商店没有有效的Reducer

Question

我无法解决这个问题

actions.js

export const UPDATE = "UPDATE";

utils.js

export default function createReducer(initialState, handlers) {
    return function reducer(state = initialState, action) {
        if (handlers.hasOwnProperty(action.type)) {
            return handlers[action.type](state, action)
        } else {
            return state
        }
    }
}

reducer.js

import createReducer from "../../lib/utils.js";
import * as actions from "./actions.js";

export const filter = createReducer({}, {

}); 

combinedReducers.js

import { 
    combineReducers
} from "redux";
import filter from "../container/filter/reducer.js";

export default combineReducers(Object.assign(
    filter,
));

那就是我试图在那store上班的地方。

index.android.js

import React, { Component } from "react";
import {
  AppRegistry,
} from "react-native";
import { 
  Provider 
} from "react-redux";
import { 
  createStore, 
  applyMiddleware, 
  compose,
} from "redux";
import {
  createLogger,
} from "redux-logger";
import reducer from "./src/lib/reducers.js";
import thunkMiddleware from "redux-thunk";
import App from "./src/config/App.js"

const loggerMiddleware = createLogger({ predicate: (getState, action) => __DEV__});

function configureStore(initialState) {
  const enhancer = compose(
    applyMiddleware(
      thunkMiddleware,
      loggerMiddleware,
    ),
  );
  return createStore(reducer, initialState, enhancer);
}

const store = configureStore({});

const HelloWorld = () => {
  <Provider store={store}>
    <App/>
  </Provider>
}
AppRegistry.registerComponent("...", () => HelloWorld);

而且我总是得到：

存储没有有效的reducer确保传递给combineReducers的参数是一个值为reducer的对象。

我在这里做错了什么？ 我假设它的createReducer()函数？

Answer 1

问题在这里：

export default combineReducers(Object.assign(
    filter,
));

filter返回一个函数，而Object.assign返回该函数，并且combineReducers期望每个键都是化combineReducers的对象。

因此，您的代码应如下所示：

export default combineReducers(Object.assign({ filter } ));

要么

export default combineReducers({ filter });

Answer 2

似乎有错字

export default combineReducers(Object.assign, {
    filter,
});

因为Object.assign没有参数。

Answer 3

这是我的减速器分解的一个例子

//reducers/index.js
import { combineReducers } from 'redux';
import MyReducer from "./MyReducer";

const rootReducer = combineReducers({    
myProp: MyReducer
});

export default rootReducer;


//reducer/MyReducer.js
export default function MyReducer (state = null, action) {
     switch (action.type) {
         case 'MY_ACTION_TYPE':
           return action.payload
     }
     return state;
 }