do not change with-slices type, and refactor

src/immer/create-slice-with-immer.ts

@@ -18,31 +18,34 @@ export type SliceConfig<
 };
 
 type ImmerActions<Value, Actions extends SliceActions<Value>> = {
-  [K in keyof Actions]: (...args: InferArgs<Actions[K]>) => (prev: Value) => Value | void;
+  [K in keyof Actions]: (
+    ...args: InferArgs<Actions[K]>
+  ) => (prev: Value) => Value;
 };
 
 export function createSliceWithImmer<
   Name extends string,
   Value,
   Actions extends SliceActions<Value>,
 >(config: SliceConfig<Name, Value, Actions>) {
-  const immerActions = Object.keys(config.actions).reduce((acc, actionKey) => {
-    const action = config.actions[actionKey as keyof Actions];
-
-    if (action) {
-      acc[actionKey as keyof Actions] = ((...args: InferArgs<typeof action>) => (prev: Value) => {
-        // Use produce to handle draft modification or return new state
-        return produce(prev, (draft: Value) => {
-          const result = (action as (...args: InferArgs<typeof action>) => (draft: Value) => Value | void)(...args)(draft);
-          if (result !== undefined) {
-            return result;
-          }
-        });
-      }) as ImmerActions<Value, Actions>[typeof actionKey];
-    }
-
-    return acc;
-  }, {} as ImmerActions<Value, Actions>);
+  const immerActions = Object.keys(config.actions).reduce(
+    (acc, actionKey) => {
+      const action = config.actions[actionKey as keyof Actions];
+
+      if (action) {
+        acc[actionKey as keyof Actions] = ((
+            ...args: InferArgs<typeof action>
+          ) =>
+          (prev: Value) =>
+            produce(prev, (draft: Value) =>
+              action(...args)(draft),
+            )) as ImmerActions<Value, Actions>[typeof actionKey];
+      }
+
+      return acc;
+    },
+    {} as ImmerActions<Value, Actions>,
+  );
 
   return {
     ...config,

src/with-slices.ts

@@ -1,16 +1,4 @@
-type SliceActions<Value> = {
-  [actionName: string]: (...args: never[]) => (prev: Value) => Value | void;
-};
-
-type SliceConfig<
-  Name extends string,
-  Value,
-  Actions extends SliceActions<Value>,
-> = {
-  name: Name;
-  value: Value;
-  actions: Actions;
-};
+import type { SliceConfig } from './create-slice.js';
 
 type ParametersIf<T> = T extends (...args: infer Args) => unknown
   ? Args

tests/01_basic.spec.tsx

@@ -1,7 +1,7 @@
 import { expect, test } from 'vitest';
 import { create } from 'zustand';
 import { createSlice, withSlices } from 'zustand-slices';
-import { createSliceWithImmer } from 'zustand-slices/immer'; 
+import { createSliceWithImmer } from 'zustand-slices/immer';
 
 test('should export functions', () => {
   expect(createSlice).toBeDefined();
@@ -25,11 +25,11 @@ test('createSliceWithImmer', () => {
   const immerSlice = createSliceWithImmer({
     name: 'counter',
     value: {
-      count: 0
+      count: 0,
     },
     actions: {
       increment: () => (prev) => {
-        prev.count += 1
+        prev.count += 1;
       },
     },
   });

tsconfig.json

@@ -12,7 +12,8 @@
     "jsx": "react-jsx",
     "baseUrl": ".",
     "paths": {
-      "zustand-slices": ["./src/index.js"]
+      "zustand-slices": ["./src/index.js"],
+      "zustand-slices/immer": ["./src/immer/index.js"]
     }
   },
   "exclude": ["dist", "examples"]