gulpfile.js

var gulp = require('gulp')
    , fs = require('fs')
    , minifyHtml= require('gulp-minify-html')
    , minifyCss = require('gulp-minify-css')
    , uglify = require("gulp-uglify")
    , clean = require('gulp-clean');

// Copy Files
gulp.task('copy', function () {
    gulp.src('./app/manifest.webapp', { base: './app' })
     .pipe(gulp.dest('./app/www/'));
    
    gulp.src('./app/src/css/*.*', { base: './app/src/css' })
     .pipe(gulp.dest('./app/www/src/css/'));
    
    gulp.src('./app/images/*.*', { base: './app' })
     .pipe(gulp.dest('./app/www/'));
    
    gulp.src('./app/lib/**/', { base: './app' })
     .pipe(gulp.dest('./app/www/'));
});

// Clean
gulp.task('clean', function () {
    gulp.src('./www/', {read: false})
     .pipe(clean());
});

// Grouped Minify
gulp.task('minify', function () {
     gulp.src('./app/src/css/*.css')
        .pipe(minifyCss())
        .pipe(gulp.dest('./app/www/src/css'));
    
     gulp.src('./app/src/js/**/*.js')
        .pipe(uglify())
        .pipe(gulp.dest('./app/www/src/js'));
    
     gulp.src('./app/src/**/*.html')
        .pipe(minifyHtml())
        .pipe(gulp.dest('./app/www/src/')); 
});

// Gulp to run
gulp.task('default', function () {
    gulp.start('clean', 'minify', 'copy');
});