Added utility types for strong typing IVs and stats

src/@types/dex-data.ts

@@ -1,3 +1,5 @@
+import type { IVTuple } from "#app/@types/stat-types";
+
 export interface DexData {
   [key: number]: DexEntry;
 }
@@ -9,5 +11,5 @@ export interface DexEntry {
   seenCount: number;
   caughtCount: number;
   hatchedCount: number;
-  ivs: number[];
+  ivs: IVTuple;
 }

src/@types/stat-types.ts

@@ -0,0 +1,59 @@
+import type { Head, Tail } from "#app/@types/utility-types/tuple";
+
+// biome-ignore lint/correctness/noUnusedImports: Type Imports
+import type { PermanentStat, BattleStat } from "#enums/stat";
+
+type StatTuple = [
+  hp: number,
+  atk: number,
+  def: number,
+  spAtk: number,
+  spDef: number,
+  spd: number,
+  acc: number,
+  eva: number,
+];
+
+/** Tuple containing all {@linkcode PermanentStat}s of a Pokemon. */
+export type PermanentStatTuple = Head<Head<StatTuple>>;
+/** Tuple containing all {@linkcode BattleStat}s of a Pokemon. */
+export type BattleStatTuple = Tail<PermanentStatTuple>;
+
+// Since typescript lacks integer range unions, we have to use THIS abomination to strongly type an IV
+export type IVType =
+  | 0
+  | 1
+  | 2
+  | 3
+  | 4
+  | 5
+  | 6
+  | 7
+  | 8
+  | 9
+  | 10
+  | 11
+  | 12
+  | 13
+  | 14
+  | 15
+  | 16
+  | 17
+  | 18
+  | 19
+  | 20
+  | 21
+  | 22
+  | 23
+  | 24
+  | 25
+  | 26
+  | 27
+  | 28
+  | 29
+  | 30
+  | 31;
+
+type toIvTuple<T extends [...any]> = { [k in keyof T]: IVType };
+
+export type IVTuple = toIvTuple<PermanentStatTuple>;

src/@types/utility-types/tuple.ts

@@ -0,0 +1,5 @@
+/** Extract the elements of a tuple type, excluding the first element. */
+export type Tail<T extends any[]> = Required<T> extends [any, ...infer Head] ? Head : never;
+
+/** Extract the elements of a tuple type, excluding the last element. */
+export type Head<T extends [...any]> = Required<T> extends [...infer Head, any] ? Head : never;

src/battle-scene.ts

@@ -160,12 +160,16 @@ import { timedEventManager } from "./global-event-manager";
 import { starterColors } from "./global-vars/starter-colors";
 import { startingWave } from "./starting-wave";
 import { PhaseManager } from "./phase-manager";
+import type { IVTuple } from "#app/@types/stat-types";
 
 const DEBUG_RNG = false;
 
-const OPP_IVS_OVERRIDE_VALIDATED: number[] = (
-  Array.isArray(Overrides.OPP_IVS_OVERRIDE) ? Overrides.OPP_IVS_OVERRIDE : new Array(6).fill(Overrides.OPP_IVS_OVERRIDE)
-).map(iv => (Number.isNaN(iv) || iv === null || iv > 31 ? -1 : iv));
+const OPP_IVS_OVERRIDE_VALIDATED: IVTuple | null =
+  Overrides.OPP_IVS_OVERRIDE === null
+    ? null
+    : Array.isArray(Overrides.OPP_IVS_OVERRIDE)
+      ? Overrides.OPP_IVS_OVERRIDE
+      : new Array(6).fill(Overrides.OPP_IVS_OVERRIDE);
 
 export interface PokeballCounts {
   [pb: string]: number;
@@ -970,12 +974,9 @@ export default class BattleScene extends SceneBase {
       postProcess(pokemon);
     }
 
-    for (let i = 0; i < pokemon.ivs.length; i++) {
-      if (OPP_IVS_OVERRIDE_VALIDATED[i] > -1) {
-        pokemon.ivs[i] = OPP_IVS_OVERRIDE_VALIDATED[i];
-      }
+    if (OPP_IVS_OVERRIDE_VALIDATED) {
+      pokemon.ivs = OPP_IVS_OVERRIDE_VALIDATED;
     }
-
     pokemon.init();
     return pokemon;
   }

src/field/pokemon.ts

@@ -193,6 +193,7 @@ import { AiType } from "#enums/ai-type";
 import type { MoveResult } from "#enums/move-result";
 import { PokemonMove } from "#app/data/moves/pokemon-move";
 import type { AbAttrMap, AbAttrString } from "#app/@types/ability-types";
+import type { IVTuple, PermanentStatTuple } from "#app/@types/stat-types";
 
 /** Base typeclass for damage parameter methods, used for DRY */
 type damageParams = {
@@ -247,8 +248,8 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
   public levelExp: number;
   public gender: Gender;
   public hp: number;
-  public stats: number[];
-  public ivs: number[];
+  public stats: PermanentStatTuple;
+  public ivs: IVTuple;
   public nature: Nature;
   public moveset: PokemonMove[];
   public status: Status | null;
@@ -317,7 +318,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
     gender?: Gender,
     shiny?: boolean,
     variant?: Variant,
-    ivs?: number[],
+    ivs?: IVTuple,
     nature?: Nature,
     dataSource?: Pokemon | PokemonData,
   ) {
@@ -5475,7 +5476,7 @@ export class PlayerPokemon extends Pokemon {
     gender?: Gender,
     shiny?: boolean,
     variant?: Variant,
-    ivs?: number[],
+    ivs?: IVTuple,
     nature?: Nature,
     dataSource?: Pokemon | PokemonData,
   ) {
@@ -6088,10 +6089,12 @@ export class EnemyPokemon extends Pokemon {
 
       if (this.hasTrainer() && globalScene.currentBattle) {
         const { waveIndex } = globalScene.currentBattle;
-        const ivs: number[] = [];
-        while (ivs.length < 6) {
-          ivs.push(randSeedIntRange(Math.floor(waveIndex / 10), 31));
-        }
+        const ivs: IVTuple = Array.from(
+          {
+            length: 6,
+          },
+          () => randSeedIntRange(Math.floor(waveIndex / 10), 31),
+        );
         this.ivs = ivs;
       }
     }

src/overrides.ts

@@ -22,6 +22,7 @@ import { TimeOfDay } from "#enums/time-of-day";
 import { TrainerType } from "#enums/trainer-type";
 import { VariantTier } from "#enums/variant-tier";
 import { WeatherType } from "#enums/weather-type";
+import type { IVTuple, IVType } from "#app/@types/stat-types";
 
 /**
  * This comment block exists to prevent IDEs from automatically removing unused imports
@@ -177,7 +178,11 @@ class DefaultOverrides {
   readonly OPP_MOVESET_OVERRIDE: MoveId | Array<MoveId> = [];
   readonly OPP_SHINY_OVERRIDE: boolean | null = null;
   readonly OPP_VARIANT_OVERRIDE: Variant | null = null;
-  readonly OPP_IVS_OVERRIDE: number | number[] = [];
+  /**
+   * An array of IVs to give the opposing pokemon.
+   * Specifying a single number will use it for all 6 IVs, while `null` will disable the override.
+  */
+  readonly OPP_IVS_OVERRIDE: IVType | IVTuple | null = null;
   readonly OPP_FORM_OVERRIDES: Partial<Record<SpeciesId, number>> = {};
   /**
    * Override to give the enemy Pokemon a given amount of health segments

src/ui/pokemon-info-container.ts

@@ -14,6 +14,7 @@ import ConfirmUiHandler from "./confirm-ui-handler";
 import { StatsContainer } from "./stats-container";
 import { TextStyle, addBBCodeTextObject, addTextObject, getTextColor } from "./text";
 import { addWindow } from "./ui-theme";
+import type { PermanentStatTuple } from "#app/@types/stat-types";
 
 interface LanguageSetting {
   infoContainerTextSize: string;
@@ -383,7 +384,7 @@ export default class PokemonInfoContainer extends Phaser.GameObjects.Container {
       }
 
       const starterSpeciesId = pokemon.species.getRootSpeciesId();
-      const originalIvs: number[] | null = eggInfo
+      const originalIvs: PermanentStatTuple | null = eggInfo
         ? dexEntry.caughtAttr
           ? dexEntry.ivs
           : null

src/utils/common.ts

@@ -3,6 +3,7 @@ import { MoveId } from "#enums/move-id";
 import i18next from "i18next";
 import { pokerogueApi } from "#app/plugins/api/pokerogue-api";
 import type { Variant } from "#app/sprites/variant";
+import type { IVTuple } from "#app/@types/stat-types";
 
 export type nil = null | undefined;
 
@@ -182,7 +183,7 @@ export function getPlayTimeString(totalSeconds: number): string {
  * @param id 32-bit number
  * @returns An array of six numbers corresponding to 5-bit chunks from {@linkcode id}
  */
-export function getIvsFromId(id: number): number[] {
+export function getIvsFromId(id: number): IVTuple {
   return [
     (id & 0x3e000000) >>> 25,
     (id & 0x01f00000) >>> 20,