webpack-dev-server热重装无法正常工作？

Question

In React, I run "start": "webpack-dev-server --hot" , but I'm getting this error:

My file structure:

package.json:

  {
    "name": "reactapp",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
        "start": "webpack-dev-server --hot"
    },
    "author": "Sheharzad",
    "license": "ISC",
    "dependencies": {
        "babel-core": "^6.26.3",
        "babel-loader": "^7.1.5",
        "babel-preset-es2015": "^6.24.1",
        "babel-preset-react": "^6.24.1",
        "react": "^16.4.2",
        "react-dom": "^16.4.2",
        "webpack": "^4.17.1",
        "webpack-dev-server": "^3.1.6"
    }
  }

App.jsx:

import React from 'react';

class App extends React.Component {
   render() {
      return (
         <div>
            Hello World!!!
         </div>
      );
   }
}
export default App;

main.js:

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.jsx';

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

Answer 1

Listen you haven't added webpack cli package which accepts --hot flag. Try after adding this package. It should work. Let me know If it doesn't help.

EDITED: "start" : "webpack-dev-server --mode development --config webpack.config.js --open --hot:

make sure you have webpack config in your root folder and restart your dev server.