refactor: update produce signature to return undefined

Change the return type of `produce` and `produceAsync` from `void` to
`undefined` in `MutableSignal` and `IGameContext` to more accurately
reflect that the mutation functions should not return a value.

src/core/game.ts

@@ -15,8 +15,8 @@ import { Mulberry32RNG, ReadonlyRNG, RNG } from "@/utils/rng";
 export interface IGameContext<TState extends Record<string, unknown> = {}> {
   get value(): TState;
   get rng(): ReadonlyRNG;
-  produce(fn: (draft: TState) => void): void;
-  produceAsync(fn: (draft: TState) => void): Promise<void>;
+  produce(fn: (draft: TState) => undefined): void;
+  produceAsync(fn: (draft: TState) => undefined): Promise<void>;
   run<T>(input: string): Promise<CommandResult<T>>;
   runParsed<T>(command: Command): Promise<CommandResult<T>>;
   prompt: <TResult, TArgs extends any[] = any[]>(
@@ -51,10 +51,10 @@ export function createGameContext<TState extends Record<string, unknown> = {}>(
     get rng() {
       return this._rng;
     },
-    produce(fn) {
+    produce(fn: (draft: TState) => undefined) {
       return state.produce(fn);
     },
-    produceAsync(fn) {
+    produceAsync(fn: (draft: TState) => undefined) {
       return state.produceAsync(fn);
     },
     run<T>(input: string) {

src/samples/slay-the-spire-like/system/combat/triggers.ts

@@ -65,9 +65,9 @@ export function createTriggers(run: IRunContext) {
       for (const cardId of Object.values(regions.hand.childIds)) {
         await triggers.onCardDiscarded.execute(ctx.game, { cardId });
       }
-      await ctx.game.produceAsync(
-        (draft) => (draft.player.energy = draft.player.maxEnergy),
-      );
+      await ctx.game.produceAsync((draft) => {
+        draft.player.energy = draft.player.maxEnergy;
+      });
       await triggers.onDraw.execute(ctx.game, { count: 5 });
     }),
     onShuffle: createTrigger("onShuffle", async (ctx) => {

src/utils/mutable-signal.ts

@@ -1,5 +1,5 @@
-import {Signal, SignalOptions} from '@preact/signals-core';
-import {create} from 'mutative';
+import { Signal, SignalOptions } from "@preact/signals-core";
+import { create } from "mutative";
 
 export class MutableSignal<T> extends Signal<T> {
   private _interruptions: Promise<void>[] = [];
@@ -7,7 +7,7 @@ export class MutableSignal<T> extends Signal<T> {
   public constructor(t?: T, options?: SignalOptions<T>) {
     super(t, options);
   }
-  produce(fn: (draft: T) => void) {
+  produce(fn: (draft: T) => undefined) {
     this.value = create(this.value, fn);
   }
 
@@ -30,13 +30,16 @@ export class MutableSignal<T> extends Signal<T> {
    * 异步版本的 produce。会先等待所有通过 `addInterruption` 添加的 Promise 完成，
    * 然后再更新状态。适用于需要在状态更新前播放动画的场景。
    */
-  async produceAsync(fn: (draft: T) => void): Promise<void> {
+  async produceAsync(fn: (draft: T) => undefined): Promise<void> {
     await Promise.allSettled(this._interruptions);
     this._interruptions = [];
     this.produce(fn);
   }
 }
 
-export function mutableSignal<T>(initial?: T, options?: SignalOptions<T>): MutableSignal<T> {
+export function mutableSignal<T>(
+  initial?: T,
+  options?: SignalOptions<T>,
+): MutableSignal<T> {
   return new MutableSignal<T>(initial, options);
 }