How to minify multiple Javascript files in a folder with UglifyJS?

Hello I'm using uglifyJs to minify my javascript files, it's working well with one file at a time, what I'm loking for is to minify all the javascript files present in a folder called JS into a folder called JSM, to be clear I have 2 files inside my JS folder called test1.js and test2.js and I want to run uglify against that folder and generate test1.min.js and test2.min.js inside the JSM folder, so is there a way to do this? a command like :

uglifyjs -c -m JS/*.js JSM/*.min.js

Or any idea that can help me.

Thanks.


I know it might seem like a huge step but I would really recommend using grunt. It's really simple once you get the hang of it.

Here's a crash course:

  1. Install NodeJS
  2. Install Grunt CLI (just enter this in console/terminal):

    npm install -g grunt-cli
    
  3. Create a simple package.json file in the root of your project:

    {
      "name": "my-project-name",
      "version": "1.0.0",
      "devDependencies": {
        "grunt": "~0.4.2",
        "grunt-contrib-uglify": "~0.2.4",
        "grunt-contrib-watch" : "~0.5.3"
      }
    }
    
  4. Once you have that, just type: npm install to the console (in the root of your project). This will install the necessary grunt plugins/dependencies (from the package file above).

  5. Now create a simple gruntfile.js in the root of your project (it's a kind of config for your project):

    module.exports = function (grunt) {
        grunt.initConfig({
    
    
        // define source files and their destinations
        uglify: {
            files: { 
                src: 'js/*.js',  // source files mask
                dest: 'jsm/',    // destination folder
                expand: true,    // allow dynamic building
                flatten: true,   // remove all unnecessary nesting
                ext: '.min.js'   // replace .js to .min.js
            }
        },
        watch: {
            js:  { files: 'js/*.js', tasks: [ 'uglify' ] },
        }
    });
    
    // load plugins
    grunt.loadNpmTasks('grunt-contrib-watch');
    grunt.loadNpmTasks('grunt-contrib-uglify');
    
    // register at least this one task
    grunt.registerTask('default', [ 'uglify' ]);
    
    };
  6. Once that's done you just need to build it. Type in the console:

    grunt
    

    or - better - if you type execute the command below - grunt will monitor your source files for changes, and if you change any of them - it will build them automatically:

    grunt watch --force
    

You can then add more plugins, like: css minification, css preprocessors (less, sass, stylus), jshint, etc.


If you're on Linux/Mac and have access to bash, you can use uglifyjs on multiple JS files like so:

rm *.min.js; for f in *.js; do short=${f%.js}; uglifyjs $f > $short.min.js; done

npm-only way:

  1. run:

    npm install uglifyjs-folder --save-dev
    
  2. and afterwards add to your package.json something like:

    "uglifyjs": "uglifyjs-folder js -eo jsm"
    
  3. then run:

     npm run uglifyjs
    

Please note, if you'd need to generate to the same folder as the source files are (js), following should do the job:

  1. run:

    npm install del-cli uglifyjs-folder --save-dev
    
  2. and afterwards add to your package.json something like:

    "uglifyjs": "del js/*.min.js; uglifyjs-folder js -eo js"
    
  3. then run:

     npm run uglifyjs