Gulpfile for some useful functions

gulpfile.js

var gulp= require('gulp');

var sass = require('gulp-sass');
var browserSync = require('browser-sync').create();
var cssnano = require('gulp-cssnano');
var rename = require('gulp-rename');
var uglify = require('gulp-uglify');
var concat = require('gulp-concat');  
var imagemin = require('gulp-imagemin');


//Compìle Css from Sass and live reload on save
gulp.task('sass', function(){
	return gulp.src('app/scss/**/*.scss')
	.pipe(sass()) //using gulp-sass
	.pipe(gulp.dest('app/css'))
	.pipe(browserSync.reload({
		stream: true
	}))
});
gulp.task('browserSync', function() {
	browserSync.init({ 
		server: {
			baseDir: 'app'
		},
	})
});  
gulp.task('watch', ['browserSync', 'sass'], function(){
	gulp.watch('app/scss/**/*.scss', ['sass']); 
  // Other watchers 
  gulp.watch('app/*.html', browserSync.reload); 
  gulp.watch('app/js/**/*.js', browserSync.reload); 
});


// Autoprefix, minify and rename CSS
gulp.task('cssnano', function() {
	return gulp.src('app/css/**/*.css')
	.pipe(autoprefixer({
			browsers: ['last 4 versions'],
			cascade: false
	}))
	.pipe(cssnano())
	.pipe(rename({suffix:'.min'}))
	.pipe(gulp.dest('./dist/css'))
});

// Minify and concatenate .js files
var jsFiles = 'app/js/**/*.js',  
jsDest = './dist/scripts';

gulp.task('scripts', function() {  
	return gulp.src(jsFiles)
	.pipe(concat('scripts.js'))
	.pipe(gulp.dest(jsDest))
	.pipe(rename('scripts.min.js'))
	.pipe(uglify())
	.pipe(gulp.dest(jsDest));
});

//optimize images 
gulp.task('jpgs', function() {
    return gulp.src('app/img/*.jpg')
    .pipe(imagemin({ progressive: true }))
    .pipe(gulp.dest('./dist/img'));
});