## - Split bundle (https://medium.com/keepitlazy/split-up-webpack-browserify-bundle-191fb8e74b24)

gulp-browserify-vendors.js

var browserify = require('browserify');
var source = require('vinyl-source-stream');
var nodeResolve = require('resolve');

/**
 * Make a browserify bundle 
 * @param isAppBundle true to bundle application without dependencies, false to bundle dependencies only
 * @returns {*} browserify bundle
 */
var makeBundle = function (isAppBundle) {
  var browerifyParams = {
    debug: true // generate source map
  };

  // Define if application must be included in bundle
  if(isAppBundle) {
    browerifyParams.entries = ['./src/scripts/index.js'];
  }

  // Define if dependencies must be included in bundle
  var bundleConfig = browserify(browerifyParams);
  var browserifyVendorFunction = (isAppBundle) ? bundleConfig.external.bind(bundleConfig) : bundleConfig.require.bind(bundleConfig);

  // Read package.json and get dependencies package ids
  var packageManifest = require('package.json');
  var packageIds = Object.keys(packageManifest.dependencies) || [];
  packageIds.forEach(function (id) {
    browserifyVendorFunction(nodeResolve.sync(id), {expose: id});
  });

  // Generate bundle
  var bundleName = (isAppBundle ? 'bundle' : 'vendor') + '.js';
  return bundleConfig.bundle()
    .pipe(source(bundleName))
    .pipe(gulp.dest('./dist'));
};