Gulpfile.js

var gulp        = require('gulp'),
    del         = require('del'),
    plugins     = require('gulp-load-plugins')(),
    bower       = require('main-bower-files'),
    source      = require('vinyl-source-stream'),
    buffer      = require('vinyl-buffer'),
    browserify  = require('browserify'),
    browserSync = require('browser-sync');

var conf = {
  build: './build/',
  src: './src/'
};

gulp.task('clean:build', function(next) {
  return del(conf.build, next);
});

gulp.task('html', function(){
  return gulp.src(conf.src + 'index.html')
    .pipe(plugins.size({title: 'html:before'}))
    .pipe(plugins.htmlmin({collapseWhitespace: true}))
    .pipe(plugins.size({title: 'html:after'}))
    .pipe(gulp.dest(conf.build));
});

gulp.task('js:lint', function() {
  return gulp.src(conf.src + '**/*.js')
    .pipe(plugins.jshint())
    .pipe(plugins.jshint.reporter('default'));
});

gulp.task('js:browserify', function() {
  return browserify(conf.src + 'js/main.js').bundle()
    .pipe(source('app.min.js'))
    .pipe(buffer())
    .pipe(plugins.size({title: 'js:before'}))
    .pipe(plugins.uglify())
    .pipe(plugins.size({title: 'js:after'}))
    .pipe(gulp.dest(conf.build));
});

gulp.task('js', ['js:lint', 'js:browserify']);

gulp.task('css', function(){
  return gulp.src(conf.src + '**/*.css')
    .pipe(plugins.csslint())
    .pipe(plugins.jshint.reporter())
    .pipe(plugins.size({title: 'css:before'}))
    .pipe(plugins.cssmin())
    .pipe(plugins.concat('app.min.css'))
    .pipe(plugins.size({title: 'css:after'}))
    .pipe(gulp.dest(conf.build));
});

gulp.task('vendors:js', function() {
  return gulp.src(bower())
    .pipe(plugins.filter('**/*.js'))
    .pipe(plugins.size({title: 'js:vendors:before'}))
    .pipe(plugins.uglify())
    .pipe(plugins.concat('vendors.min.js'))
    .pipe(plugins.size({title: 'js:vendors:after'}))
    .pipe(gulp.dest(conf.build));
});

gulp.task('vendors:css', function() {
  return gulp.src(bower())
    .pipe(plugins.filter('**/*.css'))
    .pipe(plugins.size({title: 'css:vendors:before'}))
    .pipe(plugins.cssmin())
    .pipe(plugins.concat('vendors.min.css'))
    .pipe(plugins.size({title: 'css:vendors:after'}))
    .pipe(gulp.dest(conf.build));
});

gulp.task('vendors', ['vendors:js', 'vendors:css']);

gulp.task('browser-sync', function() {
    return browserSync({
        server: {
            baseDir: conf.build,
            open: false
        }
    });
});

gulp.task('build', ['html', 'js', 'css', 'vendors']);

gulp.task('serve', ['clean:build'], function() {
  gulp.start(['build', 'browser-sync']);
  gulp.watch(conf.src + 'css/**/*.css', ['css', browserSync.reload]);
  gulp.watch(conf.src + 'js/**/*.js', ['js', browserSync.reload]);
  gulp.watch(conf.src + 'index.html', ['html', browserSync.reload]);
});

gulp.task('default', ['build']);