Spritesmith laravel example

// https://github.com/twolfson/gulp.spritesmith
// Example task with retina setup:
// @1x and @2x should have exact proportions
// otherwise spritesmith throws:
// Error: Normal sprite has inconsistent size with retina sprite.
// details and workaround: https://github.com/twolfson/gulp.spritesmith/issues/57

const elixir = require('laravel-elixir');
const Task = elixir.Task;
const gulp = require('gulp');
const spritesmith = require('gulp.spritesmith');
const buffer = require('vinyl-buffer');
const imagemin = require('gulp-imagemin');
const del = require('del');
const merge = require('merge-stream');

elixir.extend('makeSprites', function() {
   new Task('makeSprites', function() {
     let spriteData = gulp.src('path_to_source/*.png')
       .pipe(spritesmith({
         retinaSrcFilter: ['path_to_source/*@2x.png'],
         imgName: 'sprite.png',
         retinaImgName: 'sprite@2x.png',
         cssName: 'sprite.less',
         imgPath: 'path_to_use_in_css/sprite.png'
       }));

     let imgStream = spriteData.img
       .pipe(buffer())
       .pipe(imagemin())
       .pipe('path_to_source_image_folder');

     let cssStream = spriteData.css
       .pipe('path_to_source_less_folder');

     return merge(imgStream, cssStream);
  });
});

elixir(mix => {
  // ...
  mix.makeSprites();
  //...
});