gulpfile.js

/*

to install gulp at all:
> sudo npm install -g gulp

to install in the project:
> sudo npm install --save-dev gulp

than run

> sudo npm install gulp-ruby-sass gulp-autoprefixer gulp-minify-css gulp-concat gulp-uglify gulp-clean gulp-notify gulp-cache gulp-util gulp-watch --save-dev

*/

var gulp = require('gulp'),
    sass = require('gulp-ruby-sass'),
    watch = require('gulp-watch'),
    concat = require('gulp-concat'),
    notify = require('gulp-notify'),
    minifycss = require('gulp-minify-css'),
    autoprefixer = require('gulp-autoprefixer');


gulp.task('default', function(){});

// sass task
gulp.task('sass', function () {
    gulp.src('./scss/app.scss')
    .pipe(sass({
        noCache: true,
        style: "compressed",
        lineNumbers: false,
        loadPath: './scss/*',
    }))
    .pipe(minifycss())
    .pipe(autoprefixer('last 2 version'))
    .pipe(concat('app.css'))
    .pipe(gulp.dest('./css'))
    .pipe(notify({ message: 'Styles task complete' }));
});


gulp.task('watch', function() {
    gulp.watch('./scss/**/*.scss', ['sass'] );
});