 4 get tallied on turn end
       expect(farigiraf.summonData.berriesEatenLast).toEqual([
         BerryType.PETAYA,
         BerryType.PETAYA,
@@ -145,7 +145,7 @@ describe("Abilities - Cud Chew", () => {
       expect(farigiraf.getStatStage(Stat.ATK)).toBe(4); // 1+2+1
     });
 
-    it("resets array on switch", async () => {
+    it("should reset both arrays on switch", async () => {
       await game.classicMode.startBattle([Species.FARIGIRAF, Species.GIRAFARIG]);
 
       const farigiraf = game.scene.getPlayerPokemon()!;
@@ -157,12 +157,20 @@ describe("Abilities - Cud Chew", () => {
 
       const turn1Hp = farigiraf.hp;
       game.doSwitchPokemon(1);
-      await game.phaseInterceptor.to("TurnEndPhase");
+      await game.toNextTurn();
 
       // summonData got cleared due to switch, turnData got cleared due to turn end
       expect(farigiraf.summonData.berriesEatenLast).toEqual([]);
       expect(farigiraf.turnData.berriesEaten).toEqual([]);
       expect(farigiraf.hp).toEqual(turn1Hp);
+
+      game.doSwitchPokemon(1);
+      await game.toNextTurn();
+
+      // TurnData gets cleared while switching in
+      expect(farigiraf.summonData.berriesEatenLast).toEqual([]);
+      expect(farigiraf.turnData.berriesEaten).toEqual([]);
+      expect(farigiraf.hp).toEqual(turn1Hp);
     });
 
     it("clears array if disabled", async () => {