From 6af59e959b1055dbf3c4a69ef00f5d9fa59dc7ed Mon Sep 17 00:00:00 2001
From: areschen <ariesjia00@hotmail.com>
Date: Thu, 9 May 2019 11:18:47 +0800
Subject: [PATCH 1/2] chore: use useRef to save state make async action to get
 current state

---
 src/createReducer.ts | 42 ++++++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/createReducer.ts b/src/createReducer.ts
index 7ff5fd3b83..f68a3f7f06 100644
--- a/src/createReducer.ts
+++ b/src/createReducer.ts
@@ -1,35 +1,37 @@
-import { useReducer } from 'react';
+import { useMemo, useRef, useState } from 'react';
 
-function compose(...funcs) {
-  if (funcs.length === 0) {
-    return arg => arg;
-  }
-
-  if (funcs.length === 1) {
-    return funcs[0];
-  }
-
-  return funcs.reduce((a, b) => (...args) => a(b(...args)));
+function composeMiddleware(chain) {
+  return (context, dispatch) => {
+    return chain.reduceRight((res, middleware) => {
+      return middleware(context)(res);
+    }, dispatch);
+  };
 }
 
-const createReducer = (...middlewares) => (...args) => {
-  const [state, dispatch] = useReducer(...args);
-
+const createReducer = (...middlewares) => (reducer, initialState, initializer = value => value) => {
+  const ref = useRef({})
+  const [hooksState, setState] = useState(initializer(initialState))
+  ref.current = hooksState
   let middlewareDispatch = () => {
     throw new Error(
       'Dispatching while constructing your middleware is not allowed. ' +
         'Other middleware would not be applied to this dispatch.'
     );
   };
-
+  const dispatch = action => {
+    ref.current = reducer(ref.current, action)
+    setState(ref.current)
+    return action;
+  }
+  const composedMiddleware = useMemo(() => {
+    return composeMiddleware(middlewares);
+  }, middlewares);
   const middlewareAPI = {
-    getState: () => state,
+    getState: () => ref.current,
     dispatch: (...args) => middlewareDispatch(...args),
   };
-  const chain = middlewares.map(middleware => middleware(middlewareAPI));
-  middlewareDispatch = compose(...chain)(dispatch);
-
-  return [state, middlewareDispatch];
+  middlewareDispatch = composedMiddleware(middlewareAPI, dispatch);
+  return [ref.current, middlewareDispatch];
 };
 
 export default createReducer;

From 2c1a67188a88dab36e00c7f9c3a3b3af4ed7c91f Mon Sep 17 00:00:00 2001
From: areschen <ariesjia00@hotmail.com>
Date: Thu, 9 May 2019 11:30:57 +0800
Subject: [PATCH 2/2] refactor: move initialState to useRef

---
 src/createReducer.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/createReducer.ts b/src/createReducer.ts
index f68a3f7f06..749edfb11c 100644
--- a/src/createReducer.ts
+++ b/src/createReducer.ts
@@ -9,9 +9,8 @@ function composeMiddleware(chain) {
 }
 
 const createReducer = (...middlewares) => (reducer, initialState, initializer = value => value) => {
-  const ref = useRef({})
-  const [hooksState, setState] = useState(initializer(initialState))
-  ref.current = hooksState
+  const ref = useRef(initializer(initialState))
+  const [, setState] = useState(ref.current)
   let middlewareDispatch = () => {
     throw new Error(
       'Dispatching while constructing your middleware is not allowed. ' +