migrate to terser (related with #1832)

package.json

@@ -34,8 +34,8 @@
     "rewire": "^5.0.0",
     "sinon": "^9.2.2",
     "string-replace-webpack-plugin": "^0.1.3",
+    "terser-webpack-plugin": "4.2.3",
     "transform-loader": "^0.2.4",
-    "uglifyjs-webpack-plugin": "^2.2.0",
     "webpack": "^4.44.2"
   },
   "engines": {

webpack.config.js

@@ -1,5 +1,5 @@
 var path = require('path');
-var UglifyJsPlugin = require('uglifyjs-webpack-plugin');
+var TerserPlugin = require('terser-webpack-plugin');
 var StringReplacePlugin = require("string-replace-webpack-plugin");
 var webpack = require('webpack');
 var pkg = require('./package.json');
@@ -101,26 +101,30 @@ module.exports = {
 	},
 	optimization: {
 		minimizer: [
-			new UglifyJsPlugin({
+			new TerserPlugin({
 				include: /\.min\.js$/,
 				sourceMap: true,
-				uglifyOptions: {
+				extractComments: false,
+				terserOptions: {
+					format: {
+						preamble: banner,
+						comments: false,
+					},
+					output: {
+						preamble: banner,
+						comments: false,
+					},
 					compress: {
 						drop_console: true
 					},
-					mangle: {
-						reserved: ['HeadTable', 'NameTable', 'CmapTable', 'HheaTable', 'MaxpTable', 'HmtxTable', 'PostTable', 'OS2Table', 'LocaTable', 'GlyfTable']
-					}
+					keep_classnames: true,
+					keep_fnames: true
 				}
 			})
 		]
 	},
 	plugins: [
-		new StringReplacePlugin(),
-		new webpack.BannerPlugin({
-			banner: banner,
-			raw: true
-		})
+		new StringReplacePlugin()
 	],
 	devtool: 'source-map'
 };