gulpTaskLove.js

const path = require('path');
const gulp = require('gulp');
const babel = require('gulp-babel');
const sourcemaps = require('gulp-sourcemaps');
const gutil = require('gulp-util');
const clean = require('gulp-clean');
const concat = require('gulp-concat');
const uglify = require('gulp-uglify');
const rename = require('gulp-rename');
const filesize = require('gulp-filesize');
const stylus = require('gulp-stylus');
const less = require('gulp-less');
const changed = require('gulp-changed');
const watch = require('gulp-watch');

gulp.task('clean', function () {
  return gulp.src('build', {read: false})
    .pipe(clean());
});

gulp.task('js', function() {
  return gulp.src('js/*.js')
    .pipe(sourcemaps.init())
    .pipe(babel({
       presets: ['es2015']
    }))
    .pipe(concat('compile.js'))
    .pipe(gulp.dest('public/js'))
    .pipe(filesize())
    .pipe(uglify())
    .pipe(rename('compile.min.js'))
    .pipe(sourcemaps.write('.'))
    .pipe(gulp.dest('public/js'))
    .pipe(filesize())
    .on('error', gutil.log)
});

gulp.task('css', function () {
  return gulp.src('less/*.less')
    .pipe(changed('public/css'))
    .pipe(less({
      paths: [ path.join(__dirname, 'less', 'includes') ]
    }))
    .pipe(gulp.dest('public/css'))
    .on('error', gutil.log);
});

gulp.task('css:watch', function () {
  watch({
    glob: 'less/*.less',
    emit: 'one',
    emitOnGlob: false
  }, function(files) {
    return files
      .pipe(less({
        paths: [ path.join(__dirname, 'less', 'includes') ]
      }))
      .pipe(gulp.dest('build/css'))
      .on('error', gutil.log);
  });
});