Gulp config with sass

gulpfile.js

'use strict';

// Gulp modules
const gulp      = require('gulp');
const gutil     = require('gulp-util');
const concat    = require('gulp-concat');
const sass      = require('gulp-sass');
const gInclude  = require('gulp-include');
const gulpif    = require('gulp-if');
const sprity    = require('sprity');
const cleanCSS  = require('gulp-clean-css');
const uglifyjs  = require('gulp-uglify');
const notify    = require('gulp-notify');
const babel     = require('gulp-babel');

/**
 * Check if is productions environment
 * @method isProduction
 * @return {Boolean}    [description]
 */
const isProduction = function() {
  if (gutil.env.env === 'prod') {
    return true;
  } else {
    return false;
  }
}

/**
* The erro message
* @type {Object}
*/
const errorObj = {
  title     : "Assets",
  subtitle  : "Failure on compiling!",
  message   : "Error: <%= error.message %>",
  sound     : "Sosumi"
};

/**
* The success message
* @type {Object}
*/
const successObj = {
  title     : "Assets",
  subtitle  : "Compiled with success!",
  message   : "File generated!",
  sound     : "Beep"
};

/**
* Show notification on error
* @param  {[type]} err [description]
* @return {[type]}     [description]
*/
const onError = function(err) {
  if(gutil.env.env != 'prod'){
    notify.onError(errorObj)(err);
    this.emit('end');
  }
};

/**
* Compile all scss and css that are included in this file
* @type {String}
*/
const compileSass =  "./assets/stylesheet/application.scss";
const compileJs   =  "./assets/javascript/application.js";

/**
* Path to assets
* @type {Object}
*/
const assetPath = {
  "js"        : "./assets/javascript/**/*.js",
  "sass"      : "./assets/stylesheet/**/*.scss",
  "css"       : "./assets/stylesheet/**/*.css",
};

/**
* Where the assets are compiled
* @type {Object}
*/
const compileTo = {
  'js' : {
    'path'  : './',
    'file'  : 'compiled.js',
  },
  'css' : {
    'path'  : './',
    'file'  : 'compiled.css',
  }
};

/**
* Define what the gulp will run
*/
gulp.task('default', [ 'css', 'js' ], function() {
  gulp.watch([ assetPath.sass, assetPath.css, assetPath.js ], [ 'css', 'js' ]);
});

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


/**
* Task to compile css
*/
gulp.task('css', function() {
  const sassOptions = {
    outputStyle: isProduction === true ? "compressed" : "expanded",
    errLogToConsole: true
  }

  gulp.src(compileSass)
    .pipe(sass(sassOptions).on('error', onError))
    .pipe(gulpif(isProduction, cleanCSS({ compatibility: 'ie8' }).on('error', onError), gutil.noop()))
    .pipe(concat(compileTo.css.file))
    .pipe(gulp.dest(compileTo.css.path))
    .pipe(gulpif(isProduction, gutil.noop(), notify(successObj)));
});

/**
* Task to compile javascript
*/
gulp.task('js', function() {
  const uglifyOptions = {
    preserveComments: 'license'
  };

  gulp.src(compileJs)
    .pipe(gInclude().on('error', onError).on('error', onError))
    .pipe(babel({presets: ['es2015']}))
    .pipe(gulpif(isProduction, uglifyjs(uglifyOptions).on('error', onError), gutil.noop()))
    .pipe(concat(compileTo.js.file).on('error', onError))
    .pipe(gulp.dest(compileTo.js.path))
    .pipe(gulpif(isProduction, gutil.noop(), notify(successObj)));
});

/**
 * generate sprite.png and _sprite.scss
 */
gulp.task('sprites', function() {
  sprity.src({
    src: './assets/images/sprites/*.{png,jpg}',
    style: './sprites.scss',
    orientation: 'binary-tree',
    cssPath: './assets/images/'
  })
  .pipe(gulpif('*.png', gulp.dest('./assets/images/'), gulp.dest('./assets/stylesheet/')))
});

package.js

{
"name": "Project_Name",
"version": "1.0.0",
"description": "Project Description",
"author": "diegoos",
  "devDependencies": {
    "babel-preset-es2015": "^6.18.0",
    "gulp": "^3.9.1",
    "gulp-babel": "^6.1.2",
    "gulp-clean-css": "^2.0.12",
    "gulp-concat": "^2.6.0",
    "gulp-if": "^2.0.2",
    "gulp-include": "^2.3.1",
    "gulp-notify": "^2.2.0",
    "gulp-sass": "^2.3.2",
    "gulp-uglify": "^2.0.0",
    "gulp-util": "^3.0.7",
    "sprity": "^1.0.8",
    "sprity-sass": "^1.0.4"
  }
}