webpack: replace deprecated LoaderOptionsPlugin with OptimizeCSSAssetsPlugin

webpack/webpack.prod.js

@@ -2,6 +2,8 @@ const webpack = require('webpack');
 const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
 const CompressionPlugin = require("compression-webpack-plugin");
 const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
+const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");
+const cssnano = require("cssnano");
 
 const {
     root
@@ -18,12 +20,6 @@ module.exports = {
             }
         }),
 
-        // Loader options
-        new webpack.LoaderOptionsPlugin({
-            minimize: true,
-            debug: false
-        }),
-
         new BundleAnalyzerPlugin({
             analyzerMode: 'disabled', // change it to `server` to view bundle stats
             reportFilename: 'report.html',
@@ -64,6 +60,15 @@ module.exports = {
                     },
                     sourceMap: true
                 }
+            }),
+            new OptimizeCSSAssetsPlugin({
+              cssProcessor: cssnano,
+              cssProcessorOptions: {
+                discardComments: {
+                  removeAll: true,
+                }
+              },
+              safe: true
             })
         ]
     },