Gulpfile with webpack, typescript and nodemon

gulpfile.js

var gulp = require("gulp");
var gutil = require("gulp-util");
var rename = require('gulp-rename');
var webpack = require("webpack");
var nodemon = require('nodemon');
var typescript = require('gulp-typescript');

// These tasks setup nodemon.
gulp.task("start", function(cb) {
  var options = {
    watch: ["build/"],
    script: "build/server.js",
    ignore: ["build/public/**/*", "build/client.js"]
  }
  nodemon(options);
  nodemon.on("start", cb);
});

// main task for development. Depending on what has changed,
// it does the appropriate tasks.
gulp.task("watch", ["start"], function() {
	gulp.watch(["src/client.tsx", "src/routes.tsx", "src/components/**/*"], ["build:frontend"]);
	gulp.watch(["./src/config/*", "./src/public/**/*", "./src/templates/**/*"], ["copy"]);
  var backendFolders = [
    "./src/api/**/*",
    "./src/components/**/*",
    "./src/lib/**/*",
    "./src/models/**/*",
    "./src/routes.tsx",
    "./src/server.ts"
  ]

  gulp.watch(backendFolders, ["build:backend"]);
});

// build the whole server
gulp.task("build", ["build:frontend", "copy", "build:backend"]);


var tsProject = typescript.createProject("tsconfig.json", { typescript: require('typescript') });
gulp.task("build:backend", function() {
  var tsResult = tsProject.src().pipe(typescript(tsProject));

  return tsResult.js
    .pipe(rename(function (path) { path.dirname = path.dirname.replace("src", ""); }))
    .pipe(gulp.dest("build/"));
});

gulp.task("build:frontend", function(cb) {
  webpackConfig = {
    // Source maps support (or 'inline-source-map' also works)
    devtool: 'source-map',
    context: __dirname + "/src",
    entry: "./client.tsx",
    output: {
      filename: "app.js",
      path: __dirname + "/build/public/javascripts"
    },
    // Add `.ts` and `.tsx` as a resolvable extension.
    resolve: {
      extensions: ['', '.webpack.js', '.web.js', '.ts', '.tsx', '.js']
    },
    module: {
      loaders: [
        { test: /\.ts(x?)$/, loader: 'ts-loader'}
      ]
    }
  };

	webpack(webpackConfig, function(err, stats) {
		if(err) throw new gutil.PluginError("webpack:build", err);
		cb();
	});
});


gulp.task("copy", ["copy:config", "copy:public", "copy:templates"]);

gulp.task("copy:config", function() { return gulp.src('./src/config/*').pipe(gulp.dest('./build/config')); });
gulp.task("copy:public", function() { return gulp.src('./src/public/**/*').pipe(gulp.dest('./build/public')); });
gulp.task("copy:templates", function() { return gulp.src('./src/templates/**/*').pipe(gulp.dest('./build/templates')); });