webpack.dev.js

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

module.exports = {

    entry: {
        index: './src/index.js'
    },

    devServer: {
        port: 8080
    },

    module: {
        rules: [
            {
                test: /\.scss$/,
                use: [
                    {
                        loader: MiniCssExtractPlugin.loader,
                        options: {
                            hmr: process.env.NODE_ENV === 'development',
                        },
                    },
                    "css-loader",
                    "sass-loader"
                ]
            },
            {
                test: /\.(html)$/,
                use: {
                    loader: 'html-loader'
                }
            },
            {
                test: /\.(png|svg|jpg|gif)$/,
                use: [
                    'file-loader'
                ]
            }
        ],
    },

    plugins: [
        new MiniCssExtractPlugin({
            filename: '[name].css',
            chunkFilename: '[id].css',
        }),
        new HtmlWebpackPlugin({
            template: './src/index.html',
            inject: true,
            chunks: ['index'],
            filename: 'index.html'
        })
    ]
};