Gulp + Browserify + Reactify + Watch + LiveReload

gulpfile.js

var source = require('vinyl-source-stream');
var gulp = require('gulp');
var gutil = require('gulp-util');
var browserify = require('browserify');
var reactify = require('reactify');
var notify = require("gulp-notify");
var livereload = require('gulp-livereload');

var scriptsDir = './src/js';
var buildDir = './public/js';

function handleErrors() {
  var args = Array.prototype.slice.call(arguments);
  notify.onError({
    title: "Compile Error",
    message: "<%= error.message %>"
  }).apply(this, args);
  this.emit('end'); // Keep gulp from hanging on this task
}

function buildScript(file) {
  var options = {entries: [scriptsDir + '/' + file], debug: true};
  var bundler = browserify(options);
  bundler.transform(reactify);
  function rebundle() {
    var stream = bundler.bundle();
    return stream.on('error', handleErrors)
      .pipe(source(file))
      .pipe(gulp.dest(buildDir + '/'))
      .pipe(livereload());
  }
  bundler.on('update', function() {
    rebundle();
    gutil.log('Rebundle...');
  });
  return rebundle();
}

gulp.task('build', function() {
  buildScript('main.js');
});

gulp.task('watch', function() {
  livereload.listen();
  gulp.watch(scriptsDir + '/*.js', ['build']);
});

gulp.task('default', ['build', 'watch']);