webpack.config.js

const path = require('path');
module.exports = {
    entry: './src/app.js',

    output: {
        path: path.resolve(__dirname, './public'),
        filename: 'app.js',
        publicPath: '/public'
    },
    module: {
        rules: [
            {
                test: /\.js$/,
                loader: 'babel-loader'
            },
            {
                test: /\.sass$/,
                use: ['style-loader', 'css-loader', 'sass-loader']
            }
        ]
    },
    devServer: {
        host: '0.0.0.0',
        overlay: true,
        contentBase: path.resolve(__dirname, './public'),
        watchContentBase: true
    },
    devtool: 'cheap-eval-source-map' // remove for build
};