webpack setup

webpack.common.js

const path = require('path');
const CleanWebpackPlugin = require('clean-webpack-plugin');

module.exports = {
    entry: {
        login: './Scripts/apps/login.jsx',
        'mass-update': './Scripts/apps/mass-update/app.jsx',
    },
    module: {
        rules: [
            {
                test: /\.(js|jsx)$/,
                exclude: /node_modules/,
                use: ['babel-loader'],
            },
            {
                test:/\.(s*)css$/,
                use:['style-loader','css-loader', 'sass-loader'],
            },
        ]
    },
    resolve: {
        extensions: ['*', '.js', '.jsx'],
    },
    output: {
        path: path.join(__dirname, 'scripts', 'dist'),
        publicPath: '/',
        filename: '[name].bundle.js',
    },
    plugins: [
        new CleanWebpackPlugin([path.join(__dirname, 'scripts', 'dist')]),
    ]
};

webpack.dev.js

const merge = require('webpack-merge');
const common = require('./webpack.common.js');

module.exports = merge(common,
{
    mode: 'development',
    devtool: 'inline-source-map',
    devServer: {
        contentBase: './Scripts/dist'
    },
    watch: true,
    watchOptions: {
        aggregateTimeout: 300,
        poll: 1000,
        ignored: './node_modules/'
    }
});

webpack.prod.js

const webpack = require('webpack');
const merge = require('webpack-merge');
const common = require('./webpack.common.js');
const UglifyJSPlugin = require('uglifyjs-webpack-plugin');

module.exports = merge(common, {
    mode: 'production',
    devtool: 'source-map',
    plugins: [
        new UglifyJSPlugin({
            sourceMap: true
        }),
        new webpack.DefinePlugin({
            'process.env.NODE_ENV': JSON.stringify('production')
        })
    ]
});