SPA auto reload javascript and scss

package.json

{
  "name": "datepicker",
  "version": "1.0.0",
  "description": "another datepicker",
  "main": "src/index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "webpack",
    "dev": "webpack-dev-server"
  },
  "keywords": [
    "datepicker",
    "javascript",
    "chrome"
  ],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "css-loader": "^2.1.1",
    "file-loader": "^3.0.1",
    "html-webpack-plugin": "^3.2.0",
    "mini-css-extract-plugin": "^0.5.0",
    "node-sass": "^4.11.0",
    "postcss-loader": "^3.0.0",
    "sass-loader": "^7.1.0",
    "style-loader": "^0.23.1",
    "webpack": "^4.29.6",
    "webpack-cli": "^3.3.0",
    "webpack-dev-server": "^3.3.0"
  },
  "dependencies": {}
}

webpack.config.js

const path = require('path');
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const HtmlWebpackPlugin = require('html-webpack-plugin');


module.exports = {
    devServer: {
        contentBase: path.join(__dirname, 'dist'),
        compress: true,
        port: 9000,
        hot: true
    },
    entry: './src/index.js',
    output: {
        filename: 'main.js',
        path: path.resolve(__dirname, 'dist')
    },
    plugins: [
        new MiniCssExtractPlugin({
            // Options similar to the same options in webpackOptions.output
            // both options are optional
            filename: '[name].css',
            chunkFilename: '[id].css'
        }),
        new HtmlWebpackPlugin({
            template: "src/index.html"
        }),
    ],
    module: {
        rules: [
            {
                test: /\.(sa|sc|c)ss$/,
                use: [
                    {
                        loader: 'style-loader',
                        options: {
                            hmr: true
                        }
                    },
                    // MiniCssExtractPlugin.loader,
                    'css-loader',
                    'sass-loader',
                ],
            }
        ]
    }
};