text: 
  const babelify     = require('babelify');
  const browserify   = require('browserify');
  const uglify       = require('gulp-uglify');
  const buffer       = require('vinyl-buffer');
  const source       = require('vinyl-source-stream');
  
  const del = require('del');
  const combine = require('stream-combiner2').obj;
  
  const gulp = require('gulp');
  const gulpIf = require('gulp-if');
  const concat = require('gulp-concat');
  
  const isDevelopment = !process.env.NODE_ENV || process.env.NODE_ENV === 'development';
  
  const dirs = {
    application: './server/server.js',
    public: './public/'
  };
  
  const config = {
    clean: [dirs.public]
  };
  
  gulp.task('clean', function() {
    return del(config.clean);
  });
  
  gulp.task('bundle', function () {
    return browserify(dirs.application, {debug:true})
          .transform(babelify)
          .bundle()
          .pipe(source('bundle.js'))
          .pipe(gulpIf(!isDevelopment, combine(buffer())))
          .pipe(gulp.dest(dirs.public));
  });
  
  gulp.task('build',
    gulp.series('clean','bundle')
  );
  