Build: Switch the minifier from UglifyJS to Terser

UglifyJS is ES5-only, while Terser supports newer ECMAScript versions. jQuery
is authored in ES5 but jQuery 4.x will also have an ESM build that cannot be
minified using UglifyJS directly.

We could strip the `export` statement, minify via UglifyJS and re-add one but
that increases complexity & may not fully play nice with source maps.

On the other hand, switching to Terser increases the minfied size by just 324
bytes and the minified gzipped one by just 70 bytes. Such differences largely
disappear among bigger size gains from the `3.x-stable` line - around 2.7 KB
minified gzipped as of now.

Closes gh-5258

diff --git a/Gruntfile.js b/Gruntfile.js
index c5e238ced2844e63df4f84f0c3fed83df029b8e3..9029be85dca483bdbf696041779751a2cfa1f81d 100644 (file)
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -333,25 +333,26 @@ module.exports = function( grunt ) {
                        files: [ "<%= eslint.dev.src %>" ],
                        tasks: [ "dev" ]
                },
-               uglify: {
+               terser: {
                        all: {
                                files: {
                                        "dist/<%= grunt.option('filename').replace('.js', '.min.js') %>":
                                                "dist/<%= grunt.option('filename') %>"
                                },
                                options: {
-                                       preserveComments: false,
-                                       sourceMap: true,
-                                       sourceMapName:
-                                               "dist/<%= grunt.option('filename').replace('.js', '.min.map') %>",
-                                       report: "min",
-                                       output: {
-                                               "ascii_only": true
+                                       ecma: 5,
+                                       sourceMap: {
+                                               filename: "dist/<%= grunt.option('filename').replace('.js', '.min.map') %>"
+                                       },
+                                       format: {
+                                               ascii_only: true,
+                                               comments: false,
+                                               preamble: "/*! jQuery v<%= pkg.version %> | " +
+                                                       "(c) OpenJS Foundation and other contributors | " +
+                                                       "jquery.org/license */"
                                        },
-                                       banner: "/*! jQuery v<%= pkg.version %> | " +
-                                               "(c) OpenJS Foundation and other contributors | jquery.org/license */",
                                        compress: {
-                                               "hoist_funs": false,
+                                               hoist_funs: false,
                                                loops: false
                                        }
                                }
@@ -420,7 +421,7 @@ module.exports = function( grunt ) {
        grunt.registerTask( "dev", [
                "build:*:*",
                runIfNewNode( "newer:eslint:dev" ),
-               "newer:uglify",
+               "newer:terser",
                "remove_map_comment",
                "dist:*",
                "qunit_fixture",
@@ -431,7 +432,7 @@ module.exports = function( grunt ) {
                runIfNewNode( "eslint:dev" ),
                "build:*:*",
                "amd",
-               "uglify",
+               "terser",
                "remove_map_comment",
                "dist:*",
                "test:prepare",

diff --git a/build/tasks/build.js b/build/tasks/build.js
index bcfa8ceae62a74d6d7012ef91da028a476164738..98d95cbe5c8c3760d70d181802bd6797b57efaac 100644 (file)
--- a/build/tasks/build.js
+++ b/build/tasks/build.js
@@ -339,6 +339,6 @@ module.exports = function( grunt ) {
                        "";
 
                grunt.log.writeln( "Creating custom build...\n" );
-               grunt.task.run( [ "build:*:*" + ( modules ? ":" + modules : "" ), "uglify", "dist" ] );
+               grunt.task.run( [ "build:*:*" + ( modules ? ":" + modules : "" ), "terser", "dist" ] );
        } );
 };

diff --git a/build/tasks/sourcemap.js b/build/tasks/sourcemap.js
index 509374f2ee4e26a8697607b3d48b10c92dc464c3..f6ef5698e3bd3173ac490d973511a46b91c00969 100644 (file)
--- a/build/tasks/sourcemap.js
+++ b/build/tasks/sourcemap.js
@@ -3,7 +3,7 @@
 var fs = require( "fs" );
 
 module.exports = function( grunt ) {
-       var config = grunt.config( "uglify.all.files" );
+       var config = grunt.config( "terser.all.files" );
        grunt.registerTask( "remove_map_comment", function() {
                var minLoc = grunt.config.process( Object.keys( config )[ 0 ] );
 

diff --git a/package.json b/package.json
index 31166d31f128ec8b55c759b2684e1a4ce81bb5fc..56eaa6822742a66eb1f246d002d4c81d3be95050 100644 (file)
--- a/package.json
+++ b/package.json
@@ -35,7 +35,6 @@
     "grunt-babel": "8.0.0",
     "grunt-cli": "1.4.3",
     "grunt-compare-size": "0.4.2",
-    "grunt-contrib-uglify": "3.4.0",
     "grunt-contrib-watch": "1.1.0",
     "grunt-eslint": "24.0.0",
     "grunt-git-authors": "3.2.0",
@@ -43,6 +42,7 @@
     "grunt-karma": "4.0.2",
     "grunt-newer": "1.3.0",
     "grunt-npmcopy": "0.2.0",
+    "grunt-terser": "2.0.0",
     "gzip-js": "0.3.2",
     "husky": "4.2.5",
     "jsdom": "19.0.0",
@@ -67,8 +67,8 @@
     "rollup": "2.21.0",
     "sinon": "7.3.1",
     "strip-json-comments": "3.1.1",
-    "testswarm": "1.1.2",
-    "uglify-js": "3.4.7"
+    "terser": "5.17.6",
+    "testswarm": "1.1.2"
   },
   "scripts": {
     "build": "npm install && grunt",