webpack.dev.js

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

module.exports = {
    devtool: 'eval-cheap-module-source-map',
    entry: './src/index.js',
    devServer: {
        port: 3000,
        contentBase: path.join(__dirname, "dist")
    },
    node: {
        fs: 'empty'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                exclude: /node_modules/,
                loader: 'babel-loader',
                options: {
                    presets: ['@babel/preset-env']
                }
            }
        ]
    },
    plugins: [
        new HtmlWebpackPlugin({
            template: './index.html',
            inject: true
        })
    ]
};