gulpfile.js

var gulp = require('gulp');
var mocha = require('gulp-mocha');
var gutil = require('gulp-util');
var eslint = require('gulp-eslint');
var babel = require('gulp-babel');
var webpack = require('webpack');
var WebpackDevServer = require('webpack-dev-server');
var webpackConfiguration = require('./webpack.config.js');
var del = require('del');
require('babel-core/register');

/*** Unit tests ***/
gulp.task('lint', function () {
  return gulp.src(['src/**/*.js', 'test/**/*.js'])
    .pipe(eslint())
    .pipe(eslint.format())
    .pipe(eslint.failOnError());
});

gulp.task('mocha', function() {
  return gulp.src(['test/**/*.js'], { read: false })
    .pipe(mocha({ reporter: 'spec' }))
    .on('error', gutil.log);
});

gulp.task('mochaMin', function() {
  return gulp.src(['test/**/*.js'], { read: false })
    .pipe(mocha({ reporter: 'min' }))
    .on('error', gutil.log);
});

gulp.task('test', ['lint', 'mocha']);

/*** Frontend ***/
gulp.task('webpack', function(callback) {
  // run webpack
  webpack(webpackConfiguration, function(err, stats) {
    if (err) throw new gutil.PluginError('webpack', err);
    gutil.log('[webpack]', stats.toString({}));
    callback();
  });
});

gulp.task('devserver', function() {
  // Start a webpack-dev-server
  var compiler = webpack(webpackConfiguration);

  new WebpackDevServer(compiler, {
    // server and middleware options
  }).listen(8080, 'localhost', function(err) {
    if (err) throw new gutil.PluginError('webpack-dev-server', err);
    // Server listening
    gutil.log('[webpack-dev-server]',
      'http://localhost:8080/webpack-dev-server/index.html');
  });
});

gulp.task('client', ['webpack']);

/*** Backend ***/
gulp.task('babel', function() {
  return gulp.src(['src/**/*.js'])
    .pipe(babel())
    .pipe(gulp.dest('lib'));
});

gulp.task('copy', function() {
  return gulp.src(['src/**/*', '!src/**/*.js'])
    .pipe(gulp.dest('lib'));
});

gulp.task('server', ['babel', 'copy']);

/*** Wrap up ***/

gulp.task('watch', function() {
  gulp.watch(['src/**', 'test/**'], ['mochaMin']);
});

gulp.task('clean', function() {
  return del([
    'dist/**/*',
    'lib/**/*'
  ]);
});

gulp.task('default', ['test', 'client', 'server']);