Webpack 4 Hot Reload已停止工作

Question

我正在设置一个webpack 4项目，并且在开始热重新加载似乎工作但现在我注意到它已停止

webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
    entry: './src/index.js',
    output: {
        path: path.join(__dirname, '/dist'),
        filename: 'index_bundle.js'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                use: {
                    loader: 'babel-loader'
                }
            },
            {
                test: /\.scss$/,
                use: [{
                    loader: "style-loader" 
                }, {
                    loader: "css-loader"
                }, {
                    loader: "sass-loader" 
                }]
            }

        ]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: './src/index.html'
        }
        )
    ]
}

package.json

{
  "name": "webui",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "dependencies": {
    "npm": "^5.8.0",
    "react": "^16.3.1",
    "react-dom": "^16.3.1"
  },
  "scripts": {
    "start": "webpack-dev-server --mode development --open --hot",
    "build": "webpack --mode production"
  },
  "repository": {
    "type": "git",
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "babel-core": "^6.26.0",
    "babel-loader": "^7.1.4",
    "babel-preset-env": "^1.6.1",
    "babel-preset-react": "^6.24.1",
    "css-loader": "^0.28.11",
    "html-webpack-plugin": "^3.2.0",
    "node-sass": "^4.8.3",
    "sass-loader": "^6.0.7",
    "style-loader": "^0.20.3",
    "webpack": "^4.5.0",
    "webpack-cli": "^2.0.14",
    "webpack-dev-server": "^3.1.3"
  }
}