gulpfile.js

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

gulp.task('prod', ['app'], function() {
	return gulp.src('public/src/app.js')
		.pipe(plumber())
			.pipe(bytediff.start())
				.pipe(uglify({mangle: true}))
			.pipe(bytediff.stop())
			.pipe(rename('app.min.js'))
		.pipe(plumber.stop())
		.pipe(gulp.dest('public/src/'));
});