Minify JavaScript with UglifyJS2.

Install package with NPM and add it to your development dependencies:

npm install --save-dev gulp-uglify

var uglify = require('gulp-uglify');

gulp.task('compress', function() {
  return gulp.src('lib/*.js')
    .pipe(uglify())
    .pipe(gulp.dest('dist'));
});

• mangle

  Pass false to skip mangling names.

• output

  Pass an object if you wish to specify additional output options. The defaults are optimized for best compression.

• compress

  Pass an object to specify custom compressor options. Pass false to skip compression completely.

• preserveComments

  A convenience option for options.output.comments. Defaults to preserving no comments.

  • all

    Preserve all comments in code blocks

  • some

    Preserve comments that start with a bang (!) or include a Closure Compiler directive (@preserve, @license, @cc_on)

  • function

    Specify your own comment preservation function. You will be passed the current node and the current comment and are expected to return either true or false.

• banner

  This string will be prepended to the minified output.

  eg:

    var gulp    = require('gulp');
    var config  = require('../config').production;
    var size    = require('gulp-filesize');
    var uglify = require('gulp-uglify');
    var gutil = require('gulp-util');
    
    var today = gutil.date('yyyy-mm-dd HH:MM');
    
    gulp.task('uglifyJs', ['browserify'], function() {
      return gulp.src(config.jsSrc)
        .pipe(uglify({compress: {drop_console: true}, banner: '/* @date:'+ config.v + ' ' + today + ' */\n'}))
        .pipe(gulp.dest(config.jsDest))
        .pipe(size());
    });

You can also pass the uglify function any of the options listed here to modify UglifyJS's behavior.

gulp-uglify emits an 'error' event if it is unable to minify a specific file. Wherever possible, the PluginError object will contain the following properties:

• fileName
• lineNumber
• message

To handle errors across your entire pipeline, see the gulp documentation.