Broke up the test matchers into multiple smaller interfaces

test/@types/vitest.d.ts

@@ -13,6 +13,8 @@ import type { PokemonType } from "#enums/pokemon-type";
 import type { PositionalTagType } from "#enums/positional-tag-type";
 import type { BattleStat, EffectiveStat } from "#enums/stat";
 import type { WeatherType } from "#enums/weather-type";
+import type { Pokemon } from "#field/pokemon";
+import type { GameManager } from "#test/test-utils/game-manager";
 import type { toHaveArenaTagOptions } from "#test/test-utils/matchers/to-have-arena-tag";
 import type { toHaveBattlerTagOptions } from "#test/test-utils/matchers/to-have-battler-tag";
 import type { toHaveEffectiveStatOptions } from "#test/test-utils/matchers/to-have-effective-stat";
@@ -25,10 +27,15 @@ import type { AtLeastOne } from "#types/type-helpers";
 import type { toDmgValue } from "#utils/common";
 import type { expect } from "vitest";
 
+// #region Boilerplate
 declare module "vitest" {
-  interface Assertion<T> {
+  interface Assertion<T> extends GenericMatchers<T>, GameManagerMatchers<T>, ArenaMatchers<T>, PokemonMatchers<T> {}
-    // #region Generic Matchers
+}
 
+// #endregion Boilerplate
+
+// #region Generic Matchers
+interface GenericMatchers<T> {
   /**
    * Check whether an array contains EXACTLY the given items (in any order).
    *
@@ -38,7 +45,7 @@ declare module "vitest" {
    * @param expected - The expected contents of the array, in any order
    * @see {@linkcode expect.arrayContaining}
    */
-    toEqualArrayUnsorted(expected: T[]): void;
+  toEqualArrayUnsorted(expected: T extends (infer U)[] ? U[] : never): void;
 
   /**
    * Check whether a {@linkcode Map} contains the given key, disregarding its value.
@@ -49,12 +56,12 @@ declare module "vitest" {
    * `expect(x).toContain[y, expect.anything()]`,
    * this is still preferred due to being more ergonomic and provides better error messsages.
    */
-    toHaveKey<E>(expectedKey: E): void;
+  toHaveKey(expectedKey: T extends Map<infer K, unknown> ? K : never): void;
-
+}
-    // #endregion Generic Matchers
+// #endregion Generic Matchers
-
-    // #region GameManager Matchers
 
+// #region GameManager Matchers
+interface GameManagerMatchers<_T> {
   /**
    * Check if the {@linkcode GameManager} has shown the given message at least once in the current test case.
    * @param expectedMessage - The expected message to be displayed
@@ -69,10 +76,12 @@ declare module "vitest" {
    * @param expectedPhase - The expected {@linkcode PhaseString | name of the phase}
    */
   toBeAtPhase(expectedPhase: PhaseString): void;
-    // #endregion GameManager Matchers
+}
 
-    // #region Arena Matchers
+// #endregion GameManager Matchers
 
+// #region Arena Matchers
+interface ArenaMatchers<_T> {
   /**
    * Check whether the current {@linkcode WeatherType} is as expected.
    * @param expectedWeatherType - The expected {@linkcode WeatherType}
@@ -109,11 +118,11 @@ declare module "vitest" {
    * defaults to `1` and must be within the range `[0, 4]`
    */
   toHavePositionalTag(expectedType: PositionalTagType, count?: number): void;
+}
+// #endregion Arena Matchers
 
-    // #endregion Arena Matchers
+// #region Pokemon Matchers
-
+interface PokemonMatchers<_T> {
-    // #region Pokemon Matchers
-
   /**
    * Check whether a {@linkcode Pokemon}'s current typing includes the given types.
    * @param expectedTypes - The expected {@linkcode PokemonType}s to check against; must have length `>0`
@@ -197,6 +206,7 @@ declare module "vitest" {
    * Check whether a {@linkcode Pokemon} is at full HP.
    */
   toHaveFullHp(): void;
+
   /**
    * Check whether a {@linkcode Pokemon} has consumed the given amount of PP for one of its moves.
    * @param moveId - The {@linkcode MoveId} corresponding to the {@linkcode PokemonMove} that should have consumed PP
@@ -207,7 +217,6 @@ declare module "vitest" {
    * or does not contain exactly one copy of `moveId`, this will fail the test.
    */
   toHaveUsedPP(moveId: MoveId, ppUsed: number | "all"): void;
-
-    // #endregion Pokemon Matchers
-  }
 }
+
+// #endregion Pokemon Matchers

test/test-utils/matchers/to-have-terrain.ts

@@ -8,8 +8,8 @@ import { isGameManagerInstance, receivedStr } from "#test/test-utils/test-utils"
 import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 
 /**
- * Matcher that checks if the {@linkcode TerrainType} is as expected
+ * Matcher that checks if the current {@linkcode TerrainType} is as expected.
- * @param received - The object to check. Should be an instance of {@linkcode GameManager}.
+ * @param received - The object to check. Should be the current {@linkcode GameManager}.
  * @param expectedTerrainType - The expected {@linkcode TerrainType}, or {@linkcode TerrainType.NONE} if no terrain should be active
  * @returns Whether the matcher passed
  */

test/test-utils/matchers/to-have-weather.ts

@@ -8,8 +8,8 @@ import { toTitleCase } from "#utils/strings";
 import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 
 /**
- * Matcher that checks if the {@linkcode WeatherType} is as expected
+ * Matcher that checks if the current {@linkcode WeatherType} is as expected.
- * @param received - The object to check. Expects an instance of {@linkcode GameManager}.
+ * @param received - The object to check. Should be the current {@linkcode GameManager}
  * @param expectedWeatherType - The expected {@linkcode WeatherType}
  * @returns Whether the matcher passed
  */