webpack.config.js

const path = require('path')
const autoprefixer = require('autoprefixer')
const webpack = require('webpack')
const { NODE_ENV } = require('./config')
const path_node_modules = path.resolve(__dirname, 'node_modules')
const path_src = path.resolve(__dirname, 'src')
const is_development = NODE_ENV === 'development'

const plugins = {
    dev: [
        new webpack.optimize.OccurrenceOrderPlugin(),
        new webpack.HotModuleReplacementPlugin(),
        new webpack.NoEmitOnErrorsPlugin()
    ],

    prod: [
        new (require('compression-webpack-plugin'))({
            filename: '[path].gz[query]',
            algorithm: 'gzip',
            test: /\.(js|css|html)$/,
            threshold: 1024,
            minRatio: 0.8
        }),

        new (require('brotli-webpack-plugin'))({
            asset: '[path].br[query]',
            test: /\.(js|css|html)$/,
            threshold: 1024,
            minRatio: 0.8
        })
    ]
}

const webpack_modules = {
    rules: [
        {
            test: /\.tsx?$/,
            exclude: path_node_modules,
            loader: 'ts-loader'
        },

        {
            test: /\.scss/,
            use: [
                { loader: 'file-loader', options: { name: 'build.css' } },
                { loader: 'extract-loader' },
                { loader: 'css-loader' },
                { loader: 'postcss-loader', options: { plugins: () => [autoprefixer()] } },
                {
                    loader: 'sass-loader',
                    options: {
                        webpackImporter: false,
                        implementation: require('sass'),
                        sassOptions: { includePaths: [path_node_modules] }
                    }
                }
            ]
        }
    ]
}

// WEBPACK CONFIG
webpack_config = {
    mode: NODE_ENV,
    entry: ['./src/app.ts', './src/main.scss'],
    plugins: is_development ? plugins.dev : plugins.prod,
    module: webpack_modules,
    resolve: {
        extensions: ['.tsx', '.ts', '.js']
    },
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'bundle.js',
        publicPath: '/'
    }
}

if (is_development) {
    webpack_config.devtool = 'source-map'
}

module.exports = webpack_config