text: const gulp = require('gulp');
  
  const sass = require('gulp-sass');
  gulp.task('sass:compile', () => {
      return gulp.src(['./app/ui/sass/**/*.scss'])
          .pipe(sass().on('error', sass.logError))
          .pipe(gulp.dest('./app/ui/css'));
  });
  
  const concatCss = require('gulp-concat-css');
  gulp.task('css:concat', () => {
      return gulp.src('./app/ui/css/*.css')
          .pipe(concatCss("bundle.css"))
          .pipe(gulp.dest('./app/ui/css/bundle-css'));
  });
  
  const uglifyCss = require('gulp-uglifycss');
  gulp.task('css:compress', () => {
      gulp.src('./app/ui/css/bundle-css/bundle.css')
          .pipe(uglifyCss({
              'maxLineLen': 80,
              'uglyComments': true
          }))
          .pipe(gulp.dest('./app/ui'))
  });
  
  gulp.task('sass:watch', () => {
      gulp.watch('./app/ui/**/*.scss', ['sass:compile', 'css:concat', 'css:compress']);
  });