React Native中legacy_createStore报错：undefined is not a function求助

错误原因 #

你遇到的报错源于createStore变量未正确获取到函数：你从redux包中导入legacy_createStore并别名成createStore，但redux 4.2.0本身并没有导出legacy_createStore这个方法——该方法是@reduxjs/toolkit提供的兼容导出，直接从redux包导入会导致createStore为undefined，调用时触发错误。

另外你的reducer存在逻辑bug：ADD_LIST case中返回{ ...state, newList }会给state新增newList字段，而非更新原有的nameList，会导致后续无法正确获取更新后的列表数据。

修复步骤 #

方案1：使用官方推荐的@reduxjs/toolkit配置store（优先选择） #

@reduxjs/toolkit是Redux官方推荐的工具集，简化了store配置流程，同时内置了最佳实践：
修改Provider.js：

import React from "react";
import { Provider } from "react-redux";
import { configureStore } from "@reduxjs/toolkit";
import reducers from "./reducers";
import initialState from './store'

const UserProvider = ({children}) => {
    const store = configureStore({
        reducer: reducers,
        preloadedState: initialState
    })

    return <Provider store={store}>{children}</Provider>
}

export default UserProvider

方案2：使用redux原生createStore（不推荐，已标记为legacy） #

如果坚持使用原生redux，修正导入方式即可：
修改Provider.js：

import React from "react";
import { Provider } from "react-redux";
import { createStore } from "redux";
import reducers from "./reducers";
import initialState from './store'

const UserProvider = ({children}) => {
    const store = createStore(reducers, initialState)

    return <Provider store={store}>{children}</Provider>
}

export default UserProvider

修正reducer逻辑bug #

修改reducers.js中的ADD_LIST case，确保更新正确的state字段：

export default function (state, action) {
    switch (action.type) {
        case "ADD_LIST":
            const {name} = action.payload
            const newList = [...state.nameList, name]
            return { ...state, nameList: newList }
        default:
            return state
    }
}

内容的提问来源于stack exchange，提问作者baristp04