gulpfile.js

var gulp = require('gulp');
var cleanCSS = require('gulp-clean-css');
var concatCSS = require('gulp-concat-css');
var less = require('gulp-less');
var plumber = require('gulp-plumber');
var path = require('path');

gulp.task('concat-css', function() {
  gulp
    .src(['./devicon.css', './devicon-colors.css'])
    .pipe(plumber())
    .pipe(concatCSS('./devicon.min.css'))
    .pipe(gulp.dest('./'));
});

gulp.task('minify-css', function() {
  gulp
    .src('./devicon.min.css')
    .pipe(plumber())
    .pipe(cleanCSS())
    .pipe(gulp.dest('./'));
});

gulp.task('less', function() {
  return gulp
    .src('./less/devicon.less')
    .pipe(
      less({
        paths: [path.join(__dirname, 'less', 'includes')],
      }))
    .pipe(gulp.dest('./'));
});

gulp.task('default', [
  'less',
  'concat-css',
  'minify-css', 
]);