gulpfile.js with browserify, babelify, watchify, sourcemaps, gulp-connect, and node-notifier

gulpfile.js

var gulp = require("gulp");
var gutil = require("gulp-util");
var open = require("gulp-open");
var sourcemaps = require("gulp-sourcemaps");
var notifier = require("node-notifier")
var connect = require("gulp-connect");
var buffer = require("vinyl-buffer");
var source = require("vinyl-source-stream");
var chalk = require("chalk");
var browserify = require("browserify");
var watchify = require("watchify");
var babelify = require("babelify");

var browserifyOpts = {
  entries: ['./src/app.jsx'],
  extensions: [
    ".js", ".jsx"
  ],
  debug: true,
  cache: {},
  packageCache: {},
  fullPaths: true
};

var bundler = watchify(browserify(browserifyOpts)
  .transform(babelify));

bundler.on("update", bundle);
bundler.on("log", gutil.log);

function handleError(error) {
  notifier.notify({
    "title": "Build Error",
    "message": error.message
  });
  if (error.filename) {
    gutil.log(chalk.red(error.name) + " in " + chalk.white(error.filename.replace(
        __dirname + "/src/", "")) + ": Line " + chalk.magenta(error.loc.line) +
      " & Column " + chalk.magenta(error.loc.column) + " Message: " +
      chalk.yellow(error.message));
  } else {
    gutil.log(chalk.red(error.name) + ": " + chalk.yellow(error.message));
  }
}

function bundle(file) {
  if (file) {
    gutil.log(new Date()
      .toString() + ": Recompiling " + file[0].replace(__dirname + "/src/",""));
  }
  return bundler.bundle()
    .on("error", handleError)
    .pipe(source("bundle.js"))
    .pipe(buffer())
    .pipe(sourcemaps.init({
      loadMaps: true
    }))
    .pipe(sourcemaps.write("."))
    .pipe(gulp.dest("dist/js"))
    .pipe(connect.reload());
}

gulp.task("build", function() {
  bundle();
});

gulp.task("connect", function() {
  connect.server({
    port: 8709,
    root: "dist",
    livereload: true
  });
});

gulp.task("open-browser", function() {
  gulp.src("dist/index.html")
    .pipe(open({
      uri: "http://localhost:8709"
    }));
});

gulp.task("copy-index", function() {
  gulp.src("./index.html")
    .pipe(gulp.dest("./dist"));
});

gulp.task("default", [
  "connect", "build", "copy-index", "open-browser"
]);

$ npm install --save-dev gulp gulp-util gulp-open gulp-sourcemaps node-notifier gulp-connect vinyl-buffer vinyl-source-stream chalk browserify watchify babelify