Use Terser for JS minification instead of (deprecated) UglifyJS

gulpfile.js

@@ -2,7 +2,7 @@
 
 var gulp = require('gulp');
 var cleanCSS = require('gulp-clean-css');
-var uglify = require('gulp-uglify');
+var terser = require('gulp-terser');
 var concat = require('gulp-concat');
 var header = require('gulp-header');
 var buffer = require('vinyl-buffer');
@@ -31,7 +31,7 @@ function scripts() {
     return browserify({entries: './src/js/easymde.js', standalone: 'EasyMDE'}).bundle()
         .pipe(source('easymde.min.js'))
         .pipe(buffer())
-        .pipe(uglify())
+        .pipe(terser())
         .pipe(header(banner, {pkg: pkg}))
         .pipe(gulp.dest('./dist/'));
 }

package-lock.json

@@ -2753,6 +2753,29 @@
             "integrity": "sha512-swzbIGb/arEoFK89tPY58vg3Ok1bw+d35PfUNwWqdo7KM4jkmuGA78JiDNqR+JeZFaeeHnRg9N7aihX3YPmsyg==",
             "dev": true
         },
+        "gulp-terser": {
+            "version": "1.2.0",
+            "resolved": "https://registry.npmjs.org/gulp-terser/-/gulp-terser-1.2.0.tgz",
+            "integrity": "sha512-lf+jE2DALg2w32p0HRiYMlFYRYelKZPNunHp2pZccCYrrdCLOs0ItbZcN63yr2pbz116IyhUG9mD/QbtRO1FKA==",
+            "dev": true,
+            "requires": {
+                "plugin-error": "^1.0.1",
+                "terser": "^4.0.0",
+                "through2": "^3.0.1",
+                "vinyl-sourcemaps-apply": "^0.2.1"
+            },
+            "dependencies": {
+                "through2": {
+                    "version": "3.0.1",
+                    "resolved": "https://registry.npmjs.org/through2/-/through2-3.0.1.tgz",
+                    "integrity": "sha512-M96dvTalPT3YbYLaKaCuwu+j06D/8Jfib0o/PxbVt6Amhv3dUAtW6rTV1jPgJSBG83I/e04Y6xkVdVhSRhi0ww==",
+                    "dev": true,
+                    "requires": {
+                        "readable-stream": "2 || 3"
+                    }
+                }
+            }
+        },
         "gulp-uglify": {
             "version": "3.0.2",
             "resolved": "https://registry.npmjs.org/gulp-uglify/-/gulp-uglify-3.0.2.tgz",
@@ -4788,6 +4811,24 @@
                 "urix": "^0.1.0"
             }
         },
+        "source-map-support": {
+            "version": "0.5.12",
+            "resolved": "https://registry.npmjs.org/source-map-support/-/source-map-support-0.5.12.tgz",
+            "integrity": "sha512-4h2Pbvyy15EE02G+JOZpUCmqWJuqrs+sEkzewTm++BPi7Hvn/HwcqLAcNxYAyI0x13CpPPn+kMjl+hplXMHITQ==",
+            "dev": true,
+            "requires": {
+                "buffer-from": "^1.0.0",
+                "source-map": "^0.6.0"
+            },
+            "dependencies": {
+                "source-map": {
+                    "version": "0.6.1",
+                    "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+                    "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+                    "dev": true
+                }
+            }
+        },
         "source-map-url": {
             "version": "0.4.0",
             "resolved": "https://registry.npmjs.org/source-map-url/-/source-map-url-0.4.0.tgz",
@@ -5056,6 +5097,25 @@
                 }
             }
         },
+        "terser": {
+            "version": "4.0.0",
+            "resolved": "https://registry.npmjs.org/terser/-/terser-4.0.0.tgz",
+            "integrity": "sha512-dOapGTU0hETFl1tCo4t56FN+2jffoKyER9qBGoUFyZ6y7WLoKT0bF+lAYi6B6YsILcGF3q1C2FBh8QcKSCgkgA==",
+            "dev": true,
+            "requires": {
+                "commander": "^2.19.0",
+                "source-map": "~0.6.1",
+                "source-map-support": "~0.5.10"
+            },
+            "dependencies": {
+                "source-map": {
+                    "version": "0.6.1",
+                    "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.6.1.tgz",
+                    "integrity": "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==",
+                    "dev": true
+                }
+            }
+        },
         "text-table": {
             "version": "0.2.0",
             "resolved": "https://registry.npmjs.org/text-table/-/text-table-0.2.0.tgz",

package.json

@@ -32,6 +32,7 @@
         "gulp-eslint": "^5.0.0",
         "gulp-header": "^2.0.7",
         "gulp-rename": "^1.4.0",
+        "gulp-terser": "^1.2.0",
         "gulp-uglify": "^3.0.2",
         "typescript": "^3.5.1",
         "vinyl-buffer": "^1.0.0",