gulpfile.js

var gulp = require('gulp')

gulp.task('less', function () {
  var less = require('gulp-less')
  var postcss = require('gulp-postcss')
  var replace = require('gulp-replace')

  gulp.src('src/**/*.less')
    .pipe(postcss([require('postcss-for'), require('autoprefixer')({
      browsers: [
        '>1%',
        'last 4 versions',
        'Firefox ESR',
        'not ie < 9', // React doesn't support IE8 anyway
      ]
    })]))
    .pipe(less())
    .pipe(gulp.dest('lib'))

  gulp.src('lib/**/*.js')
    .pipe(replace('.less', '.css'))
    .pipe(gulp.dest('lib'))
})

gulp.task('copy', function () {
  gulp.src('src/**/*.png')
    .pipe(gulp.dest('lib'))
})

gulp.task('default', ['less', 'copy'])