Replace UglifyJS with Terser

gulpfile.js

@@ -717,18 +717,18 @@ gulp.task('minified-post', ['minified-pre'], function () {
   console.log();
   console.log('### Minifying js files');
 
-  var UglifyES = require('uglify-es');
+  var Terser = require('terser');
   // V8 chokes on very long sequences. Works around that.
   var optsForHugeFile = { compress: { sequences: false, }, };
 
   fs.writeFileSync(MINIFIED_DIR + '/web/pdf.viewer.js',
-                   UglifyES.minify(viewerFiles).code);
+                   Terser.minify(viewerFiles).code);
   fs.writeFileSync(MINIFIED_DIR + '/build/pdf.min.js',
-                   UglifyES.minify(pdfFile).code);
+                   Terser.minify(pdfFile).code);
   fs.writeFileSync(MINIFIED_DIR + '/build/pdf.worker.min.js',
-                   UglifyES.minify(pdfWorkerFile, optsForHugeFile).code);
+                   Terser.minify(pdfWorkerFile, optsForHugeFile).code);
   fs.writeFileSync(MINIFIED_DIR + 'image_decoders/pdf.image_decoders.min.js',
-                   UglifyES.minify(pdfImageDecodersFile).code);
+                   Terser.minify(pdfImageDecodersFile).code);
 
   console.log();
   console.log('### Cleaning js files');

package-lock.json

@@ -12872,6 +12872,35 @@
       "integrity": "sha512-IlqtmLVaZA2qab8epUXbVWRn3aB1imbDMJtjB3nu4X0NqPkcY/JH9ZtCBWKHWPxs8Svi9tyo8w2dBoi07qZbBA==",
       "dev": true
     },
+    "terser": {
+      "version": "3.10.12",
+      "resolved": "https://registry.npmjs.org/terser/-/terser-3.10.12.tgz",
+      "integrity": "sha512-3ODPC1eVt25EVNb04s/PkHxOmzKBQUF6bwwuR6h2DbEF8/j265Y1UkwNtOk9am/pRxfJ5HPapOlUlO6c16mKQQ==",
+      "dev": true,
+      "requires": {
+        "commander": "~2.17.1",
+        "source-map": "~0.6.1",
+        "source-map-support": "~0.5.6"
+      },
+      "dependencies": {
+        "commander": {
+          "version": "2.17.1",
+          "resolved": "https://registry.npmjs.org/commander/-/commander-2.17.1.tgz",
+          "integrity": "sha512-wPMUt6FnH2yzG95SA6mzjQOEKUU3aLaDEmzs1ti+1E9h+CsrZghRlqEM/EJ4KscsQVG8uNN4uVreUeT8+drlgg==",
+          "dev": true
+        },
+        "source-map-support": {
+          "version": "0.5.9",
+          "resolved": "https://registry.npmjs.org/source-map-support/-/source-map-support-0.5.9.tgz",
+          "integrity": "sha512-gR6Rw4MvUlYy83vP0vxoVNzM6t8MUXqNuRsuBmBHQDu1Fh6X015FrLdgoDKcNdkwGubozq0P4N0Q37UyFVr1EA==",
+          "dev": true,
+          "requires": {
+            "buffer-from": "^1.0.0",
+            "source-map": "^0.6.0"
+          }
+        }
+      }
+    },
     "text-table": {
       "version": "0.2.0",
       "resolved": "https://registry.npmjs.org/text-table/-/text-table-0.2.0.tgz",

package.json

@@ -32,9 +32,9 @@
     "streamqueue": "^1.1.2",
     "systemjs": "^0.21.5",
     "systemjs-plugin-babel": "^0.0.25",
+    "terser": "^3.10.12",
     "ttest": "^1.1.0",
     "typogr": "^0.6.8",
-    "uglify-es": "^3.3.9",
     "vinyl": "^2.2.0",
     "vinyl-fs": "^3.0.3",
     "webpack": "4.21.0",