ReactJS：启动服务器时无法编译错误

Question

我是ReactJS的初学者。在完成有关React和Redux基础知识的课程之后。我已经开始了新的Udemy课程，标题为“反应数据可视化-构建加密货币仪表板”。尝试使用yarn start命令启动服务器时，我在第4课中遇到问题：

Failed to compile
./src/index.js
Cannot find file: 'index.js' does not match the corresponding name on disk: '.\src\App\app'.

这是我在index.js目录下的app文件上的代码：

import React, { Component } from 'react';
import './App.css';

class App extends Component {
  render(){
    return (
      <div>
        Hello World
      </div>
    );
  }

}

export default App;

这是我在index.js目录下的src文件上的代码：

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import * as serviceWorker from './serviceWorker';

ReactDOM.render(<App />, document.getElementById('root'));

// If you want your app to work offline and load faster, you can change
// unregister() to register() below. Note this comes with some pitfalls.

如何解决此问题？

您可以在此处找到项目文件。

https://drive.google.com/open?id=1u-8mCYSWZtXPbIqELKsF33FOiXb3yrkH

编辑1 ：我正在按照@Wesgur的建议在package.json文件中添加代码：

{
  "name": "cryptodash",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.3.2",
    "@testing-library/user-event": "^7.1.2",
    "react": "^16.12.0",
    "react-dom": "^16.12.0",
    "react-scripts": "3.4.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

编辑2 ：我正在添加图像以显示文件夹结构，如@ Madhavan.V建议的那样：

Answer 1

@Shawan这只是将src / index中的App import语句从import App from './App';更改为import App from './app';的错字。

Answer 2

从“ ./app”导入应用； 这将导入您的app文件夹的index.js。