Basic gulpfile.js (no autoprefixer)

gulpfile.js

/**
 * This gulpfile considers the following directory structure:
 *
 * .
 * ├── app                  PHP framework stuff
 * ├── bower_components     Front-end libraries
 * ├── node_modules         Gulp & Gulp modules
 * ├── public               Production-ready assets
 * │   ├── css
 * │   ├── fonts
 * │   ├── img
 * │   └── js
 * ├── resources            Development assets
 * │   ├── images
 * │   ├── scripts
 * │   └── scss
 */
// Gulp Libraries
var gulp       = require('gulp');
var gutil      = require('gulp-util');
var notify     = require('gulp-notify');
var sass       = require('gulp-ruby-sass')
;
var uglify     = require('gulp-uglify');
var concat     = require('gulp-concat');
var livereload = require('gulp-livereload');
var watch      = require('gulp-watch');
var imagemin   = require('gulp-imagemin');
var pngquant   = require('imagemin-pngquant');



// Paths
var sassDir        = './resources/scss';
var targetCSSDir   = './public/css';
var JSDir          = './resources/scripts';
var targetJSDir    = './public/js';
var bowerDir       = './bower_components';
var imgDir         = './resources/images';
var targetImgDir   = './public/img';



// Tasks
gulp.task('css', function() {
  return gulp.src(sassDir + '/style.scss')
    .pipe(
      sass({
        style: 'compressed',
        sourcemap: true,
        loadPath: [
          sassDir,
          bowerDir + '/normalize.css',
          bowerDir + '/bourbon/dist'
        ]
      })
    )
    .pipe(gulp.dest(targetCSSDir).on("error", gutil.log))
    .pipe(notify('CSS minified.'));
});



gulp.task('js', function() {
  return gulp.src([
      bowerDir + '/angular/angular.js',
      bowerDir + '/angular-route/angular-route.js',
      JSDir    + '/app.js'
  ])
  .pipe(concat('script.js').on("error", gutil.log))
  .pipe(uglify())
  .pipe(gulp.dest(targetJSDir));
});



gulp.task('images', function () {
  return gulp.src(imgDir + '/**/*')
    .pipe(imagemin({
      progressive: true,  
      svgoPlugins: [{removeViewBox: false}],
      use: [pngquant()]
    }).on("error", gutil.log))
    .pipe(gulp.dest(targetImgDir))
    .pipe(notify('Images minified.').on("error", gutil.log));

});



gulp.task('watch', function() {
  livereload.listen();
  gulp.watch(sassDir + '/**/*.scss', ['css']);
  gulp.watch(JSDir + '/**/*.js',   ['js']);
  gulp.watch(imgDir + '/**/*',   ['images']);
  gulp.watch('./public/**').on('change', livereload.changed);
  gulp.watch('./app/**').on('change', livereload.changed);
});



gulp.task('default', ['css', 'js', 'images', 'watch']);