gulpfile.js

var gulp = require("gulp");
var gutil = require("gulp-util");
var webpack = require("webpack");
var webpackConfig = require("./webpack.config.js");

gulp.task("default", ["build-dev"]);

gulp.task("build-dev", function() {
  gulp.start('webpack:dev-server');
});

// Production build
gulp.task("build", ["webpack:build"]);

gulp.task("webpack:build", function(callback) {
  // modify some webpack config options
  var myConfig = Object.create(webpackConfig);
  myConfig.plugins = (myConfig.plugins || []).concat(
    new webpack.DefinePlugin({
      "process.env": {
        // This has effect on the react lib size
        "NODE_ENV": JSON.stringify("production")
      }
    }),
    new webpack.optimize.DedupePlugin(),
    new webpack.optimize.UglifyJsPlugin()
  );

  // run webpack
  webpack(myConfig, function(err, stats) {
    if(err) throw new gutil.PluginError("webpack:build", err);
    gutil.log("[webpack:build]", stats.toString({
      colors: true
    }));
    callback();
  });
});

gulp.task("webpack:dev-server", function(callback) {
  var WebpackDevServer = require("webpack-dev-server");

	// modify some webpack config options
	var myDevConfig = Object.create(webpackConfig);
  myDevConfig.devtool = "sourcemap";
	myDevConfig.debug = true;
  myDevConfig.output.path = "/" + myDevConfig.output.path;
  myDevConfig.output.publicPath = 'http://localhost:8090' + myDevConfig.output.publicPath;

	// Start a webpack-dev-server
	new WebpackDevServer(webpack(myDevConfig), {
		publicPath: myDevConfig.output.publicPath,
		stats: {
      colors: true,
      chunkModules: false
    }
	}).listen(8090, "localhost", function(err) {
		if(err) throw new gutil.PluginError("webpack-dev-server", err);
	});
});