feat: (TS) provide different overloads of useImmerReducer (#108)

src/index.ts

@@ -1,13 +1,10 @@
 import produce, { Draft, nothing, freeze } from "immer";
 import { useState, useReducer, useCallback, useMemo, Dispatch } from "react";
 
-export type Reducer<S = any, A = any> = (
-  draftState: Draft<S>,
-  action: A
-) => void | (S extends undefined ? typeof nothing : S);
 export type DraftFunction<S> = (draft: Draft<S>) => void;
 export type Updater<S> = (arg: S | DraftFunction<S>) => void;
 export type ImmerHook<S> = [S, Updater<S>];
+
 export function useImmer<S = any>(initialValue: S | (() => S)): ImmerHook<S>;
 
 export function useImmer(initialValue: any) {
@@ -26,16 +23,41 @@ export function useImmer(initialValue: any) {
   ];
 }
 
-export function useImmerReducer<S = any, A = any>(
-  reducer: Reducer<S, A>,
+// Provides different overloads of `useImmerReducer` similar to `useReducer` from `@types/react`.
+
+export type ImmerReducer<S, A> = (
+  draftState: Draft<S>,
+  action: A
+) => void | (S extends undefined ? typeof nothing : S);
+
+/**
+ * @deprecated Use `ImmerReducer` instead since there is already a `Reducer` type in `@types/react`.
+ */
+export type Reducer<S = any, A = any> = ImmerReducer<S, A>;
+
+export function useImmerReducer<S, A, I>(
+  reducer: ImmerReducer<S, A>,
+  initializerArg: S & I,
+  initializer: (arg: S & I) => S
+): [S, Dispatch<A>];
+
+export function useImmerReducer<S, A, I>(
+  reducer: ImmerReducer<S, A>,
+  initializerArg: I,
+  initializer: (arg: I) => S
+): [S, Dispatch<A>];
+
+export function useImmerReducer<S, A>(
+  reducer: ImmerReducer<S, A>,
   initialState: S,
-  initialAction?: (initial: any) => S
+  initializer?: undefined
 ): [S, Dispatch<A>];
-export function useImmerReducer(
-  reducer: any,
-  initialState: any,
-  initialAction: any
+
+export function useImmerReducer<S, A, I>(
+  reducer: ImmerReducer<S, A>,
+  initializerArg: S & I,
+  initializer?: (arg: S & I) => S
 ) {
   const cachedReducer = useMemo(() => produce(reducer), [reducer]);
-  return useReducer(cachedReducer, initialState as any, initialAction);
+  return useReducer(cachedReducer, initializerArg as any, initializer as any);
 }