webpack.config.js

const path = require('path');
const ExtraxtTextPlugin = require('extract-text-webpack-plugin');

console.log(path.join(__dirname,'public'))

module.exports = (env) => {
    const isProduction = env === "production";
    const CSSExtract = new ExtraxtTextPlugin('styles.css')
    return {
        entry: './src/app.js',
        output:{
            path: path.join(__dirname, 'public','dist'),
            filename:"bundle.js"
        },
        module:{
            rules:[{
                loader: 'babel-loader',
                test:/\.js$/,
                exclude:/node_modules/
            },{
                test: /\.s?css$/,
                use: CSSExtract.extract({
                    use:[
                        {
                            loader:'css-loader',
                            options:{
                                sourceMap: true
                            }
                        },
                        {
                            loader:'sass-loader',
                            options:{
                                sourceMap: true
                            }
                        }
                    ]
                })
            }]
        },
        plugins:[
            CSSExtract
        ],
        devtool: isProduction ? 'source-map' :"inline-source-map",
        devServer: {
            contentBase: path.join(__dirname,'public'),
            historyApiFallback: true,
            publicPath: "/dist/"
        }
    }
}