Laravel-Mix (webpack) drupal theme setup

package.json

{
  "name": "my_site",
  "version": "1.0.0",
  "description": "My Site",
  "main": "index.js",
  "scripts": {
    "dev": "NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
    "development": "NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
    "watch": "NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
    "hot": "NODE_ENV=development webpack-dev-server --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
    "prod": "NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
    "production": "NODE_ENV=production node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@ayctor/laravel-mix-svg-sprite": "github:superbiche/laravel-mix-svg-sprite",
    "browser-sync": "^2.26.3",
    "browser-sync-webpack-plugin": "^2.2.2",
    "laravel-mix": "^2.1.14",
    "svg-spritemap-webpack-plugin": "^1.2.0"
  }
}

webpack.mix.js

let mix = require('laravel-mix');
const BrowserSyncPlugin = require('browser-sync-webpack-plugin');
// info on browsersync with mix: https://ashokgelal.com/2017/01/29/laravel-mix-browsersync/
require('@ayctor/laravel-mix-svg-sprite');
// info on laravel-mix-svg-sprite: https://github.com/Ayctor/laravel-mix-svg-sprite
// if this breaks, need to add `@^1.0.0` to line 25 of node_modules/@ayctor/laravel-mix-svg-sprite
//   and it'll look like this: `return ['svg-spritemap-webpack-plugin@^1.0.0'];`

if(process.env.NODE_ENV == 'development') {
// DEVELOPMENT
    mix .js('scripts/**/*.js', 'public/js/bundle.js')
        .sass('scss/style.scss', 'public/css/style.css')
        .svgSprite('images/svg/**/*.svg','public/images/sprite-ui.svg')
        .options({ processCssUrls: false })
        .webpackConfig({
           plugins: [
             new BrowserSyncPlugin({
               // BrowserSync override options here: https://browsersync.io/docs/options
               open: 'external',
               host: 'mysite.lndo.site',
               proxy: 'mysite.lndo.site'
               // files: ['resources/views/**/*.php', 'app/**/*.php', 'routes/**/*.php']
             })
           ]
        });
} else {
// PRODUCTION
    mix .js('scripts/**/*.js', 'public/js/bundle.min.js')
        .sass('scss/style.scss', 'public/css/style.min.css')
        .svgSprite('images/svg/**/*.svg','public/images/sprite-ui.svg')
        .options({ processCssUrls: false })
        .sourceMaps();
}


  // Full API
  // docs: https://laravel.com/docs/5.7/mix
  //
  // mix.js(src, output);
  // mix.react(src, output); <-- Identical to mix.js(), but registers React Babel compilation.
  // mix.preact(src, output); <-- Identical to mix.js(), but registers Preact compilation.
  // mix.coffee(src, output); <-- Identical to mix.js(), but registers CoffeeScript compilation.
  // mix.ts(src, output); <-- TypeScript support. Requires tsconfig.json to exist in the same folder as webpack.mix.js
  // mix.extract(vendorLibs);
  // mix.sass(src, output);
  // mix.standaloneSass('src', output); <-- Faster, but isolated from Webpack.
  // mix.fastSass('src', output); <-- Alias for mix.standaloneSass().
  // mix.less(src, output);
  // mix.stylus(src, output);
  // mix.postCss(src, output, [require('postcss-some-plugin')()]);
  // mix.browserSync('my-site.test');
  // mix.combine(files, destination);
  // mix.babel(files, destination); <-- Identical to mix.combine(), but also includes Babel compilation.
  // mix.copy(from, to);
  // mix.copyDirectory(fromDir, toDir);
  // mix.minify(file);
  // mix.sourceMaps(); // Enable sourcemaps
  // mix.version(); // Enable versioning.
  // mix.disableNotifications();
  // mix.setPublicPath('path/to/public');
  // mix.setResourceRoot('prefix/for/resource/locators');
  // mix.autoload({}); <-- Will be passed to Webpack's ProvidePlugin.
  // mix.webpackConfig({}); <-- Override webpack.config.js, without editing the file directly.
  // mix.babelConfig({}); <-- Merge extra Babel configuration (plugins, etc.) with Mix's default.
  // mix.then(function () {}) <-- Will be triggered each time Webpack finishes building.
  // mix.extend(name, handler) <-- Extend Mix's API with your own components.
  // mix.options({
  //   extractVueStyles: false, // Extract .vue component styling to file, rather than inline.
  //   globalVueStyles: file, // Variables file to be imported in every component.
  //   processCssUrls: true, // Process/optimize relative stylesheet url()'s. Set to false, if you don't want them touched.
  //   purifyCss: false, // Remove unused CSS selectors.
  //   uglify: {}, // Uglify-specific options. https://webpack.github.io/docs/list-of-plugins.html#uglifyjsplugin
  //   postCss: [] // Post-CSS options: https://github.com/postcss/postcss/blob/master/docs/plugins.md
  // });